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| -rw-r--r-- | gfx/layers/apz/src/AsyncPanZoomController.cpp | 6848 |
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diff --git a/gfx/layers/apz/src/AsyncPanZoomController.cpp b/gfx/layers/apz/src/AsyncPanZoomController.cpp new file mode 100644 index 0000000000..342375c019 --- /dev/null +++ b/gfx/layers/apz/src/AsyncPanZoomController.cpp @@ -0,0 +1,6848 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* vim: set ts=8 sts=2 et sw=2 tw=80: */ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +#include "AsyncPanZoomController.h" // for AsyncPanZoomController, etc + +#include <math.h> // for fabsf, fabs, atan2 +#include <stdint.h> // for uint32_t, uint64_t +#include <sys/types.h> // for int32_t +#include <algorithm> // for max, min +#include <utility> // for std::make_pair + +#include "APZCTreeManager.h" // for APZCTreeManager +#include "AsyncPanZoomAnimation.h" // for AsyncPanZoomAnimation +#include "AutoDirWheelDeltaAdjuster.h" // for APZAutoDirWheelDeltaAdjuster +#include "AutoscrollAnimation.h" // for AutoscrollAnimation +#include "Axis.h" // for AxisX, AxisY, Axis, etc +#include "CheckerboardEvent.h" // for CheckerboardEvent +#include "Compositor.h" // for Compositor +#include "DesktopFlingPhysics.h" // for DesktopFlingPhysics +#include "FrameMetrics.h" // for FrameMetrics, etc +#include "GenericFlingAnimation.h" // for GenericFlingAnimation +#include "GestureEventListener.h" // for GestureEventListener +#include "HitTestingTreeNode.h" // for HitTestingTreeNode +#include "InputData.h" // for MultiTouchInput, etc +#include "InputBlockState.h" // for InputBlockState, TouchBlockState +#include "InputQueue.h" // for InputQueue +#include "Overscroll.h" // for OverscrollAnimation +#include "OverscrollHandoffState.h" // for OverscrollHandoffState +#include "SimpleVelocityTracker.h" // for SimpleVelocityTracker +#include "Units.h" // for CSSRect, CSSPoint, etc +#include "UnitTransforms.h" // for TransformTo +#include "base/message_loop.h" // for MessageLoop +#include "base/task.h" // for NewRunnableMethod, etc +#include "gfxTypes.h" // for gfxFloat +#include "mozilla/Assertions.h" // for MOZ_ASSERT, etc +#include "mozilla/BasicEvents.h" // for Modifiers, MODIFIER_* +#include "mozilla/ClearOnShutdown.h" // for ClearOnShutdown +#include "mozilla/ServoStyleConsts.h" // for StyleComputedTimingFunction +#include "mozilla/EventForwards.h" // for nsEventStatus_* +#include "mozilla/EventStateManager.h" // for EventStateManager +#include "mozilla/glean/GleanMetrics.h" +#include "mozilla/MouseEvents.h" // for WidgetWheelEvent +#include "mozilla/Preferences.h" // for Preferences +#include "mozilla/RecursiveMutex.h" // for RecursiveMutexAutoLock, etc +#include "mozilla/RefPtr.h" // for RefPtr +#include "mozilla/ScrollTypes.h" +#include "mozilla/StaticPrefs_apz.h" +#include "mozilla/StaticPrefs_general.h" +#include "mozilla/StaticPrefs_gfx.h" +#include "mozilla/StaticPrefs_mousewheel.h" +#include "mozilla/StaticPrefs_layers.h" +#include "mozilla/StaticPrefs_layout.h" +#include "mozilla/StaticPrefs_slider.h" +#include "mozilla/StaticPrefs_test.h" +#include "mozilla/StaticPrefs_toolkit.h" +#include "mozilla/Telemetry.h" // for Telemetry +#include "mozilla/TimeStamp.h" // for TimeDuration, TimeStamp +#include "mozilla/dom/CheckerboardReportService.h" // for CheckerboardEventStorage +// note: CheckerboardReportService.h actually lives in gfx/layers/apz/util/ +#include "mozilla/dom/Touch.h" // for Touch +#include "mozilla/gfx/gfxVars.h" // for gfxVars +#include "mozilla/gfx/BasePoint.h" // for BasePoint +#include "mozilla/gfx/BaseRect.h" // for BaseRect +#include "mozilla/gfx/Point.h" // for Point, RoundedToInt, etc +#include "mozilla/gfx/Rect.h" // for RoundedIn +#include "mozilla/gfx/ScaleFactor.h" // for ScaleFactor +#include "mozilla/layers/APZThreadUtils.h" // for AssertOnControllerThread, etc +#include "mozilla/layers/APZUtils.h" // for AsyncTransform +#include "mozilla/layers/CompositorController.h" // for CompositorController +#include "mozilla/layers/DirectionUtils.h" // for GetAxis{Start,End,Length,Scale} +#include "mozilla/layers/APZPublicUtils.h" // for GetScrollMode +#include "mozilla/webrender/WebRenderAPI.h" // for MinimapData +#include "mozilla/mozalloc.h" // for operator new, etc +#include "mozilla/Unused.h" // for unused +#include "mozilla/webrender/WebRenderTypes.h" +#include "nsAlgorithm.h" // for clamped +#include "nsCOMPtr.h" // for already_AddRefed +#include "nsDebug.h" // for NS_WARNING +#include "nsLayoutUtils.h" +#include "nsMathUtils.h" // for NS_hypot +#include "nsPoint.h" // for nsIntPoint +#include "nsStyleConsts.h" +#include "nsTArray.h" // for nsTArray, nsTArray_Impl, etc +#include "nsThreadUtils.h" // for NS_IsMainThread +#include "nsViewportInfo.h" // for ViewportMinScale(), ViewportMaxScale() +#include "prsystem.h" // for PR_GetPhysicalMemorySize +#include "mozilla/ipc/SharedMemoryBasic.h" // for SharedMemoryBasic +#include "ScrollSnap.h" // for ScrollSnapUtils +#include "ScrollAnimationPhysics.h" // for ComputeAcceleratedWheelDelta +#include "SmoothMsdScrollAnimation.h" +#include "SmoothScrollAnimation.h" +#include "WheelScrollAnimation.h" +#if defined(MOZ_WIDGET_ANDROID) +# include "AndroidAPZ.h" +#endif // defined(MOZ_WIDGET_ANDROID) + +static mozilla::LazyLogModule sApzCtlLog("apz.controller"); +#define APZC_LOG(...) MOZ_LOG(sApzCtlLog, LogLevel::Debug, (__VA_ARGS__)) +#define APZC_LOGV(...) MOZ_LOG(sApzCtlLog, LogLevel::Verbose, (__VA_ARGS__)) + +// Log to the apz.controller log with additional info from the APZC +#define APZC_LOG_DETAIL(fmt, apzc, ...) \ + APZC_LOG("%p(%s scrollId=%" PRIu64 "): " fmt, (apzc), \ + (apzc)->IsRootContent() ? "root" : "subframe", \ + (apzc)->GetScrollId(), ##__VA_ARGS__) + +#define APZC_LOG_FM_COMMON(fm, prefix, level, ...) \ + if (MOZ_LOG_TEST(sApzCtlLog, level)) { \ + std::stringstream ss; \ + ss << nsPrintfCString(prefix, __VA_ARGS__).get() << ":" << fm; \ + MOZ_LOG(sApzCtlLog, level, ("%s\n", ss.str().c_str())); \ + } +#define APZC_LOG_FM(fm, prefix, ...) \ + APZC_LOG_FM_COMMON(fm, prefix, LogLevel::Debug, __VA_ARGS__) +#define APZC_LOGV_FM(fm, prefix, ...) \ + APZC_LOG_FM_COMMON(fm, prefix, LogLevel::Verbose, __VA_ARGS__) + +namespace mozilla { +namespace layers { + +typedef mozilla::layers::AllowedTouchBehavior AllowedTouchBehavior; +typedef GeckoContentController::APZStateChange APZStateChange; +typedef GeckoContentController::TapType TapType; +typedef mozilla::gfx::Point Point; +typedef mozilla::gfx::Matrix4x4 Matrix4x4; + +// Choose between platform-specific implementations. +#ifdef MOZ_WIDGET_ANDROID +typedef WidgetOverscrollEffect OverscrollEffect; +typedef AndroidSpecificState PlatformSpecificState; +#else +typedef GenericOverscrollEffect OverscrollEffect; +typedef PlatformSpecificStateBase + PlatformSpecificState; // no extra state, just use the base class +#endif + +/** + * \page APZCPrefs APZ preferences + * + * The following prefs are used to control the behaviour of the APZC. + * The default values are provided in StaticPrefList.yaml. + * + * \li\b apz.allow_double_tap_zooming + * Pref that allows or disallows double tap to zoom + * + * \li\b apz.allow_immediate_handoff + * If set to true, scroll can be handed off from one APZC to another within + * a single input block. If set to false, a single input block can only + * scroll one APZC. + * + * \li\b apz.allow_zooming_out + * If set to true, APZ will allow zooming out past the initial scale on + * desktop. This is false by default to match Chrome's behaviour. + * + * \li\b apz.android.chrome_fling_physics.friction + * A tunable parameter for Chrome fling physics on Android that governs + * how quickly a fling animation slows down due to friction (and therefore + * also how far it reaches). Should be in the range [0-1]. + * + * \li\b apz.android.chrome_fling_physics.inflexion + * A tunable parameter for Chrome fling physics on Android that governs + * the shape of the fling curve. Should be in the range [0-1]. + * + * \li\b apz.android.chrome_fling_physics.stop_threshold + * A tunable parameter for Chrome fling physics on Android that governs + * how close the fling animation has to get to its target destination + * before it stops. + * Units: ParentLayer pixels + * + * \li\b apz.autoscroll.enabled + * If set to true, autoscrolling is driven by APZ rather than the content + * process main thread. + * + * \li\b apz.axis_lock.mode + * The preferred axis locking style. See AxisLockMode for possible values. + * + * \li\b apz.axis_lock.lock_angle + * Angle from axis within which we stay axis-locked.\n + * Units: radians + * + * \li\b apz.axis_lock.breakout_threshold + * Distance in inches the user must pan before axis lock can be broken.\n + * Units: (real-world, i.e. screen) inches + * + * \li\b apz.axis_lock.breakout_angle + * Angle at which axis lock can be broken.\n + * Units: radians + * + * \li\b apz.axis_lock.direct_pan_angle + * If the angle from an axis to the line drawn by a pan move is less than + * this value, we can assume that panning can be done in the allowed direction + * (horizontal or vertical).\n + * Currently used only for touch-action css property stuff and was addded to + * keep behaviour consistent with IE.\n + * Units: radians + * + * \li\b apz.content_response_timeout + * Amount of time before we timeout response from content. For example, if + * content is being unruly/slow and we don't get a response back within this + * time, we will just pretend that content did not preventDefault any touch + * events we dispatched to it.\n + * Units: milliseconds + * + * \li\b apz.danger_zone_x + * \li\b apz.danger_zone_y + * When drawing high-res tiles, we drop down to drawing low-res tiles + * when we know we can't keep up with the scrolling. The way we determine + * this is by checking if we are entering the "danger zone", which is the + * boundary of the painted content. For example, if the painted content + * goes from y=0...1000 and the visible portion is y=250...750 then + * we're far from checkerboarding. If we get to y=490...990 though then we're + * only 10 pixels away from showing checkerboarding so we are probably in + * a state where we can't keep up with scrolling. The danger zone prefs specify + * how wide this margin is; in the above example a y-axis danger zone of 10 + * pixels would make us drop to low-res at y=490...990.\n + * This value is in screen pixels. + * + * \li\b apz.disable_for_scroll_linked_effects + * Setting this pref to true will disable APZ scrolling on documents where + * scroll-linked effects are detected. A scroll linked effect is detected if + * positioning or transform properties are updated inside a scroll event + * dispatch; we assume that such an update is in response to the scroll event + * and is therefore a scroll-linked effect which will be laggy with APZ + * scrolling. + * + * \li\b apz.displayport_expiry_ms + * While a scrollable frame is scrolling async, we set a displayport on it + * to make sure it is layerized. However this takes up memory, so once the + * scrolling stops we want to remove the displayport. This pref controls how + * long after scrolling stops the displayport is removed. A value of 0 will + * disable the expiry behavior entirely. + * Units: milliseconds + * + * \li\b apz.drag.enabled + * Setting this pref to true will cause APZ to handle mouse-dragging of + * scrollbar thumbs. + * + * \li\b apz.drag.initial.enabled + * Setting this pref to true will cause APZ to try to handle mouse-dragging + * of scrollbar thumbs without an initial round-trip to content to start it + * if possible. Only has an effect if apz.drag.enabled is also true. + * + * \li\b apz.drag.touch.enabled + * Setting this pref to true will cause APZ to handle touch-dragging of + * scrollbar thumbs. Only has an effect if apz.drag.enabled is also true. + * + * \li\b apz.enlarge_displayport_when_clipped + * Pref that enables enlarging of the displayport along one axis when the + * generated displayport's size is beyond that of the scrollable rect on the + * opposite axis. + * + * \li\b apz.fling_accel_min_fling_velocity + * The minimum velocity of the second fling, and the minimum velocity of the + * previous fling animation at the point of interruption, for the new fling to + * be considered for fling acceleration. + * Units: screen pixels per milliseconds + * + * \li\b apz.fling_accel_min_pan_velocity + * The minimum velocity during the pan gesture that causes a fling for that + * fling to be considered for fling acceleration. + * Units: screen pixels per milliseconds + * + * \li\b apz.fling_accel_max_pause_interval_ms + * The maximum time that is allowed to elapse between the touch start event that + * interrupts the previous fling, and the touch move that initiates panning for + * the current fling, for that fling to be considered for fling acceleration. + * Units: milliseconds + * + * \li\b apz.fling_accel_base_mult + * \li\b apz.fling_accel_supplemental_mult + * When applying an acceleration on a fling, the new computed velocity is + * (new_fling_velocity * base_mult) + (old_velocity * supplemental_mult). + * The base_mult and supplemental_mult multiplier values are controlled by + * these prefs. Note that "old_velocity" here is the initial velocity of the + * previous fling _after_ acceleration was applied to it (if applicable). + * + * \li\b apz.fling_curve_function_x1 + * \li\b apz.fling_curve_function_y1 + * \li\b apz.fling_curve_function_x2 + * \li\b apz.fling_curve_function_y2 + * \li\b apz.fling_curve_threshold_inches_per_ms + * These five parameters define a Bezier curve function and threshold used to + * increase the actual velocity relative to the user's finger velocity. When the + * finger velocity is below the threshold (or if the threshold is not positive), + * the velocity is used as-is. If the finger velocity exceeds the threshold + * velocity, then the function defined by the curve is applied on the part of + * the velocity that exceeds the threshold. Note that the upper bound of the + * velocity is still specified by the \b apz.max_velocity_inches_per_ms pref, + * and the function will smoothly curve the velocity from the threshold to the + * max. In general the function parameters chosen should define an ease-out + * curve in order to increase the velocity in this range, or an ease-in curve to + * decrease the velocity. A straight-line curve is equivalent to disabling the + * curve entirely by setting the threshold to -1. The max velocity pref must + * also be set in order for the curving to take effect, as it defines the upper + * bound of the velocity curve.\n + * The points (x1, y1) and (x2, y2) used as the two intermediate control points + * in the cubic bezier curve; the first and last points are (0,0) and (1,1).\n + * Some example values for these prefs can be found at\n + * https://searchfox.org/mozilla-central/rev/f82d5c549f046cb64ce5602bfd894b7ae807c8f8/dom/animation/ComputedTimingFunction.cpp#27-33 + * + * \li\b apz.fling_friction + * Amount of friction applied during flings. This is used in the following + * formula: v(t1) = v(t0) * (1 - f)^(t1 - t0), where v(t1) is the velocity + * for a new sample, v(t0) is the velocity at the previous sample, f is the + * value of this pref, and (t1 - t0) is the amount of time, in milliseconds, + * that has elapsed between the two samples.\n + * NOTE: Not currently used in Android fling calculations. + * + * \li\b apz.fling_min_velocity_threshold + * Minimum velocity for a fling to actually kick off. If the user pans and lifts + * their finger such that the velocity is smaller than or equal to this amount, + * no fling is initiated.\n + * Units: screen pixels per millisecond + * + * \li\b apz.fling_stop_on_tap_threshold + * When flinging, if the velocity is above this number, then a tap on the + * screen will stop the fling without dispatching a tap to content. If the + * velocity is below this threshold a tap will also be dispatched. + * Note: when modifying this pref be sure to run the APZC gtests as some of + * them depend on the value of this pref.\n + * Units: screen pixels per millisecond + * + * \li\b apz.fling_stopped_threshold + * When flinging, if the velocity goes below this number, we just stop the + * animation completely. This is to prevent asymptotically approaching 0 + * velocity and rerendering unnecessarily.\n + * Units: screen pixels per millisecond.\n + * NOTE: Should not be set to anything + * other than 0.0 for Android except for tests to disable flings. + * + * \li\b apz.keyboard.enabled + * Determines whether scrolling with the keyboard will be allowed to be handled + * by APZ. + * + * \li\b apz.keyboard.passive-listeners + * When enabled, APZ will interpret the passive event listener flag to mean + * that the event listener won't change the focused element or selection of + * the page. With this, web content can use passive key listeners and not have + * keyboard APZ disabled. + * + * \li\b apz.max_tap_time + * Maximum time for a touch on the screen and corresponding lift of the finger + * to be considered a tap. This also applies to double taps, except that it is + * used both for the interval between the first touchdown and first touchup, + * and for the interval between the first touchup and the second touchdown.\n + * Units: milliseconds. + * + * \li\b apz.max_velocity_inches_per_ms + * Maximum velocity. Velocity will be capped at this value if a faster fling + * occurs. Negative values indicate unlimited velocity.\n + * Units: (real-world, i.e. screen) inches per millisecond + * + * \li\b apz.max_velocity_queue_size + * Maximum size of velocity queue. The queue contains last N velocity records. + * On touch end we calculate the average velocity in order to compensate + * touch/mouse drivers misbehaviour. + * + * \li\b apz.min_skate_speed + * Minimum amount of speed along an axis before we switch to "skate" multipliers + * rather than using the "stationary" multipliers.\n + * Units: CSS pixels per millisecond + * + * \li\b apz.one_touch_pinch.enabled + * Whether or not the "one-touch-pinch" gesture (for zooming with one finger) + * is enabled or not. + * + * \li\b apz.overscroll.enabled + * Pref that enables overscrolling. If this is disabled, excess scroll that + * cannot be handed off is discarded. + * + * \li\b apz.overscroll.min_pan_distance_ratio + * The minimum ratio of the pan distance along one axis to the pan distance + * along the other axis needed to initiate overscroll along the first axis + * during panning. + * + * \li\b apz.overscroll.stretch_factor + * How much overscrolling can stretch content along an axis. + * The maximum stretch along an axis is a factor of (1 + kStretchFactor). + * (So if kStretchFactor is 0, you can't stretch at all; if kStretchFactor + * is 1, you can stretch at most by a factor of 2). + * + * \li\b apz.overscroll.stop_distance_threshold + * \li\b apz.overscroll.stop_velocity_threshold + * Thresholds for stopping the overscroll animation. When both the distance + * and the velocity fall below their thresholds, we stop oscillating.\n + * Units: screen pixels (for distance) + * screen pixels per millisecond (for velocity) + * + * \li\b apz.overscroll.spring_stiffness + * The spring stiffness constant for the overscroll mass-spring-damper model. + * + * \li\b apz.overscroll.damping + * The damping constant for the overscroll mass-spring-damper model. + * + * \li\b apz.overscroll.max_velocity + * The maximum velocity (in ParentLayerPixels per millisecond) allowed when + * initiating the overscroll snap-back animation. + * + * \li\b apz.paint_skipping.enabled + * When APZ is scrolling and sending repaint requests to the main thread, often + * the main thread doesn't actually need to do a repaint. This pref allows the + * main thread to skip doing those repaints in cases where it doesn't need to. + * + * \li\b apz.pinch_lock.mode + * The preferred pinch locking style. See PinchLockMode for possible values. + * + * \li\b apz.pinch_lock.scroll_lock_threshold + * Pinch locking is triggered if the user scrolls more than this distance + * and pinches less than apz.pinch_lock.span_lock_threshold.\n + * Units: (real-world, i.e. screen) inches + * + * \li\b apz.pinch_lock.span_breakout_threshold + * Distance in inches the user must pinch before lock can be broken.\n + * Units: (real-world, i.e. screen) inches measured between two touch points + * + * \li\b apz.pinch_lock.span_lock_threshold + * Pinch locking is triggered if the user pinches less than this distance + * and scrolls more than apz.pinch_lock.scroll_lock_threshold.\n + * Units: (real-world, i.e. screen) inches measured between two touch points + * + * \li\b apz.pinch_lock.buffer_max_age + * To ensure that pinch locking threshold calculations are not affected by + * variations in touch screen sensitivity, calculations draw from a buffer of + * recent events. This preference specifies the maximum time that events are + * held in this buffer. + * Units: milliseconds + * + * \li\b apz.popups.enabled + * Determines whether APZ is used for XUL popup widgets with remote content. + * Ideally, this should always be true, but it is currently not well tested, and + * has known issues, so needs to be prefable. + * + * \li\b apz.record_checkerboarding + * Whether or not to record detailed info on checkerboarding events. + * + * \li\b apz.second_tap_tolerance + * Constant describing the tolerance in distance we use, multiplied by the + * device DPI, within which a second tap is counted as part of a gesture + * continuing from the first tap. Making this larger allows the user more + * distance between the first and second taps in a "double tap" or "one touch + * pinch" gesture.\n + * Units: (real-world, i.e. screen) inches + * + * \li\b apz.test.logging_enabled + * Enable logging of APZ test data (see bug 961289). + * + * \li\b apz.touch_move_tolerance + * See the description for apz.touch_start_tolerance below. This is a similar + * threshold, except it is used to suppress touchmove events from being + * delivered to content for NON-scrollable frames (or more precisely, for APZCs + * where ArePointerEventsConsumable returns false).\n Units: (real-world, i.e. + * screen) inches + * + * \li\b apz.touch_start_tolerance + * Constant describing the tolerance in distance we use, multiplied by the + * device DPI, before we start panning the screen. This is to prevent us from + * accidentally processing taps as touch moves, and from very short/accidental + * touches moving the screen. touchmove events are also not delivered to content + * within this distance on scrollable frames.\n + * Units: (real-world, i.e. screen) inches + * + * \li\b apz.velocity_bias + * How much to adjust the displayport in the direction of scrolling. This value + * is multiplied by the velocity and added to the displayport offset. + * + * \li\b apz.velocity_relevance_time_ms + * When computing a fling velocity from the most recently stored velocity + * information, only velocities within the most X milliseconds are used. + * This pref controls the value of X.\n + * Units: ms + * + * \li\b apz.x_skate_size_multiplier + * \li\b apz.y_skate_size_multiplier + * The multiplier we apply to the displayport size if it is skating (current + * velocity is above \b apz.min_skate_speed). We prefer to increase the size of + * the Y axis because it is more natural in the case that a user is reading a + * page page that scrolls up/down. Note that one, both or neither of these may + * be used at any instant.\n In general we want \b + * apz.[xy]_skate_size_multiplier to be smaller than the corresponding + * stationary size multiplier because when panning fast we would like to paint + * less and get faster, more predictable paint times. When panning slowly we + * can afford to paint more even though it's slower. + * + * \li\b apz.x_stationary_size_multiplier + * \li\b apz.y_stationary_size_multiplier + * The multiplier we apply to the displayport size if it is not skating (see + * documentation for the skate size multipliers above). + * + * \li\b apz.x_skate_highmem_adjust + * \li\b apz.y_skate_highmem_adjust + * On high memory systems, we adjust the displayport during skating + * to be larger so we can reduce checkerboarding. + * + * \li\b apz.zoom_animation_duration_ms + * This controls how long the zoom-to-rect animation takes.\n + * Units: ms + * + * \li\b apz.scale_repaint_delay_ms + * How long to delay between repaint requests during a scale. + * A negative number prevents repaint requests during a scale.\n + * Units: ms + */ + +/** + * Computed time function used for sampling frames of a zoom to animation. + */ +StaticAutoPtr<StyleComputedTimingFunction> gZoomAnimationFunction; + +/** + * Computed time function used for curving up velocity when it gets high. + */ +StaticAutoPtr<StyleComputedTimingFunction> gVelocityCurveFunction; + +/** + * The estimated duration of a paint for the purposes of calculating a new + * displayport, in milliseconds. + */ +static const double kDefaultEstimatedPaintDurationMs = 50; + +/** + * Returns true if this is a high memory system and we can use + * extra memory for a larger displayport to reduce checkerboarding. + */ +static bool gIsHighMemSystem = false; +static bool IsHighMemSystem() { return gIsHighMemSystem; } + +AsyncPanZoomAnimation* PlatformSpecificStateBase::CreateFlingAnimation( + AsyncPanZoomController& aApzc, const FlingHandoffState& aHandoffState, + float aPLPPI) { + return new GenericFlingAnimation<DesktopFlingPhysics>(aApzc, aHandoffState, + aPLPPI); +} + +UniquePtr<VelocityTracker> PlatformSpecificStateBase::CreateVelocityTracker( + Axis* aAxis) { + return MakeUnique<SimpleVelocityTracker>(aAxis); +} + +SampleTime AsyncPanZoomController::GetFrameTime() const { + APZCTreeManager* treeManagerLocal = GetApzcTreeManager(); + return treeManagerLocal ? treeManagerLocal->GetFrameTime() + : SampleTime::FromNow(); +} + +bool AsyncPanZoomController::IsZero(const ParentLayerPoint& aPoint) const { + RecursiveMutexAutoLock lock(mRecursiveMutex); + + const auto zoom = Metrics().GetZoom(); + + if (zoom == CSSToParentLayerScale(0)) { + return true; + } + + return layers::IsZero(aPoint / zoom); +} + +bool AsyncPanZoomController::IsZero(ParentLayerCoord aCoord) const { + RecursiveMutexAutoLock lock(mRecursiveMutex); + + const auto zoom = Metrics().GetZoom(); + + if (zoom == CSSToParentLayerScale(0)) { + return true; + } + + return FuzzyEqualsAdditive((aCoord / zoom), CSSCoord(), COORDINATE_EPSILON); +} + +bool AsyncPanZoomController::FuzzyGreater(ParentLayerCoord aCoord1, + ParentLayerCoord aCoord2) const { + RecursiveMutexAutoLock lock(mRecursiveMutex); + + const auto zoom = Metrics().GetZoom(); + + if (zoom == CSSToParentLayerScale(0)) { + return false; + } + + return (aCoord1 - aCoord2) / zoom > COORDINATE_EPSILON; +} + +class MOZ_STACK_CLASS StateChangeNotificationBlocker final { + public: + explicit StateChangeNotificationBlocker(AsyncPanZoomController* aApzc) + : mApzc(aApzc) { + RecursiveMutexAutoLock lock(mApzc->mRecursiveMutex); + mInitialState = mApzc->mState; + mApzc->mNotificationBlockers++; + } + + ~StateChangeNotificationBlocker() { + AsyncPanZoomController::PanZoomState newState; + { + RecursiveMutexAutoLock lock(mApzc->mRecursiveMutex); + mApzc->mNotificationBlockers--; + newState = mApzc->mState; + } + mApzc->DispatchStateChangeNotification(mInitialState, newState); + } + + private: + AsyncPanZoomController* mApzc; + AsyncPanZoomController::PanZoomState mInitialState; +}; + +/** + * An RAII class to temporarily apply async test attributes to the provided + * AsyncPanZoomController. + * + * This class should be used in the implementation of any AsyncPanZoomController + * method that queries the async scroll offset or async zoom (this includes + * the async layout viewport offset, since modifying the async scroll offset + * may result in the layout viewport moving as well). + */ +class MOZ_RAII AutoApplyAsyncTestAttributes final { + public: + explicit AutoApplyAsyncTestAttributes( + const AsyncPanZoomController*, + const RecursiveMutexAutoLock& aProofOfLock); + ~AutoApplyAsyncTestAttributes(); + + private: + AsyncPanZoomController* mApzc; + FrameMetrics mPrevFrameMetrics; + ParentLayerPoint mPrevOverscroll; + const RecursiveMutexAutoLock& mProofOfLock; +}; + +AutoApplyAsyncTestAttributes::AutoApplyAsyncTestAttributes( + const AsyncPanZoomController* aApzc, + const RecursiveMutexAutoLock& aProofOfLock) + // Having to use const_cast here seems less ugly than the alternatives + // of making several members of AsyncPanZoomController that + // ApplyAsyncTestAttributes() modifies |mutable|, or several methods that + // query the async transforms non-const. + : mApzc(const_cast<AsyncPanZoomController*>(aApzc)), + mPrevFrameMetrics(aApzc->Metrics()), + mPrevOverscroll(aApzc->GetOverscrollAmountInternal()), + mProofOfLock(aProofOfLock) { + mApzc->ApplyAsyncTestAttributes(aProofOfLock); +} + +AutoApplyAsyncTestAttributes::~AutoApplyAsyncTestAttributes() { + mApzc->UnapplyAsyncTestAttributes(mProofOfLock, mPrevFrameMetrics, + mPrevOverscroll); +} + +class ZoomAnimation : public AsyncPanZoomAnimation { + public: + ZoomAnimation(AsyncPanZoomController& aApzc, const CSSPoint& aStartOffset, + const CSSToParentLayerScale& aStartZoom, + const CSSPoint& aEndOffset, + const CSSToParentLayerScale& aEndZoom) + : mApzc(aApzc), + mTotalDuration(TimeDuration::FromMilliseconds( + StaticPrefs::apz_zoom_animation_duration_ms())), + mStartOffset(aStartOffset), + mStartZoom(aStartZoom), + mEndOffset(aEndOffset), + mEndZoom(aEndZoom) {} + + virtual bool DoSample(FrameMetrics& aFrameMetrics, + const TimeDuration& aDelta) override { + mDuration += aDelta; + double animPosition = mDuration / mTotalDuration; + + if (animPosition >= 1.0) { + aFrameMetrics.SetZoom(mEndZoom); + mApzc.SetVisualScrollOffset(mEndOffset); + return false; + } + + // Sample the zoom at the current time point. The sampled zoom + // will affect the final computed resolution. + float sampledPosition = + gZoomAnimationFunction->At(animPosition, /* aBeforeFlag = */ false); + + // We scale the scrollOffset linearly with sampledPosition, so the zoom + // needs to scale inversely to match. + if (mStartZoom == CSSToParentLayerScale(0) || + mEndZoom == CSSToParentLayerScale(0)) { + return false; + } + + aFrameMetrics.SetZoom( + CSSToParentLayerScale(1 / (sampledPosition / mEndZoom.scale + + (1 - sampledPosition) / mStartZoom.scale))); + + mApzc.SetVisualScrollOffset(CSSPoint::FromUnknownPoint(gfx::Point( + mEndOffset.x * sampledPosition + mStartOffset.x * (1 - sampledPosition), + mEndOffset.y * sampledPosition + + mStartOffset.y * (1 - sampledPosition)))); + return true; + } + + virtual bool WantsRepaints() override { return true; } + + private: + AsyncPanZoomController& mApzc; + + TimeDuration mDuration; + const TimeDuration mTotalDuration; + + // Old metrics from before we started a zoom animation. This is only valid + // when we are in the "ANIMATED_ZOOM" state. This is used so that we can + // interpolate between the start and end frames. We only use the + // |mViewportScrollOffset| and |mResolution| fields on this. + CSSPoint mStartOffset; + CSSToParentLayerScale mStartZoom; + + // Target metrics for a zoom to animation. This is only valid when we are in + // the "ANIMATED_ZOOM" state. We only use the |mViewportScrollOffset| and + // |mResolution| fields on this. + CSSPoint mEndOffset; + CSSToParentLayerScale mEndZoom; +}; + +/*static*/ +void AsyncPanZoomController::InitializeGlobalState() { + static bool sInitialized = false; + if (sInitialized) return; + sInitialized = true; + + MOZ_ASSERT(NS_IsMainThread()); + + gZoomAnimationFunction = new StyleComputedTimingFunction( + StyleComputedTimingFunction::Keyword(StyleTimingKeyword::Ease)); + ClearOnShutdown(&gZoomAnimationFunction); + gVelocityCurveFunction = + new StyleComputedTimingFunction(StyleComputedTimingFunction::CubicBezier( + StaticPrefs::apz_fling_curve_function_x1_AtStartup(), + StaticPrefs::apz_fling_curve_function_y1_AtStartup(), + StaticPrefs::apz_fling_curve_function_x2_AtStartup(), + StaticPrefs::apz_fling_curve_function_y2_AtStartup())); + ClearOnShutdown(&gVelocityCurveFunction); + + uint64_t sysmem = PR_GetPhysicalMemorySize(); + uint64_t threshold = 1LL << 32; // 4 GB in bytes + gIsHighMemSystem = sysmem >= threshold; + + PlatformSpecificState::InitializeGlobalState(); +} + +AsyncPanZoomController::AsyncPanZoomController( + LayersId aLayersId, APZCTreeManager* aTreeManager, + const RefPtr<InputQueue>& aInputQueue, + GeckoContentController* aGeckoContentController, GestureBehavior aGestures) + : mLayersId(aLayersId), + mGeckoContentController(aGeckoContentController), + mRefPtrMonitor("RefPtrMonitor"), + // mTreeManager must be initialized before GetFrameTime() is called + mTreeManager(aTreeManager), + mRecursiveMutex("AsyncPanZoomController"), + mLastContentPaintMetrics(mLastContentPaintMetadata.GetMetrics()), + mPanDirRestricted(false), + mPinchLocked(false), + mPinchEventBuffer(TimeDuration::FromMilliseconds( + StaticPrefs::apz_pinch_lock_buffer_max_age_AtStartup())), + mZoomConstraints(false, false, + mScrollMetadata.GetMetrics().GetDevPixelsPerCSSPixel() * + ViewportMinScale() / ParentLayerToScreenScale(1), + mScrollMetadata.GetMetrics().GetDevPixelsPerCSSPixel() * + ViewportMaxScale() / ParentLayerToScreenScale(1)), + mLastSampleTime(GetFrameTime()), + mLastCheckerboardReport(GetFrameTime()), + mOverscrollEffect(MakeUnique<OverscrollEffect>(*this)), + mState(NOTHING), + mX(this), + mY(this), + mNotificationBlockers(0), + mInputQueue(aInputQueue), + mPinchPaintTimerSet(false), + mDelayedTransformEnd(false), + mTestAttributeAppliers(0), + mTestHasAsyncKeyScrolled(false), + mCheckerboardEventLock("APZCBELock") { + if (aGestures == USE_GESTURE_DETECTOR) { + mGestureEventListener = new GestureEventListener(this); + } + // Put one default-constructed sampled state in the queue. + RecursiveMutexAutoLock lock(mRecursiveMutex); + mSampledState.emplace_back(); +} + +AsyncPanZoomController::~AsyncPanZoomController() { MOZ_ASSERT(IsDestroyed()); } + +PlatformSpecificStateBase* AsyncPanZoomController::GetPlatformSpecificState() { + if (!mPlatformSpecificState) { + mPlatformSpecificState = MakeUnique<PlatformSpecificState>(); + } + return mPlatformSpecificState.get(); +} + +already_AddRefed<GeckoContentController> +AsyncPanZoomController::GetGeckoContentController() const { + MonitorAutoLock lock(mRefPtrMonitor); + RefPtr<GeckoContentController> controller = mGeckoContentController; + return controller.forget(); +} + +already_AddRefed<GestureEventListener> +AsyncPanZoomController::GetGestureEventListener() const { + MonitorAutoLock lock(mRefPtrMonitor); + RefPtr<GestureEventListener> listener = mGestureEventListener; + return listener.forget(); +} + +const RefPtr<InputQueue>& AsyncPanZoomController::GetInputQueue() const { + return mInputQueue; +} + +void AsyncPanZoomController::Destroy() { + AssertOnUpdaterThread(); + + CancelAnimation(CancelAnimationFlags::ScrollSnap); + + { // scope the lock + MonitorAutoLock lock(mRefPtrMonitor); + mGeckoContentController = nullptr; + mGestureEventListener = nullptr; + } + mParent = nullptr; + mTreeManager = nullptr; +} + +bool AsyncPanZoomController::IsDestroyed() const { + return mTreeManager == nullptr; +} + +float AsyncPanZoomController::GetDPI() const { + if (APZCTreeManager* localPtr = mTreeManager) { + return localPtr->GetDPI(); + } + // If this APZC has been destroyed then this value is not going to be + // used for anything that the user will end up seeing, so we can just + // return 0. + return 0.0; +} + +ScreenCoord AsyncPanZoomController::GetTouchStartTolerance() const { + return (StaticPrefs::apz_touch_start_tolerance() * GetDPI()); +} + +ScreenCoord AsyncPanZoomController::GetTouchMoveTolerance() const { + return (StaticPrefs::apz_touch_move_tolerance() * GetDPI()); +} + +ScreenCoord AsyncPanZoomController::GetSecondTapTolerance() const { + return (StaticPrefs::apz_second_tap_tolerance() * GetDPI()); +} + +/* static */ AsyncPanZoomController::AxisLockMode +AsyncPanZoomController::GetAxisLockMode() { + return static_cast<AxisLockMode>(StaticPrefs::apz_axis_lock_mode()); +} + +bool AsyncPanZoomController::UsingStatefulAxisLock() const { + return (GetAxisLockMode() == STANDARD || GetAxisLockMode() == STICKY); +} + +/* static */ AsyncPanZoomController::PinchLockMode +AsyncPanZoomController::GetPinchLockMode() { + return static_cast<PinchLockMode>(StaticPrefs::apz_pinch_lock_mode()); +} + +PointerEventsConsumableFlags AsyncPanZoomController::ArePointerEventsConsumable( + TouchBlockState* aBlock, const MultiTouchInput& aInput) { + uint32_t touchPoints = aInput.mTouches.Length(); + if (touchPoints == 0) { + // Cant' do anything with zero touch points + return {false, false}; + } + + // This logic is simplified, erring on the side of returning true if we're + // not sure. It's safer to pretend that we can consume the event and then + // not be able to than vice-versa. But at the same time, we should try hard + // to return an accurate result, because returning true can trigger a + // pointercancel event to web content, which can break certain features + // that are using touch-action and handling the pointermove events. + // + // Note that in particular this function can return true if APZ is waiting on + // the main thread for touch-action information. In this scenario, the + // APZEventState::MainThreadAgreesEventsAreConsumableByAPZ() function tries + // to use the main-thread touch-action information to filter out false + // positives. + // + // We could probably enhance this logic to determine things like "we're + // not pannable, so we can only zoom in, and the zoom is already maxed + // out, so we're not zoomable either" but no need for that at this point. + + bool pannableX = aBlock->GetOverscrollHandoffChain()->CanScrollInDirection( + this, ScrollDirection::eHorizontal); + bool touchActionAllowsX = aBlock->TouchActionAllowsPanningX(); + bool pannableY = (aBlock->GetOverscrollHandoffChain()->CanScrollInDirection( + this, ScrollDirection::eVertical) || + // In the case of the root APZC with any dynamic toolbar, it + // shoule be pannable if there is room moving the dynamic + // toolbar. + (IsRootContent() && CanVerticalScrollWithDynamicToolbar())); + bool touchActionAllowsY = aBlock->TouchActionAllowsPanningY(); + + bool pannable; + bool touchActionAllowsPanning; + + Maybe<ScrollDirection> panDirection = + aBlock->GetBestGuessPanDirection(aInput); + if (panDirection == Some(ScrollDirection::eVertical)) { + pannable = pannableY; + touchActionAllowsPanning = touchActionAllowsY; + } else if (panDirection == Some(ScrollDirection::eHorizontal)) { + pannable = pannableX; + touchActionAllowsPanning = touchActionAllowsX; + } else { + // If we don't have a guessed pan direction, err on the side of returning + // true. + pannable = pannableX || pannableY; + touchActionAllowsPanning = touchActionAllowsX || touchActionAllowsY; + } + + if (touchPoints == 1) { + return {pannable, touchActionAllowsPanning}; + } + + bool zoomable = ZoomConstraintsAllowZoom(); + bool touchActionAllowsZoom = aBlock->TouchActionAllowsPinchZoom(); + + return {pannable || zoomable, + touchActionAllowsPanning || touchActionAllowsZoom}; +} + +nsEventStatus AsyncPanZoomController::HandleDragEvent( + const MouseInput& aEvent, const AsyncDragMetrics& aDragMetrics, + OuterCSSCoord aInitialThumbPos, const CSSRect& aInitialScrollableRect) { + // RDM is a special case where touch events will be synthesized in response + // to mouse events, and APZ will receive both even though RDM prevent-defaults + // the mouse events. This is because mouse events don't opt into APZ waiting + // to check if the event has been prevent-defaulted and are still processed + // as a result. To handle this, have APZ ignore mouse events when RDM and + // touch simulation are active. + bool isRDMTouchSimulationActive = false; + { + RecursiveMutexAutoLock lock(mRecursiveMutex); + isRDMTouchSimulationActive = + mScrollMetadata.GetIsRDMTouchSimulationActive(); + } + + if (!StaticPrefs::apz_drag_enabled() || isRDMTouchSimulationActive) { + return nsEventStatus_eIgnore; + } + + if (!GetApzcTreeManager()) { + return nsEventStatus_eConsumeNoDefault; + } + + { + RecursiveMutexAutoLock lock(mRecursiveMutex); + + if (aEvent.mType == MouseInput::MouseType::MOUSE_UP) { + if (mState == SCROLLBAR_DRAG) { + APZC_LOG("%p ending drag\n", this); + SetState(NOTHING); + } + + SnapBackIfOverscrolled(); + + return nsEventStatus_eConsumeNoDefault; + } + } + + HitTestingTreeNodeAutoLock node; + GetApzcTreeManager()->FindScrollThumbNode(aDragMetrics, mLayersId, node); + if (!node) { + APZC_LOG("%p unable to find scrollthumb node with viewid %" PRIu64 "\n", + this, aDragMetrics.mViewId); + return nsEventStatus_eConsumeNoDefault; + } + + if (aEvent.mType == MouseInput::MouseType::MOUSE_DOWN) { + APZC_LOG("%p starting scrollbar drag\n", this); + SetState(SCROLLBAR_DRAG); + } + + if (aEvent.mType != MouseInput::MouseType::MOUSE_MOVE) { + APZC_LOG("%p discarding event of type %d\n", this, aEvent.mType); + return nsEventStatus_eConsumeNoDefault; + } + + const ScrollbarData& scrollbarData = node->GetScrollbarData(); + MOZ_ASSERT(scrollbarData.mScrollbarLayerType == + layers::ScrollbarLayerType::Thumb); + MOZ_ASSERT(scrollbarData.mDirection.isSome()); + ScrollDirection direction = *scrollbarData.mDirection; + + bool isMouseAwayFromThumb = false; + if (int snapMultiplier = StaticPrefs::slider_snapMultiplier()) { + // It's fine to ignore the async component of the thumb's transform, + // because any async transform of the thumb will be in the direction of + // scrolling, but here we're interested in the other direction. + ParentLayerRect thumbRect = + (node->GetTransform() * AsyncTransformMatrix()) + .TransformBounds(LayerRect(node->GetVisibleRect())); + ScrollDirection otherDirection = GetPerpendicularDirection(direction); + ParentLayerCoord distance = + GetAxisStart(otherDirection, thumbRect.DistanceTo(aEvent.mLocalOrigin)); + ParentLayerCoord thumbWidth = GetAxisLength(otherDirection, thumbRect); + // Avoid triggering this condition spuriously when the thumb is + // offscreen and its visible region is therefore empty. + if (thumbWidth > 0 && thumbWidth * snapMultiplier < distance) { + isMouseAwayFromThumb = true; + APZC_LOG("%p determined mouse is away from thumb, will snap\n", this); + } + } + + RecursiveMutexAutoLock lock(mRecursiveMutex); + OuterCSSCoord thumbPosition; + if (isMouseAwayFromThumb) { + thumbPosition = aInitialThumbPos; + } else { + thumbPosition = ConvertScrollbarPoint(aEvent.mLocalOrigin, scrollbarData) - + aDragMetrics.mScrollbarDragOffset; + } + + OuterCSSCoord maxThumbPos = scrollbarData.mScrollTrackLength; + maxThumbPos -= scrollbarData.mThumbLength; + + float scrollPercent = + maxThumbPos.value == 0.0f ? 0.0f : (float)(thumbPosition / maxThumbPos); + APZC_LOG("%p scrollbar dragged to %f percent\n", this, scrollPercent); + + CSSCoord minScrollPosition = + GetAxisStart(direction, aInitialScrollableRect.TopLeft()); + CSSCoord maxScrollPosition = + GetAxisStart(direction, aInitialScrollableRect.BottomRight()) - + GetAxisLength(direction, Metrics().CalculateCompositedSizeInCssPixels()); + CSSCoord scrollPosition = + minScrollPosition + + (scrollPercent * (maxScrollPosition - minScrollPosition)); + + scrollPosition = std::max(scrollPosition, minScrollPosition); + scrollPosition = std::min(scrollPosition, maxScrollPosition); + + CSSPoint scrollOffset = Metrics().GetVisualScrollOffset(); + if (direction == ScrollDirection::eHorizontal) { + scrollOffset.x = scrollPosition; + } else { + scrollOffset.y = scrollPosition; + } + APZC_LOG("%p set scroll offset to %s from scrollbar drag\n", this, + ToString(scrollOffset).c_str()); + // Since the scroll position was calculated based on the scrollable rect at + // the start of the drag, we need to clamp the scroll position in case the + // scrollable rect has since shrunk. + ClampAndSetVisualScrollOffset(scrollOffset); + ScheduleCompositeAndMaybeRepaint(); + + return nsEventStatus_eConsumeNoDefault; +} + +nsEventStatus AsyncPanZoomController::HandleInputEvent( + const InputData& aEvent, + const ScreenToParentLayerMatrix4x4& aTransformToApzc) { + APZThreadUtils::AssertOnControllerThread(); + + nsEventStatus rv = nsEventStatus_eIgnore; + + switch (aEvent.mInputType) { + case MULTITOUCH_INPUT: { + MultiTouchInput multiTouchInput = aEvent.AsMultiTouchInput(); + RefPtr<GestureEventListener> listener = GetGestureEventListener(); + if (listener) { + // We only care about screen coordinates in the gesture listener, + // so we don't bother transforming the event to parent layer coordinates + rv = listener->HandleInputEvent(multiTouchInput); + if (rv == nsEventStatus_eConsumeNoDefault) { + return rv; + } + } + + if (!multiTouchInput.TransformToLocal(aTransformToApzc)) { + return rv; + } + + switch (multiTouchInput.mType) { + case MultiTouchInput::MULTITOUCH_START: + rv = OnTouchStart(multiTouchInput); + break; + case MultiTouchInput::MULTITOUCH_MOVE: + rv = OnTouchMove(multiTouchInput); + break; + case MultiTouchInput::MULTITOUCH_END: + rv = OnTouchEnd(multiTouchInput); + break; + case MultiTouchInput::MULTITOUCH_CANCEL: + rv = OnTouchCancel(multiTouchInput); + break; + } + break; + } + case PANGESTURE_INPUT: { + PanGestureInput panGestureInput = aEvent.AsPanGestureInput(); + if (!panGestureInput.TransformToLocal(aTransformToApzc)) { + return rv; + } + + switch (panGestureInput.mType) { + case PanGestureInput::PANGESTURE_MAYSTART: + rv = OnPanMayBegin(panGestureInput); + break; + case PanGestureInput::PANGESTURE_CANCELLED: + rv = OnPanCancelled(panGestureInput); + break; + case PanGestureInput::PANGESTURE_START: + rv = OnPanBegin(panGestureInput); + break; + case PanGestureInput::PANGESTURE_PAN: + rv = OnPan(panGestureInput, FingersOnTouchpad::Yes); + break; + case PanGestureInput::PANGESTURE_END: + rv = OnPanEnd(panGestureInput); + break; + case PanGestureInput::PANGESTURE_MOMENTUMSTART: + rv = OnPanMomentumStart(panGestureInput); + break; + case PanGestureInput::PANGESTURE_MOMENTUMPAN: + rv = OnPan(panGestureInput, FingersOnTouchpad::No); + break; + case PanGestureInput::PANGESTURE_MOMENTUMEND: + rv = OnPanMomentumEnd(panGestureInput); + break; + case PanGestureInput::PANGESTURE_INTERRUPTED: + rv = OnPanInterrupted(panGestureInput); + break; + } + break; + } + case MOUSE_INPUT: { + MouseInput mouseInput = aEvent.AsMouseInput(); + if (!mouseInput.TransformToLocal(aTransformToApzc)) { + return rv; + } + break; + } + case SCROLLWHEEL_INPUT: { + ScrollWheelInput scrollInput = aEvent.AsScrollWheelInput(); + if (!scrollInput.TransformToLocal(aTransformToApzc)) { + return rv; + } + + rv = OnScrollWheel(scrollInput); + break; + } + case PINCHGESTURE_INPUT: { + // The APZCTreeManager should take care of ensuring that only root-content + // APZCs get pinch inputs. + MOZ_ASSERT(IsRootContent()); + PinchGestureInput pinchInput = aEvent.AsPinchGestureInput(); + if (!pinchInput.TransformToLocal(aTransformToApzc)) { + return rv; + } + + rv = HandleGestureEvent(pinchInput); + break; + } + case TAPGESTURE_INPUT: { + TapGestureInput tapInput = aEvent.AsTapGestureInput(); + if (!tapInput.TransformToLocal(aTransformToApzc)) { + return rv; + } + + rv = HandleGestureEvent(tapInput); + break; + } + case KEYBOARD_INPUT: { + const KeyboardInput& keyInput = aEvent.AsKeyboardInput(); + rv = OnKeyboard(keyInput); + break; + } + } + + return rv; +} + +nsEventStatus AsyncPanZoomController::HandleGestureEvent( + const InputData& aEvent) { + APZThreadUtils::AssertOnControllerThread(); + + nsEventStatus rv = nsEventStatus_eIgnore; + + switch (aEvent.mInputType) { + case PINCHGESTURE_INPUT: { + // This may be invoked via a one-touch-pinch gesture from + // GestureEventListener. In that case we want redirect it to the enclosing + // root-content APZC. + if (!IsRootContent()) { + if (APZCTreeManager* treeManagerLocal = GetApzcTreeManager()) { + if (RefPtr<AsyncPanZoomController> root = + treeManagerLocal->FindZoomableApzc(this)) { + rv = root->HandleGestureEvent(aEvent); + } + } + break; + } + PinchGestureInput pinchGestureInput = aEvent.AsPinchGestureInput(); + pinchGestureInput.TransformToLocal(GetTransformToThis()); + switch (pinchGestureInput.mType) { + case PinchGestureInput::PINCHGESTURE_START: + rv = OnScaleBegin(pinchGestureInput); + break; + case PinchGestureInput::PINCHGESTURE_SCALE: + rv = OnScale(pinchGestureInput); + break; + case PinchGestureInput::PINCHGESTURE_FINGERLIFTED: + case PinchGestureInput::PINCHGESTURE_END: + rv = OnScaleEnd(pinchGestureInput); + break; + } + break; + } + case TAPGESTURE_INPUT: { + TapGestureInput tapGestureInput = aEvent.AsTapGestureInput(); + tapGestureInput.TransformToLocal(GetTransformToThis()); + switch (tapGestureInput.mType) { + case TapGestureInput::TAPGESTURE_LONG: + rv = OnLongPress(tapGestureInput); + break; + case TapGestureInput::TAPGESTURE_LONG_UP: + rv = OnLongPressUp(tapGestureInput); + break; + case TapGestureInput::TAPGESTURE_UP: + rv = OnSingleTapUp(tapGestureInput); + break; + case TapGestureInput::TAPGESTURE_CONFIRMED: + rv = OnSingleTapConfirmed(tapGestureInput); + break; + case TapGestureInput::TAPGESTURE_DOUBLE: + if (!IsRootContent()) { + if (APZCTreeManager* treeManagerLocal = GetApzcTreeManager()) { + if (AsyncPanZoomController* apzc = + treeManagerLocal->FindRootApzcFor(GetLayersId())) { + rv = apzc->OnDoubleTap(tapGestureInput); + } + } + break; + } + rv = OnDoubleTap(tapGestureInput); + break; + case TapGestureInput::TAPGESTURE_SECOND: + rv = OnSecondTap(tapGestureInput); + break; + case TapGestureInput::TAPGESTURE_CANCEL: + rv = OnCancelTap(tapGestureInput); + break; + } + break; + } + default: + MOZ_ASSERT_UNREACHABLE("Unhandled input event"); + break; + } + + return rv; +} + +void AsyncPanZoomController::StartAutoscroll(const ScreenPoint& aPoint) { + // Cancel any existing animation. + CancelAnimation(); + + SetState(AUTOSCROLL); + StartAnimation(do_AddRef(new AutoscrollAnimation(*this, aPoint))); +} + +void AsyncPanZoomController::StopAutoscroll() { + if (mState == AUTOSCROLL) { + CancelAnimation(TriggeredExternally); + } +} + +nsEventStatus AsyncPanZoomController::OnTouchStart( + const MultiTouchInput& aEvent) { + APZC_LOG_DETAIL("got a touch-start in state %s\n", this, + ToString(mState).c_str()); + mPanDirRestricted = false; + + switch (mState) { + case FLING: + case ANIMATING_ZOOM: + case SMOOTH_SCROLL: + case SMOOTHMSD_SCROLL: + case OVERSCROLL_ANIMATION: + case WHEEL_SCROLL: + case KEYBOARD_SCROLL: + case PAN_MOMENTUM: + case AUTOSCROLL: + MOZ_ASSERT(GetCurrentTouchBlock()); + GetCurrentTouchBlock()->GetOverscrollHandoffChain()->CancelAnimations( + ExcludeOverscroll); + [[fallthrough]]; + case SCROLLBAR_DRAG: + case NOTHING: { + ParentLayerPoint point = GetFirstTouchPoint(aEvent); + mLastTouch.mPosition = mStartTouch = GetFirstExternalTouchPoint(aEvent); + StartTouch(point, aEvent.mTimeStamp); + if (RefPtr<GeckoContentController> controller = + GetGeckoContentController()) { + MOZ_ASSERT(GetCurrentTouchBlock()); + controller->NotifyAPZStateChange( + GetGuid(), APZStateChange::eStartTouch, + GetCurrentTouchBlock()->GetOverscrollHandoffChain()->CanBePanned( + this), + Some(GetCurrentTouchBlock()->GetBlockId())); + } + mLastTouch.mTimeStamp = mTouchStartTime = aEvent.mTimeStamp; + SetState(TOUCHING); + break; + } + case TOUCHING: + case PANNING: + case PANNING_LOCKED_X: + case PANNING_LOCKED_Y: + case PINCHING: + NS_WARNING("Received impossible touch in OnTouchStart"); + break; + } + + return nsEventStatus_eConsumeNoDefault; +} + +nsEventStatus AsyncPanZoomController::OnTouchMove( + const MultiTouchInput& aEvent) { + APZC_LOG_DETAIL("got a touch-move in state %s\n", this, + ToString(mState).c_str()); + switch (mState) { + case FLING: + case SMOOTHMSD_SCROLL: + case NOTHING: + case ANIMATING_ZOOM: + // May happen if the user double-taps and drags without lifting after the + // second tap. Ignore the move if this happens. + return nsEventStatus_eIgnore; + + case TOUCHING: { + ScreenCoord panThreshold = GetTouchStartTolerance(); + ExternalPoint extPoint = GetFirstExternalTouchPoint(aEvent); + Maybe<std::pair<MultiTouchInput, MultiTouchInput>> splitEvent; + + // We intentionally skip the UpdateWithTouchAtDevicePoint call when the + // panThreshold is zero. This ensures more deterministic behaviour during + // testing. If we call that, Axis::mPos gets updated to the point of this + // touchmove event, but we "consume" the move to overcome the + // panThreshold, so it's hard to pan a specific amount reliably from a + // mochitest. + if (panThreshold > 0.0f) { + const float vectorLength = PanVector(extPoint).Length(); + + if (vectorLength < panThreshold) { + UpdateWithTouchAtDevicePoint(aEvent); + mLastTouch = {extPoint, aEvent.mTimeStamp}; + + return nsEventStatus_eIgnore; + } + + splitEvent = MaybeSplitTouchMoveEvent(aEvent, panThreshold, + vectorLength, extPoint); + + UpdateWithTouchAtDevicePoint(splitEvent ? splitEvent->first : aEvent); + } + + nsEventStatus result; + const MultiTouchInput& firstEvent = + splitEvent ? splitEvent->first : aEvent; + + MOZ_ASSERT(GetCurrentTouchBlock()); + if (GetCurrentTouchBlock()->TouchActionAllowsPanningXY()) { + // In the calls to StartPanning() below, the first argument needs to be + // the External position of |firstEvent|. + // However, instead of computing that using + // GetFirstExternalTouchPoint(firstEvent), we pass |extPoint| which + // has been modified by MaybeSplitTouchMoveEvent() to the desired + // value. This is a workaround for the fact that recomputing the + // External point would require a round-trip through |mScreenPoint| + // which is an integer. + + // User tries to trigger a touch behavior. If allowed touch behavior is + // vertical pan + horizontal pan (touch-action value is equal to AUTO) + // we can return ConsumeNoDefault status immediately to trigger cancel + // event further. + // It should happen independent of the parent type (whether it is + // scrolling or not). + StartPanning(extPoint, firstEvent.mTimeStamp); + result = nsEventStatus_eConsumeNoDefault; + } else { + result = StartPanning(extPoint, firstEvent.mTimeStamp); + } + + if (splitEvent && IsInPanningState()) { + TrackTouch(splitEvent->second); + return nsEventStatus_eConsumeNoDefault; + } + + return result; + } + + case PANNING: + case PANNING_LOCKED_X: + case PANNING_LOCKED_Y: + case PAN_MOMENTUM: + TrackTouch(aEvent); + return nsEventStatus_eConsumeNoDefault; + + case PINCHING: + // The scale gesture listener should have handled this. + NS_WARNING( + "Gesture listener should have handled pinching in OnTouchMove."); + return nsEventStatus_eIgnore; + + case SMOOTH_SCROLL: + case WHEEL_SCROLL: + case KEYBOARD_SCROLL: + case OVERSCROLL_ANIMATION: + case AUTOSCROLL: + case SCROLLBAR_DRAG: + // Should not receive a touch-move in the OVERSCROLL_ANIMATION state + // as touch blocks that begin in an overscrolled state cancel the + // animation. The same is true for wheel scroll animations. + NS_WARNING("Received impossible touch in OnTouchMove"); + break; + } + + return nsEventStatus_eConsumeNoDefault; +} + +nsEventStatus AsyncPanZoomController::OnTouchEnd( + const MultiTouchInput& aEvent) { + APZC_LOG_DETAIL("got a touch-end in state %s\n", this, + ToString(mState).c_str()); + OnTouchEndOrCancel(); + + // In case no touch behavior triggered previously we can avoid sending + // scroll events or requesting content repaint. This condition is added + // to make tests consistent - in case touch-action is NONE (and therefore + // no pans/zooms can be performed) we expected neither scroll or repaint + // events. + if (mState != NOTHING) { + RecursiveMutexAutoLock lock(mRecursiveMutex); + } + + switch (mState) { + case FLING: + // Should never happen. + NS_WARNING("Received impossible touch end in OnTouchEnd."); + [[fallthrough]]; + case ANIMATING_ZOOM: + case SMOOTHMSD_SCROLL: + case NOTHING: + // May happen if the user double-taps and drags without lifting after the + // second tap. Ignore if this happens. + return nsEventStatus_eIgnore; + + case TOUCHING: + // We may have some velocity stored on the axis from move events + // that were not big enough to trigger scrolling. Clear that out. + SetVelocityVector(ParentLayerPoint(0, 0)); + MOZ_ASSERT(GetCurrentTouchBlock()); + APZC_LOG("%p still has %u touch points active\n", this, + GetCurrentTouchBlock()->GetActiveTouchCount()); + // In cases where the user is panning, then taps the second finger without + // entering a pinch, we will arrive here when the second finger is lifted. + // However the first finger is still down so we want to remain in state + // TOUCHING. + if (GetCurrentTouchBlock()->GetActiveTouchCount() == 0) { + // It's possible we may be overscrolled if the user tapped during a + // previous overscroll pan. Make sure to snap back in this situation. + // An ancestor APZC could be overscrolled instead of this APZC, so + // walk the handoff chain as well. + GetCurrentTouchBlock() + ->GetOverscrollHandoffChain() + ->SnapBackOverscrolledApzc(this); + mFlingAccelerator.Reset(); + // SnapBackOverscrolledApzc() will put any APZC it causes to snap back + // into the OVERSCROLL_ANIMATION state. If that's not us, since we're + // done TOUCHING enter the NOTHING state. + if (mState != OVERSCROLL_ANIMATION) { + SetState(NOTHING); + } + } + return nsEventStatus_eIgnore; + + case PANNING: + case PANNING_LOCKED_X: + case PANNING_LOCKED_Y: + case PAN_MOMENTUM: { + MOZ_ASSERT(GetCurrentTouchBlock()); + EndTouch(aEvent.mTimeStamp, Axis::ClearAxisLock::Yes); + return HandleEndOfPan(); + } + case PINCHING: + SetState(NOTHING); + // Scale gesture listener should have handled this. + NS_WARNING( + "Gesture listener should have handled pinching in OnTouchEnd."); + return nsEventStatus_eIgnore; + + case SMOOTH_SCROLL: + case WHEEL_SCROLL: + case KEYBOARD_SCROLL: + case OVERSCROLL_ANIMATION: + case AUTOSCROLL: + case SCROLLBAR_DRAG: + // Should not receive a touch-end in the OVERSCROLL_ANIMATION state + // as touch blocks that begin in an overscrolled state cancel the + // animation. The same is true for WHEEL_SCROLL. + NS_WARNING("Received impossible touch in OnTouchEnd"); + break; + } + + return nsEventStatus_eConsumeNoDefault; +} + +nsEventStatus AsyncPanZoomController::OnTouchCancel( + const MultiTouchInput& aEvent) { + APZC_LOG_DETAIL("got a touch-cancel in state %s\n", this, + ToString(mState).c_str()); + OnTouchEndOrCancel(); + CancelAnimationAndGestureState(); + return nsEventStatus_eConsumeNoDefault; +} + +nsEventStatus AsyncPanZoomController::OnScaleBegin( + const PinchGestureInput& aEvent) { + APZC_LOG_DETAIL("got a scale-begin in state %s\n", this, + ToString(mState).c_str()); + + mPinchLocked = false; + mPinchPaintTimerSet = false; + // Note that there may not be a touch block at this point, if we received the + // PinchGestureEvent directly from widget code without any touch events. + if (HasReadyTouchBlock() && + !GetCurrentTouchBlock()->TouchActionAllowsPinchZoom()) { + return nsEventStatus_eIgnore; + } + + // For platforms that don't support APZ zooming, dispatch a message to the + // content controller, it may want to do something else with this gesture. + // FIXME: bug 1525793 -- this may need to handle zooming or not on a + // per-document basis. + if (!StaticPrefs::apz_allow_zooming()) { + if (RefPtr<GeckoContentController> controller = + GetGeckoContentController()) { + APZC_LOG("%p notifying controller of pinch gesture start\n", this); + controller->NotifyPinchGesture( + aEvent.mType, GetGuid(), + ViewAs<LayoutDevicePixel>( + aEvent.mFocusPoint, + PixelCastJustification:: + LayoutDeviceIsScreenForUntransformedEvent), + 0, aEvent.modifiers); + } + } + + SetState(PINCHING); + Telemetry::Accumulate(Telemetry::APZ_ZOOM_PINCHSOURCE, (int)aEvent.mSource); + SetVelocityVector(ParentLayerPoint(0, 0)); + RecursiveMutexAutoLock lock(mRecursiveMutex); + mLastZoomFocus = + aEvent.mLocalFocusPoint - Metrics().GetCompositionBounds().TopLeft(); + + mPinchEventBuffer.push(aEvent); + + return nsEventStatus_eConsumeNoDefault; +} + +nsEventStatus AsyncPanZoomController::OnScale(const PinchGestureInput& aEvent) { + APZC_LOG_DETAIL("got a scale in state %s\n", this, ToString(mState).c_str()); + + if (HasReadyTouchBlock() && + !GetCurrentTouchBlock()->TouchActionAllowsPinchZoom()) { + return nsEventStatus_eIgnore; + } + + if (mState != PINCHING) { + return nsEventStatus_eConsumeNoDefault; + } + + mPinchEventBuffer.push(aEvent); + HandlePinchLocking(aEvent); + bool allowZoom = ZoomConstraintsAllowZoom() && !mPinchLocked; + + // If we are pinch-locked, this is a two-finger pan. + // Tracking panning distance and velocity. + // UpdateWithTouchAtDevicePoint() acquires the tree lock, so + // it cannot be called while the mRecursiveMutex lock is held. + if (mPinchLocked) { + mX.UpdateWithTouchAtDevicePoint(aEvent.mLocalFocusPoint.x, + aEvent.mTimeStamp); + mY.UpdateWithTouchAtDevicePoint(aEvent.mLocalFocusPoint.y, + aEvent.mTimeStamp); + } + + // FIXME: bug 1525793 -- this may need to handle zooming or not on a + // per-document basis. + if (!StaticPrefs::apz_allow_zooming()) { + if (RefPtr<GeckoContentController> controller = + GetGeckoContentController()) { + APZC_LOG("%p notifying controller of pinch gesture\n", this); + controller->NotifyPinchGesture( + aEvent.mType, GetGuid(), + ViewAs<LayoutDevicePixel>( + aEvent.mFocusPoint, + PixelCastJustification:: + LayoutDeviceIsScreenForUntransformedEvent), + ViewAs<LayoutDevicePixel>( + aEvent.mCurrentSpan - aEvent.mPreviousSpan, + PixelCastJustification:: + LayoutDeviceIsScreenForUntransformedEvent), + aEvent.modifiers); + } + } + + { + RecursiveMutexAutoLock lock(mRecursiveMutex); + // Only the root APZC is zoomable, and the root APZC is not allowed to have + // different x and y scales. If it did, the calculations in this function + // would have to be adjusted (as e.g. it would no longer be valid to take + // the minimum or maximum of the ratios of the widths and heights of the + // page rect and the composition bounds). + MOZ_ASSERT(Metrics().IsRootContent()); + + CSSToParentLayerScale userZoom = Metrics().GetZoom(); + ParentLayerPoint focusPoint = + aEvent.mLocalFocusPoint - Metrics().GetCompositionBounds().TopLeft(); + CSSPoint cssFocusPoint; + if (Metrics().GetZoom() != CSSToParentLayerScale(0)) { + cssFocusPoint = focusPoint / Metrics().GetZoom(); + } + + ParentLayerPoint focusChange = mLastZoomFocus - focusPoint; + mLastZoomFocus = focusPoint; + // If displacing by the change in focus point will take us off page bounds, + // then reduce the displacement such that it doesn't. + focusChange.x -= mX.DisplacementWillOverscrollAmount(focusChange.x); + focusChange.y -= mY.DisplacementWillOverscrollAmount(focusChange.y); + if (userZoom != CSSToParentLayerScale(0)) { + ScrollBy(focusChange / userZoom); + } + + // If the span is zero or close to it, we don't want to process this zoom + // change because we're going to get wonky numbers for the spanRatio. So + // let's bail out here. Note that we do this after the focus-change-scroll + // above, so that if we have a pinch with zero span but changing focus, + // such as generated by some Synaptics touchpads on Windows, we still + // scroll properly. + float prevSpan = aEvent.mPreviousSpan; + if (fabsf(prevSpan) <= EPSILON || fabsf(aEvent.mCurrentSpan) <= EPSILON) { + // We might have done a nonzero ScrollBy above, so update metrics and + // repaint/recomposite + ScheduleCompositeAndMaybeRepaint(); + return nsEventStatus_eConsumeNoDefault; + } + float spanRatio = aEvent.mCurrentSpan / aEvent.mPreviousSpan; + + // When we zoom in with focus, we can zoom too much towards the boundaries + // that we actually go over them. These are the needed displacements along + // either axis such that we don't overscroll the boundaries when zooming. + CSSPoint neededDisplacement; + + CSSToParentLayerScale realMinZoom = mZoomConstraints.mMinZoom; + CSSToParentLayerScale realMaxZoom = mZoomConstraints.mMaxZoom; + realMinZoom.scale = + std::max(realMinZoom.scale, Metrics().GetCompositionBounds().Width() / + Metrics().GetScrollableRect().Width()); + realMinZoom.scale = + std::max(realMinZoom.scale, Metrics().GetCompositionBounds().Height() / + Metrics().GetScrollableRect().Height()); + if (realMaxZoom < realMinZoom) { + realMaxZoom = realMinZoom; + } + + bool doScale = allowZoom && ((spanRatio > 1.0 && userZoom < realMaxZoom) || + (spanRatio < 1.0 && userZoom > realMinZoom)); + + if (doScale) { + spanRatio = clamped(spanRatio, realMinZoom.scale / userZoom.scale, + realMaxZoom.scale / userZoom.scale); + + // Note that the spanRatio here should never put us into OVERSCROLL_BOTH + // because up above we clamped it. + neededDisplacement.x = + -mX.ScaleWillOverscrollAmount(spanRatio, cssFocusPoint.x); + neededDisplacement.y = + -mY.ScaleWillOverscrollAmount(spanRatio, cssFocusPoint.y); + + ScaleWithFocus(spanRatio, cssFocusPoint); + + if (neededDisplacement != CSSPoint()) { + ScrollBy(neededDisplacement); + } + + // We don't want to redraw on every scale, so throttle it. + if (!mPinchPaintTimerSet) { + const int delay = StaticPrefs::apz_scale_repaint_delay_ms(); + if (delay >= 0) { + if (RefPtr<GeckoContentController> controller = + GetGeckoContentController()) { + mPinchPaintTimerSet = true; + controller->PostDelayedTask( + NewRunnableMethod( + "layers::AsyncPanZoomController::" + "DoDelayedRequestContentRepaint", + this, + &AsyncPanZoomController::DoDelayedRequestContentRepaint), + delay); + } + } + } else if (apz::AboutToCheckerboard(mLastContentPaintMetrics, + Metrics())) { + // If we already scheduled a throttled repaint request but are also + // in danger of checkerboarding soon, trigger the repaint request to + // go out immediately. This should reduce the amount of time we spend + // checkerboarding. + // + // Note that if we remain in this "about to + // checkerboard" state over a period of time with multiple pinch input + // events (which is quite likely), then we will flip-flop between taking + // the above branch (!mPinchPaintTimerSet) and this branch (which will + // flush the repaint request and reset mPinchPaintTimerSet to false). + // This is sort of desirable because it halves the number of repaint + // requests we send, and therefore reduces IPC traffic. + // Keep in mind that many of these repaint requests will be ignored on + // the main-thread anyway due to the resolution mismatch - the first + // repaint request will be honored because APZ's notion of the painted + // resolution matches the actual main thread resolution, but that first + // repaint request will change the resolution on the main thread. + // Subsequent repaint requests will be ignored in APZCCallbackHelper, at + // https://searchfox.org/mozilla-central/rev/e0eb861a187f0bb6d994228f2e0e49b2c9ee455e/gfx/layers/apz/util/APZCCallbackHelper.cpp#331-338, + // until we receive a NotifyLayersUpdated call that re-syncs APZ's + // notion of the painted resolution to the main thread. These ignored + // repaint requests are contributing to IPC traffic needlessly, and so + // halving the number of repaint requests (as mentioned above) seems + // desirable. + DoDelayedRequestContentRepaint(); + } + } else { + // Trigger a repaint request after scrolling. + RequestContentRepaint(); + } + + // We did a ScrollBy call above even if we didn't do a scale, so we + // should composite for that. + ScheduleComposite(); + } + + return nsEventStatus_eConsumeNoDefault; +} + +nsEventStatus AsyncPanZoomController::OnScaleEnd( + const PinchGestureInput& aEvent) { + APZC_LOG_DETAIL("got a scale-end in state %s\n", this, + ToString(mState).c_str()); + + mPinchPaintTimerSet = false; + + if (HasReadyTouchBlock() && + !GetCurrentTouchBlock()->TouchActionAllowsPinchZoom()) { + return nsEventStatus_eIgnore; + } + + // FIXME: bug 1525793 -- this may need to handle zooming or not on a + // per-document basis. + if (!StaticPrefs::apz_allow_zooming()) { + if (RefPtr<GeckoContentController> controller = + GetGeckoContentController()) { + controller->NotifyPinchGesture( + aEvent.mType, GetGuid(), + ViewAs<LayoutDevicePixel>( + aEvent.mFocusPoint, + PixelCastJustification:: + LayoutDeviceIsScreenForUntransformedEvent), + 0, aEvent.modifiers); + } + } + + { + RecursiveMutexAutoLock lock(mRecursiveMutex); + ScheduleComposite(); + RequestContentRepaint(); + } + + mPinchEventBuffer.clear(); + + if (aEvent.mType == PinchGestureInput::PINCHGESTURE_FINGERLIFTED) { + // One finger is still down, so transition to a TOUCHING state + if (!mPinchLocked) { + mPanDirRestricted = false; + mLastTouch.mPosition = mStartTouch = + ToExternalPoint(aEvent.mScreenOffset, aEvent.mFocusPoint); + mLastTouch.mTimeStamp = mTouchStartTime = aEvent.mTimeStamp; + StartTouch(aEvent.mLocalFocusPoint, aEvent.mTimeStamp); + SetState(TOUCHING); + } else { + // If we are pinch locked, StartTouch() was already called + // when we entered the pinch lock. + StartPanning(ToExternalPoint(aEvent.mScreenOffset, aEvent.mFocusPoint), + aEvent.mTimeStamp); + } + } else { + // Otherwise, handle the gesture being completely done. + + // Some of the code paths below, like ScrollSnap() or HandleEndOfPan(), + // may start an animation, but otherwise we want to end up in the NOTHING + // state. To avoid state change notification churn, we use a + // notification blocker. + bool stateWasPinching = (mState == PINCHING); + StateChangeNotificationBlocker blocker(this); + SetState(NOTHING); + + if (ZoomConstraintsAllowZoom()) { + RecursiveMutexAutoLock lock(mRecursiveMutex); + + // We can get into a situation where we are overscrolled at the end of a + // pinch if we go into overscroll with a two-finger pan, and then turn + // that into a pinch by increasing the span sufficiently. In such a case, + // there is no snap-back animation to get us out of overscroll, so we need + // to get out of it somehow. + // Moreover, in cases of scroll handoff, the overscroll can be on an APZC + // further up in the handoff chain rather than on the current APZC, so + // we need to clear overscroll along the entire handoff chain. + if (HasReadyTouchBlock()) { + GetCurrentTouchBlock()->GetOverscrollHandoffChain()->ClearOverscroll(); + } else { + ClearOverscroll(); + } + // Along with clearing the overscroll, we also want to snap to the nearest + // snap point as appropriate. + ScrollSnap(ScrollSnapFlags::IntendedEndPosition); + } else { + // when zoom is not allowed + EndTouch(aEvent.mTimeStamp, Axis::ClearAxisLock::Yes); + if (stateWasPinching) { + // still pinching + if (HasReadyTouchBlock()) { + return HandleEndOfPan(); + } + } + } + } + return nsEventStatus_eConsumeNoDefault; +} + +nsEventStatus AsyncPanZoomController::HandleEndOfPan() { + MOZ_ASSERT(!mAnimation); + MOZ_ASSERT(GetCurrentTouchBlock() || GetCurrentPanGestureBlock()); + GetCurrentInputBlock()->GetOverscrollHandoffChain()->FlushRepaints(); + ParentLayerPoint flingVelocity = GetVelocityVector(); + + // Clear our velocities; if DispatchFling() gives the fling to us, + // the fling velocity gets *added* to our existing velocity in + // AcceptFling(). + SetVelocityVector(ParentLayerPoint(0, 0)); + // Clear our state so that we don't stay in the PANNING state + // if DispatchFling() gives the fling to somone else. However, + // don't send the state change notification until we've determined + // what our final state is to avoid notification churn. + StateChangeNotificationBlocker blocker(this); + SetState(NOTHING); + + APZC_LOG("%p starting a fling animation if %f > %f\n", this, + flingVelocity.Length().value, + StaticPrefs::apz_fling_min_velocity_threshold()); + + if (flingVelocity.Length() <= + StaticPrefs::apz_fling_min_velocity_threshold()) { + // Relieve overscroll now if needed, since we will not transition to a fling + // animation and then an overscroll animation, and relieve it then. + GetCurrentInputBlock() + ->GetOverscrollHandoffChain() + ->SnapBackOverscrolledApzc(this); + mFlingAccelerator.Reset(); + return nsEventStatus_eConsumeNoDefault; + } + + // Make a local copy of the tree manager pointer and check that it's not + // null before calling DispatchFling(). This is necessary because Destroy(), + // which nulls out mTreeManager, could be called concurrently. + if (APZCTreeManager* treeManagerLocal = GetApzcTreeManager()) { + const FlingHandoffState handoffState{ + flingVelocity, + GetCurrentInputBlock()->GetOverscrollHandoffChain(), + Some(mTouchStartRestingTimeBeforePan), + mMinimumVelocityDuringPan.valueOr(0), + false /* not handoff */, + GetCurrentInputBlock()->GetScrolledApzc()}; + treeManagerLocal->DispatchFling(this, handoffState); + } + return nsEventStatus_eConsumeNoDefault; +} + +Maybe<LayoutDevicePoint> AsyncPanZoomController::ConvertToGecko( + const ScreenIntPoint& aPoint) { + if (APZCTreeManager* treeManagerLocal = GetApzcTreeManager()) { + if (Maybe<ScreenIntPoint> layoutPoint = + treeManagerLocal->ConvertToGecko(aPoint, this)) { + return Some(LayoutDevicePoint(ViewAs<LayoutDevicePixel>( + *layoutPoint, + PixelCastJustification::LayoutDeviceIsScreenForUntransformedEvent))); + } + } + return Nothing(); +} + +OuterCSSCoord AsyncPanZoomController::ConvertScrollbarPoint( + const ParentLayerPoint& aScrollbarPoint, + const ScrollbarData& aThumbData) const { + RecursiveMutexAutoLock lock(mRecursiveMutex); + + CSSPoint scrollbarPoint; + if (Metrics().GetZoom() != CSSToParentLayerScale(0)) { + // First, get it into the right coordinate space. + scrollbarPoint = aScrollbarPoint / Metrics().GetZoom(); + } + + // The scrollbar can be transformed with the frame but the pres shell + // resolution is only applied to the scroll frame. + OuterCSSPoint outerScrollbarPoint = + scrollbarPoint * Metrics().GetCSSToOuterCSSScale(); + + // Now, get it to be relative to the beginning of the scroll track. + OuterCSSRect cssCompositionBound = + Metrics().CalculateCompositionBoundsInOuterCssPixels(); + return GetAxisStart(*aThumbData.mDirection, outerScrollbarPoint) - + GetAxisStart(*aThumbData.mDirection, cssCompositionBound) - + aThumbData.mScrollTrackStart; +} + +static bool AllowsScrollingMoreThanOnePage(double aMultiplier) { + return Abs(aMultiplier) >= + EventStateManager::MIN_MULTIPLIER_VALUE_ALLOWING_OVER_ONE_PAGE_SCROLL; +} + +ParentLayerPoint AsyncPanZoomController::GetScrollWheelDelta( + const ScrollWheelInput& aEvent) const { + return GetScrollWheelDelta(aEvent, aEvent.mDeltaX, aEvent.mDeltaY, + aEvent.mUserDeltaMultiplierX, + aEvent.mUserDeltaMultiplierY); +} + +ParentLayerPoint AsyncPanZoomController::GetScrollWheelDelta( + const ScrollWheelInput& aEvent, double aDeltaX, double aDeltaY, + double aMultiplierX, double aMultiplierY) const { + ParentLayerSize scrollAmount; + ParentLayerSize pageScrollSize; + + { + // Grab the lock to access the frame metrics. + RecursiveMutexAutoLock lock(mRecursiveMutex); + LayoutDeviceIntSize scrollAmountLD = mScrollMetadata.GetLineScrollAmount(); + LayoutDeviceIntSize pageScrollSizeLD = + mScrollMetadata.GetPageScrollAmount(); + scrollAmount = scrollAmountLD / Metrics().GetDevPixelsPerCSSPixel() * + Metrics().GetZoom(); + pageScrollSize = pageScrollSizeLD / Metrics().GetDevPixelsPerCSSPixel() * + Metrics().GetZoom(); + } + + ParentLayerPoint delta; + switch (aEvent.mDeltaType) { + case ScrollWheelInput::SCROLLDELTA_LINE: { + delta.x = aDeltaX * scrollAmount.width; + delta.y = aDeltaY * scrollAmount.height; + break; + } + case ScrollWheelInput::SCROLLDELTA_PAGE: { + delta.x = aDeltaX * pageScrollSize.width; + delta.y = aDeltaY * pageScrollSize.height; + break; + } + case ScrollWheelInput::SCROLLDELTA_PIXEL: { + delta = ToParentLayerCoordinates(ScreenPoint(aDeltaX, aDeltaY), + aEvent.mOrigin); + break; + } + } + + // Apply user-set multipliers. + delta.x *= aMultiplierX; + delta.y *= aMultiplierY; + + // For the conditions under which we allow system scroll overrides, see + // WidgetWheelEvent::OverriddenDelta{X,Y}. + // Note that we do *not* restrict this to the root content, see bug 1217715 + // for discussion on this. + if (StaticPrefs::mousewheel_system_scroll_override_enabled() && + !aEvent.IsCustomizedByUserPrefs() && + aEvent.mDeltaType == ScrollWheelInput::SCROLLDELTA_LINE && + aEvent.mAllowToOverrideSystemScrollSpeed) { + delta.x = WidgetWheelEvent::ComputeOverriddenDelta(delta.x, false); + delta.y = WidgetWheelEvent::ComputeOverriddenDelta(delta.y, true); + } + + // If this is a line scroll, and this event was part of a scroll series, then + // it might need extra acceleration. See WheelHandlingHelper.cpp. + if (aEvent.mDeltaType == ScrollWheelInput::SCROLLDELTA_LINE && + aEvent.mScrollSeriesNumber > 0) { + int32_t start = StaticPrefs::mousewheel_acceleration_start(); + if (start >= 0 && aEvent.mScrollSeriesNumber >= uint32_t(start)) { + int32_t factor = StaticPrefs::mousewheel_acceleration_factor(); + if (factor > 0) { + delta.x = ComputeAcceleratedWheelDelta( + delta.x, aEvent.mScrollSeriesNumber, factor); + delta.y = ComputeAcceleratedWheelDelta( + delta.y, aEvent.mScrollSeriesNumber, factor); + } + } + } + + // We shouldn't scroll more than one page at once except when the + // user preference is large. + if (!AllowsScrollingMoreThanOnePage(aMultiplierX) && + Abs(delta.x) > pageScrollSize.width) { + delta.x = (delta.x >= 0) ? pageScrollSize.width : -pageScrollSize.width; + } + if (!AllowsScrollingMoreThanOnePage(aMultiplierY) && + Abs(delta.y) > pageScrollSize.height) { + delta.y = (delta.y >= 0) ? pageScrollSize.height : -pageScrollSize.height; + } + + return delta; +} + +nsEventStatus AsyncPanZoomController::OnKeyboard(const KeyboardInput& aEvent) { + // Mark that this APZC has async key scrolled + mTestHasAsyncKeyScrolled = true; + + // Calculate the destination for this keyboard scroll action + CSSPoint destination = GetKeyboardDestination(aEvent.mAction); + ScrollOrigin scrollOrigin = + SmoothScrollAnimation::GetScrollOriginForAction(aEvent.mAction.mType); + Maybe<CSSSnapDestination> snapDestination = + MaybeAdjustDestinationForScrollSnapping( + aEvent, destination, + GetScrollSnapFlagsForKeyboardAction(aEvent.mAction)); + ScrollMode scrollMode = apz::GetScrollModeForOrigin(scrollOrigin); + + RecordScrollPayload(aEvent.mTimeStamp); + // If the scrolling is instant, then scroll immediately to the destination + if (scrollMode == ScrollMode::Instant) { + CancelAnimation(); + + ParentLayerPoint startPoint, endPoint; + + { + RecursiveMutexAutoLock lock(mRecursiveMutex); + + // CallDispatchScroll interprets the start and end points as the start and + // end of a touch scroll so they need to be reversed. + startPoint = destination * Metrics().GetZoom(); + endPoint = Metrics().GetVisualScrollOffset() * Metrics().GetZoom(); + } + + ParentLayerPoint delta = endPoint - startPoint; + + ScreenPoint distance = ToScreenCoordinates( + ParentLayerPoint(fabs(delta.x), fabs(delta.y)), startPoint); + + OverscrollHandoffState handoffState( + *mInputQueue->GetCurrentKeyboardBlock()->GetOverscrollHandoffChain(), + distance, ScrollSource::Keyboard); + + CallDispatchScroll(startPoint, endPoint, handoffState); + ParentLayerPoint remainingDelta = endPoint - startPoint; + if (remainingDelta != delta) { + // If any scrolling happened, set KEYBOARD_SCROLL explicitly so that it + // will trigger a TransformEnd notification. + SetState(KEYBOARD_SCROLL); + } + + if (snapDestination) { + { + RecursiveMutexAutoLock lock(mRecursiveMutex); + mLastSnapTargetIds = std::move(snapDestination->mTargetIds); + } + } + SetState(NOTHING); + + return nsEventStatus_eConsumeDoDefault; + } + + // The lock must be held across the entire update operation, so the + // compositor doesn't end the animation before we get a chance to + // update it. + RecursiveMutexAutoLock lock(mRecursiveMutex); + + if (snapDestination) { + // If we're scroll snapping, use a smooth scroll animation to get + // the desired physics. Note that SmoothMsdScrollTo() will re-use an + // existing smooth scroll animation if there is one. + APZC_LOG("%p keyboard scrolling to snap point %s\n", this, + ToString(destination).c_str()); + SmoothMsdScrollTo(std::move(*snapDestination), ScrollTriggeredByScript::No); + return nsEventStatus_eConsumeDoDefault; + } + + // Use a keyboard scroll animation to scroll, reusing an existing one if it + // exists + if (mState != KEYBOARD_SCROLL) { + CancelAnimation(); + + // Keyboard input that does not change the scroll position should not + // cause a TransformBegin state change, in order to avoid firing a + // scrollend event when no scrolling occurred. + if (!CanScroll(ConvertDestinationToDelta(destination))) { + return nsEventStatus_eConsumeDoDefault; + } + SetState(KEYBOARD_SCROLL); + + nsPoint initialPosition = + CSSPoint::ToAppUnits(Metrics().GetVisualScrollOffset()); + StartAnimation(do_AddRef( + new SmoothScrollAnimation(*this, initialPosition, scrollOrigin))); + } + + // Convert velocity from ParentLayerPoints/ms to ParentLayerPoints/s and then + // to appunits/second. + nsPoint velocity; + if (Metrics().GetZoom() != CSSToParentLayerScale(0)) { + velocity = + CSSPoint::ToAppUnits(ParentLayerPoint(mX.GetVelocity() * 1000.0f, + mY.GetVelocity() * 1000.0f) / + Metrics().GetZoom()); + } + + SmoothScrollAnimation* animation = mAnimation->AsSmoothScrollAnimation(); + MOZ_ASSERT(animation); + + animation->UpdateDestination(aEvent.mTimeStamp, + CSSPixel::ToAppUnits(destination), + nsSize(velocity.x, velocity.y)); + + return nsEventStatus_eConsumeDoDefault; +} + +CSSPoint AsyncPanZoomController::GetKeyboardDestination( + const KeyboardScrollAction& aAction) const { + CSSSize lineScrollSize; + CSSSize pageScrollSize; + CSSPoint scrollOffset; + CSSRect scrollRect; + ParentLayerRect compositionBounds; + + { + // Grab the lock to access the frame metrics. + RecursiveMutexAutoLock lock(mRecursiveMutex); + + lineScrollSize = mScrollMetadata.GetLineScrollAmount() / + Metrics().GetDevPixelsPerCSSPixel(); + pageScrollSize = mScrollMetadata.GetPageScrollAmount() / + Metrics().GetDevPixelsPerCSSPixel(); + + scrollOffset = GetCurrentAnimationDestination(lock).valueOr( + Metrics().GetVisualScrollOffset()); + + scrollRect = Metrics().GetScrollableRect(); + compositionBounds = Metrics().GetCompositionBounds(); + } + + // Calculate the scroll destination based off of the scroll type and direction + CSSPoint scrollDestination = scrollOffset; + + switch (aAction.mType) { + case KeyboardScrollAction::eScrollCharacter: { + int32_t scrollDistance = + StaticPrefs::toolkit_scrollbox_horizontalScrollDistance(); + + if (aAction.mForward) { + scrollDestination.x += scrollDistance * lineScrollSize.width; + } else { + scrollDestination.x -= scrollDistance * lineScrollSize.width; + } + break; + } + case KeyboardScrollAction::eScrollLine: { + int32_t scrollDistance = + StaticPrefs::toolkit_scrollbox_verticalScrollDistance(); + if (scrollDistance * lineScrollSize.height <= + compositionBounds.Height()) { + if (aAction.mForward) { + scrollDestination.y += scrollDistance * lineScrollSize.height; + } else { + scrollDestination.y -= scrollDistance * lineScrollSize.height; + } + break; + } + [[fallthrough]]; + } + case KeyboardScrollAction::eScrollPage: { + if (aAction.mForward) { + scrollDestination.y += pageScrollSize.height; + } else { + scrollDestination.y -= pageScrollSize.height; + } + break; + } + case KeyboardScrollAction::eScrollComplete: { + if (aAction.mForward) { + scrollDestination.y = scrollRect.YMost(); + } else { + scrollDestination.y = scrollRect.Y(); + } + break; + } + } + + return scrollDestination; +} + +ScrollSnapFlags AsyncPanZoomController::GetScrollSnapFlagsForKeyboardAction( + const KeyboardScrollAction& aAction) const { + switch (aAction.mType) { + case KeyboardScrollAction::eScrollCharacter: + case KeyboardScrollAction::eScrollLine: + return ScrollSnapFlags::IntendedDirection; + case KeyboardScrollAction::eScrollPage: + return ScrollSnapFlags::IntendedDirection | + ScrollSnapFlags::IntendedEndPosition; + case KeyboardScrollAction::eScrollComplete: + return ScrollSnapFlags::IntendedEndPosition; + } + return ScrollSnapFlags::Disabled; +} + +ParentLayerPoint AsyncPanZoomController::GetDeltaForEvent( + const InputData& aEvent) const { + ParentLayerPoint delta; + if (aEvent.mInputType == SCROLLWHEEL_INPUT) { + delta = GetScrollWheelDelta(aEvent.AsScrollWheelInput()); + } else if (aEvent.mInputType == PANGESTURE_INPUT) { + const PanGestureInput& panInput = aEvent.AsPanGestureInput(); + delta = ToParentLayerCoordinates(panInput.UserMultipliedPanDisplacement(), + panInput.mPanStartPoint); + } + return delta; +} + +CSSRect AsyncPanZoomController::GetCurrentScrollRangeInCssPixels() const { + RecursiveMutexAutoLock lock(mRecursiveMutex); + return Metrics().CalculateScrollRange(); +} + +// Return whether or not the underlying layer can be scrolled on either axis. +bool AsyncPanZoomController::CanScroll(const InputData& aEvent) const { + ParentLayerPoint delta = GetDeltaForEvent(aEvent); + if (!delta.x && !delta.y) { + return false; + } + + if (SCROLLWHEEL_INPUT == aEvent.mInputType) { + const ScrollWheelInput& scrollWheelInput = aEvent.AsScrollWheelInput(); + // If it's a wheel scroll, we first check if it is an auto-dir scroll. + // 1. For an auto-dir scroll, check if it's delta should be adjusted, if it + // is, then we can conclude it must be scrollable; otherwise, fall back + // to checking if it is scrollable without adjusting its delta. + // 2. For a non-auto-dir scroll, simply check if it is scrollable without + // adjusting its delta. + RecursiveMutexAutoLock lock(mRecursiveMutex); + if (scrollWheelInput.IsAutoDir(mScrollMetadata.ForceMousewheelAutodir())) { + auto deltaX = scrollWheelInput.mDeltaX; + auto deltaY = scrollWheelInput.mDeltaY; + bool isRTL = + IsContentOfHonouredTargetRightToLeft(scrollWheelInput.HonoursRoot( + mScrollMetadata.ForceMousewheelAutodirHonourRoot())); + APZAutoDirWheelDeltaAdjuster adjuster(deltaX, deltaY, mX, mY, isRTL); + if (adjuster.ShouldBeAdjusted()) { + // If we detect that the delta values should be adjusted for an auto-dir + // wheel scroll, then it is impossible to be an unscrollable scroll. + return true; + } + } + return CanScrollWithWheel(delta); + } + return CanScroll(delta); +} + +ScrollDirections AsyncPanZoomController::GetAllowedHandoffDirections() const { + ScrollDirections result; + RecursiveMutexAutoLock lock(mRecursiveMutex); + + // In Fission there can be non-scrollable APZCs. It's unclear whether + // overscroll-behavior should be respected for these + // (see https://github.com/w3c/csswg-drafts/issues/6523) but + // we currently don't, to match existing practice. + const bool isScrollable = mX.CanScroll() || mY.CanScroll(); + const bool isRoot = IsRootContent(); + if ((!isScrollable && !isRoot) || mX.OverscrollBehaviorAllowsHandoff()) { + result += ScrollDirection::eHorizontal; + } + if ((!isScrollable && !isRoot) || mY.OverscrollBehaviorAllowsHandoff()) { + result += ScrollDirection::eVertical; + } + return result; +} + +bool AsyncPanZoomController::CanScroll(const ParentLayerPoint& aDelta) const { + RecursiveMutexAutoLock lock(mRecursiveMutex); + return mX.CanScroll(ParentLayerCoord(aDelta.x)) || + mY.CanScroll(ParentLayerCoord(aDelta.y)); +} + +bool AsyncPanZoomController::CanScrollWithWheel( + const ParentLayerPoint& aDelta) const { + RecursiveMutexAutoLock lock(mRecursiveMutex); + + // For more details about the concept of a disregarded direction, refer to the + // code in struct ScrollMetadata which defines mDisregardedDirection. + Maybe<ScrollDirection> disregardedDirection = + mScrollMetadata.GetDisregardedDirection(); + if (mX.CanScroll(ParentLayerCoord(aDelta.x)) && + disregardedDirection != Some(ScrollDirection::eHorizontal)) { + return true; + } + if (mY.CanScroll(ParentLayerCoord(aDelta.y)) && + disregardedDirection != Some(ScrollDirection::eVertical)) { + return true; + } + return false; +} + +bool AsyncPanZoomController::CanScroll(ScrollDirection aDirection) const { + RecursiveMutexAutoLock lock(mRecursiveMutex); + switch (aDirection) { + case ScrollDirection::eHorizontal: + return mX.CanScroll(); + case ScrollDirection::eVertical: + return mY.CanScroll(); + } + MOZ_ASSERT_UNREACHABLE("Invalid value"); + return false; +} + +bool AsyncPanZoomController::CanVerticalScrollWithDynamicToolbar() const { + MOZ_ASSERT(IsRootContent()); + + RecursiveMutexAutoLock lock(mRecursiveMutex); + return mY.CanVerticalScrollWithDynamicToolbar(); +} + +bool AsyncPanZoomController::CanOverscrollUpwards() const { + RecursiveMutexAutoLock lock(mRecursiveMutex); + return !mY.CanScrollTo(eSideTop) && mY.OverscrollBehaviorAllowsHandoff(); +} + +bool AsyncPanZoomController::CanScrollDownwards() const { + RecursiveMutexAutoLock lock(mRecursiveMutex); + return mY.CanScrollTo(eSideBottom); +} + +SideBits AsyncPanZoomController::ScrollableDirections() const { + SideBits result; + { // scope lock to respect lock ordering with APZCTreeManager::mTreeLock + // which will be acquired in the `GetCompositorFixedLayerMargins` below. + RecursiveMutexAutoLock lock(mRecursiveMutex); + result = mX.ScrollableDirections() | mY.ScrollableDirections(); + } + + if (IsRootContent()) { + if (APZCTreeManager* treeManagerLocal = GetApzcTreeManager()) { + ScreenMargin fixedLayerMargins = + treeManagerLocal->GetCompositorFixedLayerMargins(); + { + RecursiveMutexAutoLock lock(mRecursiveMutex); + result |= mY.ScrollableDirectionsWithDynamicToolbar(fixedLayerMargins); + } + } + } + + return result; +} + +bool AsyncPanZoomController::IsContentOfHonouredTargetRightToLeft( + bool aHonoursRoot) const { + if (aHonoursRoot) { + return mScrollMetadata.IsAutoDirRootContentRTL(); + } + RecursiveMutexAutoLock lock(mRecursiveMutex); + return Metrics().IsHorizontalContentRightToLeft(); +} + +bool AsyncPanZoomController::AllowScrollHandoffInCurrentBlock() const { + bool result = mInputQueue->AllowScrollHandoff(); + if (!StaticPrefs::apz_allow_immediate_handoff()) { + if (InputBlockState* currentBlock = GetCurrentInputBlock()) { + // Do not allow handoff beyond the first APZC to scroll. + if (currentBlock->GetScrolledApzc() == this) { + result = false; + APZC_LOG("%p dropping handoff; AllowImmediateHandoff=false\n", this); + } + } + } + return result; +} + +void AsyncPanZoomController::DoDelayedRequestContentRepaint() { + if (!IsDestroyed() && mPinchPaintTimerSet) { + RecursiveMutexAutoLock lock(mRecursiveMutex); + RequestContentRepaint(); + } + mPinchPaintTimerSet = false; +} + +void AsyncPanZoomController::DoDelayedTransformEndNotification( + PanZoomState aOldState) { + if (!IsDestroyed() && IsDelayedTransformEndSet()) { + DispatchStateChangeNotification(aOldState, NOTHING); + } + SetDelayedTransformEnd(false); +} + +static void AdjustDeltaForAllowedScrollDirections( + ParentLayerPoint& aDelta, + const ScrollDirections& aAllowedScrollDirections) { + if (!aAllowedScrollDirections.contains(ScrollDirection::eHorizontal)) { + aDelta.x = 0; + } + if (!aAllowedScrollDirections.contains(ScrollDirection::eVertical)) { + aDelta.y = 0; + } +} + +nsEventStatus AsyncPanZoomController::OnScrollWheel( + const ScrollWheelInput& aEvent) { + // Get the scroll wheel's delta values in parent-layer pixels. But before + // getting the values, we need to check if it is an auto-dir scroll and if it + // should be adjusted, if both answers are yes, let's adjust X and Y values + // first, and then get the delta values in parent-layer pixels based on the + // adjusted values. + bool adjustedByAutoDir = false; + auto deltaX = aEvent.mDeltaX; + auto deltaY = aEvent.mDeltaY; + ParentLayerPoint delta; + { + RecursiveMutexAutoLock lock(mRecursiveMutex); + if (aEvent.IsAutoDir(mScrollMetadata.ForceMousewheelAutodir())) { + // It's an auto-dir scroll, so check if its delta should be adjusted, if + // so, adjust it. + bool isRTL = IsContentOfHonouredTargetRightToLeft(aEvent.HonoursRoot( + mScrollMetadata.ForceMousewheelAutodirHonourRoot())); + APZAutoDirWheelDeltaAdjuster adjuster(deltaX, deltaY, mX, mY, isRTL); + if (adjuster.ShouldBeAdjusted()) { + adjuster.Adjust(); + adjustedByAutoDir = true; + } + } + } + // Ensure the calls to GetScrollWheelDelta are outside the mRecursiveMutex + // lock since these calls may acquire the APZ tree lock. Holding + // mRecursiveMutex while acquiring the APZ tree lock is lock ordering + // violation. + if (adjustedByAutoDir) { + // If the original delta values have been adjusted, we pass them to + // replace the original delta values in |aEvent| so that the delta values + // in parent-layer pixels are caculated based on the adjusted values, not + // the original ones. + // Pay special attention to the last two parameters. They are in a swaped + // order so that they still correspond to their delta after adjustment. + delta = GetScrollWheelDelta(aEvent, deltaX, deltaY, + aEvent.mUserDeltaMultiplierY, + aEvent.mUserDeltaMultiplierX); + } else { + // If the original delta values haven't been adjusted by auto-dir, just pass + // the |aEvent| and caculate the delta values in parent-layer pixels based + // on the original delta values from |aEvent|. + delta = GetScrollWheelDelta(aEvent); + } + + APZC_LOG("%p got a scroll-wheel with delta in parent-layer pixels: %s\n", + this, ToString(delta).c_str()); + + if (adjustedByAutoDir) { + MOZ_ASSERT(delta.x || delta.y, + "Adjusted auto-dir delta values can never be all-zero."); + APZC_LOG("%p got a scroll-wheel with adjusted auto-dir delta values\n", + this); + } else if ((delta.x || delta.y) && !CanScrollWithWheel(delta)) { + // We can't scroll this apz anymore, so we simply drop the event. + if (mInputQueue->GetActiveWheelTransaction() && + StaticPrefs::test_mousescroll()) { + if (RefPtr<GeckoContentController> controller = + GetGeckoContentController()) { + controller->NotifyMozMouseScrollEvent(GetScrollId(), + u"MozMouseScrollFailed"_ns); + } + } + return nsEventStatus_eConsumeNoDefault; + } + + MOZ_ASSERT(mInputQueue->GetCurrentWheelBlock()); + AdjustDeltaForAllowedScrollDirections( + delta, mInputQueue->GetCurrentWheelBlock()->GetAllowedScrollDirections()); + + if (delta.x == 0 && delta.y == 0) { + // Avoid spurious state changes and unnecessary work + return nsEventStatus_eIgnore; + } + + switch (aEvent.mScrollMode) { + case ScrollWheelInput::SCROLLMODE_INSTANT: { + // Wheel events from "clicky" mouse wheels trigger scroll snapping to the + // next snap point. Check for this, and adjust the delta to take into + // account the snap point. + CSSPoint startPosition; + { + RecursiveMutexAutoLock lock(mRecursiveMutex); + startPosition = Metrics().GetVisualScrollOffset(); + } + Maybe<CSSSnapDestination> snapDestination = + MaybeAdjustDeltaForScrollSnappingOnWheelInput(aEvent, delta, + startPosition); + + ScreenPoint distance = ToScreenCoordinates( + ParentLayerPoint(fabs(delta.x), fabs(delta.y)), aEvent.mLocalOrigin); + + CancelAnimation(); + + OverscrollHandoffState handoffState( + *mInputQueue->GetCurrentWheelBlock()->GetOverscrollHandoffChain(), + distance, ScrollSource::Wheel); + ParentLayerPoint startPoint = aEvent.mLocalOrigin; + ParentLayerPoint endPoint = aEvent.mLocalOrigin - delta; + RecordScrollPayload(aEvent.mTimeStamp); + + CallDispatchScroll(startPoint, endPoint, handoffState); + ParentLayerPoint remainingDelta = endPoint - startPoint; + if (remainingDelta != delta) { + // If any scrolling happened, set WHEEL_SCROLL explicitly so that it + // will trigger a TransformEnd notification. + SetState(WHEEL_SCROLL); + } + + if (snapDestination) { + { + RecursiveMutexAutoLock lock(mRecursiveMutex); + mLastSnapTargetIds = std::move(snapDestination->mTargetIds); + } + } + SetState(NOTHING); + + // The calls above handle their own locking; moreover, + // ToScreenCoordinates() and CallDispatchScroll() can grab the tree lock. + RecursiveMutexAutoLock lock(mRecursiveMutex); + RequestContentRepaint(); + + break; + } + + case ScrollWheelInput::SCROLLMODE_SMOOTH: { + // The lock must be held across the entire update operation, so the + // compositor doesn't end the animation before we get a chance to + // update it. + RecursiveMutexAutoLock lock(mRecursiveMutex); + + RecordScrollPayload(aEvent.mTimeStamp); + // Perform scroll snapping if appropriate. + // If we're already in a wheel scroll or smooth scroll animation, + // the delta is applied to its destination, not to the current + // scroll position. Take this into account when finding a snap point. + CSSPoint startPosition = GetCurrentAnimationDestination(lock).valueOr( + Metrics().GetVisualScrollOffset()); + + if (Maybe<CSSSnapDestination> snapDestination = + MaybeAdjustDeltaForScrollSnappingOnWheelInput(aEvent, delta, + startPosition)) { + // If we're scroll snapping, use a smooth scroll animation to get + // the desired physics. Note that SmoothMsdScrollTo() will re-use an + // existing smooth scroll animation if there is one. + APZC_LOG("%p wheel scrolling to snap point %s\n", this, + ToString(startPosition).c_str()); + SmoothMsdScrollTo(std::move(*snapDestination), + ScrollTriggeredByScript::No); + break; + } + + // Otherwise, use a wheel scroll animation, also reusing one if possible. + if (mState != WHEEL_SCROLL) { + CancelAnimation(); + SetState(WHEEL_SCROLL); + + nsPoint initialPosition = + CSSPoint::ToAppUnits(Metrics().GetVisualScrollOffset()); + StartAnimation(do_AddRef(new WheelScrollAnimation( + *this, initialPosition, aEvent.mDeltaType))); + } + // Convert velocity from ParentLayerPoints/ms to ParentLayerPoints/s and + // then to appunits/second. + + nsPoint deltaInAppUnits; + nsPoint velocity; + if (Metrics().GetZoom() != CSSToParentLayerScale(0)) { + deltaInAppUnits = CSSPoint::ToAppUnits(delta / Metrics().GetZoom()); + velocity = + CSSPoint::ToAppUnits(ParentLayerPoint(mX.GetVelocity() * 1000.0f, + mY.GetVelocity() * 1000.0f) / + Metrics().GetZoom()); + } + + WheelScrollAnimation* animation = mAnimation->AsWheelScrollAnimation(); + animation->UpdateDelta(aEvent.mTimeStamp, deltaInAppUnits, + nsSize(velocity.x, velocity.y)); + break; + } + } + + return nsEventStatus_eConsumeNoDefault; +} + +void AsyncPanZoomController::NotifyMozMouseScrollEvent( + const nsString& aString) const { + RefPtr<GeckoContentController> controller = GetGeckoContentController(); + if (!controller) { + return; + } + controller->NotifyMozMouseScrollEvent(GetScrollId(), aString); +} + +nsEventStatus AsyncPanZoomController::OnPanMayBegin( + const PanGestureInput& aEvent) { + APZC_LOG_DETAIL("got a pan-maybegin in state %s\n", this, + ToString(mState).c_str()); + + StartTouch(aEvent.mLocalPanStartPoint, aEvent.mTimeStamp); + MOZ_ASSERT(GetCurrentPanGestureBlock()); + GetCurrentPanGestureBlock()->GetOverscrollHandoffChain()->CancelAnimations(); + + return nsEventStatus_eConsumeNoDefault; +} + +nsEventStatus AsyncPanZoomController::OnPanCancelled( + const PanGestureInput& aEvent) { + APZC_LOG_DETAIL("got a pan-cancelled in state %s\n", this, + ToString(mState).c_str()); + + mX.CancelGesture(); + mY.CancelGesture(); + + return nsEventStatus_eConsumeNoDefault; +} + +nsEventStatus AsyncPanZoomController::OnPanBegin( + const PanGestureInput& aEvent) { + APZC_LOG_DETAIL("got a pan-begin in state %s\n", this, + ToString(mState).c_str()); + + if (mState == SMOOTHMSD_SCROLL) { + // SMOOTHMSD_SCROLL scrolls are cancelled by pan gestures. + CancelAnimation(); + } + + StartTouch(aEvent.mLocalPanStartPoint, aEvent.mTimeStamp); + + if (!UsingStatefulAxisLock()) { + SetState(PANNING); + } else { + float dx = aEvent.mPanDisplacement.x, dy = aEvent.mPanDisplacement.y; + + if (dx != 0.0f || dy != 0.0f) { + double angle = atan2(dy, dx); // range [-pi, pi] + angle = fabs(angle); // range [0, pi] + HandlePanning(angle); + } else { + SetState(PANNING); + } + } + + // Call into OnPan in order to process any delta included in this event. + OnPan(aEvent, FingersOnTouchpad::Yes); + + return nsEventStatus_eConsumeNoDefault; +} + +std::tuple<ParentLayerPoint, ScreenPoint> +AsyncPanZoomController::GetDisplacementsForPanGesture( + const PanGestureInput& aEvent) { + // Note that there is a multiplier that applies onto the "physical" pan + // displacement (how much the user's fingers moved) that produces the + // "logical" pan displacement (how much the page should move). For some of the + // code below it makes more sense to use the physical displacement rather than + // the logical displacement, and vice-versa. + ScreenPoint physicalPanDisplacement = aEvent.mPanDisplacement; + ParentLayerPoint logicalPanDisplacement = + aEvent.UserMultipliedLocalPanDisplacement(); + if (aEvent.mDeltaType == PanGestureInput::PANDELTA_PAGE) { + // Pan events with page units are used by Gtk, so this replicates Gtk: + // https://gitlab.gnome.org/GNOME/gtk/blob/c734c7e9188b56f56c3a504abee05fa40c5475ac/gtk/gtkrange.c#L3065-3073 + CSSSize pageScrollSize; + CSSToParentLayerScale zoom; + { + // Grab the lock to access the frame metrics. + RecursiveMutexAutoLock lock(mRecursiveMutex); + pageScrollSize = mScrollMetadata.GetPageScrollAmount() / + Metrics().GetDevPixelsPerCSSPixel(); + zoom = Metrics().GetZoom(); + } + // scrollUnit* is in units of "ParentLayer pixels per page proportion"... + auto scrollUnitWidth = std::min(std::pow(pageScrollSize.width, 2.0 / 3.0), + pageScrollSize.width / 2.0) * + zoom.scale; + auto scrollUnitHeight = std::min(std::pow(pageScrollSize.height, 2.0 / 3.0), + pageScrollSize.height / 2.0) * + zoom.scale; + // ... and pan displacements are in units of "page proportion count" + // here, so the products of them and scrollUnit* are in ParentLayer pixels + ParentLayerPoint physicalPanDisplacementPL( + physicalPanDisplacement.x * scrollUnitWidth, + physicalPanDisplacement.y * scrollUnitHeight); + physicalPanDisplacement = ToScreenCoordinates(physicalPanDisplacementPL, + aEvent.mLocalPanStartPoint); + logicalPanDisplacement.x *= scrollUnitWidth; + logicalPanDisplacement.y *= scrollUnitHeight; + + // Accelerate (decelerate) any pans by raising it to a user configurable + // power (apz.touch_acceleration_factor_x, apz.touch_acceleration_factor_y) + // + // Confine input for pow() to greater than or equal to 0 to avoid domain + // errors with non-integer exponents + if (mX.GetVelocity() != 0) { + float absVelocity = std::abs(mX.GetVelocity()); + logicalPanDisplacement.x *= + std::pow(absVelocity, + StaticPrefs::apz_touch_acceleration_factor_x()) / + absVelocity; + } + + if (mY.GetVelocity() != 0) { + float absVelocity = std::abs(mY.GetVelocity()); + logicalPanDisplacement.y *= + std::pow(absVelocity, + StaticPrefs::apz_touch_acceleration_factor_y()) / + absVelocity; + } + } + + MOZ_ASSERT(GetCurrentPanGestureBlock()); + AdjustDeltaForAllowedScrollDirections( + logicalPanDisplacement, + GetCurrentPanGestureBlock()->GetAllowedScrollDirections()); + + if (GetAxisLockMode() == DOMINANT_AXIS) { + // Given a pan gesture and both directions have a delta, implement + // dominant axis scrolling and only use the delta for the larger + // axis. + if (logicalPanDisplacement.y != 0 && logicalPanDisplacement.x != 0) { + if (fabs(logicalPanDisplacement.y) >= fabs(logicalPanDisplacement.x)) { + logicalPanDisplacement.x = 0; + physicalPanDisplacement.x = 0; + } else { + logicalPanDisplacement.y = 0; + physicalPanDisplacement.y = 0; + } + } + } + + return {logicalPanDisplacement, physicalPanDisplacement}; +} + +nsEventStatus AsyncPanZoomController::OnPan( + const PanGestureInput& aEvent, FingersOnTouchpad aFingersOnTouchpad) { + APZC_LOG_DETAIL("got a pan-pan in state %s\n", this, + ToString(GetState()).c_str()); + + if (GetState() == SMOOTHMSD_SCROLL) { + if (aFingersOnTouchpad == FingersOnTouchpad::No) { + // When a SMOOTHMSD_SCROLL scroll is being processed on a frame, mouse + // wheel and trackpad momentum scroll position updates will not cancel the + // SMOOTHMSD_SCROLL scroll animations, enabling scripts that depend on + // them to be responsive without forcing the user to wait for the momentum + // scrolling to completely stop. + return nsEventStatus_eConsumeNoDefault; + } + + // SMOOTHMSD_SCROLL scrolls are cancelled by pan gestures. + CancelAnimation(); + } + + if (GetState() == NOTHING) { + // This event block was interrupted by something else. If the user's fingers + // are still on on the touchpad we want to resume scrolling, otherwise we + // ignore the rest of the scroll gesture. + if (aFingersOnTouchpad == FingersOnTouchpad::No) { + return nsEventStatus_eConsumeNoDefault; + } + // Resume / restart the pan. + // PanBegin will call back into this function with mState == PANNING. + return OnPanBegin(aEvent); + } + + auto [logicalPanDisplacement, physicalPanDisplacement] = + GetDisplacementsForPanGesture(aEvent); + + { + // Grab the lock to protect the animation from being canceled on the updater + // thread. + RecursiveMutexAutoLock lock(mRecursiveMutex); + MOZ_ASSERT_IF(GetState() == OVERSCROLL_ANIMATION, mAnimation); + + if (GetState() == OVERSCROLL_ANIMATION && mAnimation && + aFingersOnTouchpad == FingersOnTouchpad::No) { + // If there is an on-going overscroll animation, we tell the animation + // whether the displacements should be handled by the animation or not. + MOZ_ASSERT(mAnimation->AsOverscrollAnimation()); + if (RefPtr<OverscrollAnimation> overscrollAnimation = + mAnimation->AsOverscrollAnimation()) { + overscrollAnimation->HandlePanMomentum(logicalPanDisplacement); + // And then as a result of the above call, if the animation is currently + // affecting on the axis, drop the displacement value on the axis so + // that we stop further oversrolling on the axis. + if (overscrollAnimation->IsManagingXAxis()) { + logicalPanDisplacement.x = 0; + physicalPanDisplacement.x = 0; + } + if (overscrollAnimation->IsManagingYAxis()) { + logicalPanDisplacement.y = 0; + physicalPanDisplacement.y = 0; + } + } + } + } + + HandlePanningUpdate(physicalPanDisplacement); + + MOZ_ASSERT(GetCurrentPanGestureBlock()); + ScreenPoint panDistance(fabs(physicalPanDisplacement.x), + fabs(physicalPanDisplacement.y)); + OverscrollHandoffState handoffState( + *GetCurrentPanGestureBlock()->GetOverscrollHandoffChain(), panDistance, + ScrollSource::Touchpad); + + // Create fake "touch" positions that will result in the desired scroll + // motion. Note that the pan displacement describes the change in scroll + // position: positive displacement values mean that the scroll position + // increases. However, an increase in scroll position means that the scrolled + // contents are moved to the left / upwards. Since our simulated "touches" + // determine the motion of the scrolled contents, not of the scroll position, + // they need to move in the opposite direction of the pan displacement. + ParentLayerPoint startPoint = aEvent.mLocalPanStartPoint; + ParentLayerPoint endPoint = + aEvent.mLocalPanStartPoint - logicalPanDisplacement; + if (logicalPanDisplacement != ParentLayerPoint()) { + // Don't expect a composite to be triggered if the displacement is zero + RecordScrollPayload(aEvent.mTimeStamp); + } + + const ParentLayerPoint velocity = GetVelocityVector(); + bool consumed = CallDispatchScroll(startPoint, endPoint, handoffState); + + const ParentLayerPoint visualDisplacement = ToParentLayerCoordinates( + handoffState.mTotalMovement, aEvent.mPanStartPoint); + // We need to update the axis velocity in order to get a useful display port + // size and position. We need to do so even if this is a momentum pan (i.e. + // aFingersOnTouchpad == No); in that case the "with touch" part is not + // really appropriate, so we may want to rethink this at some point. + // Note that we have to make all simulated positions relative to + // Axis::GetPos(), because the current position is an invented position, and + // because resetting the position to the mouse position (e.g. + // aEvent.mLocalStartPoint) would mess up velocity calculation. (This is + // the only caller of UpdateWithTouchAtDevicePoint() for pan events, so + // there is no risk of other calls resetting the position.) + // Also note that if there is an on-going overscroll animation in the axis, + // we shouldn't call UpdateWithTouchAtDevicePoint because the call changes + // the velocity which should be managed by the overscroll animation. + // Finally, note that we do this *after* CallDispatchScroll(), so that the + // position we use reflects the actual amount of movement that occurred + // (in particular, if we're in overscroll, if reflects the amount of movement + // *after* applying resistance). This is important because we want the axis + // velocity to track the visual movement speed of the page. + if (visualDisplacement.x != 0) { + mX.UpdateWithTouchAtDevicePoint(mX.GetPos() - visualDisplacement.x, + aEvent.mTimeStamp); + } + if (visualDisplacement.y != 0) { + mY.UpdateWithTouchAtDevicePoint(mY.GetPos() - visualDisplacement.y, + aEvent.mTimeStamp); + } + + if (aFingersOnTouchpad == FingersOnTouchpad::No) { + if (IsOverscrolled() && GetState() != OVERSCROLL_ANIMATION) { + StartOverscrollAnimation(velocity, GetOverscrollSideBits()); + } else if (!consumed) { + // If there is unconsumed scroll and we're in the momentum part of the + // pan gesture, terminate the momentum scroll. This prevents momentum + // scroll events from unexpectedly causing scrolling later if somehow + // the APZC becomes scrollable again in this direction (e.g. if the user + // uses some other input method to scroll in the opposite direction). + SetState(NOTHING); + } + } + + return nsEventStatus_eConsumeNoDefault; +} + +nsEventStatus AsyncPanZoomController::OnPanEnd(const PanGestureInput& aEvent) { + APZC_LOG_DETAIL("got a pan-end in state %s\n", this, + ToString(mState).c_str()); + + // This can happen if the OS sends a second pan-end event after the first one + // has already started an overscroll animation or entered a fling state. + // This has been observed on some Wayland versions. + PanZoomState currentState = GetState(); + if (currentState == OVERSCROLL_ANIMATION || currentState == NOTHING || + currentState == FLING) { + return nsEventStatus_eIgnore; + } + + if (aEvent.mPanDisplacement != ScreenPoint{}) { + // Call into OnPan in order to process the delta included in this event. + OnPan(aEvent, FingersOnTouchpad::Yes); + } + + // Do not unlock the axis lock at the end of a pan gesture. The axis lock + // should extend into the momentum scroll. + EndTouch(aEvent.mTimeStamp, Axis::ClearAxisLock::No); + + // Use HandleEndOfPan for fling on platforms that don't + // emit momentum events (Gtk). + if (aEvent.mSimulateMomentum) { + return HandleEndOfPan(); + } + + MOZ_ASSERT(GetCurrentPanGestureBlock()); + RefPtr<const OverscrollHandoffChain> overscrollHandoffChain = + GetCurrentPanGestureBlock()->GetOverscrollHandoffChain(); + + // Call SnapBackOverscrolledApzcForMomentum regardless whether this APZC is + // overscrolled or not since overscroll animations for ancestor APZCs in this + // overscroll handoff chain might have been cancelled by the current pan + // gesture block. + overscrollHandoffChain->SnapBackOverscrolledApzcForMomentum( + this, GetVelocityVector()); + // If this APZC is overscrolled, the above SnapBackOverscrolledApzcForMomentum + // triggers an overscroll animation. When we're finished with the overscroll + // animation, the state will be reset and a TransformEnd will be sent to the + // main thread. + currentState = GetState(); + if (currentState != OVERSCROLL_ANIMATION) { + // Do not send a state change notification to the content controller here. + // Instead queue a delayed task to dispatch the notification if no + // momentum pan or scroll snap follows the pan-end. + RefPtr<GeckoContentController> controller = GetGeckoContentController(); + if (controller) { + SetDelayedTransformEnd(true); + controller->PostDelayedTask( + NewRunnableMethod<PanZoomState>( + "layers::AsyncPanZoomController::" + "DoDelayedTransformEndNotification", + this, &AsyncPanZoomController::DoDelayedTransformEndNotification, + currentState), + StaticPrefs::apz_scrollend_event_content_delay_ms()); + SetStateNoContentControllerDispatch(NOTHING); + } else { + SetState(NOTHING); + } + } + + // Drop any velocity on axes where we don't have room to scroll anyways + // (in this APZC, or an APZC further in the handoff chain). + // This ensures that we don't enlarge the display port unnecessarily. + { + RecursiveMutexAutoLock lock(mRecursiveMutex); + if (!overscrollHandoffChain->CanScrollInDirection( + this, ScrollDirection::eHorizontal)) { + mX.SetVelocity(0); + } + if (!overscrollHandoffChain->CanScrollInDirection( + this, ScrollDirection::eVertical)) { + mY.SetVelocity(0); + } + } + + RequestContentRepaint(); + ScrollSnapToDestination(); + + return nsEventStatus_eConsumeNoDefault; +} + +nsEventStatus AsyncPanZoomController::OnPanMomentumStart( + const PanGestureInput& aEvent) { + APZC_LOG_DETAIL("got a pan-momentumstart in state %s\n", this, + ToString(mState).c_str()); + + if (mState == SMOOTHMSD_SCROLL || mState == OVERSCROLL_ANIMATION) { + return nsEventStatus_eConsumeNoDefault; + } + + if (IsDelayedTransformEndSet()) { + // Do not send another TransformBegin notification if we have not + // delivered a corresponding TransformEnd. Also ensure that any + // queued transform-end due to a pan-end is not sent. Instead rely + // on the transform-end sent due to the momentum pan. + SetDelayedTransformEnd(false); + SetStateNoContentControllerDispatch(PAN_MOMENTUM); + } else { + SetState(PAN_MOMENTUM); + } + + // Call into OnPan in order to process any delta included in this event. + OnPan(aEvent, FingersOnTouchpad::No); + + return nsEventStatus_eConsumeNoDefault; +} + +nsEventStatus AsyncPanZoomController::OnPanMomentumEnd( + const PanGestureInput& aEvent) { + APZC_LOG_DETAIL("got a pan-momentumend in state %s\n", this, + ToString(mState).c_str()); + + if (mState == OVERSCROLL_ANIMATION) { + return nsEventStatus_eConsumeNoDefault; + } + + // Call into OnPan in order to process any delta included in this event. + OnPan(aEvent, FingersOnTouchpad::No); + + // We need to reset the velocity to zero. We don't really have a "touch" + // here because the touch has already ended long before the momentum + // animation started, but I guess it doesn't really matter for now. + mX.CancelGesture(); + mY.CancelGesture(); + SetState(NOTHING); + + RequestContentRepaint(); + + return nsEventStatus_eConsumeNoDefault; +} + +nsEventStatus AsyncPanZoomController::OnPanInterrupted( + const PanGestureInput& aEvent) { + APZC_LOG_DETAIL("got a pan-interrupted in state %s\n", this, + ToString(mState).c_str()); + + CancelAnimation(); + + return nsEventStatus_eIgnore; +} + +nsEventStatus AsyncPanZoomController::OnLongPress( + const TapGestureInput& aEvent) { + APZC_LOG_DETAIL("got a long-press in state %s\n", this, + ToString(mState).c_str()); + RefPtr<GeckoContentController> controller = GetGeckoContentController(); + if (controller) { + if (Maybe<LayoutDevicePoint> geckoScreenPoint = + ConvertToGecko(aEvent.mPoint)) { + TouchBlockState* touch = GetCurrentTouchBlock(); + if (!touch) { + APZC_LOG( + "%p dropping long-press because some non-touch block interrupted " + "it\n", + this); + return nsEventStatus_eIgnore; + } + if (touch->IsDuringFastFling()) { + APZC_LOG("%p dropping long-press because of fast fling\n", this); + return nsEventStatus_eIgnore; + } + uint64_t blockId = GetInputQueue()->InjectNewTouchBlock(this); + controller->HandleTap(TapType::eLongTap, *geckoScreenPoint, + aEvent.modifiers, GetGuid(), blockId, Nothing()); + return nsEventStatus_eConsumeNoDefault; + } + } + return nsEventStatus_eIgnore; +} + +nsEventStatus AsyncPanZoomController::OnLongPressUp( + const TapGestureInput& aEvent) { + APZC_LOG_DETAIL("got a long-tap-up in state %s\n", this, + ToString(mState).c_str()); + return GenerateSingleTap(TapType::eLongTapUp, aEvent.mPoint, + aEvent.modifiers); +} + +nsEventStatus AsyncPanZoomController::GenerateSingleTap( + TapType aType, const ScreenIntPoint& aPoint, + mozilla::Modifiers aModifiers) { + RefPtr<GeckoContentController> controller = GetGeckoContentController(); + if (controller) { + if (Maybe<LayoutDevicePoint> geckoScreenPoint = ConvertToGecko(aPoint)) { + TouchBlockState* touch = GetCurrentTouchBlock(); + // |touch| may be null in the case where this function is + // invoked by GestureEventListener on a timeout. In that case we already + // verified that the single tap is allowed so we let it through. + // XXX there is a bug here that in such a case the touch block that + // generated this tap will not get its mSingleTapOccurred flag set. + // See https://bugzilla.mozilla.org/show_bug.cgi?id=1256344#c6 + if (touch) { + if (touch->IsDuringFastFling()) { + APZC_LOG( + "%p dropping single-tap because it was during a fast-fling\n", + this); + return nsEventStatus_eIgnore; + } + + // The below `single-tap-occurred` flag is only used to tell whether the + // touch block caused a `click` event or not, thus for long-tap events, + // it's not necessary. + if (aType != TapType::eLongTapUp) { + touch->SetSingleTapOccurred(); + } + } + // Because this may be being running as part of + // APZCTreeManager::ReceiveInputEvent, calling controller->HandleTap + // directly might mean that content receives the single tap message before + // the corresponding touch-up. To avoid that we schedule the singletap + // message to run on the next spin of the event loop. See bug 965381 for + // the issue this was causing. + APZC_LOG("posting runnable for HandleTap from GenerateSingleTap"); + RefPtr<Runnable> runnable = + NewRunnableMethod<TapType, LayoutDevicePoint, mozilla::Modifiers, + ScrollableLayerGuid, uint64_t, + Maybe<DoubleTapToZoomMetrics>>( + "layers::GeckoContentController::HandleTap", controller, + &GeckoContentController::HandleTap, aType, *geckoScreenPoint, + aModifiers, GetGuid(), touch ? touch->GetBlockId() : 0, + Nothing()); + + controller->PostDelayedTask(runnable.forget(), 0); + return nsEventStatus_eConsumeNoDefault; + } + } + return nsEventStatus_eIgnore; +} + +void AsyncPanZoomController::OnTouchEndOrCancel() { + if (RefPtr<GeckoContentController> controller = GetGeckoContentController()) { + MOZ_ASSERT(GetCurrentTouchBlock()); + controller->NotifyAPZStateChange( + GetGuid(), APZStateChange::eEndTouch, + GetCurrentTouchBlock()->SingleTapOccurred(), + Some(GetCurrentTouchBlock()->GetBlockId())); + } +} + +nsEventStatus AsyncPanZoomController::OnSingleTapUp( + const TapGestureInput& aEvent) { + APZC_LOG_DETAIL("got a single-tap-up in state %s\n", this, + ToString(mState).c_str()); + // If mZoomConstraints.mAllowDoubleTapZoom is true we wait for a call to + // OnSingleTapConfirmed before sending event to content + MOZ_ASSERT(GetCurrentTouchBlock()); + if (!(ZoomConstraintsAllowDoubleTapZoom() && + GetCurrentTouchBlock()->TouchActionAllowsDoubleTapZoom())) { + return GenerateSingleTap(TapType::eSingleTap, aEvent.mPoint, + aEvent.modifiers); + } + return nsEventStatus_eIgnore; +} + +nsEventStatus AsyncPanZoomController::OnSingleTapConfirmed( + const TapGestureInput& aEvent) { + APZC_LOG_DETAIL("got a single-tap-confirmed in state %s\n", this, + ToString(mState).c_str()); + return GenerateSingleTap(TapType::eSingleTap, aEvent.mPoint, + aEvent.modifiers); +} + +nsEventStatus AsyncPanZoomController::OnDoubleTap( + const TapGestureInput& aEvent) { + APZC_LOG_DETAIL("got a double-tap in state %s\n", this, + ToString(mState).c_str()); + + MOZ_ASSERT(IsRootForLayersId(), + "This function should be called for the root content APZC or " + "OOPIF root APZC"); + + CSSToCSSMatrix4x4 transformToRootContentApzc; + RefPtr<AsyncPanZoomController> rootContentApzc; + if (IsRootContent()) { + rootContentApzc = RefPtr{this}; + } else { + if (APZCTreeManager* treeManagerLocal = GetApzcTreeManager()) { + rootContentApzc = treeManagerLocal->FindZoomableApzc(this); + if (rootContentApzc) { + MOZ_ASSERT(rootContentApzc->GetLayersId() != GetLayersId()); + MOZ_ASSERT(this == treeManagerLocal->FindRootApzcFor(GetLayersId())); + transformToRootContentApzc = + treeManagerLocal->GetOopifToRootContentTransform(this); + } + } + } + + if (!rootContentApzc) { + return nsEventStatus_eIgnore; + } + + RefPtr<GeckoContentController> controller = GetGeckoContentController(); + if (controller) { + if (rootContentApzc->ZoomConstraintsAllowDoubleTapZoom() && + (!GetCurrentTouchBlock() || + GetCurrentTouchBlock()->TouchActionAllowsDoubleTapZoom())) { + if (Maybe<LayoutDevicePoint> geckoScreenPoint = + ConvertToGecko(aEvent.mPoint)) { + controller->HandleTap( + TapType::eDoubleTap, *geckoScreenPoint, aEvent.modifiers, GetGuid(), + GetCurrentTouchBlock() ? GetCurrentTouchBlock()->GetBlockId() : 0, + Some(DoubleTapToZoomMetrics{rootContentApzc->GetVisualViewport(), + rootContentApzc->GetScrollableRect(), + transformToRootContentApzc})); + } + } + return nsEventStatus_eConsumeNoDefault; + } + return nsEventStatus_eIgnore; +} + +nsEventStatus AsyncPanZoomController::OnSecondTap( + const TapGestureInput& aEvent) { + APZC_LOG_DETAIL("got a second-tap in state %s\n", this, + ToString(mState).c_str()); + return GenerateSingleTap(TapType::eSecondTap, aEvent.mPoint, + aEvent.modifiers); +} + +nsEventStatus AsyncPanZoomController::OnCancelTap( + const TapGestureInput& aEvent) { + APZC_LOG_DETAIL("got a cancel-tap in state %s\n", this, + ToString(mState).c_str()); + // XXX: Implement this. + return nsEventStatus_eIgnore; +} + +ScreenToParentLayerMatrix4x4 AsyncPanZoomController::GetTransformToThis() + const { + if (APZCTreeManager* treeManagerLocal = GetApzcTreeManager()) { + return treeManagerLocal->GetScreenToApzcTransform(this); + } + return ScreenToParentLayerMatrix4x4(); +} + +ScreenPoint AsyncPanZoomController::ToScreenCoordinates( + const ParentLayerPoint& aVector, const ParentLayerPoint& aAnchor) const { + return TransformVector(GetTransformToThis().Inverse(), aVector, aAnchor); +} + +// TODO: figure out a good way to check the w-coordinate is positive and return +// the result +ParentLayerPoint AsyncPanZoomController::ToParentLayerCoordinates( + const ScreenPoint& aVector, const ScreenPoint& aAnchor) const { + return TransformVector(GetTransformToThis(), aVector, aAnchor); +} + +ParentLayerPoint AsyncPanZoomController::ToParentLayerCoordinates( + const ScreenPoint& aVector, const ExternalPoint& aAnchor) const { + return ToParentLayerCoordinates( + aVector, + ViewAs<ScreenPixel>(aAnchor, PixelCastJustification::ExternalIsScreen)); +} + +ExternalPoint AsyncPanZoomController::ToExternalPoint( + const ExternalPoint& aScreenOffset, const ScreenPoint& aScreenPoint) { + return aScreenOffset + + ViewAs<ExternalPixel>(aScreenPoint, + PixelCastJustification::ExternalIsScreen); +} + +ScreenPoint AsyncPanZoomController::PanVector(const ExternalPoint& aPos) const { + return ScreenPoint(fabs(aPos.x - mStartTouch.x), + fabs(aPos.y - mStartTouch.y)); +} + +bool AsyncPanZoomController::Contains(const ScreenIntPoint& aPoint) const { + ScreenToParentLayerMatrix4x4 transformToThis = GetTransformToThis(); + Maybe<ParentLayerIntPoint> point = UntransformBy(transformToThis, aPoint); + if (!point) { + return false; + } + + ParentLayerIntRect cb; + { + RecursiveMutexAutoLock lock(mRecursiveMutex); + GetFrameMetrics().GetCompositionBounds().ToIntRect(&cb); + } + return cb.Contains(*point); +} + +bool AsyncPanZoomController::IsInOverscrollGutter( + const ScreenPoint& aHitTestPoint) const { + if (!IsPhysicallyOverscrolled()) { + return false; + } + + Maybe<ParentLayerPoint> apzcPoint = + UntransformBy(GetTransformToThis(), aHitTestPoint); + if (!apzcPoint) return false; + return IsInOverscrollGutter(*apzcPoint); +} + +bool AsyncPanZoomController::IsInOverscrollGutter( + const ParentLayerPoint& aHitTestPoint) const { + ParentLayerRect compositionBounds; + { + RecursiveMutexAutoLock lock(mRecursiveMutex); + compositionBounds = GetFrameMetrics().GetCompositionBounds(); + } + if (!compositionBounds.Contains(aHitTestPoint)) { + // Point is outside of scrollable element's bounds altogether. + return false; + } + auto overscrollTransform = GetOverscrollTransform(eForEventHandling); + ParentLayerPoint overscrollUntransformed = + overscrollTransform.Inverse().TransformPoint(aHitTestPoint); + + if (compositionBounds.Contains(overscrollUntransformed)) { + // Point is over scrollable content. + return false; + } + + // Point is in gutter. + return true; +} + +bool AsyncPanZoomController::IsOverscrolled() const { + return mOverscrollEffect->IsOverscrolled(); +} + +bool AsyncPanZoomController::IsPhysicallyOverscrolled() const { + // As an optimization, avoid calling Apply/UnapplyAsyncTestAttributes + // unless we're in a test environment where we need it. + if (StaticPrefs::apz_overscroll_test_async_scroll_offset_enabled()) { + RecursiveMutexAutoLock lock(mRecursiveMutex); + AutoApplyAsyncTestAttributes testAttributeApplier(this, lock); + return mX.IsOverscrolled() || mY.IsOverscrolled(); + } + RecursiveMutexAutoLock lock(mRecursiveMutex); + return mX.IsOverscrolled() || mY.IsOverscrolled(); +} + +bool AsyncPanZoomController::IsInInvalidOverscroll() const { + return mX.IsInInvalidOverscroll() || mY.IsInInvalidOverscroll(); +} + +ParentLayerPoint AsyncPanZoomController::PanStart() const { + return ParentLayerPoint(mX.PanStart(), mY.PanStart()); +} + +const ParentLayerPoint AsyncPanZoomController::GetVelocityVector() const { + RecursiveMutexAutoLock lock(mRecursiveMutex); + return ParentLayerPoint(mX.GetVelocity(), mY.GetVelocity()); +} + +void AsyncPanZoomController::SetVelocityVector( + const ParentLayerPoint& aVelocityVector) { + RecursiveMutexAutoLock lock(mRecursiveMutex); + mX.SetVelocity(aVelocityVector.x); + mY.SetVelocity(aVelocityVector.y); +} + +void AsyncPanZoomController::HandlePanningWithTouchAction(double aAngle) { + // Handling of cross sliding will need to be added in this method after + // touch-action released enabled by default. + MOZ_ASSERT(GetCurrentTouchBlock()); + RefPtr<const OverscrollHandoffChain> overscrollHandoffChain = + GetCurrentInputBlock()->GetOverscrollHandoffChain(); + bool canScrollHorizontal = + !mX.IsAxisLocked() && overscrollHandoffChain->CanScrollInDirection( + this, ScrollDirection::eHorizontal); + bool canScrollVertical = + !mY.IsAxisLocked() && overscrollHandoffChain->CanScrollInDirection( + this, ScrollDirection::eVertical); + if (GetCurrentTouchBlock()->TouchActionAllowsPanningXY()) { + if (canScrollHorizontal && canScrollVertical) { + if (apz::IsCloseToHorizontal(aAngle, + StaticPrefs::apz_axis_lock_lock_angle())) { + mY.SetAxisLocked(true); + SetState(PANNING_LOCKED_X); + } else if (apz::IsCloseToVertical( + aAngle, StaticPrefs::apz_axis_lock_lock_angle())) { + mX.SetAxisLocked(true); + SetState(PANNING_LOCKED_Y); + } else { + SetState(PANNING); + } + } else if (canScrollHorizontal || canScrollVertical) { + SetState(PANNING); + } else { + SetState(NOTHING); + } + } else if (GetCurrentTouchBlock()->TouchActionAllowsPanningX()) { + // Using bigger angle for panning to keep behavior consistent + // with IE. + if (apz::IsCloseToHorizontal( + aAngle, StaticPrefs::apz_axis_lock_direct_pan_angle())) { + mY.SetAxisLocked(true); + SetState(PANNING_LOCKED_X); + mPanDirRestricted = true; + } else { + // Don't treat these touches as pan/zoom movements since 'touch-action' + // value requires it. + SetState(NOTHING); + } + } else if (GetCurrentTouchBlock()->TouchActionAllowsPanningY()) { + if (apz::IsCloseToVertical(aAngle, + StaticPrefs::apz_axis_lock_direct_pan_angle())) { + mX.SetAxisLocked(true); + SetState(PANNING_LOCKED_Y); + mPanDirRestricted = true; + } else { + SetState(NOTHING); + } + } else { + SetState(NOTHING); + } + if (!IsInPanningState()) { + // If we didn't enter a panning state because touch-action disallowed it, + // make sure to clear any leftover velocity from the pre-threshold + // touchmoves. + mX.SetVelocity(0); + mY.SetVelocity(0); + } +} + +void AsyncPanZoomController::HandlePanning(double aAngle) { + RecursiveMutexAutoLock lock(mRecursiveMutex); + MOZ_ASSERT(GetCurrentInputBlock()); + RefPtr<const OverscrollHandoffChain> overscrollHandoffChain = + GetCurrentInputBlock()->GetOverscrollHandoffChain(); + bool canScrollHorizontal = + !mX.IsAxisLocked() && overscrollHandoffChain->CanScrollInDirection( + this, ScrollDirection::eHorizontal); + bool canScrollVertical = + !mY.IsAxisLocked() && overscrollHandoffChain->CanScrollInDirection( + this, ScrollDirection::eVertical); + + MOZ_ASSERT(UsingStatefulAxisLock()); + + if (!canScrollHorizontal || !canScrollVertical) { + SetState(PANNING); + } else if (apz::IsCloseToHorizontal( + aAngle, StaticPrefs::apz_axis_lock_lock_angle())) { + mY.SetAxisLocked(true); + if (canScrollHorizontal) { + SetState(PANNING_LOCKED_X); + } + } else if (apz::IsCloseToVertical(aAngle, + StaticPrefs::apz_axis_lock_lock_angle())) { + mX.SetAxisLocked(true); + if (canScrollVertical) { + SetState(PANNING_LOCKED_Y); + } + } else { + SetState(PANNING); + } +} + +void AsyncPanZoomController::HandlePanningUpdate( + const ScreenPoint& aPanDistance) { + // If we're axis-locked, check if the user is trying to break the lock + if (GetAxisLockMode() == STICKY && !mPanDirRestricted) { + ParentLayerPoint vector = + ToParentLayerCoordinates(aPanDistance, mStartTouch); + + float angle = atan2f(vector.y, vector.x); // range [-pi, pi] + angle = fabsf(angle); // range [0, pi] + + float breakThreshold = + StaticPrefs::apz_axis_lock_breakout_threshold() * GetDPI(); + + if (fabs(aPanDistance.x) > breakThreshold || + fabs(aPanDistance.y) > breakThreshold) { + switch (mState) { + case PANNING_LOCKED_X: + if (!apz::IsCloseToHorizontal( + angle, StaticPrefs::apz_axis_lock_breakout_angle())) { + mY.SetAxisLocked(false); + // If we are within the lock angle from the Y axis, lock + // onto the Y axis. + if (apz::IsCloseToVertical( + angle, StaticPrefs::apz_axis_lock_lock_angle())) { + mX.SetAxisLocked(true); + SetState(PANNING_LOCKED_Y); + } else { + SetState(PANNING); + } + } + break; + + case PANNING_LOCKED_Y: + if (!apz::IsCloseToVertical( + angle, StaticPrefs::apz_axis_lock_breakout_angle())) { + mX.SetAxisLocked(false); + // If we are within the lock angle from the X axis, lock + // onto the X axis. + if (apz::IsCloseToHorizontal( + angle, StaticPrefs::apz_axis_lock_lock_angle())) { + mY.SetAxisLocked(true); + SetState(PANNING_LOCKED_X); + } else { + SetState(PANNING); + } + } + break; + + case PANNING: + HandlePanning(angle); + break; + + default: + break; + } + } + } +} + +void AsyncPanZoomController::HandlePinchLocking( + const PinchGestureInput& aEvent) { + // Focus change and span distance calculated from an event buffer + // Used to handle pinch locking irrespective of touch screen sensitivity + // Note: both values fall back to the same value as + // their un-buffered counterparts if there is only one (the latest) + // event in the buffer. ie: when the touch screen is dispatching + // events slower than the lifetime of the buffer + ParentLayerCoord bufferedSpanDistance; + ParentLayerPoint focusPoint, bufferedFocusChange; + { + RecursiveMutexAutoLock lock(mRecursiveMutex); + + focusPoint = mPinchEventBuffer.back().mLocalFocusPoint - + Metrics().GetCompositionBounds().TopLeft(); + ParentLayerPoint bufferedLastZoomFocus = + (mPinchEventBuffer.size() > 1) + ? mPinchEventBuffer.front().mLocalFocusPoint - + Metrics().GetCompositionBounds().TopLeft() + : mLastZoomFocus; + + bufferedFocusChange = bufferedLastZoomFocus - focusPoint; + bufferedSpanDistance = fabsf(mPinchEventBuffer.front().mPreviousSpan - + mPinchEventBuffer.back().mCurrentSpan); + } + + // Convert to screen coordinates + ScreenCoord spanDistance = + ToScreenCoordinates(ParentLayerPoint(0, bufferedSpanDistance), focusPoint) + .Length(); + ScreenPoint focusChange = + ToScreenCoordinates(bufferedFocusChange, focusPoint); + + if (mPinchLocked) { + if (GetPinchLockMode() == PINCH_STICKY) { + ScreenCoord spanBreakoutThreshold = + StaticPrefs::apz_pinch_lock_span_breakout_threshold() * GetDPI(); + mPinchLocked = !(spanDistance > spanBreakoutThreshold); + } + } else { + if (GetPinchLockMode() != PINCH_FREE) { + ScreenCoord spanLockThreshold = + StaticPrefs::apz_pinch_lock_span_lock_threshold() * GetDPI(); + ScreenCoord scrollLockThreshold = + StaticPrefs::apz_pinch_lock_scroll_lock_threshold() * GetDPI(); + + if (spanDistance < spanLockThreshold && + focusChange.Length() > scrollLockThreshold) { + mPinchLocked = true; + + // We are transitioning to a two-finger pan that could trigger + // a fling at its end, so start tracking velocity. + StartTouch(aEvent.mLocalFocusPoint, aEvent.mTimeStamp); + } + } + } +} + +nsEventStatus AsyncPanZoomController::StartPanning( + const ExternalPoint& aStartPoint, const TimeStamp& aEventTime) { + ParentLayerPoint vector = + ToParentLayerCoordinates(PanVector(aStartPoint), mStartTouch); + double angle = atan2(vector.y, vector.x); // range [-pi, pi] + angle = fabs(angle); // range [0, pi] + + RecursiveMutexAutoLock lock(mRecursiveMutex); + HandlePanningWithTouchAction(angle); + + if (IsInPanningState()) { + mTouchStartRestingTimeBeforePan = aEventTime - mTouchStartTime; + mMinimumVelocityDuringPan = Nothing(); + + if (RefPtr<GeckoContentController> controller = + GetGeckoContentController()) { + controller->NotifyAPZStateChange(GetGuid(), + APZStateChange::eStartPanning); + } + return nsEventStatus_eConsumeNoDefault; + } + // Don't consume an event that didn't trigger a panning. + return nsEventStatus_eIgnore; +} + +void AsyncPanZoomController::UpdateWithTouchAtDevicePoint( + const MultiTouchInput& aEvent) { + const SingleTouchData& touchData = aEvent.mTouches[0]; + // Take historical touch data into account in order to improve the accuracy + // of the velocity estimate. On many Android devices, the touch screen samples + // at a higher rate than vsync (e.g. 100Hz vs 60Hz), and the historical data + // lets us take advantage of those high-rate samples. + for (const auto& historicalData : touchData.mHistoricalData) { + ParentLayerPoint historicalPoint = historicalData.mLocalScreenPoint; + mX.UpdateWithTouchAtDevicePoint(historicalPoint.x, + historicalData.mTimeStamp); + mY.UpdateWithTouchAtDevicePoint(historicalPoint.y, + historicalData.mTimeStamp); + } + ParentLayerPoint point = touchData.mLocalScreenPoint; + mX.UpdateWithTouchAtDevicePoint(point.x, aEvent.mTimeStamp); + mY.UpdateWithTouchAtDevicePoint(point.y, aEvent.mTimeStamp); +} + +Maybe<CompositionPayload> AsyncPanZoomController::NotifyScrollSampling() { + RecursiveMutexAutoLock lock(mRecursiveMutex); + return mSampledState.front().TakeScrollPayload(); +} + +bool AsyncPanZoomController::AttemptScroll( + ParentLayerPoint& aStartPoint, ParentLayerPoint& aEndPoint, + OverscrollHandoffState& aOverscrollHandoffState) { + // "start - end" rather than "end - start" because e.g. moving your finger + // down (*positive* direction along y axis) causes the vertical scroll offset + // to *decrease* as the page follows your finger. + ParentLayerPoint displacement = aStartPoint - aEndPoint; + + ParentLayerPoint overscroll; // will be used outside monitor block + + // If the direction of panning is reversed within the same input block, + // a later event in the block could potentially scroll an APZC earlier + // in the handoff chain, than an earlier event in the block (because + // the earlier APZC was scrolled to its extent in the original direction). + // We want to disallow this. + bool scrollThisApzc = false; + if (InputBlockState* block = GetCurrentInputBlock()) { + scrollThisApzc = + !block->GetScrolledApzc() || block->IsDownchainOfScrolledApzc(this); + } + + ParentLayerPoint adjustedDisplacement; + if (scrollThisApzc) { + RecursiveMutexAutoLock lock(mRecursiveMutex); + bool respectDisregardedDirections = + ScrollSourceRespectsDisregardedDirections( + aOverscrollHandoffState.mScrollSource); + bool forcesVerticalOverscroll = respectDisregardedDirections && + mScrollMetadata.GetDisregardedDirection() == + Some(ScrollDirection::eVertical); + bool forcesHorizontalOverscroll = + respectDisregardedDirections && + mScrollMetadata.GetDisregardedDirection() == + Some(ScrollDirection::eHorizontal); + + bool yChanged = + mY.AdjustDisplacement(displacement.y, adjustedDisplacement.y, + overscroll.y, forcesVerticalOverscroll); + bool xChanged = + mX.AdjustDisplacement(displacement.x, adjustedDisplacement.x, + overscroll.x, forcesHorizontalOverscroll); + if (xChanged || yChanged) { + ScheduleComposite(); + } + + if (!IsZero(adjustedDisplacement) && + Metrics().GetZoom() != CSSToParentLayerScale(0)) { + ScrollBy(adjustedDisplacement / Metrics().GetZoom()); + if (InputBlockState* block = GetCurrentInputBlock()) { + bool displacementIsUserVisible = true; + + { // Release the APZC lock before calling ToScreenCoordinates which + // acquires the APZ tree lock. Note that this just unlocks the mutex + // once, so if we're locking it multiple times on the callstack then + // this will be insufficient. + RecursiveMutexAutoUnlock unlock(mRecursiveMutex); + + ScreenIntPoint screenDisplacement = RoundedToInt( + ToScreenCoordinates(adjustedDisplacement, aStartPoint)); + // If the displacement we just applied rounds to zero in screen space, + // then it's probably not going to be visible to the user. In that + // case let's not mark this APZC as scrolled, so that even if the + // immediate handoff pref is disabled, we'll allow doing the handoff + // to the next APZC. + if (screenDisplacement == ScreenIntPoint()) { + displacementIsUserVisible = false; + } + } + if (displacementIsUserVisible) { + block->SetScrolledApzc(this); + } + } + // Note that in the case of instant scrolling, the last snap target ids + // will be set after AttemptScroll call so that we can clobber them + // unconditionally here. + mLastSnapTargetIds = ScrollSnapTargetIds{}; + ScheduleCompositeAndMaybeRepaint(); + } + + // Adjust the start point to reflect the consumed portion of the scroll. + aStartPoint = aEndPoint + overscroll; + } else { + overscroll = displacement; + } + + // Accumulate the amount of actual scrolling that occurred into the handoff + // state. Note that ToScreenCoordinates() needs to be called outside the + // mutex. + if (!IsZero(adjustedDisplacement)) { + aOverscrollHandoffState.mTotalMovement += + ToScreenCoordinates(adjustedDisplacement, aEndPoint); + } + + // If we consumed the entire displacement as a normal scroll, great. + if (IsZero(overscroll)) { + return true; + } + + if (AllowScrollHandoffInCurrentBlock()) { + // If there is overscroll, first try to hand it off to an APZC later + // in the handoff chain to consume (either as a normal scroll or as + // overscroll). + // Note: "+ overscroll" rather than "- overscroll" because "overscroll" + // is what's left of "displacement", and "displacement" is "start - end". + ++aOverscrollHandoffState.mChainIndex; + bool consumed = + CallDispatchScroll(aStartPoint, aEndPoint, aOverscrollHandoffState); + if (consumed) { + return true; + } + + overscroll = aStartPoint - aEndPoint; + MOZ_ASSERT(!IsZero(overscroll)); + } + + // If there is no APZC later in the handoff chain that accepted the + // overscroll, try to accept it ourselves. We only accept it if we + // are pannable. + if (ScrollSourceAllowsOverscroll(aOverscrollHandoffState.mScrollSource)) { + APZC_LOG("%p taking overscroll during panning\n", this); + + ParentLayerPoint prevVisualOverscroll = GetOverscrollAmount(); + + OverscrollForPanning(overscroll, aOverscrollHandoffState.mPanDistance); + + // Accumulate the amount of change to the overscroll that occurred into the + // handoff state. Note that the input amount, |overscroll|, is turned into + // some smaller visual overscroll amount (queried via GetOverscrollAmount()) + // by applying resistance (Axis::ApplyResistance()), and it's the latter we + // want to count towards OverscrollHandoffState::mTotalMovement. + ParentLayerPoint visualOverscrollChange = + GetOverscrollAmount() - prevVisualOverscroll; + if (!IsZero(visualOverscrollChange)) { + aOverscrollHandoffState.mTotalMovement += + ToScreenCoordinates(visualOverscrollChange, aEndPoint); + } + } + + aStartPoint = aEndPoint + overscroll; + + return IsZero(overscroll); +} + +void AsyncPanZoomController::OverscrollForPanning( + ParentLayerPoint& aOverscroll, const ScreenPoint& aPanDistance) { + // Only allow entering overscroll along an axis if the pan distance along + // that axis is greater than the pan distance along the other axis by a + // configurable factor. If we are already overscrolled, don't check this. + if (!IsOverscrolled()) { + if (aPanDistance.x < + StaticPrefs::apz_overscroll_min_pan_distance_ratio() * aPanDistance.y) { + aOverscroll.x = 0; + } + if (aPanDistance.y < + StaticPrefs::apz_overscroll_min_pan_distance_ratio() * aPanDistance.x) { + aOverscroll.y = 0; + } + } + + OverscrollBy(aOverscroll); +} + +ScrollDirections AsyncPanZoomController::GetOverscrollableDirections() const { + ScrollDirections result; + + RecursiveMutexAutoLock lock(mRecursiveMutex); + + // If the target has the disregarded direction, it means it's single line + // text control, thus we don't want to overscroll in both directions. + if (mScrollMetadata.GetDisregardedDirection()) { + return result; + } + + if (mX.CanScroll() && mX.OverscrollBehaviorAllowsOverscrollEffect()) { + result += ScrollDirection::eHorizontal; + } + + if (mY.CanScroll() && mY.OverscrollBehaviorAllowsOverscrollEffect()) { + result += ScrollDirection::eVertical; + } + + return result; +} + +void AsyncPanZoomController::OverscrollBy(ParentLayerPoint& aOverscroll) { + if (!StaticPrefs::apz_overscroll_enabled()) { + return; + } + + RecursiveMutexAutoLock lock(mRecursiveMutex); + // Do not go into overscroll in a direction in which we have no room to + // scroll to begin with. + ScrollDirections overscrollableDirections = GetOverscrollableDirections(); + if (IsZero(aOverscroll.x)) { + overscrollableDirections -= ScrollDirection::eHorizontal; + } + if (IsZero(aOverscroll.y)) { + overscrollableDirections -= ScrollDirection::eVertical; + } + + mOverscrollEffect->ConsumeOverscroll(aOverscroll, overscrollableDirections); +} + +RefPtr<const OverscrollHandoffChain> +AsyncPanZoomController::BuildOverscrollHandoffChain() { + if (APZCTreeManager* treeManagerLocal = GetApzcTreeManager()) { + return treeManagerLocal->BuildOverscrollHandoffChain(this); + } + + // This APZC IsDestroyed(). To avoid callers having to special-case this + // scenario, just build a 1-element chain containing ourselves. + OverscrollHandoffChain* result = new OverscrollHandoffChain; + result->Add(this); + return result; +} + +ParentLayerPoint AsyncPanZoomController::AttemptFling( + const FlingHandoffState& aHandoffState) { + // The PLPPI computation acquires the tree lock, so it needs to be performed + // on the controller thread, and before the APZC lock is acquired. + APZThreadUtils::AssertOnControllerThread(); + float PLPPI = ComputePLPPI(PanStart(), aHandoffState.mVelocity); + + RecursiveMutexAutoLock lock(mRecursiveMutex); + + if (!IsPannable()) { + return aHandoffState.mVelocity; + } + + // We may have a pre-existing velocity for whatever reason (for example, + // a previously handed off fling). We don't want to clobber that. + APZC_LOG("%p accepting fling with velocity %s\n", this, + ToString(aHandoffState.mVelocity).c_str()); + ParentLayerPoint residualVelocity = aHandoffState.mVelocity; + if (mX.CanScroll()) { + mX.SetVelocity(mX.GetVelocity() + aHandoffState.mVelocity.x); + residualVelocity.x = 0; + } + if (mY.CanScroll()) { + mY.SetVelocity(mY.GetVelocity() + aHandoffState.mVelocity.y); + residualVelocity.y = 0; + } + + // If we're not scrollable in at least one of the directions in which we + // were handed velocity, don't start a fling animation. + // The |IsFinite()| condition should only fail when running some tests + // that generate events faster than the clock resolution. + ParentLayerPoint velocity = GetVelocityVector(); + if (!velocity.IsFinite() || + velocity.Length() <= StaticPrefs::apz_fling_min_velocity_threshold()) { + // Relieve overscroll now if needed, since we will not transition to a fling + // animation and then an overscroll animation, and relieve it then. + aHandoffState.mChain->SnapBackOverscrolledApzc(this); + return residualVelocity; + } + + // If there's a scroll snap point near the predicted fling destination, + // scroll there using a smooth scroll animation. Otherwise, start a + // fling animation. + ScrollSnapToDestination(); + if (mState != SMOOTHMSD_SCROLL) { + SetState(FLING); + RefPtr<AsyncPanZoomAnimation> fling = + GetPlatformSpecificState()->CreateFlingAnimation(*this, aHandoffState, + PLPPI); + StartAnimation(fling.forget()); + } + + return residualVelocity; +} + +float AsyncPanZoomController::ComputePLPPI(ParentLayerPoint aPoint, + ParentLayerPoint aDirection) const { + // Avoid division-by-zero. + if (aDirection == ParentLayerPoint()) { + return GetDPI(); + } + + // Convert |aDirection| into a unit vector. + aDirection = aDirection / aDirection.Length(); + + // Place the vector at |aPoint| and convert to screen coordinates. + // The length of the resulting vector is the number of Screen coordinates + // that equal 1 ParentLayer coordinate in the given direction. + float screenPerParent = ToScreenCoordinates(aDirection, aPoint).Length(); + + // Finally, factor in the DPI scale. + return GetDPI() / screenPerParent; +} + +Maybe<CSSPoint> AsyncPanZoomController::GetCurrentAnimationDestination( + const RecursiveMutexAutoLock& aProofOfLock) const { + if (mState == WHEEL_SCROLL) { + return Some(mAnimation->AsWheelScrollAnimation()->GetDestination()); + } + if (mState == SMOOTH_SCROLL) { + return Some(mAnimation->AsSmoothScrollAnimation()->GetDestination()); + } + if (mState == SMOOTHMSD_SCROLL) { + return Some(mAnimation->AsSmoothMsdScrollAnimation()->GetDestination()); + } + if (mState == KEYBOARD_SCROLL) { + return Some(mAnimation->AsSmoothScrollAnimation()->GetDestination()); + } + + return Nothing(); +} + +ParentLayerPoint +AsyncPanZoomController::AdjustHandoffVelocityForOverscrollBehavior( + ParentLayerPoint& aHandoffVelocity) const { + ParentLayerPoint residualVelocity; + ScrollDirections handoffDirections = GetAllowedHandoffDirections(); + if (!handoffDirections.contains(ScrollDirection::eHorizontal)) { + residualVelocity.x = aHandoffVelocity.x; + aHandoffVelocity.x = 0; + } + if (!handoffDirections.contains(ScrollDirection::eVertical)) { + residualVelocity.y = aHandoffVelocity.y; + aHandoffVelocity.y = 0; + } + return residualVelocity; +} + +bool AsyncPanZoomController::OverscrollBehaviorAllowsSwipe() const { + // Swipe navigation is a "non-local" overscroll behavior like handoff. + return GetAllowedHandoffDirections().contains(ScrollDirection::eHorizontal); +} + +void AsyncPanZoomController::HandleFlingOverscroll( + const ParentLayerPoint& aVelocity, SideBits aOverscrollSideBits, + const RefPtr<const OverscrollHandoffChain>& aOverscrollHandoffChain, + const RefPtr<const AsyncPanZoomController>& aScrolledApzc) { + APZCTreeManager* treeManagerLocal = GetApzcTreeManager(); + if (treeManagerLocal) { + const FlingHandoffState handoffState{ + aVelocity, aOverscrollHandoffChain, Nothing(), + 0, true /* handoff */, aScrolledApzc}; + ParentLayerPoint residualVelocity = + treeManagerLocal->DispatchFling(this, handoffState); + FLING_LOG("APZC %p left with residual velocity %s\n", this, + ToString(residualVelocity).c_str()); + if (!IsZero(residualVelocity) && IsPannable() && + StaticPrefs::apz_overscroll_enabled()) { + // Obey overscroll-behavior. + RecursiveMutexAutoLock lock(mRecursiveMutex); + if (!mX.OverscrollBehaviorAllowsOverscrollEffect()) { + residualVelocity.x = 0; + } + if (!mY.OverscrollBehaviorAllowsOverscrollEffect()) { + residualVelocity.y = 0; + } + + if (!IsZero(residualVelocity)) { + mOverscrollEffect->RelieveOverscroll(residualVelocity, + aOverscrollSideBits); + } + } + } +} + +void AsyncPanZoomController::HandleSmoothScrollOverscroll( + const ParentLayerPoint& aVelocity, SideBits aOverscrollSideBits) { + // We must call BuildOverscrollHandoffChain from this deferred callback + // function in order to avoid a deadlock when acquiring the tree lock. + HandleFlingOverscroll(aVelocity, aOverscrollSideBits, + BuildOverscrollHandoffChain(), nullptr); +} + +ParentLayerPoint AsyncPanZoomController::ConvertDestinationToDelta( + CSSPoint& aDestination) const { + ParentLayerPoint startPoint, endPoint; + + { + RecursiveMutexAutoLock lock(mRecursiveMutex); + + startPoint = aDestination * Metrics().GetZoom(); + endPoint = Metrics().GetVisualScrollOffset() * Metrics().GetZoom(); + } + + return startPoint - endPoint; +} + +void AsyncPanZoomController::SmoothScrollTo( + CSSSnapDestination&& aDestination, + ScrollTriggeredByScript aTriggeredByScript, const ScrollOrigin& aOrigin) { + // Convert velocity from ParentLayerPoints/ms to ParentLayerPoints/s and then + // to appunits/second. + nsPoint destination = CSSPoint::ToAppUnits(aDestination.mPosition); + nsSize velocity; + if (Metrics().GetZoom() != CSSToParentLayerScale(0)) { + velocity = CSSSize::ToAppUnits(ParentLayerSize(mX.GetVelocity() * 1000.0f, + mY.GetVelocity() * 1000.0f) / + Metrics().GetZoom()); + } + + if (mState == SMOOTH_SCROLL && mAnimation) { + RefPtr<SmoothScrollAnimation> animation( + mAnimation->AsSmoothScrollAnimation()); + if (animation->GetScrollOrigin() == aOrigin) { + APZC_LOG("%p updating destination on existing animation\n", this); + animation->UpdateDestinationAndSnapTargets( + GetFrameTime().Time(), destination, velocity, + std::move(aDestination.mTargetIds), aTriggeredByScript); + return; + } + } + + CancelAnimation(); + + // If no scroll is required, we should exit early to avoid triggering + // a scrollend event when no scrolling occurred. + if (ConvertDestinationToDelta(aDestination.mPosition) == ParentLayerPoint()) { + return; + } + + SetState(SMOOTH_SCROLL); + nsPoint initialPosition = + CSSPoint::ToAppUnits(Metrics().GetVisualScrollOffset()); + RefPtr<SmoothScrollAnimation> animation = + new SmoothScrollAnimation(*this, initialPosition, aOrigin); + animation->UpdateDestinationAndSnapTargets( + GetFrameTime().Time(), destination, velocity, + std::move(aDestination.mTargetIds), aTriggeredByScript); + StartAnimation(animation.forget()); +} + +void AsyncPanZoomController::SmoothMsdScrollTo( + CSSSnapDestination&& aDestination, + ScrollTriggeredByScript aTriggeredByScript) { + if (mState == SMOOTHMSD_SCROLL && mAnimation) { + APZC_LOG("%p updating destination on existing animation\n", this); + RefPtr<SmoothMsdScrollAnimation> animation( + static_cast<SmoothMsdScrollAnimation*>(mAnimation.get())); + animation->SetDestination(aDestination.mPosition, + std::move(aDestination.mTargetIds), + aTriggeredByScript); + return; + } + + // If no scroll is required, we should exit early to avoid triggering + // a scrollend event when no scrolling occurred. + if (ConvertDestinationToDelta(aDestination.mPosition) == ParentLayerPoint()) { + return; + } + CancelAnimation(); + SetState(SMOOTHMSD_SCROLL); + // Convert velocity from ParentLayerPoints/ms to ParentLayerPoints/s. + CSSPoint initialVelocity; + if (Metrics().GetZoom() != CSSToParentLayerScale(0)) { + initialVelocity = ParentLayerPoint(mX.GetVelocity() * 1000.0f, + mY.GetVelocity() * 1000.0f) / + Metrics().GetZoom(); + } + + StartAnimation(do_AddRef(new SmoothMsdScrollAnimation( + *this, Metrics().GetVisualScrollOffset(), initialVelocity, + aDestination.mPosition, + StaticPrefs::layout_css_scroll_behavior_spring_constant(), + StaticPrefs::layout_css_scroll_behavior_damping_ratio(), + std::move(aDestination.mTargetIds), aTriggeredByScript))); +} + +void AsyncPanZoomController::StartOverscrollAnimation( + const ParentLayerPoint& aVelocity, SideBits aOverscrollSideBits) { + MOZ_ASSERT(mState != OVERSCROLL_ANIMATION); + + SetState(OVERSCROLL_ANIMATION); + + ParentLayerPoint velocity = aVelocity; + AdjustDeltaForAllowedScrollDirections(velocity, + GetOverscrollableDirections()); + StartAnimation( + do_AddRef(new OverscrollAnimation(*this, velocity, aOverscrollSideBits))); +} + +bool AsyncPanZoomController::CallDispatchScroll( + ParentLayerPoint& aStartPoint, ParentLayerPoint& aEndPoint, + OverscrollHandoffState& aOverscrollHandoffState) { + // Make a local copy of the tree manager pointer and check if it's not + // null before calling DispatchScroll(). This is necessary because + // Destroy(), which nulls out mTreeManager, could be called concurrently. + APZCTreeManager* treeManagerLocal = GetApzcTreeManager(); + if (!treeManagerLocal) { + return false; + } + + // Obey overscroll-behavior. + ParentLayerPoint endPoint = aEndPoint; + if (aOverscrollHandoffState.mChainIndex > 0) { + ScrollDirections handoffDirections = GetAllowedHandoffDirections(); + if (!handoffDirections.contains(ScrollDirection::eHorizontal)) { + endPoint.x = aStartPoint.x; + } + if (!handoffDirections.contains(ScrollDirection::eVertical)) { + endPoint.y = aStartPoint.y; + } + if (aStartPoint == endPoint) { + // Handoff not allowed in either direction - don't even bother. + return false; + } + } + + return treeManagerLocal->DispatchScroll(this, aStartPoint, endPoint, + aOverscrollHandoffState); +} + +void AsyncPanZoomController::RecordScrollPayload(const TimeStamp& aTimeStamp) { + RecursiveMutexAutoLock lock(mRecursiveMutex); + if (!mScrollPayload) { + mScrollPayload = Some( + CompositionPayload{CompositionPayloadType::eAPZScroll, aTimeStamp}); + } +} + +void AsyncPanZoomController::StartTouch(const ParentLayerPoint& aPoint, + TimeStamp aTimestamp) { + RecursiveMutexAutoLock lock(mRecursiveMutex); + mX.StartTouch(aPoint.x, aTimestamp); + mY.StartTouch(aPoint.y, aTimestamp); +} + +void AsyncPanZoomController::EndTouch(TimeStamp aTimestamp, + Axis::ClearAxisLock aClearAxisLock) { + RecursiveMutexAutoLock lock(mRecursiveMutex); + mX.EndTouch(aTimestamp, aClearAxisLock); + mY.EndTouch(aTimestamp, aClearAxisLock); +} + +void AsyncPanZoomController::TrackTouch(const MultiTouchInput& aEvent) { + ExternalPoint extPoint = GetFirstExternalTouchPoint(aEvent); + ScreenPoint panVector = PanVector(extPoint); + HandlePanningUpdate(panVector); + + ParentLayerPoint prevTouchPoint(mX.GetPos(), mY.GetPos()); + ParentLayerPoint touchPoint = GetFirstTouchPoint(aEvent); + + UpdateWithTouchAtDevicePoint(aEvent); + + auto velocity = GetVelocityVector().Length(); + if (mMinimumVelocityDuringPan) { + mMinimumVelocityDuringPan = + Some(std::min(*mMinimumVelocityDuringPan, velocity)); + } else { + mMinimumVelocityDuringPan = Some(velocity); + } + + if (prevTouchPoint != touchPoint) { + MOZ_ASSERT(GetCurrentTouchBlock()); + OverscrollHandoffState handoffState( + *GetCurrentTouchBlock()->GetOverscrollHandoffChain(), panVector, + ScrollSource::Touchscreen); + RecordScrollPayload(aEvent.mTimeStamp); + CallDispatchScroll(prevTouchPoint, touchPoint, handoffState); + } +} + +ParentLayerPoint AsyncPanZoomController::GetFirstTouchPoint( + const MultiTouchInput& aEvent) { + return ((SingleTouchData&)aEvent.mTouches[0]).mLocalScreenPoint; +} + +ExternalPoint AsyncPanZoomController::GetFirstExternalTouchPoint( + const MultiTouchInput& aEvent) { + return ToExternalPoint(aEvent.mScreenOffset, + ((SingleTouchData&)aEvent.mTouches[0]).mScreenPoint); +} + +ParentLayerPoint AsyncPanZoomController::GetOverscrollAmount() const { + if (StaticPrefs::apz_overscroll_test_async_scroll_offset_enabled()) { + RecursiveMutexAutoLock lock(mRecursiveMutex); + AutoApplyAsyncTestAttributes testAttributeApplier(this, lock); + return GetOverscrollAmountInternal(); + } + RecursiveMutexAutoLock lock(mRecursiveMutex); + return GetOverscrollAmountInternal(); +} + +ParentLayerPoint AsyncPanZoomController::GetOverscrollAmountInternal() const { + return {mX.GetOverscroll(), mY.GetOverscroll()}; +} + +SideBits AsyncPanZoomController::GetOverscrollSideBits() const { + return apz::GetOverscrollSideBits({mX.GetOverscroll(), mY.GetOverscroll()}); +} + +void AsyncPanZoomController::RestoreOverscrollAmount( + const ParentLayerPoint& aOverscroll) { + mX.RestoreOverscroll(aOverscroll.x); + mY.RestoreOverscroll(aOverscroll.y); +} + +void AsyncPanZoomController::StartAnimation( + already_AddRefed<AsyncPanZoomAnimation> aAnimation) { + RecursiveMutexAutoLock lock(mRecursiveMutex); + mAnimation = aAnimation; + mLastSampleTime = GetFrameTime(); + ScheduleComposite(); +} + +void AsyncPanZoomController::CancelAnimation(CancelAnimationFlags aFlags) { + RecursiveMutexAutoLock lock(mRecursiveMutex); + APZC_LOG_DETAIL("running CancelAnimation(0x%x) in state %s\n", this, aFlags, + ToString(mState).c_str()); + + if ((aFlags & ExcludeWheel) && mState == WHEEL_SCROLL) { + return; + } + + if (mAnimation) { + mAnimation->Cancel(aFlags); + } + + SetState(NOTHING); + mLastSnapTargetIds = ScrollSnapTargetIds{}; + mAnimation = nullptr; + // Since there is no animation in progress now the axes should + // have no velocity either. If we are dropping the velocity from a non-zero + // value we should trigger a repaint as the displayport margins are dependent + // on the velocity and the last repaint request might not have good margins + // any more. + bool repaint = !IsZero(GetVelocityVector()); + mX.SetVelocity(0); + mY.SetVelocity(0); + mX.SetAxisLocked(false); + mY.SetAxisLocked(false); + // Setting the state to nothing and cancelling the animation can + // preempt normal mechanisms for relieving overscroll, so we need to clear + // overscroll here. + if (!(aFlags & ExcludeOverscroll) && IsOverscrolled()) { + ClearOverscroll(); + repaint = true; + } + // Similar to relieving overscroll, we also need to snap to any snap points + // if appropriate. + if (aFlags & CancelAnimationFlags::ScrollSnap) { + ScrollSnap(ScrollSnapFlags::IntendedEndPosition); + } + if (repaint) { + RequestContentRepaint(); + ScheduleComposite(); + } +} + +void AsyncPanZoomController::ClearOverscroll() { + mOverscrollEffect->ClearOverscroll(); +} + +void AsyncPanZoomController::ClearPhysicalOverscroll() { + RecursiveMutexAutoLock lock(mRecursiveMutex); + mX.ClearOverscroll(); + mY.ClearOverscroll(); +} + +void AsyncPanZoomController::SetCompositorController( + CompositorController* aCompositorController) { + mCompositorController = aCompositorController; +} + +void AsyncPanZoomController::SetVisualScrollOffset(const CSSPoint& aOffset) { + Metrics().SetVisualScrollOffset(aOffset); + Metrics().RecalculateLayoutViewportOffset(); +} + +void AsyncPanZoomController::ClampAndSetVisualScrollOffset( + const CSSPoint& aOffset) { + Metrics().ClampAndSetVisualScrollOffset(aOffset); + Metrics().RecalculateLayoutViewportOffset(); +} + +void AsyncPanZoomController::ScrollBy(const CSSPoint& aOffset) { + SetVisualScrollOffset(Metrics().GetVisualScrollOffset() + aOffset); +} + +void AsyncPanZoomController::ScrollByAndClamp(const CSSPoint& aOffset) { + ClampAndSetVisualScrollOffset(Metrics().GetVisualScrollOffset() + aOffset); +} + +void AsyncPanZoomController::ScaleWithFocus(float aScale, + const CSSPoint& aFocus) { + Metrics().ZoomBy(aScale); + // We want to adjust the scroll offset such that the CSS point represented by + // aFocus remains at the same position on the screen before and after the + // change in zoom. The below code accomplishes this; see + // https://bugzilla.mozilla.org/show_bug.cgi?id=923431#c6 for an in-depth + // explanation of how. + SetVisualScrollOffset((Metrics().GetVisualScrollOffset() + aFocus) - + (aFocus / aScale)); +} + +/*static*/ +gfx::IntSize AsyncPanZoomController::GetDisplayportAlignmentMultiplier( + const ScreenSize& aBaseSize) { + gfx::IntSize multiplier(1, 1); + float baseWidth = aBaseSize.width; + while (baseWidth > 500) { + baseWidth /= 2; + multiplier.width *= 2; + if (multiplier.width >= 8) { + break; + } + } + float baseHeight = aBaseSize.height; + while (baseHeight > 500) { + baseHeight /= 2; + multiplier.height *= 2; + if (multiplier.height >= 8) { + break; + } + } + return multiplier; +} + +/** + * Enlarges the displayport along both axes based on the velocity. + */ +static CSSSize CalculateDisplayPortSize( + const CSSSize& aCompositionSize, const CSSPoint& aVelocity, + AsyncPanZoomController::ZoomInProgress aZoomInProgress, + const CSSToScreenScale2D& aDpPerCSS) { + bool xIsStationarySpeed = + fabsf(aVelocity.x) < StaticPrefs::apz_min_skate_speed(); + bool yIsStationarySpeed = + fabsf(aVelocity.y) < StaticPrefs::apz_min_skate_speed(); + float xMultiplier = xIsStationarySpeed + ? StaticPrefs::apz_x_stationary_size_multiplier() + : StaticPrefs::apz_x_skate_size_multiplier(); + float yMultiplier = yIsStationarySpeed + ? StaticPrefs::apz_y_stationary_size_multiplier() + : StaticPrefs::apz_y_skate_size_multiplier(); + + if (IsHighMemSystem() && !xIsStationarySpeed) { + xMultiplier += StaticPrefs::apz_x_skate_highmem_adjust(); + } + + if (IsHighMemSystem() && !yIsStationarySpeed) { + yMultiplier += StaticPrefs::apz_y_skate_highmem_adjust(); + } + + if (aZoomInProgress == AsyncPanZoomController::ZoomInProgress::Yes) { + // If a zoom is in progress, we will be making content visible on the + // x and y axes in equal proportion, because the zoom operation scales + // equally on the x and y axes. The default multipliers computed above are + // biased towards the y-axis since that's where most scrolling occurs, but + // in the case of zooming, we should really use equal multipliers on both + // axes. This does that while preserving the total displayport area + // quantity (aCompositionSize.Area() * xMultiplier * yMultiplier). + // Note that normally changing the shape of the displayport is expensive + // and should be avoided, but if a zoom is in progress the displayport + // is likely going to be fully repainted anyway due to changes in resolution + // so there should be no marginal cost to also changing the shape of it. + float areaMultiplier = xMultiplier * yMultiplier; + xMultiplier = sqrt(areaMultiplier); + yMultiplier = xMultiplier; + } + + // Scale down the margin multipliers by the alignment multiplier because + // the alignment code will expand the displayport outward to the multiplied + // alignment. This is not necessary for correctness, but for performance; + // if we don't do this the displayport can end up much larger. The math here + // is actually just scaling the part of the multipler that is > 1, so that + // we never end up with xMultiplier or yMultiplier being less than 1 (that + // would result in a guaranteed checkerboarding situation). Note that the + // calculation doesn't cancel exactly the increased margin from applying + // the alignment multiplier, but this is simple and should provide + // reasonable behaviour in most cases. + gfx::IntSize alignmentMultipler = + AsyncPanZoomController::GetDisplayportAlignmentMultiplier( + aCompositionSize * aDpPerCSS); + if (xMultiplier > 1) { + xMultiplier = ((xMultiplier - 1) / alignmentMultipler.width) + 1; + } + if (yMultiplier > 1) { + yMultiplier = ((yMultiplier - 1) / alignmentMultipler.height) + 1; + } + + return aCompositionSize * CSSSize(xMultiplier, yMultiplier); +} + +/** + * Ensures that the displayport is at least as large as the visible area + * inflated by the danger zone. If this is not the case then the + * "AboutToCheckerboard" function in TiledContentClient.cpp will return true + * even in the stable state. + */ +static CSSSize ExpandDisplayPortToDangerZone( + const CSSSize& aDisplayPortSize, const FrameMetrics& aFrameMetrics) { + CSSSize dangerZone(0.0f, 0.0f); + if (aFrameMetrics.DisplayportPixelsPerCSSPixel().xScale != 0 && + aFrameMetrics.DisplayportPixelsPerCSSPixel().yScale != 0) { + dangerZone = ScreenSize(StaticPrefs::apz_danger_zone_x(), + StaticPrefs::apz_danger_zone_y()) / + aFrameMetrics.DisplayportPixelsPerCSSPixel(); + } + const CSSSize compositionSize = + aFrameMetrics.CalculateBoundedCompositedSizeInCssPixels(); + + const float xSize = std::max(aDisplayPortSize.width, + compositionSize.width + (2 * dangerZone.width)); + + const float ySize = + std::max(aDisplayPortSize.height, + compositionSize.height + (2 * dangerZone.height)); + + return CSSSize(xSize, ySize); +} + +/** + * Attempts to redistribute any area in the displayport that would get clipped + * by the scrollable rect, or be inaccessible due to disabled scrolling, to the + * other axis, while maintaining total displayport area. + */ +static void RedistributeDisplayPortExcess(CSSSize& aDisplayPortSize, + const CSSRect& aScrollableRect) { + // As aDisplayPortSize.height * aDisplayPortSize.width does not change, + // we are just scaling by the ratio and its inverse. + if (aDisplayPortSize.height > aScrollableRect.Height()) { + aDisplayPortSize.width *= + (aDisplayPortSize.height / aScrollableRect.Height()); + aDisplayPortSize.height = aScrollableRect.Height(); + } else if (aDisplayPortSize.width > aScrollableRect.Width()) { + aDisplayPortSize.height *= + (aDisplayPortSize.width / aScrollableRect.Width()); + aDisplayPortSize.width = aScrollableRect.Width(); + } +} + +/* static */ +const ScreenMargin AsyncPanZoomController::CalculatePendingDisplayPort( + const FrameMetrics& aFrameMetrics, const ParentLayerPoint& aVelocity, + ZoomInProgress aZoomInProgress) { + if (aFrameMetrics.IsScrollInfoLayer()) { + // Don't compute margins. Since we can't asynchronously scroll this frame, + // we don't want to paint anything more than the composition bounds. + return ScreenMargin(); + } + + CSSSize compositionSize = + aFrameMetrics.CalculateBoundedCompositedSizeInCssPixels(); + CSSPoint velocity; + if (aFrameMetrics.GetZoom() != CSSToParentLayerScale(0)) { + velocity = aVelocity / aFrameMetrics.GetZoom(); // avoid division by zero + } + CSSRect scrollableRect = aFrameMetrics.GetExpandedScrollableRect(); + + // Calculate the displayport size based on how fast we're moving along each + // axis. + CSSSize displayPortSize = + CalculateDisplayPortSize(compositionSize, velocity, aZoomInProgress, + aFrameMetrics.DisplayportPixelsPerCSSPixel()); + + displayPortSize = + ExpandDisplayPortToDangerZone(displayPortSize, aFrameMetrics); + + if (StaticPrefs::apz_enlarge_displayport_when_clipped()) { + RedistributeDisplayPortExcess(displayPortSize, scrollableRect); + } + + // We calculate a "displayport" here which is relative to the scroll offset. + // Note that the scroll offset we have here in the APZ code may not be the + // same as the base rect that gets used on the layout side when the + // displayport margins are actually applied, so it is important to only + // consider the displayport as margins relative to a scroll offset rather than + // relative to something more unchanging like the scrollable rect origin. + + // Center the displayport based on its expansion over the composition size. + CSSRect displayPort((compositionSize.width - displayPortSize.width) / 2.0f, + (compositionSize.height - displayPortSize.height) / 2.0f, + displayPortSize.width, displayPortSize.height); + + // Offset the displayport, depending on how fast we're moving and the + // estimated time it takes to paint, to try to minimise checkerboarding. + float paintFactor = kDefaultEstimatedPaintDurationMs; + displayPort.MoveBy(velocity * paintFactor * StaticPrefs::apz_velocity_bias()); + + APZC_LOGV_FM(aFrameMetrics, + "Calculated displayport as %s from velocity %s zooming %d paint " + "time %f metrics", + ToString(displayPort).c_str(), ToString(aVelocity).c_str(), + (int)aZoomInProgress, paintFactor); + + CSSMargin cssMargins; + cssMargins.left = -displayPort.X(); + cssMargins.top = -displayPort.Y(); + cssMargins.right = + displayPort.Width() - compositionSize.width - cssMargins.left; + cssMargins.bottom = + displayPort.Height() - compositionSize.height - cssMargins.top; + + return cssMargins * aFrameMetrics.DisplayportPixelsPerCSSPixel(); +} + +void AsyncPanZoomController::ScheduleComposite() { + if (mCompositorController) { + mCompositorController->ScheduleRenderOnCompositorThread( + wr::RenderReasons::APZ); + } +} + +void AsyncPanZoomController::ScheduleCompositeAndMaybeRepaint() { + ScheduleComposite(); + RequestContentRepaint(); +} + +void AsyncPanZoomController::FlushRepaintForOverscrollHandoff() { + RecursiveMutexAutoLock lock(mRecursiveMutex); + RequestContentRepaint(); +} + +void AsyncPanZoomController::FlushRepaintForNewInputBlock() { + APZC_LOG("%p flushing repaint for new input block\n", this); + + RecursiveMutexAutoLock lock(mRecursiveMutex); + RequestContentRepaint(); +} + +bool AsyncPanZoomController::SnapBackIfOverscrolled() { + RecursiveMutexAutoLock lock(mRecursiveMutex); + if (SnapBackIfOverscrolledForMomentum(ParentLayerPoint(0, 0))) { + return true; + } + // If we don't kick off an overscroll animation, we still need to snap to any + // nearby snap points, assuming we haven't already done so when we started + // this fling + if (mState != FLING) { + ScrollSnap(ScrollSnapFlags::IntendedEndPosition); + } + return false; +} + +bool AsyncPanZoomController::SnapBackIfOverscrolledForMomentum( + const ParentLayerPoint& aVelocity) { + RecursiveMutexAutoLock lock(mRecursiveMutex); + // It's possible that we're already in the middle of an overscroll + // animation - if so, don't start a new one. + if (IsOverscrolled() && mState != OVERSCROLL_ANIMATION) { + APZC_LOG("%p is overscrolled, starting snap-back\n", this); + mOverscrollEffect->RelieveOverscroll(aVelocity, GetOverscrollSideBits()); + return true; + } + return false; +} + +bool AsyncPanZoomController::IsFlingingFast() const { + RecursiveMutexAutoLock lock(mRecursiveMutex); + if (mState == FLING && GetVelocityVector().Length() > + StaticPrefs::apz_fling_stop_on_tap_threshold()) { + APZC_LOG("%p is moving fast\n", this); + return true; + } + return false; +} + +bool AsyncPanZoomController::IsPannable() const { + RecursiveMutexAutoLock lock(mRecursiveMutex); + return mX.CanScroll() || mY.CanScroll(); +} + +bool AsyncPanZoomController::IsScrollInfoLayer() const { + RecursiveMutexAutoLock lock(mRecursiveMutex); + return Metrics().IsScrollInfoLayer(); +} + +int32_t AsyncPanZoomController::GetLastTouchIdentifier() const { + RefPtr<GestureEventListener> listener = GetGestureEventListener(); + return listener ? listener->GetLastTouchIdentifier() : -1; +} + +void AsyncPanZoomController::RequestContentRepaint( + RepaintUpdateType aUpdateType) { + // Reinvoke this method on the repaint thread if it's not there already. It's + // important to do this before the call to CalculatePendingDisplayPort, so + // that CalculatePendingDisplayPort uses the most recent available version of + // Metrics(). just before the paint request is dispatched to content. + RefPtr<GeckoContentController> controller = GetGeckoContentController(); + if (!controller) { + return; + } + if (!controller->IsRepaintThread()) { + // Even though we want to do the actual repaint request on the repaint + // thread, we want to update the expected gecko metrics synchronously. + // Otherwise we introduce a race condition where we might read from the + // expected gecko metrics on the controller thread before or after it gets + // updated on the repaint thread, when in fact we always want the updated + // version when reading. + { // scope lock + RecursiveMutexAutoLock lock(mRecursiveMutex); + mExpectedGeckoMetrics.UpdateFrom(Metrics()); + } + + // use the local variable to resolve the function overload. + auto func = + static_cast<void (AsyncPanZoomController::*)(RepaintUpdateType)>( + &AsyncPanZoomController::RequestContentRepaint); + controller->DispatchToRepaintThread(NewRunnableMethod<RepaintUpdateType>( + "layers::AsyncPanZoomController::RequestContentRepaint", this, func, + aUpdateType)); + return; + } + + MOZ_ASSERT(controller->IsRepaintThread()); + + RecursiveMutexAutoLock lock(mRecursiveMutex); + ParentLayerPoint velocity = GetVelocityVector(); + ScreenMargin displayportMargins = CalculatePendingDisplayPort( + Metrics(), velocity, + (mState == PINCHING || mState == ANIMATING_ZOOM) ? ZoomInProgress::Yes + : ZoomInProgress::No); + Metrics().SetPaintRequestTime(TimeStamp::Now()); + RequestContentRepaint(velocity, displayportMargins, aUpdateType); +} + +static CSSRect GetDisplayPortRect(const FrameMetrics& aFrameMetrics, + const ScreenMargin& aDisplayportMargins) { + // This computation is based on what happens in CalculatePendingDisplayPort. + // If that changes then this might need to change too. + // Note that the display port rect APZ computes is relative to the visual + // scroll offset. It's adjusted to be relative to the layout scroll offset + // when the main thread processes a repaint request (in + // APZCCallbackHelper::AdjustDisplayPortForScrollDelta()) and ultimately + // applied (in DisplayPortUtils::GetDisplayPort()) in this adjusted form. + CSSRect baseRect(aFrameMetrics.GetVisualScrollOffset(), + aFrameMetrics.CalculateBoundedCompositedSizeInCssPixels()); + baseRect.Inflate(aDisplayportMargins / + aFrameMetrics.DisplayportPixelsPerCSSPixel()); + return baseRect; +} + +void AsyncPanZoomController::RequestContentRepaint( + const ParentLayerPoint& aVelocity, const ScreenMargin& aDisplayportMargins, + RepaintUpdateType aUpdateType) { + mRecursiveMutex.AssertCurrentThreadIn(); + + RefPtr<GeckoContentController> controller = GetGeckoContentController(); + if (!controller) { + return; + } + MOZ_ASSERT(controller->IsRepaintThread()); + + APZScrollAnimationType animationType = APZScrollAnimationType::No; + if (mAnimation) { + animationType = mAnimation->WasTriggeredByScript() + ? APZScrollAnimationType::TriggeredByScript + : APZScrollAnimationType::TriggeredByUserInput; + } + RepaintRequest request(Metrics(), aDisplayportMargins, aUpdateType, + animationType, mScrollGeneration, mLastSnapTargetIds, + IsInScrollingGesture()); + + if (request.IsRootContent() && request.GetZoom() != mLastNotifiedZoom && + mState != PINCHING && mState != ANIMATING_ZOOM) { + controller->NotifyScaleGestureComplete( + GetGuid(), + (request.GetZoom() / request.GetDevPixelsPerCSSPixel()).scale); + mLastNotifiedZoom = request.GetZoom(); + } + + // If we're trying to paint what we already think is painted, discard this + // request since it's a pointless paint. + if (request.GetDisplayPortMargins().WithinEpsilonOf( + mLastPaintRequestMetrics.GetDisplayPortMargins(), EPSILON) && + request.GetVisualScrollOffset().WithinEpsilonOf( + mLastPaintRequestMetrics.GetVisualScrollOffset(), EPSILON) && + request.GetPresShellResolution() == + mLastPaintRequestMetrics.GetPresShellResolution() && + request.GetZoom() == mLastPaintRequestMetrics.GetZoom() && + request.GetLayoutViewport().WithinEpsilonOf( + mLastPaintRequestMetrics.GetLayoutViewport(), EPSILON) && + request.GetScrollGeneration() == + mLastPaintRequestMetrics.GetScrollGeneration() && + request.GetScrollUpdateType() == + mLastPaintRequestMetrics.GetScrollUpdateType() && + request.GetScrollAnimationType() == + mLastPaintRequestMetrics.GetScrollAnimationType() && + request.GetLastSnapTargetIds() == + mLastPaintRequestMetrics.GetLastSnapTargetIds()) { + return; + } + + APZC_LOGV("%p requesting content repaint %s", this, + ToString(request).c_str()); + { // scope lock + MutexAutoLock lock(mCheckerboardEventLock); + if (mCheckerboardEvent && mCheckerboardEvent->IsRecordingTrace()) { + std::stringstream info; + info << " velocity " << aVelocity; + std::string str = info.str(); + mCheckerboardEvent->UpdateRendertraceProperty( + CheckerboardEvent::RequestedDisplayPort, + GetDisplayPortRect(Metrics(), aDisplayportMargins), str); + } + } + + controller->RequestContentRepaint(request); + mExpectedGeckoMetrics.UpdateFrom(Metrics()); + mLastPaintRequestMetrics = request; + + // We're holding the APZC lock here, so redispatch this so we can get + // the tree lock without the APZC lock. + controller->DispatchToRepaintThread( + NewRunnableMethod<AsyncPanZoomController*>( + "layers::APZCTreeManager::SendSubtreeTransformsToChromeMainThread", + GetApzcTreeManager(), + &APZCTreeManager::SendSubtreeTransformsToChromeMainThread, this)); +} + +bool AsyncPanZoomController::UpdateAnimation( + const RecursiveMutexAutoLock& aProofOfLock, const SampleTime& aSampleTime, + nsTArray<RefPtr<Runnable>>* aOutDeferredTasks) { + AssertOnSamplerThread(); + + // This function may get called multiple with the same sample time, if we + // composite multiple times at the same timestamp. + // However we only want to do one animation step per composition so we need + // to deduplicate these calls first. + // Even if there's no animation, if we have a scroll offset change pending due + // to the frame delay, we need to keep compositing. + if (mLastSampleTime == aSampleTime) { + APZC_LOG_DETAIL( + "UpdateAnimation short-circuit, animation=%p, pending frame-delayed " + "offset=%d\n", + this, mAnimation.get(), HavePendingFrameDelayedOffset()); + return !!mAnimation || HavePendingFrameDelayedOffset(); + } + + // We're at a new timestamp, so advance to the next sample in the deque, if + // there is one. That one will be used for all the code that reads the + // eForCompositing transforms in this vsync interval. + AdvanceToNextSample(); + + // And then create a new sample, which will be used in the *next* vsync + // interval. We do the sample at this point and not later in order to try + // and enforce one frame delay between computing the async transform and + // compositing it to the screen. This one-frame delay gives code running on + // the main thread a chance to try and respond to the scroll position change, + // so that e.g. a main-thread animation can stay in sync with user-driven + // scrolling or a compositor animation. + bool needComposite = SampleCompositedAsyncTransform(aProofOfLock); + APZC_LOG_DETAIL("UpdateAnimation needComposite=%d mAnimation=%p\n", this, + needComposite, mAnimation.get()); + + TimeDuration sampleTimeDelta = aSampleTime - mLastSampleTime; + mLastSampleTime = aSampleTime; + + if (needComposite || mAnimation) { + // Bump the scroll generation before we call RequestContentRepaint below + // so that the RequestContentRepaint call will surely use the new + // generation. + if (APZCTreeManager* treeManagerLocal = GetApzcTreeManager()) { + mScrollGeneration = treeManagerLocal->NewAPZScrollGeneration(); + } + } + + if (mAnimation) { + bool continueAnimation = mAnimation->Sample(Metrics(), sampleTimeDelta); + bool wantsRepaints = mAnimation->WantsRepaints(); + *aOutDeferredTasks = mAnimation->TakeDeferredTasks(); + if (!continueAnimation) { + SetState(NOTHING); + if (mAnimation->AsSmoothMsdScrollAnimation()) { + { + RecursiveMutexAutoLock lock(mRecursiveMutex); + mLastSnapTargetIds = + mAnimation->AsSmoothMsdScrollAnimation()->TakeSnapTargetIds(); + } + } else if (mAnimation->AsSmoothScrollAnimation()) { + RecursiveMutexAutoLock lock(mRecursiveMutex); + mLastSnapTargetIds = + mAnimation->AsSmoothScrollAnimation()->TakeSnapTargetIds(); + } + mAnimation = nullptr; + } + // Request a repaint at the end of the animation in case something such as a + // call to NotifyLayersUpdated was invoked during the animation and Gecko's + // current state is some intermediate point of the animation. + if (!continueAnimation || wantsRepaints) { + RequestContentRepaint(); + } + needComposite = true; + } + return needComposite; +} + +AsyncTransformComponentMatrix AsyncPanZoomController::GetOverscrollTransform( + AsyncTransformConsumer aMode) const { + RecursiveMutexAutoLock lock(mRecursiveMutex); + AutoApplyAsyncTestAttributes testAttributeApplier(this, lock); + + if (aMode == eForCompositing && mScrollMetadata.IsApzForceDisabled()) { + return AsyncTransformComponentMatrix(); + } + + if (!IsPhysicallyOverscrolled()) { + return AsyncTransformComponentMatrix(); + } + + // The overscroll effect is a simple translation by the overscroll offset. + ParentLayerPoint overscrollOffset(-mX.GetOverscroll(), -mY.GetOverscroll()); + return AsyncTransformComponentMatrix().PostTranslate(overscrollOffset.x, + overscrollOffset.y, 0); +} + +bool AsyncPanZoomController::AdvanceAnimations(const SampleTime& aSampleTime) { + AssertOnSamplerThread(); + + // Don't send any state-change notifications until the end of the function, + // because we may go through some intermediate states while we finish + // animations and start new ones. + StateChangeNotificationBlocker blocker(this); + + // The eventual return value of this function. The compositor needs to know + // whether or not to advance by a frame as soon as it can. For example, if a + // fling is happening, it has to keep compositing so that the animation is + // smooth. If an animation frame is requested, it is the compositor's + // responsibility to schedule a composite. + bool requestAnimationFrame = false; + nsTArray<RefPtr<Runnable>> deferredTasks; + + { + RecursiveMutexAutoLock lock(mRecursiveMutex); + { // scope lock + CSSRect visibleRect = GetVisibleRect(lock); + MutexAutoLock lock2(mCheckerboardEventLock); + // Update RendertraceProperty before UpdateAnimation() call, since + // the UpdateAnimation() updates effective ScrollOffset for next frame + // if APZFrameDelay is enabled. + if (mCheckerboardEvent) { + mCheckerboardEvent->UpdateRendertraceProperty( + CheckerboardEvent::UserVisible, visibleRect); + } + } + + requestAnimationFrame = UpdateAnimation(lock, aSampleTime, &deferredTasks); + } + // Execute any deferred tasks queued up by mAnimation's Sample() (called by + // UpdateAnimation()). This needs to be done after the monitor is released + // since the tasks are allowed to call APZCTreeManager methods which can grab + // the tree lock. + for (uint32_t i = 0; i < deferredTasks.Length(); ++i) { + APZThreadUtils::RunOnControllerThread(std::move(deferredTasks[i])); + } + + // If any of the deferred tasks starts a new animation, it will request a + // new composite directly, so we can just return requestAnimationFrame here. + return requestAnimationFrame; +} + +ParentLayerPoint AsyncPanZoomController::GetCurrentAsyncScrollOffset( + AsyncTransformConsumer aMode) const { + RecursiveMutexAutoLock lock(mRecursiveMutex); + AutoApplyAsyncTestAttributes testAttributeApplier(this, lock); + + return GetEffectiveScrollOffset(aMode, lock) * GetEffectiveZoom(aMode, lock); +} + +CSSRect AsyncPanZoomController::GetCurrentAsyncVisualViewport( + AsyncTransformConsumer aMode) const { + RecursiveMutexAutoLock lock(mRecursiveMutex); + AutoApplyAsyncTestAttributes testAttributeApplier(this, lock); + + return CSSRect( + GetEffectiveScrollOffset(aMode, lock), + FrameMetrics::CalculateCompositedSizeInCssPixels( + Metrics().GetCompositionBounds(), GetEffectiveZoom(aMode, lock))); +} + +AsyncTransform AsyncPanZoomController::GetCurrentAsyncTransform( + AsyncTransformConsumer aMode, AsyncTransformComponents aComponents, + std::size_t aSampleIndex) const { + RecursiveMutexAutoLock lock(mRecursiveMutex); + AutoApplyAsyncTestAttributes testAttributeApplier(this, lock); + + CSSToParentLayerScale effectiveZoom; + if (aComponents.contains(AsyncTransformComponent::eVisual)) { + effectiveZoom = GetEffectiveZoom(aMode, lock, aSampleIndex); + } else { + effectiveZoom = + Metrics().LayersPixelsPerCSSPixel() * LayerToParentLayerScale(1.0f); + } + + LayerToParentLayerScale compositedAsyncZoom = + effectiveZoom / Metrics().LayersPixelsPerCSSPixel(); + + ParentLayerPoint translation; + if (aComponents.contains(AsyncTransformComponent::eVisual)) { + // There is no "lastPaintVisualOffset" to subtract here; the visual offset + // is entirely async. + + CSSPoint currentVisualOffset = + GetEffectiveScrollOffset(aMode, lock, aSampleIndex) - + GetEffectiveLayoutViewport(aMode, lock, aSampleIndex).TopLeft(); + + translation += currentVisualOffset * effectiveZoom; + } + if (aComponents.contains(AsyncTransformComponent::eLayout)) { + CSSPoint lastPaintLayoutOffset; + if (mLastContentPaintMetrics.IsScrollable()) { + lastPaintLayoutOffset = mLastContentPaintMetrics.GetLayoutScrollOffset(); + } + + CSSPoint currentLayoutOffset = + GetEffectiveLayoutViewport(aMode, lock, aSampleIndex).TopLeft(); + + translation += + (currentLayoutOffset - lastPaintLayoutOffset) * effectiveZoom; + } + + return AsyncTransform(compositedAsyncZoom, -translation); +} + +AsyncTransformComponentMatrix +AsyncPanZoomController::GetAsyncTransformForInputTransformation( + AsyncTransformComponents aComponents, LayersId aForLayersId) const { + AsyncTransformComponentMatrix result; + // If we are the root, and |aForLayersId| is different from our LayersId, + // |aForLayersId| must be in a remote subdocument. + if (IsRootContent() && aForLayersId != GetLayersId()) { + result = + ViewAs<AsyncTransformComponentMatrix>(GetPaintedResolutionTransform()); + } + // Order of transforms: the painted resolution (if any) applies first, and + // any async transform on top of that. + result = result * AsyncTransformComponentMatrix(GetCurrentAsyncTransform( + eForEventHandling, aComponents)); + // The overscroll transform is considered part of the layout component of + // the async transform, because it should not apply to fixed content. + if (aComponents.contains(AsyncTransformComponent::eLayout)) { + result = result * GetOverscrollTransform(eForEventHandling); + } + return result; +} + +Matrix4x4 AsyncPanZoomController::GetPaintedResolutionTransform() const { + RecursiveMutexAutoLock lock(mRecursiveMutex); + MOZ_ASSERT(IsRootContent()); + float resolution = mLastContentPaintMetrics.GetPresShellResolution(); + return Matrix4x4::Scaling(resolution, resolution, 1.f); +} + +LayoutDeviceToParentLayerScale AsyncPanZoomController::GetCurrentPinchZoomScale( + AsyncTransformConsumer aMode) const { + RecursiveMutexAutoLock lock(mRecursiveMutex); + AutoApplyAsyncTestAttributes testAttributeApplier(this, lock); + CSSToParentLayerScale scale = GetEffectiveZoom(aMode, lock); + return scale / Metrics().GetDevPixelsPerCSSPixel(); +} + +AutoTArray<wr::SampledScrollOffset, 2> +AsyncPanZoomController::GetSampledScrollOffsets() const { + AssertOnSamplerThread(); + + RecursiveMutexAutoLock lock(mRecursiveMutex); + + const AsyncTransformComponents asyncTransformComponents = + GetZoomAnimationId() + ? AsyncTransformComponents{AsyncTransformComponent::eLayout} + : LayoutAndVisual; + + // If layerTranslation includes only the layout component of the async + // transform then it has not been scaled by the async zoom, so we want to + // divide it by the resolution. If layerTranslation includes the visual + // component, then we should use the pinch zoom scale, which includes the + // async zoom. However, we only use LayoutAndVisual for non-zoomable APZCs, + // so it makes no difference. + LayoutDeviceToParentLayerScale resolution = + GetCumulativeResolution() * LayerToParentLayerScale(1.0f); + + AutoTArray<wr::SampledScrollOffset, 2> sampledOffsets; + + for (std::deque<SampledAPZCState>::size_type index = 0; + index < mSampledState.size(); index++) { + ParentLayerPoint layerTranslation = + GetCurrentAsyncTransform(AsyncPanZoomController::eForCompositing, + asyncTransformComponents, index) + .mTranslation; + + // Include the overscroll transform here in scroll offsets transform + // to ensure that we do not overscroll fixed content. + layerTranslation = + GetOverscrollTransform(AsyncPanZoomController::eForCompositing) + .TransformPoint(layerTranslation); + // The positive translation means the painted content is supposed to + // move down (or to the right), and that corresponds to a reduction in + // the scroll offset. Since we are effectively giving WR the async + // scroll delta here, we want to negate the translation. + LayoutDevicePoint asyncScrollDelta = -layerTranslation / resolution; + sampledOffsets.AppendElement(wr::SampledScrollOffset{ + wr::ToLayoutVector2D(asyncScrollDelta), + wr::ToWrAPZScrollGeneration(mSampledState[index].Generation())}); + } + + return sampledOffsets; +} + +bool AsyncPanZoomController::SuppressAsyncScrollOffset() const { + return mScrollMetadata.IsApzForceDisabled() || + (Metrics().IsMinimalDisplayPort() && + StaticPrefs::apz_prefer_jank_minimal_displayports()); +} + +CSSRect AsyncPanZoomController::GetEffectiveLayoutViewport( + AsyncTransformConsumer aMode, const RecursiveMutexAutoLock& aProofOfLock, + std::size_t aSampleIndex) const { + if (aMode == eForCompositing && SuppressAsyncScrollOffset()) { + return mLastContentPaintMetrics.GetLayoutViewport(); + } + if (aMode == eForCompositing) { + return mSampledState[aSampleIndex].GetLayoutViewport(); + } + return Metrics().GetLayoutViewport(); +} + +CSSPoint AsyncPanZoomController::GetEffectiveScrollOffset( + AsyncTransformConsumer aMode, const RecursiveMutexAutoLock& aProofOfLock, + std::size_t aSampleIndex) const { + if (aMode == eForCompositing && SuppressAsyncScrollOffset()) { + return mLastContentPaintMetrics.GetVisualScrollOffset(); + } + if (aMode == eForCompositing) { + return mSampledState[aSampleIndex].GetVisualScrollOffset(); + } + return Metrics().GetVisualScrollOffset(); +} + +CSSToParentLayerScale AsyncPanZoomController::GetEffectiveZoom( + AsyncTransformConsumer aMode, const RecursiveMutexAutoLock& aProofOfLock, + std::size_t aSampleIndex) const { + if (aMode == eForCompositing && SuppressAsyncScrollOffset()) { + return mLastContentPaintMetrics.GetZoom(); + } + if (aMode == eForCompositing) { + return mSampledState[aSampleIndex].GetZoom(); + } + return Metrics().GetZoom(); +} + +void AsyncPanZoomController::AdvanceToNextSample() { + AssertOnSamplerThread(); + RecursiveMutexAutoLock lock(mRecursiveMutex); + // Always keep at least one state in mSampledState. + if (mSampledState.size() > 1) { + mSampledState.pop_front(); + } +} + +bool AsyncPanZoomController::HavePendingFrameDelayedOffset() const { + AssertOnSamplerThread(); + RecursiveMutexAutoLock lock(mRecursiveMutex); + + const bool nextFrameWillChange = + mSampledState.size() >= 2 && mSampledState[0] != mSampledState[1]; + const bool frameAfterThatWillChange = + mSampledState.back() != SampledAPZCState(Metrics()); + return nextFrameWillChange || frameAfterThatWillChange; +} + +bool AsyncPanZoomController::SampleCompositedAsyncTransform( + const RecursiveMutexAutoLock& aProofOfLock) { + MOZ_ASSERT(mSampledState.size() <= 2); + bool sampleChanged = (mSampledState.back() != SampledAPZCState(Metrics())); + mSampledState.emplace_back(Metrics(), std::move(mScrollPayload), + mScrollGeneration); + return sampleChanged; +} + +void AsyncPanZoomController::ResampleCompositedAsyncTransform( + const RecursiveMutexAutoLock& aProofOfLock) { + // This only gets called during testing situations, so the fact that this + // drops the scroll payload from mSampledState.front() is not really a + // problem. + if (APZCTreeManager* treeManagerLocal = GetApzcTreeManager()) { + mScrollGeneration = treeManagerLocal->NewAPZScrollGeneration(); + } + mSampledState.front() = SampledAPZCState(Metrics(), {}, mScrollGeneration); +} + +void AsyncPanZoomController::ApplyAsyncTestAttributes( + const RecursiveMutexAutoLock& aProofOfLock) { + if (mTestAttributeAppliers == 0) { + if (mTestAsyncScrollOffset != CSSPoint() || + mTestAsyncZoom != LayerToParentLayerScale()) { + // TODO Currently we update Metrics() and resample, which will cause + // the very latest user input to get immediately captured in the sample, + // and may defeat our attempt at "frame delay" (i.e. delaying the user + // input from affecting composition by one frame). + // Instead, maybe we should just apply the mTest* stuff directly to + // mSampledState.front(). We can even save/restore that SampledAPZCState + // instance in the AutoApplyAsyncTestAttributes instead of Metrics(). + Metrics().ZoomBy(mTestAsyncZoom.scale); + CSSPoint asyncScrollPosition = Metrics().GetVisualScrollOffset(); + CSSPoint requestedPoint = + asyncScrollPosition + this->mTestAsyncScrollOffset; + CSSPoint clampedPoint = + Metrics().CalculateScrollRange().ClampPoint(requestedPoint); + CSSPoint difference = mTestAsyncScrollOffset - clampedPoint; + + ScrollByAndClamp(mTestAsyncScrollOffset); + + if (StaticPrefs::apz_overscroll_test_async_scroll_offset_enabled()) { + ParentLayerPoint overscroll = difference * Metrics().GetZoom(); + OverscrollBy(overscroll); + } + ResampleCompositedAsyncTransform(aProofOfLock); + } + } + ++mTestAttributeAppliers; +} + +void AsyncPanZoomController::UnapplyAsyncTestAttributes( + const RecursiveMutexAutoLock& aProofOfLock, + const FrameMetrics& aPrevFrameMetrics, + const ParentLayerPoint& aPrevOverscroll) { + MOZ_ASSERT(mTestAttributeAppliers >= 1); + --mTestAttributeAppliers; + if (mTestAttributeAppliers == 0) { + if (mTestAsyncScrollOffset != CSSPoint() || + mTestAsyncZoom != LayerToParentLayerScale()) { + Metrics() = aPrevFrameMetrics; + RestoreOverscrollAmount(aPrevOverscroll); + ResampleCompositedAsyncTransform(aProofOfLock); + } + } +} + +Matrix4x4 AsyncPanZoomController::GetTransformToLastDispatchedPaint( + const AsyncTransformComponents& aComponents, LayersId aForLayersId) const { + RecursiveMutexAutoLock lock(mRecursiveMutex); + CSSPoint componentOffset; + + // The computation of the componentOffset should roughly be the negation + // of the translation in GetCurrentAsyncTransform() with the expected + // gecko metrics substituted for the effective scroll offsets. + if (aComponents.contains(AsyncTransformComponent::eVisual)) { + componentOffset += mExpectedGeckoMetrics.GetLayoutScrollOffset() - + mExpectedGeckoMetrics.GetVisualScrollOffset(); + } + + if (aComponents.contains(AsyncTransformComponent::eLayout)) { + CSSPoint lastPaintLayoutOffset; + + if (mLastContentPaintMetrics.IsScrollable()) { + lastPaintLayoutOffset = mLastContentPaintMetrics.GetLayoutScrollOffset(); + } + + componentOffset += + lastPaintLayoutOffset - mExpectedGeckoMetrics.GetLayoutScrollOffset(); + } + + LayerPoint scrollChange = componentOffset * + mLastContentPaintMetrics.GetDevPixelsPerCSSPixel() * + mLastContentPaintMetrics.GetCumulativeResolution(); + + // We're interested in the async zoom change. Factor out the content scale + // that may change when dragging the window to a monitor with a different + // content scale. + LayoutDeviceToParentLayerScale lastContentZoom = + mLastContentPaintMetrics.GetZoom() / + mLastContentPaintMetrics.GetDevPixelsPerCSSPixel(); + LayoutDeviceToParentLayerScale lastDispatchedZoom = + mExpectedGeckoMetrics.GetZoom() / + mExpectedGeckoMetrics.GetDevPixelsPerCSSPixel(); + float zoomChange = 1.0; + if (aComponents.contains(AsyncTransformComponent::eVisual) && + lastDispatchedZoom != LayoutDeviceToParentLayerScale(0)) { + zoomChange = lastContentZoom.scale / lastDispatchedZoom.scale; + } + Matrix4x4 result; + // If we are the root, and |aForLayersId| is different from our LayersId, + // |aForLayersId| must be in a remote subdocument. + if (IsRootContent() && aForLayersId != GetLayersId()) { + result = GetPaintedResolutionTransform(); + } + // Order of transforms: the painted resolution (if any) applies first, and + // any async transform on top of that. + return result * Matrix4x4::Translation(scrollChange.x, scrollChange.y, 0) + .PostScale(zoomChange, zoomChange, 1); +} + +CSSRect AsyncPanZoomController::GetVisibleRect( + const RecursiveMutexAutoLock& aProofOfLock) const { + AutoApplyAsyncTestAttributes testAttributeApplier(this, aProofOfLock); + CSSPoint currentScrollOffset = GetEffectiveScrollOffset( + AsyncPanZoomController::eForCompositing, aProofOfLock); + CSSRect visible = CSSRect(currentScrollOffset, + Metrics().CalculateCompositedSizeInCssPixels()); + return visible; +} + +static CSSRect GetPaintedRect(const FrameMetrics& aFrameMetrics) { + CSSRect displayPort = aFrameMetrics.GetDisplayPort(); + if (displayPort.IsEmpty()) { + // Fallback to use the viewport if the diplayport hasn't been set. + // This situation often happens non-scrollable iframe's root scroller in + // Fission. + return aFrameMetrics.GetVisualViewport(); + } + + return displayPort + aFrameMetrics.GetLayoutScrollOffset(); +} + +uint32_t AsyncPanZoomController::GetCheckerboardMagnitude( + const ParentLayerRect& aClippedCompositionBounds) const { + RecursiveMutexAutoLock lock(mRecursiveMutex); + + CSSRect painted = GetPaintedRect(mLastContentPaintMetrics); + painted.Inflate(CSSMargin::FromAppUnits( + nsMargin(1, 1, 1, 1))); // fuzz for rounding error + + CSSRect visible = GetVisibleRect(lock); // relative to scrolled frame origin + if (visible.IsEmpty() || painted.Contains(visible)) { + // early-exit if we're definitely not checkerboarding + return 0; + } + + // aClippedCompositionBounds and Metrics().GetCompositionBounds() are both + // relative to the layer tree origin. + // The "*RelativeToItself*" variables are relative to the comp bounds origin + ParentLayerRect visiblePartOfCompBoundsRelativeToItself = + aClippedCompositionBounds - Metrics().GetCompositionBounds().TopLeft(); + CSSRect visiblePartOfCompBoundsRelativeToItselfInCssSpace; + if (Metrics().GetZoom() != CSSToParentLayerScale(0)) { + visiblePartOfCompBoundsRelativeToItselfInCssSpace = + (visiblePartOfCompBoundsRelativeToItself / Metrics().GetZoom()); + } + + // This one is relative to the scrolled frame origin, same as `visible` + CSSRect visiblePartOfCompBoundsInCssSpace = + visiblePartOfCompBoundsRelativeToItselfInCssSpace + visible.TopLeft(); + + visible = visible.Intersect(visiblePartOfCompBoundsInCssSpace); + + CSSIntRegion checkerboard; + // Round so as to minimize checkerboarding; if we're only showing fractional + // pixels of checkerboarding it's not really worth counting + checkerboard.Sub(RoundedIn(visible), RoundedOut(painted)); + uint32_t area = checkerboard.Area(); + if (area) { + APZC_LOG_FM(Metrics(), + "%p is currently checkerboarding (painted %s visible %s)", this, + ToString(painted).c_str(), ToString(visible).c_str()); + } + return area; +} + +void AsyncPanZoomController::ReportCheckerboard( + const SampleTime& aSampleTime, + const ParentLayerRect& aClippedCompositionBounds) { + if (mLastCheckerboardReport == aSampleTime) { + // This function will get called multiple times for each APZC on a single + // composite (once for each layer it is attached to). Only report the + // checkerboard once per composite though. + return; + } + mLastCheckerboardReport = aSampleTime; + + bool recordTrace = StaticPrefs::apz_record_checkerboarding(); + bool forTelemetry = Telemetry::CanRecordBase(); + uint32_t magnitude = GetCheckerboardMagnitude(aClippedCompositionBounds); + + // IsInTransformingState() acquires the APZC lock and thus needs to + // be called before acquiring mCheckerboardEventLock. + bool inTransformingState = IsInTransformingState(); + + MutexAutoLock lock(mCheckerboardEventLock); + if (!mCheckerboardEvent && (recordTrace || forTelemetry)) { + mCheckerboardEvent = MakeUnique<CheckerboardEvent>(recordTrace); + } + mPotentialCheckerboardTracker.InTransform(inTransformingState, + recordTrace || forTelemetry); + if (magnitude) { + mPotentialCheckerboardTracker.CheckerboardSeen(); + } + UpdateCheckerboardEvent(lock, magnitude); +} + +void AsyncPanZoomController::UpdateCheckerboardEvent( + const MutexAutoLock& aProofOfLock, uint32_t aMagnitude) { + if (mCheckerboardEvent && mCheckerboardEvent->RecordFrameInfo(aMagnitude)) { + // This checkerboard event is done. Report some metrics to telemetry. + mozilla::glean::gfx_checkerboard::severity.AccumulateSamples( + {mCheckerboardEvent->GetSeverity()}); + mozilla::glean::gfx_checkerboard::peak_pixel_count.AccumulateSamples( + {mCheckerboardEvent->GetPeak()}); + mozilla::glean::gfx_checkerboard::duration.AccumulateRawDuration( + mCheckerboardEvent->GetDuration()); + + // mCheckerboardEvent only gets created if we are supposed to record + // telemetry so we always pass true for aRecordTelemetry. + mPotentialCheckerboardTracker.CheckerboardDone( + /* aRecordTelemetry = */ true); + + if (StaticPrefs::apz_record_checkerboarding()) { + // if the pref is enabled, also send it to the storage class. it may be + // chosen for public display on about:checkerboard, the hall of fame for + // checkerboard events. + uint32_t severity = mCheckerboardEvent->GetSeverity(); + std::string log = mCheckerboardEvent->GetLog(); + CheckerboardEventStorage::Report(severity, log); + } + mCheckerboardEvent = nullptr; + } +} + +void AsyncPanZoomController::FlushActiveCheckerboardReport() { + MutexAutoLock lock(mCheckerboardEventLock); + // Pretend like we got a frame with 0 pixels checkerboarded. This will + // terminate the checkerboard event and flush it out + UpdateCheckerboardEvent(lock, 0); +} + +void AsyncPanZoomController::NotifyLayersUpdated( + const ScrollMetadata& aScrollMetadata, bool aIsFirstPaint, + bool aThisLayerTreeUpdated) { + AssertOnUpdaterThread(); + + RecursiveMutexAutoLock lock(mRecursiveMutex); + bool isDefault = mScrollMetadata.IsDefault(); + + const FrameMetrics& aLayerMetrics = aScrollMetadata.GetMetrics(); + + if ((aScrollMetadata == mLastContentPaintMetadata) && !isDefault) { + // No new information here, skip it. + APZC_LOGV("%p NotifyLayersUpdated short-circuit\n", this); + return; + } + + // If the Metrics scroll offset is different from the last scroll offset + // that the main-thread sent us, then we know that the user has been doing + // something that triggers a scroll. This check is the APZ equivalent of the + // check on the main-thread at + // https://hg.mozilla.org/mozilla-central/file/97a52326b06a/layout/generic/nsGfxScrollFrame.cpp#l4050 + // There is code below (the use site of userScrolled) that prevents a + // restored- scroll-position update from overwriting a user scroll, again + // equivalent to how the main thread code does the same thing. + // XXX Suspicious comparison between layout and visual scroll offsets. + // This may not do the right thing when we're zoomed in. + CSSPoint lastScrollOffset = mLastContentPaintMetrics.GetLayoutScrollOffset(); + bool userScrolled = + !FuzzyEqualsCoordinate(Metrics().GetVisualScrollOffset().x, + lastScrollOffset.x) || + !FuzzyEqualsCoordinate(Metrics().GetVisualScrollOffset().y, + lastScrollOffset.y); + + if (aScrollMetadata.DidContentGetPainted()) { + mLastContentPaintMetadata = aScrollMetadata; + } + + mScrollMetadata.SetScrollParentId(aScrollMetadata.GetScrollParentId()); + APZC_LOGV_FM(aLayerMetrics, + "%p got a NotifyLayersUpdated with aIsFirstPaint=%d, " + "aThisLayerTreeUpdated=%d", + this, aIsFirstPaint, aThisLayerTreeUpdated); + + { // scope lock + MutexAutoLock lock(mCheckerboardEventLock); + if (mCheckerboardEvent && mCheckerboardEvent->IsRecordingTrace()) { + std::string str; + if (aThisLayerTreeUpdated) { + if (!aLayerMetrics.GetPaintRequestTime().IsNull()) { + // Note that we might get the paint request time as non-null, but with + // aThisLayerTreeUpdated false. That can happen if we get a layer + // transaction from a different process right after we get the layer + // transaction with aThisLayerTreeUpdated == true. In this case we + // want to ignore the paint request time because it was already dumped + // in the previous layer transaction. + TimeDuration paintTime = + TimeStamp::Now() - aLayerMetrics.GetPaintRequestTime(); + std::stringstream info; + info << " painttime " << paintTime.ToMilliseconds(); + str = info.str(); + } else { + // This might be indicative of a wasted paint particularly if it + // happens during a checkerboard event. + str = " (this layertree updated)"; + } + } + mCheckerboardEvent->UpdateRendertraceProperty( + CheckerboardEvent::Page, aLayerMetrics.GetScrollableRect()); + mCheckerboardEvent->UpdateRendertraceProperty( + CheckerboardEvent::PaintedDisplayPort, GetPaintedRect(aLayerMetrics), + str); + } + } + + // The main thread may send us a visual scroll offset update. This is + // different from a layout viewport offset update in that the layout viewport + // offset is limited to the layout scroll range, while the visual viewport + // offset is not. + // However, there are some conditions in which the layout update will clobber + // the visual update, and we want to ignore the visual update in those cases. + // This variable tracks that. + bool ignoreVisualUpdate = false; + + // TODO if we're in a drag and scrollOffsetUpdated is set then we want to + // ignore it + + bool needContentRepaint = false; + RepaintUpdateType contentRepaintType = RepaintUpdateType::eNone; + bool viewportSizeUpdated = false; + bool needToReclampScroll = false; + + if ((aIsFirstPaint && aThisLayerTreeUpdated) || isDefault || + Metrics().IsRootContent() != aLayerMetrics.IsRootContent()) { + if (Metrics().IsRootContent() && !aLayerMetrics.IsRootContent()) { + // We only support zooming on root content APZCs + SetZoomAnimationId(Nothing()); + } + + // Initialize our internal state to something sane when the content + // that was just painted is something we knew nothing about previously + CancelAnimation(); + + // Keep our existing scroll generation, if there are scroll updates. In this + // case we'll update our scroll generation when processing the scroll update + // array below. If there are no scroll updates, take the generation from the + // incoming metrics. Bug 1662019 will simplify this later. + ScrollGeneration oldScrollGeneration = Metrics().GetScrollGeneration(); + mScrollMetadata = aScrollMetadata; + if (!aScrollMetadata.GetScrollUpdates().IsEmpty()) { + Metrics().SetScrollGeneration(oldScrollGeneration); + } + + mExpectedGeckoMetrics.UpdateFrom(aLayerMetrics); + + for (auto& sampledState : mSampledState) { + sampledState.UpdateScrollProperties(Metrics()); + sampledState.UpdateZoomProperties(Metrics()); + } + + if (aLayerMetrics.HasNonZeroDisplayPortMargins()) { + // A non-zero display port margin here indicates a displayport has + // been set by a previous APZC for the content at this guid. The + // scrollable rect may have changed since then, making the margins + // wrong, so we need to calculate a new display port. + // It is important that we request a repaint here only when we need to + // otherwise we will end up setting a display port on every frame that + // gets a view id. + APZC_LOG("%p detected non-empty margins which probably need updating\n", + this); + needContentRepaint = true; + } + } else { + // If we're not taking the aLayerMetrics wholesale we still need to pull + // in some things into our local Metrics() because these things are + // determined by Gecko and our copy in Metrics() may be stale. + + if (Metrics().GetLayoutViewport().Size() != + aLayerMetrics.GetLayoutViewport().Size()) { + CSSRect layoutViewport = Metrics().GetLayoutViewport(); + // The offset will be updated if necessary via + // RecalculateLayoutViewportOffset(). + layoutViewport.SizeTo(aLayerMetrics.GetLayoutViewport().Size()); + Metrics().SetLayoutViewport(layoutViewport); + + needContentRepaint = true; + viewportSizeUpdated = true; + } + + // TODO: Rely entirely on |aScrollMetadata.IsResolutionUpdated()| to + // determine which branch to take, and drop the other conditions. + CSSToParentLayerScale oldZoom = Metrics().GetZoom(); + if (FuzzyEqualsAdditive( + Metrics().GetCompositionBoundsWidthIgnoringScrollbars(), + aLayerMetrics.GetCompositionBoundsWidthIgnoringScrollbars()) && + Metrics().GetDevPixelsPerCSSPixel() == + aLayerMetrics.GetDevPixelsPerCSSPixel() && + !viewportSizeUpdated && !aScrollMetadata.IsResolutionUpdated()) { + // Any change to the pres shell resolution was requested by APZ and is + // already included in our zoom; however, other components of the + // cumulative resolution (a parent document's pres-shell resolution, or + // the css-driven resolution) may have changed, and we need to update + // our zoom to reflect that. Note that we can't just take + // aLayerMetrics.mZoom because the APZ may have additional async zoom + // since the repaint request. + float totalResolutionChange = 1.0; + + if (Metrics().GetCumulativeResolution() != LayoutDeviceToLayerScale(0)) { + totalResolutionChange = aLayerMetrics.GetCumulativeResolution().scale / + Metrics().GetCumulativeResolution().scale; + } + + float presShellResolutionChange = aLayerMetrics.GetPresShellResolution() / + Metrics().GetPresShellResolution(); + if (presShellResolutionChange != 1.0f) { + needContentRepaint = true; + } + Metrics().ZoomBy(totalResolutionChange / presShellResolutionChange); + for (auto& sampledState : mSampledState) { + sampledState.ZoomBy(totalResolutionChange / presShellResolutionChange); + } + } else { + // Take the new zoom as either device scale or composition width or + // viewport size got changed (e.g. due to orientation change, or content + // changing the meta-viewport tag), or the main thread originated a + // resolution change for another reason (e.g. Ctrl+0 was pressed to + // reset the zoom). + Metrics().SetZoom(aLayerMetrics.GetZoom()); + for (auto& sampledState : mSampledState) { + sampledState.UpdateZoomProperties(aLayerMetrics); + } + Metrics().SetDevPixelsPerCSSPixel( + aLayerMetrics.GetDevPixelsPerCSSPixel()); + } + + if (Metrics().GetZoom() != oldZoom) { + // If the zoom changed, the scroll range in CSS pixels may have changed + // even if the composition bounds didn't. + needToReclampScroll = true; + } + + mExpectedGeckoMetrics.UpdateZoomFrom(aLayerMetrics); + + if (!Metrics().GetScrollableRect().IsEqualEdges( + aLayerMetrics.GetScrollableRect())) { + Metrics().SetScrollableRect(aLayerMetrics.GetScrollableRect()); + needContentRepaint = true; + needToReclampScroll = true; + } + if (!Metrics().GetCompositionBounds().IsEqualEdges( + aLayerMetrics.GetCompositionBounds())) { + Metrics().SetCompositionBounds(aLayerMetrics.GetCompositionBounds()); + needToReclampScroll = true; + } + Metrics().SetCompositionBoundsWidthIgnoringScrollbars( + aLayerMetrics.GetCompositionBoundsWidthIgnoringScrollbars()); + + if (Metrics().IsRootContent() && + Metrics().GetCompositionSizeWithoutDynamicToolbar() != + aLayerMetrics.GetCompositionSizeWithoutDynamicToolbar()) { + Metrics().SetCompositionSizeWithoutDynamicToolbar( + aLayerMetrics.GetCompositionSizeWithoutDynamicToolbar()); + needToReclampScroll = true; + } + Metrics().SetBoundingCompositionSize( + aLayerMetrics.GetBoundingCompositionSize()); + Metrics().SetPresShellResolution(aLayerMetrics.GetPresShellResolution()); + Metrics().SetCumulativeResolution(aLayerMetrics.GetCumulativeResolution()); + Metrics().SetTransformToAncestorScale( + aLayerMetrics.GetTransformToAncestorScale()); + mScrollMetadata.SetHasScrollgrab(aScrollMetadata.GetHasScrollgrab()); + mScrollMetadata.SetLineScrollAmount(aScrollMetadata.GetLineScrollAmount()); + mScrollMetadata.SetPageScrollAmount(aScrollMetadata.GetPageScrollAmount()); + mScrollMetadata.SetSnapInfo(ScrollSnapInfo(aScrollMetadata.GetSnapInfo())); + mScrollMetadata.SetIsLayersIdRoot(aScrollMetadata.IsLayersIdRoot()); + mScrollMetadata.SetIsAutoDirRootContentRTL( + aScrollMetadata.IsAutoDirRootContentRTL()); + Metrics().SetIsScrollInfoLayer(aLayerMetrics.IsScrollInfoLayer()); + Metrics().SetHasNonZeroDisplayPortMargins( + aLayerMetrics.HasNonZeroDisplayPortMargins()); + Metrics().SetMinimalDisplayPort(aLayerMetrics.IsMinimalDisplayPort()); + mScrollMetadata.SetForceDisableApz(aScrollMetadata.IsApzForceDisabled()); + mScrollMetadata.SetIsRDMTouchSimulationActive( + aScrollMetadata.GetIsRDMTouchSimulationActive()); + mScrollMetadata.SetForceMousewheelAutodir( + aScrollMetadata.ForceMousewheelAutodir()); + mScrollMetadata.SetForceMousewheelAutodirHonourRoot( + aScrollMetadata.ForceMousewheelAutodirHonourRoot()); + mScrollMetadata.SetIsPaginatedPresentation( + aScrollMetadata.IsPaginatedPresentation()); + mScrollMetadata.SetDisregardedDirection( + aScrollMetadata.GetDisregardedDirection()); + mScrollMetadata.SetOverscrollBehavior( + aScrollMetadata.GetOverscrollBehavior()); + } + + if (needToReclampScroll) { + // Whenever scrollable rect or composition bounds has changed, we need to + // re-clamp the scroll offset since it may be out of bounds. Also note that + // we need to re-clamp before updating new scroll offsets from content since + // we will use the last scroll offset to reflect the new offsets. + ClampAndSetVisualScrollOffset(Metrics().GetVisualScrollOffset()); + for (auto& sampledState : mSampledState) { + sampledState.ClampVisualScrollOffset(Metrics()); + } + } + + bool instantScrollMayTriggerTransform = false; + bool scrollOffsetUpdated = false; + bool smoothScrollRequested = false; + bool didCancelAnimation = false; + Maybe<CSSPoint> cumulativeRelativeDelta; + for (const auto& scrollUpdate : aScrollMetadata.GetScrollUpdates()) { + APZC_LOG("%p processing scroll update %s\n", this, + ToString(scrollUpdate).c_str()); + if (!(Metrics().GetScrollGeneration() < scrollUpdate.GetGeneration())) { + // This is stale, let's ignore it + APZC_LOG("%p scrollupdate generation stale, dropping\n", this); + continue; + } + Metrics().SetScrollGeneration(scrollUpdate.GetGeneration()); + + MOZ_ASSERT(scrollUpdate.GetOrigin() != ScrollOrigin::Apz); + if (userScrolled && + !nsLayoutUtils::CanScrollOriginClobberApz(scrollUpdate.GetOrigin())) { + APZC_LOG("%p scrollupdate cannot clobber APZ userScrolled\n", this); + continue; + } + // XXX: if we get here, |scrollUpdate| is clobbering APZ, so we may want + // to reset |userScrolled| back to false so that subsequent scrollUpdates + // in this loop don't get dropped by the check above. Need to add a test + // that exercises this scenario, as we don't currently have one. + + if (scrollUpdate.GetMode() == ScrollMode::Smooth || + scrollUpdate.GetMode() == ScrollMode::SmoothMsd) { + smoothScrollRequested = true; + + // Requests to animate the visual scroll position override requests to + // simply update the visual scroll offset to a particular point. Since + // we have an animation request, we set ignoreVisualUpdate to true to + // indicate we don't need to apply the visual scroll update in + // aLayerMetrics. + ignoreVisualUpdate = true; + + // For relative updates we want to add the relative offset to any existing + // destination, or the current visual offset if there is no existing + // destination. + CSSPoint base = GetCurrentAnimationDestination(lock).valueOr( + Metrics().GetVisualScrollOffset()); + + CSSPoint destination; + if (scrollUpdate.GetType() == ScrollUpdateType::Relative) { + CSSPoint delta = + scrollUpdate.GetDestination() - scrollUpdate.GetSource(); + APZC_LOG("%p relative smooth scrolling from %s by %s\n", this, + ToString(base).c_str(), ToString(delta).c_str()); + destination = Metrics().CalculateScrollRange().ClampPoint(base + delta); + } else if (scrollUpdate.GetType() == ScrollUpdateType::PureRelative) { + CSSPoint delta = scrollUpdate.GetDelta(); + APZC_LOG("%p pure-relative smooth scrolling from %s by %s\n", this, + ToString(base).c_str(), ToString(delta).c_str()); + destination = Metrics().CalculateScrollRange().ClampPoint(base + delta); + } else { + APZC_LOG("%p smooth scrolling to %s\n", this, + ToString(scrollUpdate.GetDestination()).c_str()); + destination = scrollUpdate.GetDestination(); + } + + if (scrollUpdate.GetMode() == ScrollMode::SmoothMsd) { + SmoothMsdScrollTo( + CSSSnapDestination{destination, scrollUpdate.GetSnapTargetIds()}, + scrollUpdate.GetScrollTriggeredByScript()); + } else { + MOZ_ASSERT(scrollUpdate.GetMode() == ScrollMode::Smooth); + SmoothScrollTo( + CSSSnapDestination{destination, scrollUpdate.GetSnapTargetIds()}, + scrollUpdate.GetScrollTriggeredByScript(), + scrollUpdate.GetOrigin()); + } + continue; + } + + MOZ_ASSERT(scrollUpdate.GetMode() == ScrollMode::Instant || + scrollUpdate.GetMode() == ScrollMode::Normal); + + instantScrollMayTriggerTransform = + scrollUpdate.GetMode() == ScrollMode::Instant && + scrollUpdate.GetScrollTriggeredByScript() == + ScrollTriggeredByScript::No; + + // If the layout update is of a higher priority than the visual update, then + // we don't want to apply the visual update. + // If the layout update is of a clobbering type (or a smooth scroll request, + // which is handled above) then it takes precedence over an eRestore visual + // update. But we also allow the possibility for the main thread to ask us + // to scroll both the layout and visual viewports to distinct (but + // compatible) locations (via e.g. both updates being of a non-clobbering/ + // eRestore type). + if (nsLayoutUtils::CanScrollOriginClobberApz(scrollUpdate.GetOrigin()) && + aLayerMetrics.GetVisualScrollUpdateType() != + FrameMetrics::eMainThread) { + ignoreVisualUpdate = true; + } + + Maybe<CSSPoint> relativeDelta; + if (scrollUpdate.GetType() == ScrollUpdateType::Relative) { + APZC_LOG( + "%p relative updating scroll offset from %s by %s\n", this, + ToString(Metrics().GetVisualScrollOffset()).c_str(), + ToString(scrollUpdate.GetDestination() - scrollUpdate.GetSource()) + .c_str()); + + scrollOffsetUpdated = true; + + // It's possible that the main thread has ignored an APZ scroll offset + // update for the pending relative scroll that we have just received. + // When this happens, we need to send a new scroll offset update with + // the combined scroll offset or else the main thread may have an + // incorrect scroll offset for a period of time. + if (Metrics().HasPendingScroll(aLayerMetrics)) { + needContentRepaint = true; + contentRepaintType = RepaintUpdateType::eUserAction; + } + + relativeDelta = + Some(Metrics().ApplyRelativeScrollUpdateFrom(scrollUpdate)); + Metrics().RecalculateLayoutViewportOffset(); + } else if (scrollUpdate.GetType() == ScrollUpdateType::PureRelative) { + APZC_LOG("%p pure-relative updating scroll offset from %s by %s\n", this, + ToString(Metrics().GetVisualScrollOffset()).c_str(), + ToString(scrollUpdate.GetDelta()).c_str()); + + scrollOffsetUpdated = true; + + // Always need a repaint request with a repaint type for pure relative + // scrolls because apz is doing the scroll at the main thread's request. + // The main thread has not updated it's scroll offset yet, it is depending + // on apz to tell it where to scroll. + needContentRepaint = true; + contentRepaintType = RepaintUpdateType::eVisualUpdate; + + // We have to ignore a visual scroll offset update otherwise it will + // clobber the relative scrolling we are about to do. We perform + // visualScrollOffset = visualScrollOffset + delta. Then the + // visualScrollOffsetUpdated block below will do visualScrollOffset = + // aLayerMetrics.GetVisualDestination(). We need visual scroll offset + // updates to be incorporated into this scroll update loop to properly fix + // this. + ignoreVisualUpdate = true; + + relativeDelta = + Some(Metrics().ApplyPureRelativeScrollUpdateFrom(scrollUpdate)); + Metrics().RecalculateLayoutViewportOffset(); + } else if (scrollUpdate.GetType() == ScrollUpdateType::MergeableAbsolute) { + APZC_LOG("%p mergeable updating scroll offset from %s to %s\n", this, + ToString(Metrics().GetVisualScrollOffset()).c_str(), + ToString(scrollUpdate.GetDestination()).c_str()); + relativeDelta = + Some(Metrics().ApplyAbsoluteScrollUpdateFrom(scrollUpdate).second); + Metrics().RecalculateLayoutViewportOffset(); + scrollOffsetUpdated = true; + } else { + APZC_LOG("%p updating scroll offset from %s to %s\n", this, + ToString(Metrics().GetVisualScrollOffset()).c_str(), + ToString(scrollUpdate.GetDestination()).c_str()); + auto [offsetChanged, _] = + Metrics().ApplyAbsoluteScrollUpdateFrom(scrollUpdate); + Metrics().RecalculateLayoutViewportOffset(); + + if (offsetChanged || scrollUpdate.GetMode() != ScrollMode::Instant || + scrollUpdate.GetType() != ScrollUpdateType::Absolute || + scrollUpdate.GetOrigin() != ScrollOrigin::None) { + // We get a NewScrollFrame update for newly created scroll frames. Only + // if this was not a NewScrollFrame update or the offset changed do we + // request repaint. This is important so that we don't request repaint + // for every new content and set a full display port on it. + scrollOffsetUpdated = true; + } + } + + if (relativeDelta) { + cumulativeRelativeDelta = + !cumulativeRelativeDelta + ? relativeDelta + : Some(*cumulativeRelativeDelta + *relativeDelta); + } else { + // If the scroll update is not relative, clobber the cumulative delta, + // i.e. later updates win. + cumulativeRelativeDelta.reset(); + } + + // If an animation is underway, tell it about the scroll offset update. + // Some animations can handle some scroll offset updates and continue + // running. Those that can't will return false, and we cancel them. + if (ShouldCancelAnimationForScrollUpdate(relativeDelta)) { + // Cancel the animation (which might also trigger a repaint request) + // after we update the scroll offset above. Otherwise we can be left + // in a state where things are out of sync. + CancelAnimation(); + didCancelAnimation = true; + } + } + + if (scrollOffsetUpdated) { + for (auto& sampledState : mSampledState) { + if (!didCancelAnimation && cumulativeRelativeDelta.isSome()) { + sampledState.UpdateScrollPropertiesWithRelativeDelta( + Metrics(), *cumulativeRelativeDelta); + } else { + sampledState.UpdateScrollProperties(Metrics()); + } + } + + // Because of the scroll generation update, any inflight paint requests + // are going to be ignored by layout, and so mExpectedGeckoMetrics becomes + // incorrect for the purposes of calculating the LD transform. To correct + // this we need to update mExpectedGeckoMetrics to be the last thing we + // know was painted by Gecko. + mExpectedGeckoMetrics.UpdateFrom(aLayerMetrics); + + // Since the scroll offset has changed, we need to recompute the + // displayport margins and send them to layout. Otherwise there might be + // scenarios where for example we scroll from the top of a page (where the + // top displayport margin is zero) to the bottom of a page, which will + // result in a displayport that doesn't extend upwards at all. + // Note that even if the CancelAnimation call above requested a repaint + // this is fine because we already have repaint request deduplication. + needContentRepaint = true; + // Since the main-thread scroll offset changed we should trigger a + // recomposite to make sure it becomes user-visible. + ScheduleComposite(); + + // If the scroll offset was updated, we're not in a transforming state, + // and we are scrolling by a non-zero delta, we should ensure + // TransformBegin and TransformEnd notifications are sent. + if (!IsTransformingState(mState) && instantScrollMayTriggerTransform && + cumulativeRelativeDelta && *cumulativeRelativeDelta != CSSPoint() && + !didCancelAnimation) { + SendTransformBeginAndEnd(); + } + } + + // If our scroll range changed (for example, because the page dynamically + // loaded new content, thereby increasing the size of the scrollable rect), + // and we're overscrolled, being overscrolled may no longer be a valid + // state (for example, we may no longer be at the edge of our scroll range), + // so clear overscroll and discontinue any overscroll animation. + // Ideas for improvements here: + // - Instead of collapsing the overscroll gutter, try to "fill it" + // with newly loaded content. This would basically entail checking + // if (GetVisualScrollOffset() + GetOverscrollAmount()) is a valid + // visual scroll offset in our new scroll range, and if so, scrolling + // there. + if (needToReclampScroll) { + if (IsInInvalidOverscroll()) { + if (mState == OVERSCROLL_ANIMATION) { + CancelAnimation(); + } else if (IsOverscrolled()) { + ClearOverscroll(); + } + } + } + + if (smoothScrollRequested && !scrollOffsetUpdated) { + mExpectedGeckoMetrics.UpdateFrom(aLayerMetrics); + // Need to acknowledge the request. + needContentRepaint = true; + } + + // If `isDefault` is true, this APZC is a "new" one (this is the first time + // it's getting a NotifyLayersUpdated call). In this case we want to apply the + // visual scroll offset from the main thread to our scroll offset. + // The main thread may also ask us to scroll the visual viewport to a + // particular location. However, in all cases, we want to ignore the visual + // offset update if ignoreVisualUpdate is true, because we're clobbering + // the visual update with a layout update. + bool visualScrollOffsetUpdated = + !ignoreVisualUpdate && + (isDefault || + aLayerMetrics.GetVisualScrollUpdateType() != FrameMetrics::eNone); + + if (visualScrollOffsetUpdated) { + APZC_LOG("%p updating visual scroll offset from %s to %s (updateType %d)\n", + this, ToString(Metrics().GetVisualScrollOffset()).c_str(), + ToString(aLayerMetrics.GetVisualDestination()).c_str(), + (int)aLayerMetrics.GetVisualScrollUpdateType()); + bool offsetChanged = Metrics().ClampAndSetVisualScrollOffset( + aLayerMetrics.GetVisualDestination()); + + // If this is the first time we got metrics for this content (isDefault) and + // the update type was none and the offset didn't change then we don't have + // to do anything. This is important because we don't want to request + // repaint on the initial NotifyLayersUpdated for every content and thus set + // a full display port. + if (aLayerMetrics.GetVisualScrollUpdateType() == FrameMetrics::eNone && + !offsetChanged) { + visualScrollOffsetUpdated = false; + } + } + if (visualScrollOffsetUpdated) { + // The rest of this branch largely follows the code in the + // |if (scrollOffsetUpdated)| branch above. Eventually it should get + // merged into that branch. + Metrics().RecalculateLayoutViewportOffset(); + for (auto& sampledState : mSampledState) { + sampledState.UpdateScrollProperties(Metrics()); + } + mExpectedGeckoMetrics.UpdateFrom(aLayerMetrics); + if (ShouldCancelAnimationForScrollUpdate(Nothing())) { + CancelAnimation(); + } + // The main thread did not actually paint a displayport at the target + // visual offset, so we need to ask it to repaint. We need to set the + // contentRepaintType to something other than eNone, otherwise the main + // thread will short-circuit the repaint request. + // Don't do this for eRestore visual updates as a repaint coming from APZ + // breaks the scroll offset restoration mechanism. + needContentRepaint = true; + if (aLayerMetrics.GetVisualScrollUpdateType() == + FrameMetrics::eMainThread) { + contentRepaintType = RepaintUpdateType::eVisualUpdate; + } + ScheduleComposite(); + } + + if (viewportSizeUpdated) { + // While we want to accept the main thread's layout viewport _size_, + // its position may be out of date in light of async scrolling, to + // adjust it if necessary to make sure it continues to enclose the + // visual viewport. + // Note: it's important to do this _after_ we've accepted any + // updated composition bounds. + Metrics().RecalculateLayoutViewportOffset(); + } + + if (needContentRepaint) { + // This repaint request could be driven by a user action if we accept a + // relative scroll offset update + RequestContentRepaint(contentRepaintType); + } +} + +FrameMetrics& AsyncPanZoomController::Metrics() { + mRecursiveMutex.AssertCurrentThreadIn(); + return mScrollMetadata.GetMetrics(); +} + +const FrameMetrics& AsyncPanZoomController::Metrics() const { + mRecursiveMutex.AssertCurrentThreadIn(); + return mScrollMetadata.GetMetrics(); +} + +GeckoViewMetrics AsyncPanZoomController::GetGeckoViewMetrics() const { + RecursiveMutexAutoLock lock(mRecursiveMutex); + return GeckoViewMetrics{GetEffectiveScrollOffset(eForCompositing, lock), + GetEffectiveZoom(eForCompositing, lock)}; +} + +wr::MinimapData AsyncPanZoomController::GetMinimapData() const { + RecursiveMutexAutoLock lock(mRecursiveMutex); + wr::MinimapData result; + result.is_root_content = IsRootContent(); + // We want the minimap to reflect the scroll offset actually composited, + // which could be older than the latest one in Metrics() due to the frame + // delay. + CSSRect visualViewport = GetCurrentAsyncVisualViewport(eForCompositing); + result.visual_viewport = wr::ToLayoutRect(visualViewport.ToUnknownRect()); + CSSRect layoutViewport = GetEffectiveLayoutViewport(eForCompositing, lock); + result.layout_viewport = wr::ToLayoutRect(layoutViewport.ToUnknownRect()); + result.scrollable_rect = + wr::ToLayoutRect(Metrics().GetScrollableRect().ToUnknownRect()); + // The display port is stored relative to the layout viewport origin. + // Translate it to be relative to the document origin, like the other rects. + CSSRect displayPort = mLastContentPaintMetrics.GetDisplayPort() + + mLastContentPaintMetrics.GetLayoutScrollOffset(); + result.displayport = wr::ToLayoutRect(displayPort.ToUnknownRect()); + // Remaining fields (zoom_transform, root_content_scroll_id, + // root_content_pipeline_id) will be populated by the caller, since they + // require information from other APZCs to compute. + return result; +} + +bool AsyncPanZoomController::UpdateRootFrameMetricsIfChanged( + GeckoViewMetrics& aMetrics) { + RecursiveMutexAutoLock lock(mRecursiveMutex); + + if (!Metrics().IsRootContent()) { + return false; + } + + GeckoViewMetrics newMetrics = GetGeckoViewMetrics(); + bool hasChanged = RoundedToInt(aMetrics.mVisualScrollOffset) != + RoundedToInt(newMetrics.mVisualScrollOffset) || + aMetrics.mZoom != newMetrics.mZoom; + + if (hasChanged) { + aMetrics = newMetrics; + } + + return hasChanged; +} + +const FrameMetrics& AsyncPanZoomController::GetFrameMetrics() const { + return Metrics(); +} + +const ScrollMetadata& AsyncPanZoomController::GetScrollMetadata() const { + mRecursiveMutex.AssertCurrentThreadIn(); + return mScrollMetadata; +} + +void AsyncPanZoomController::AssertOnSamplerThread() const { + if (APZCTreeManager* treeManagerLocal = GetApzcTreeManager()) { + treeManagerLocal->AssertOnSamplerThread(); + } +} + +void AsyncPanZoomController::AssertOnUpdaterThread() const { + if (APZCTreeManager* treeManagerLocal = GetApzcTreeManager()) { + treeManagerLocal->AssertOnUpdaterThread(); + } +} + +APZCTreeManager* AsyncPanZoomController::GetApzcTreeManager() const { + mRecursiveMutex.AssertNotCurrentThreadIn(); + return mTreeManager; +} + +void AsyncPanZoomController::ZoomToRect(const ZoomTarget& aZoomTarget, + const uint32_t aFlags) { + CSSRect rect = aZoomTarget.targetRect; + if (!rect.IsFinite()) { + NS_WARNING("ZoomToRect got called with a non-finite rect; ignoring..."); + return; + } + + if (rect.IsEmpty() && (aFlags & DISABLE_ZOOM_OUT)) { + // Double-tap-to-zooming uses an empty rect to mean "zoom out". + // If zooming out is disabled, an empty rect is nonsensical + // and will produce undesirable scrolling. + NS_WARNING( + "ZoomToRect got called with an empty rect and zoom out disabled; " + "ignoring..."); + return; + } + + SetState(ANIMATING_ZOOM); + + { + RecursiveMutexAutoLock lock(mRecursiveMutex); + + MOZ_ASSERT(Metrics().IsRootContent()); + + const float defaultZoomInAmount = + StaticPrefs::apz_doubletapzoom_defaultzoomin(); + + ParentLayerRect compositionBounds = Metrics().GetCompositionBounds(); + CSSRect cssPageRect = Metrics().GetScrollableRect(); + CSSPoint scrollOffset = Metrics().GetVisualScrollOffset(); + CSSSize sizeBeforeZoom = Metrics().CalculateCompositedSizeInCssPixels(); + CSSToParentLayerScale currentZoom = Metrics().GetZoom(); + CSSToParentLayerScale targetZoom; + + // The minimum zoom to prevent over-zoom-out. + // If the zoom factor is lower than this (i.e. we are zoomed more into the + // page), then the CSS content rect, in layers pixels, will be smaller than + // the composition bounds. If this happens, we can't fill the target + // composited area with this frame. + const CSSRect cssExpandedPageRect = Metrics().GetExpandedScrollableRect(); + CSSToParentLayerScale localMinZoom( + std::max(compositionBounds.Width() / cssExpandedPageRect.Width(), + compositionBounds.Height() / cssExpandedPageRect.Height())); + + localMinZoom.scale = + clamped(localMinZoom.scale, mZoomConstraints.mMinZoom.scale, + mZoomConstraints.mMaxZoom.scale); + + localMinZoom = std::max(mZoomConstraints.mMinZoom, localMinZoom); + CSSToParentLayerScale localMaxZoom = + std::max(localMinZoom, mZoomConstraints.mMaxZoom); + + if (!rect.IsEmpty()) { + // Intersect the zoom-to-rect to the CSS rect to make sure it fits. + rect = rect.Intersect(cssPageRect); + targetZoom = CSSToParentLayerScale( + std::min(compositionBounds.Width() / rect.Width(), + compositionBounds.Height() / rect.Height())); + if (aFlags & DISABLE_ZOOM_OUT) { + targetZoom = std::max(targetZoom, currentZoom); + } + } + + // 1. If the rect is empty, the content-side logic for handling a double-tap + // requested that we zoom out. + // 2. currentZoom is equal to mZoomConstraints.mMaxZoom and user still + // double-tapping it + // Treat these cases as a request to zoom out as much as possible + // unless cantZoomOutBehavior == ZoomIn and currentZoom + // is equal to localMinZoom and user still double-tapping it, then try to + // zoom in a small amount to provide feedback to the user. + bool zoomOut = false; + // True if we are already zoomed out and we are asked to either stay there + // or zoom out more and cantZoomOutBehavior == ZoomIn. + bool zoomInDefaultAmount = false; + if (aFlags & DISABLE_ZOOM_OUT) { + zoomOut = false; + } else { + if (rect.IsEmpty()) { + if (currentZoom == localMinZoom && + aZoomTarget.cantZoomOutBehavior == CantZoomOutBehavior::ZoomIn && + (defaultZoomInAmount != 1.f)) { + zoomInDefaultAmount = true; + } else { + zoomOut = true; + } + } else if (currentZoom == localMaxZoom && targetZoom >= localMaxZoom) { + zoomOut = true; + } + } + + // already at min zoom and asked to zoom out further + if (!zoomOut && currentZoom == localMinZoom && targetZoom <= localMinZoom && + aZoomTarget.cantZoomOutBehavior == CantZoomOutBehavior::ZoomIn && + (defaultZoomInAmount != 1.f)) { + zoomInDefaultAmount = true; + } + MOZ_ASSERT(!(zoomInDefaultAmount && zoomOut)); + + if (zoomInDefaultAmount) { + targetZoom = + CSSToParentLayerScale(currentZoom.scale * defaultZoomInAmount); + } + + if (zoomOut) { + targetZoom = localMinZoom; + } + + if (aFlags & PAN_INTO_VIEW_ONLY) { + targetZoom = currentZoom; + } else if (aFlags & ONLY_ZOOM_TO_DEFAULT_SCALE) { + CSSToParentLayerScale zoomAtDefaultScale = + Metrics().GetDevPixelsPerCSSPixel() * + LayoutDeviceToParentLayerScale(1.0); + if (targetZoom.scale > zoomAtDefaultScale.scale) { + // Only change the zoom if we are less than the default zoom + if (currentZoom.scale < zoomAtDefaultScale.scale) { + targetZoom = zoomAtDefaultScale; + } else { + targetZoom = currentZoom; + } + } + } + + targetZoom.scale = + clamped(targetZoom.scale, localMinZoom.scale, localMaxZoom.scale); + + FrameMetrics endZoomToMetrics = Metrics(); + endZoomToMetrics.SetZoom(CSSToParentLayerScale(targetZoom)); + CSSSize sizeAfterZoom = + endZoomToMetrics.CalculateCompositedSizeInCssPixels(); + + if (zoomInDefaultAmount || zoomOut) { + // For the zoom out case we should always center what was visible + // otherwise it feels like we are scrolling as well as zooming out. For + // the non-zoomOut case, if we've been provided a pointer location, zoom + // around that, otherwise just zoom in to the center of what's currently + // visible. + if (!zoomOut && aZoomTarget.documentRelativePointerPosition.isSome()) { + rect = CSSRect(aZoomTarget.documentRelativePointerPosition->x - + sizeAfterZoom.width / 2, + aZoomTarget.documentRelativePointerPosition->y - + sizeAfterZoom.height / 2, + sizeAfterZoom.Width(), sizeAfterZoom.Height()); + } else { + rect = CSSRect( + scrollOffset.x + (sizeBeforeZoom.width - sizeAfterZoom.width) / 2, + scrollOffset.y + (sizeBeforeZoom.height - sizeAfterZoom.height) / 2, + sizeAfterZoom.Width(), sizeAfterZoom.Height()); + } + + rect = rect.Intersect(cssPageRect); + } + + // Check if we can fit the full elementBoundingRect. + if (!aZoomTarget.targetRect.IsEmpty() && !zoomOut && + aZoomTarget.elementBoundingRect.isSome()) { + MOZ_ASSERT(aZoomTarget.elementBoundingRect->Contains(rect)); + CSSRect elementBoundingRect = + aZoomTarget.elementBoundingRect->Intersect(cssPageRect); + if (elementBoundingRect.width <= sizeAfterZoom.width && + elementBoundingRect.height <= sizeAfterZoom.height) { + rect = elementBoundingRect; + } + } + + // Vertically center the zoomed element in the screen. + if (!zoomOut && (sizeAfterZoom.height > rect.Height())) { + rect.MoveByY(-(sizeAfterZoom.height - rect.Height()) * 0.5f); + if (rect.Y() < 0.0f) { + rect.MoveToY(0.0f); + } + } + + // Horizontally center the zoomed element in the screen. + if (!zoomOut && (sizeAfterZoom.width > rect.Width())) { + rect.MoveByX(-(sizeAfterZoom.width - rect.Width()) * 0.5f); + if (rect.X() < 0.0f) { + rect.MoveToX(0.0f); + } + } + + bool intersectRectAgain = false; + // If we can't zoom out enough to show the full rect then shift the rect we + // are able to show to center what was visible. + // Note that this calculation works no matter the relation of sizeBeforeZoom + // to sizeAfterZoom, ie whether we are increasing or decreasing zoom. + if (!zoomOut && (sizeAfterZoom.height < rect.Height())) { + rect.y = + scrollOffset.y + (sizeBeforeZoom.height - sizeAfterZoom.height) / 2; + rect.height = sizeAfterZoom.Height(); + + intersectRectAgain = true; + } + + if (!zoomOut && (sizeAfterZoom.width < rect.Width())) { + rect.x = + scrollOffset.x + (sizeBeforeZoom.width - sizeAfterZoom.width) / 2; + rect.width = sizeAfterZoom.Width(); + + intersectRectAgain = true; + } + if (intersectRectAgain) { + rect = rect.Intersect(cssPageRect); + } + + // If any of these conditions are met, the page will be overscrolled after + // zoomed. Attempting to scroll outside of the valid scroll range will cause + // problems. + if (rect.Y() + sizeAfterZoom.height > cssPageRect.YMost()) { + rect.MoveToY(std::max(cssPageRect.Y(), + cssPageRect.YMost() - sizeAfterZoom.height)); + } + if (rect.Y() < cssPageRect.Y()) { + rect.MoveToY(cssPageRect.Y()); + } + if (rect.X() + sizeAfterZoom.width > cssPageRect.XMost()) { + rect.MoveToX( + std::max(cssPageRect.X(), cssPageRect.XMost() - sizeAfterZoom.width)); + } + if (rect.X() < cssPageRect.X()) { + rect.MoveToY(cssPageRect.X()); + } + + endZoomToMetrics.SetVisualScrollOffset(rect.TopLeft()); + endZoomToMetrics.RecalculateLayoutViewportOffset(); + + StartAnimation(do_AddRef(new ZoomAnimation( + *this, Metrics().GetVisualScrollOffset(), Metrics().GetZoom(), + endZoomToMetrics.GetVisualScrollOffset(), endZoomToMetrics.GetZoom()))); + + RequestContentRepaint(RepaintUpdateType::eUserAction); + } +} + +InputBlockState* AsyncPanZoomController::GetCurrentInputBlock() const { + return GetInputQueue()->GetCurrentBlock(); +} + +TouchBlockState* AsyncPanZoomController::GetCurrentTouchBlock() const { + return GetInputQueue()->GetCurrentTouchBlock(); +} + +PanGestureBlockState* AsyncPanZoomController::GetCurrentPanGestureBlock() + const { + return GetInputQueue()->GetCurrentPanGestureBlock(); +} + +PinchGestureBlockState* AsyncPanZoomController::GetCurrentPinchGestureBlock() + const { + return GetInputQueue()->GetCurrentPinchGestureBlock(); +} + +void AsyncPanZoomController::ResetTouchInputState() { + MultiTouchInput cancel(MultiTouchInput::MULTITOUCH_CANCEL, 0, + TimeStamp::Now(), 0); + RefPtr<GestureEventListener> listener = GetGestureEventListener(); + if (listener) { + listener->HandleInputEvent(cancel); + } + CancelAnimationAndGestureState(); + // Clear overscroll along the entire handoff chain, in case an APZC + // later in the chain is overscrolled. + if (TouchBlockState* block = GetCurrentTouchBlock()) { + block->GetOverscrollHandoffChain()->ClearOverscroll(); + } +} + +void AsyncPanZoomController::ResetPanGestureInputState() { + // No point sending a PANGESTURE_INTERRUPTED as all it does is + // call CancelAnimation(), which we also do here. + CancelAnimationAndGestureState(); + // Clear overscroll along the entire handoff chain, in case an APZC + // later in the chain is overscrolled. + if (PanGestureBlockState* block = GetCurrentPanGestureBlock()) { + block->GetOverscrollHandoffChain()->ClearOverscroll(); + } +} + +void AsyncPanZoomController::CancelAnimationAndGestureState() { + mX.CancelGesture(); + mY.CancelGesture(); + CancelAnimation(CancelAnimationFlags::ScrollSnap); +} + +bool AsyncPanZoomController::HasReadyTouchBlock() const { + return GetInputQueue()->HasReadyTouchBlock(); +} + +bool AsyncPanZoomController::CanHandleScrollOffsetUpdate(PanZoomState aState) { + return aState == NOTHING || aState == PAN_MOMENTUM || aState == TOUCHING || + IsPanningState(aState); +} + +bool AsyncPanZoomController::ShouldCancelAnimationForScrollUpdate( + const Maybe<CSSPoint>& aRelativeDelta) { + // Never call CancelAnimation() for a no-op relative update. + if (aRelativeDelta == Some(CSSPoint())) { + return false; + } + + if (mAnimation) { + return !mAnimation->HandleScrollOffsetUpdate(aRelativeDelta); + } + + return !CanHandleScrollOffsetUpdate(mState); +} + +AsyncPanZoomController::PanZoomState +AsyncPanZoomController::SetStateNoContentControllerDispatch( + PanZoomState aNewState) { + RecursiveMutexAutoLock lock(mRecursiveMutex); + APZC_LOG_DETAIL("changing from state %s to %s\n", this, + ToString(mState).c_str(), ToString(aNewState).c_str()); + PanZoomState oldState = mState; + mState = aNewState; + return oldState; +} + +void AsyncPanZoomController::SetState(PanZoomState aNewState) { + // When a state transition to a transforming state is occuring and a delayed + // transform end notification exists, send the TransformEnd notification + // before the TransformBegin notification is sent for the input state change. + if (IsTransformingState(aNewState) && IsDelayedTransformEndSet()) { + MOZ_ASSERT(!IsTransformingState(mState)); + SetDelayedTransformEnd(false); + DispatchStateChangeNotification(PANNING, NOTHING); + } + + PanZoomState oldState = SetStateNoContentControllerDispatch(aNewState); + + DispatchStateChangeNotification(oldState, aNewState); +} + +auto AsyncPanZoomController::GetState() const -> PanZoomState { + RecursiveMutexAutoLock lock(mRecursiveMutex); + return mState; +} + +void AsyncPanZoomController::DispatchStateChangeNotification( + PanZoomState aOldState, PanZoomState aNewState) { + { // scope the lock + RecursiveMutexAutoLock lock(mRecursiveMutex); + if (mNotificationBlockers > 0) { + return; + } + } + + if (RefPtr<GeckoContentController> controller = GetGeckoContentController()) { + if (!IsTransformingState(aOldState) && IsTransformingState(aNewState)) { + controller->NotifyAPZStateChange(GetGuid(), + APZStateChange::eTransformBegin); + } else if (IsTransformingState(aOldState) && + !IsTransformingState(aNewState)) { + controller->NotifyAPZStateChange(GetGuid(), + APZStateChange::eTransformEnd); + } + } +} +void AsyncPanZoomController::SendTransformBeginAndEnd() { + RefPtr<GeckoContentController> controller = GetGeckoContentController(); + if (controller) { + controller->NotifyAPZStateChange(GetGuid(), + APZStateChange::eTransformBegin); + controller->NotifyAPZStateChange(GetGuid(), APZStateChange::eTransformEnd); + } +} + +bool AsyncPanZoomController::IsInTransformingState() const { + RecursiveMutexAutoLock lock(mRecursiveMutex); + return IsTransformingState(mState); +} + +bool AsyncPanZoomController::IsTransformingState(PanZoomState aState) { + return !(aState == NOTHING || aState == TOUCHING); +} + +bool AsyncPanZoomController::IsPanningState(PanZoomState aState) { + return (aState == PANNING || aState == PANNING_LOCKED_X || + aState == PANNING_LOCKED_Y); +} + +bool AsyncPanZoomController::IsInPanningState() const { + return IsPanningState(mState); +} + +bool AsyncPanZoomController::IsInScrollingGesture() const { + return IsPanningState(mState) || mState == SCROLLBAR_DRAG || + mState == TOUCHING || mState == PINCHING; +} + +bool AsyncPanZoomController::IsDelayedTransformEndSet() { + RecursiveMutexAutoLock lock(mRecursiveMutex); + return mDelayedTransformEnd; +} + +void AsyncPanZoomController::SetDelayedTransformEnd(bool aDelayedTransformEnd) { + RecursiveMutexAutoLock lock(mRecursiveMutex); + mDelayedTransformEnd = aDelayedTransformEnd; +} + +void AsyncPanZoomController::UpdateZoomConstraints( + const ZoomConstraints& aConstraints) { + if ((MOZ_LOG_TEST(sApzCtlLog, LogLevel::Debug) && + (aConstraints != mZoomConstraints)) || + MOZ_LOG_TEST(sApzCtlLog, LogLevel::Verbose)) { + APZC_LOG("%p updating zoom constraints to %d %d %f %f\n", this, + aConstraints.mAllowZoom, aConstraints.mAllowDoubleTapZoom, + aConstraints.mMinZoom.scale, aConstraints.mMaxZoom.scale); + } + + if (std::isnan(aConstraints.mMinZoom.scale) || + std::isnan(aConstraints.mMaxZoom.scale)) { + NS_WARNING("APZC received zoom constraints with NaN values; dropping..."); + return; + } + + RecursiveMutexAutoLock lock(mRecursiveMutex); + CSSToParentLayerScale min = Metrics().GetDevPixelsPerCSSPixel() * + ViewportMinScale() / ParentLayerToScreenScale(1); + CSSToParentLayerScale max = Metrics().GetDevPixelsPerCSSPixel() * + ViewportMaxScale() / ParentLayerToScreenScale(1); + + // inf float values and other bad cases should be sanitized by the code below. + mZoomConstraints.mAllowZoom = aConstraints.mAllowZoom; + mZoomConstraints.mAllowDoubleTapZoom = aConstraints.mAllowDoubleTapZoom; + mZoomConstraints.mMinZoom = + (min > aConstraints.mMinZoom ? min : aConstraints.mMinZoom); + mZoomConstraints.mMaxZoom = + (max > aConstraints.mMaxZoom ? aConstraints.mMaxZoom : max); + if (mZoomConstraints.mMaxZoom < mZoomConstraints.mMinZoom) { + mZoomConstraints.mMaxZoom = mZoomConstraints.mMinZoom; + } +} + +bool AsyncPanZoomController::ZoomConstraintsAllowZoom() const { + RecursiveMutexAutoLock lock(mRecursiveMutex); + return mZoomConstraints.mAllowZoom; +} + +bool AsyncPanZoomController::ZoomConstraintsAllowDoubleTapZoom() const { + RecursiveMutexAutoLock lock(mRecursiveMutex); + return mZoomConstraints.mAllowDoubleTapZoom; +} + +void AsyncPanZoomController::PostDelayedTask(already_AddRefed<Runnable> aTask, + int aDelayMs) { + APZThreadUtils::AssertOnControllerThread(); + RefPtr<Runnable> task = aTask; + RefPtr<GeckoContentController> controller = GetGeckoContentController(); + if (controller) { + controller->PostDelayedTask(task.forget(), aDelayMs); + } + // If there is no controller, that means this APZC has been destroyed, and + // we probably don't need to run the task. It will get destroyed when the + // RefPtr goes out of scope. +} + +bool AsyncPanZoomController::Matches(const ScrollableLayerGuid& aGuid) { + return aGuid == GetGuid(); +} + +bool AsyncPanZoomController::HasTreeManager( + const APZCTreeManager* aTreeManager) const { + return GetApzcTreeManager() == aTreeManager; +} + +void AsyncPanZoomController::GetGuid(ScrollableLayerGuid* aGuidOut) const { + if (aGuidOut) { + *aGuidOut = GetGuid(); + } +} + +ScrollableLayerGuid AsyncPanZoomController::GetGuid() const { + RecursiveMutexAutoLock lock(mRecursiveMutex); + return ScrollableLayerGuid(mLayersId, Metrics().GetPresShellId(), + Metrics().GetScrollId()); +} + +void AsyncPanZoomController::SetTestAsyncScrollOffset(const CSSPoint& aPoint) { + RecursiveMutexAutoLock lock(mRecursiveMutex); + mTestAsyncScrollOffset = aPoint; + ScheduleComposite(); +} + +void AsyncPanZoomController::SetTestAsyncZoom( + const LayerToParentLayerScale& aZoom) { + RecursiveMutexAutoLock lock(mRecursiveMutex); + mTestAsyncZoom = aZoom; + ScheduleComposite(); +} + +Maybe<CSSSnapDestination> AsyncPanZoomController::FindSnapPointNear( + const CSSPoint& aDestination, ScrollUnit aUnit, + ScrollSnapFlags aSnapFlags) { + mRecursiveMutex.AssertCurrentThreadIn(); + APZC_LOG("%p scroll snapping near %s\n", this, + ToString(aDestination).c_str()); + CSSRect scrollRange = Metrics().CalculateScrollRange(); + if (auto snapDestination = ScrollSnapUtils::GetSnapPointForDestination( + mScrollMetadata.GetSnapInfo(), aUnit, aSnapFlags, + CSSRect::ToAppUnits(scrollRange), + CSSPoint::ToAppUnits(Metrics().GetVisualScrollOffset()), + CSSPoint::ToAppUnits(aDestination))) { + CSSPoint cssSnapPoint = CSSPoint::FromAppUnits(snapDestination->mPosition); + // GetSnapPointForDestination() can produce a destination that's outside + // of the scroll frame's scroll range. Clamp it here (this matches the + // behaviour of the main-thread code path, which clamps it in + // nsGfxScrollFrame::ScrollTo()). + return Some(CSSSnapDestination{scrollRange.ClampPoint(cssSnapPoint), + snapDestination->mTargetIds}); + } + return Nothing(); +} + +Maybe<std::pair<MultiTouchInput, MultiTouchInput>> +AsyncPanZoomController::MaybeSplitTouchMoveEvent( + const MultiTouchInput& aOriginalEvent, ScreenCoord aPanThreshold, + float aVectorLength, ExternalPoint& aExtPoint) { + if (aVectorLength <= aPanThreshold) { + return Nothing(); + } + + auto splitEvent = std::make_pair(aOriginalEvent, aOriginalEvent); + + SingleTouchData& firstTouchData = splitEvent.first.mTouches[0]; + SingleTouchData& secondTouchData = splitEvent.second.mTouches[0]; + + firstTouchData.mHistoricalData.Clear(); + secondTouchData.mHistoricalData.Clear(); + + ExternalPoint destination = aExtPoint; + ExternalPoint thresholdPosition; + + const float ratio = aPanThreshold / aVectorLength; + thresholdPosition.x = mStartTouch.x + ratio * (destination.x - mStartTouch.x); + thresholdPosition.y = mStartTouch.y + ratio * (destination.y - mStartTouch.y); + + TouchSample start{mLastTouch}; + // To compute the timestamp of the first event (which is at the threshold), + // use linear interpolation with the starting point |start| being the last + // event that's before the threshold, and the end point |end| being the first + // event after the threshold. + + // The initial choice for |start| is the last touch event before + // |aOriginalEvent|, and the initial choice for |end| is |aOriginalEvent|. + + // However, the historical data points stored in |aOriginalEvent| may contain + // intermediate positions that can serve as tighter bounds for the + // interpolation. + TouchSample end{destination, aOriginalEvent.mTimeStamp}; + + for (const auto& historicalData : + aOriginalEvent.mTouches[0].mHistoricalData) { + ExternalPoint histExtPoint = ToExternalPoint(aOriginalEvent.mScreenOffset, + historicalData.mScreenPoint); + + if (PanVector(histExtPoint).Length() < + PanVector(thresholdPosition).Length()) { + start = {histExtPoint, historicalData.mTimeStamp}; + } else { + break; + } + } + + for (const SingleTouchData::HistoricalTouchData& histData : + Reversed(aOriginalEvent.mTouches[0].mHistoricalData)) { + ExternalPoint histExtPoint = + ToExternalPoint(aOriginalEvent.mScreenOffset, histData.mScreenPoint); + + if (PanVector(histExtPoint).Length() > + PanVector(thresholdPosition).Length()) { + end = {histExtPoint, histData.mTimeStamp}; + } else { + break; + } + } + + const float totalLength = + ScreenPoint(fabs(end.mPosition.x - start.mPosition.x), + fabs(end.mPosition.y - start.mPosition.y)) + .Length(); + const float thresholdLength = + ScreenPoint(fabs(thresholdPosition.x - start.mPosition.x), + fabs(thresholdPosition.y - start.mPosition.y)) + .Length(); + const float splitRatio = thresholdLength / totalLength; + + splitEvent.first.mTimeStamp = + start.mTimeStamp + + (end.mTimeStamp - start.mTimeStamp).MultDouble(splitRatio); + + for (const auto& historicalData : + aOriginalEvent.mTouches[0].mHistoricalData) { + if (historicalData.mTimeStamp > splitEvent.first.mTimeStamp) { + secondTouchData.mHistoricalData.AppendElement(historicalData); + } else { + firstTouchData.mHistoricalData.AppendElement(historicalData); + } + } + + firstTouchData.mScreenPoint = RoundedToInt( + ViewAs<ScreenPixel>(thresholdPosition - splitEvent.first.mScreenOffset, + PixelCastJustification::ExternalIsScreen)); + + // Recompute firstTouchData.mLocalScreenPoint. + splitEvent.first.TransformToLocal(GetTransformToThis()); + + // Pass |thresholdPosition| back out to the caller via |aExtPoint| + aExtPoint = thresholdPosition; + + return Some(splitEvent); +} + +void AsyncPanZoomController::ScrollSnapNear(const CSSPoint& aDestination, + ScrollSnapFlags aSnapFlags) { + if (Maybe<CSSSnapDestination> snapDestination = FindSnapPointNear( + aDestination, ScrollUnit::DEVICE_PIXELS, aSnapFlags)) { + if (snapDestination->mPosition != Metrics().GetVisualScrollOffset()) { + APZC_LOG("%p smooth scrolling to snap point %s\n", this, + ToString(snapDestination->mPosition).c_str()); + SmoothMsdScrollTo(std::move(*snapDestination), + ScrollTriggeredByScript::No); + } + } +} + +void AsyncPanZoomController::ScrollSnap(ScrollSnapFlags aSnapFlags) { + RecursiveMutexAutoLock lock(mRecursiveMutex); + ScrollSnapNear(Metrics().GetVisualScrollOffset(), aSnapFlags); +} + +void AsyncPanZoomController::ScrollSnapToDestination() { + RecursiveMutexAutoLock lock(mRecursiveMutex); + + float friction = StaticPrefs::apz_fling_friction(); + ParentLayerPoint velocity(mX.GetVelocity(), mY.GetVelocity()); + ParentLayerPoint predictedDelta; + // "-velocity / log(1.0 - friction)" is the integral of the deceleration + // curve modeled for flings in the "Axis" class. + if (velocity.x != 0.0f && friction != 0.0f) { + predictedDelta.x = -velocity.x / log(1.0 - friction); + } + if (velocity.y != 0.0f && friction != 0.0f) { + predictedDelta.y = -velocity.y / log(1.0 - friction); + } + + // If the fling will overscroll, don't scroll snap, because then the user + // user would not see any overscroll animation. + bool flingWillOverscroll = + IsOverscrolled() && ((velocity.x.value * mX.GetOverscroll() >= 0) || + (velocity.y.value * mY.GetOverscroll() >= 0)); + if (flingWillOverscroll) { + return; + } + + CSSPoint startPosition = Metrics().GetVisualScrollOffset(); + ScrollSnapFlags snapFlags = ScrollSnapFlags::IntendedEndPosition; + if (predictedDelta != ParentLayerPoint()) { + snapFlags |= ScrollSnapFlags::IntendedDirection; + } + if (Maybe<CSSSnapDestination> snapDestination = + MaybeAdjustDeltaForScrollSnapping(ScrollUnit::DEVICE_PIXELS, + snapFlags, predictedDelta, + startPosition)) { + APZC_LOG( + "%p fling snapping. friction: %f velocity: %f, %f " + "predictedDelta: %f, %f position: %f, %f " + "snapDestination: %f, %f\n", + this, friction, velocity.x.value, velocity.y.value, + predictedDelta.x.value, predictedDelta.y.value, + Metrics().GetVisualScrollOffset().x.value, + Metrics().GetVisualScrollOffset().y.value, startPosition.x.value, + startPosition.y.value); + + // Ensure that any queued transform-end due to a pan-end is not + // sent. Instead rely on the transform-end sent due to the + // scroll snap animation. + SetDelayedTransformEnd(false); + + SmoothMsdScrollTo(std::move(*snapDestination), ScrollTriggeredByScript::No); + } +} + +Maybe<CSSSnapDestination> +AsyncPanZoomController::MaybeAdjustDeltaForScrollSnapping( + ScrollUnit aUnit, ScrollSnapFlags aSnapFlags, ParentLayerPoint& aDelta, + CSSPoint& aStartPosition) { + RecursiveMutexAutoLock lock(mRecursiveMutex); + CSSToParentLayerScale zoom = Metrics().GetZoom(); + if (zoom == CSSToParentLayerScale(0)) { + return Nothing(); + } + CSSPoint destination = Metrics().CalculateScrollRange().ClampPoint( + aStartPosition + (aDelta / zoom)); + + if (Maybe<CSSSnapDestination> snapDestination = + FindSnapPointNear(destination, aUnit, aSnapFlags)) { + aDelta = (snapDestination->mPosition - aStartPosition) * zoom; + aStartPosition = snapDestination->mPosition; + return snapDestination; + } + return Nothing(); +} + +Maybe<CSSSnapDestination> +AsyncPanZoomController::MaybeAdjustDeltaForScrollSnappingOnWheelInput( + const ScrollWheelInput& aEvent, ParentLayerPoint& aDelta, + CSSPoint& aStartPosition) { + // Don't scroll snap for pixel scrolls. This matches the main thread + // behaviour in EventStateManager::DoScrollText(). + if (aEvent.mDeltaType == ScrollWheelInput::SCROLLDELTA_PIXEL) { + return Nothing(); + } + + // Note that this MaybeAdjustDeltaForScrollSnappingOnWheelInput also gets + // called for pan gestures at least on older Mac and Windows. In such cases + // `aEvent.mDeltaType` is `SCROLLDELTA_PIXEL` which should be filtered out by + // the above `if` block, so we assume all incoming `aEvent` are purely wheel + // events, thus we basically use `IntendedDirection` here. + // If we want to change the behavior, i.e. we want to do scroll snap for + // such cases as well, we need to use `IntendedEndPoint`. + ScrollSnapFlags snapFlags = ScrollSnapFlags::IntendedDirection; + if (aEvent.mDeltaType == ScrollWheelInput::SCROLLDELTA_PAGE) { + // On Windows there are a couple of cases where scroll events happen with + // SCROLLDELTA_PAGE, in such case we consider it's a page scroll. + snapFlags |= ScrollSnapFlags::IntendedEndPosition; + } + return MaybeAdjustDeltaForScrollSnapping( + ScrollWheelInput::ScrollUnitForDeltaType(aEvent.mDeltaType), + ScrollSnapFlags::IntendedDirection, aDelta, aStartPosition); +} + +Maybe<CSSSnapDestination> +AsyncPanZoomController::MaybeAdjustDestinationForScrollSnapping( + const KeyboardInput& aEvent, CSSPoint& aDestination, + ScrollSnapFlags aSnapFlags) { + RecursiveMutexAutoLock lock(mRecursiveMutex); + ScrollUnit unit = KeyboardScrollAction::GetScrollUnit(aEvent.mAction.mType); + + if (Maybe<CSSSnapDestination> snapPoint = + FindSnapPointNear(aDestination, unit, aSnapFlags)) { + aDestination = snapPoint->mPosition; + return snapPoint; + } + return Nothing(); +} + +void AsyncPanZoomController::SetZoomAnimationId( + const Maybe<uint64_t>& aZoomAnimationId) { + RecursiveMutexAutoLock lock(mRecursiveMutex); + mZoomAnimationId = aZoomAnimationId; +} + +Maybe<uint64_t> AsyncPanZoomController::GetZoomAnimationId() const { + RecursiveMutexAutoLock lock(mRecursiveMutex); + return mZoomAnimationId; +} + +std::ostream& operator<<(std::ostream& aOut, + const AsyncPanZoomController::PanZoomState& aState) { + switch (aState) { + case AsyncPanZoomController::PanZoomState::NOTHING: + aOut << "NOTHING"; + break; + case AsyncPanZoomController::PanZoomState::FLING: + aOut << "FLING"; + break; + case AsyncPanZoomController::PanZoomState::TOUCHING: + aOut << "TOUCHING"; + break; + case AsyncPanZoomController::PanZoomState::PANNING: + aOut << "PANNING"; + break; + case AsyncPanZoomController::PanZoomState::PANNING_LOCKED_X: + aOut << "PANNING_LOCKED_X"; + break; + case AsyncPanZoomController::PanZoomState::PANNING_LOCKED_Y: + aOut << "PANNING_LOCKED_Y"; + break; + case AsyncPanZoomController::PanZoomState::PAN_MOMENTUM: + aOut << "PAN_MOMENTUM"; + break; + case AsyncPanZoomController::PanZoomState::PINCHING: + aOut << "PINCHING"; + break; + case AsyncPanZoomController::PanZoomState::ANIMATING_ZOOM: + aOut << "ANIMATING_ZOOM"; + break; + case AsyncPanZoomController::PanZoomState::OVERSCROLL_ANIMATION: + aOut << "OVERSCROLL_ANIMATION"; + break; + case AsyncPanZoomController::PanZoomState::SMOOTH_SCROLL: + aOut << "SMOOTH_SCROLL"; + break; + case AsyncPanZoomController::PanZoomState::SMOOTHMSD_SCROLL: + aOut << "SMOOTHMSD_SCROLL"; + break; + case AsyncPanZoomController::PanZoomState::WHEEL_SCROLL: + aOut << "WHEEL_SCROLL"; + break; + case AsyncPanZoomController::PanZoomState::KEYBOARD_SCROLL: + aOut << "KEYBOARD_SCROLL"; + break; + case AsyncPanZoomController::PanZoomState::AUTOSCROLL: + aOut << "AUTOSCROLL"; + break; + case AsyncPanZoomController::PanZoomState::SCROLLBAR_DRAG: + aOut << "SCROLLBAR_DRAG"; + break; + default: + aOut << "UNKNOWN_STATE"; + break; + } + return aOut; +} + +bool operator==(const PointerEventsConsumableFlags& aLhs, + const PointerEventsConsumableFlags& aRhs) { + return (aLhs.mHasRoom == aRhs.mHasRoom) && + (aLhs.mAllowedByTouchAction == aRhs.mAllowedByTouchAction); +} + +std::ostream& operator<<(std::ostream& aOut, + const PointerEventsConsumableFlags& aFlags) { + aOut << std::boolalpha << "{ hasRoom: " << aFlags.mHasRoom + << ", allowedByTouchAction: " << aFlags.mAllowedByTouchAction << "}"; + return aOut; +} + +} // namespace layers +} // namespace mozilla |