Adding upstream version 124.0.1.upstream/124.0.1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 272 insertions, 0 deletions

diff --git a/widget/SwipeTracker.cpp b/widget/SwipeTracker.cpp
new file mode 100644
index 0000000000..7474432e71
--- /dev/null
+++ b/widget/SwipeTracker.cpp
@@ -0,0 +1,272 @@
+/* -*- 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 "SwipeTracker.h"
+
+#include "InputData.h"
+#include "mozilla/FlushType.h"
+#include "mozilla/PresShell.h"
+#include "mozilla/StaticPrefs_widget.h"
+#include "mozilla/StaticPrefs_browser.h"
+#include "mozilla/TimeStamp.h"
+#include "mozilla/TouchEvents.h"
+#include "mozilla/dom/SimpleGestureEventBinding.h"
+#include "nsAlgorithm.h"
+#include "nsIWidget.h"
+#include "nsRefreshDriver.h"
+#include "UnitTransforms.h"
+
+// These values were tweaked to make the physics feel similar to the native
+// swipe.
+static const double kSpringForce = 250.0;
+static const double kSwipeSuccessThreshold = 0.25;
+
+namespace mozilla {
+
+static already_AddRefed<nsRefreshDriver> GetRefreshDriver(nsIWidget& aWidget) {
+  nsIWidgetListener* widgetListener = aWidget.GetWidgetListener();
+  PresShell* presShell =
+      widgetListener ? widgetListener->GetPresShell() : nullptr;
+  nsPresContext* presContext =
+      presShell ? presShell->GetPresContext() : nullptr;
+  RefPtr<nsRefreshDriver> refreshDriver =
+      presContext ? presContext->RefreshDriver() : nullptr;
+  return refreshDriver.forget();
+}
+
+SwipeTracker::SwipeTracker(nsIWidget& aWidget,
+                           const PanGestureInput& aSwipeStartEvent,
+                           uint32_t aAllowedDirections,
+                           uint32_t aSwipeDirection)
+    : mWidget(aWidget),
+      mRefreshDriver(GetRefreshDriver(mWidget)),
+      mAxis(0.0, 0.0, 0.0, kSpringForce, 1.0),
+      mEventPosition(RoundedToInt(ViewAs<LayoutDevicePixel>(
+          aSwipeStartEvent.mPanStartPoint,
+          PixelCastJustification::LayoutDeviceIsScreenForUntransformedEvent))),
+      mLastEventTimeStamp(aSwipeStartEvent.mTimeStamp),
+      mAllowedDirections(aAllowedDirections),
+      mSwipeDirection(aSwipeDirection) {
+  SendSwipeEvent(eSwipeGestureStart, 0, 0.0, aSwipeStartEvent.mTimeStamp);
+  ProcessEvent(aSwipeStartEvent, /* aProcessingFirstEvent = */ true);
+}
+
+void SwipeTracker::Destroy() { UnregisterFromRefreshDriver(); }
+
+SwipeTracker::~SwipeTracker() {
+  MOZ_RELEASE_ASSERT(!mRegisteredWithRefreshDriver,
+                     "Destroy needs to be called before deallocating");
+}
+
+double SwipeTracker::SwipeSuccessTargetValue() const {
+  return mSwipeDirection == dom::SimpleGestureEvent_Binding::DIRECTION_RIGHT
+             ? -1.0
+             : 1.0;
+}
+
+double SwipeTracker::ClampToAllowedRange(double aGestureAmount) const {
+  // gestureAmount needs to stay between -1 and 0 when swiping right and
+  // between 0 and 1 when swiping left.
+  double min =
+      mSwipeDirection == dom::SimpleGestureEvent_Binding::DIRECTION_RIGHT ? -1.0
+                                                                          : 0.0;
+  double max =
+      mSwipeDirection == dom::SimpleGestureEvent_Binding::DIRECTION_LEFT ? 1.0
+                                                                         : 0.0;
+  return clamped(aGestureAmount, min, max);
+}
+
+bool SwipeTracker::ComputeSwipeSuccess() const {
+  double targetValue = SwipeSuccessTargetValue();
+
+  // If the fingers were moving away from the target direction when they were
+  // lifted from the touchpad, abort the swipe.
+  if (mCurrentVelocity * targetValue <
+      -StaticPrefs::widget_swipe_velocity_twitch_tolerance()) {
+    return false;
+  }
+
+  return (mGestureAmount * targetValue +
+          mCurrentVelocity * targetValue *
+              StaticPrefs::widget_swipe_success_velocity_contribution()) >=
+         kSwipeSuccessThreshold;
+}
+
+nsEventStatus SwipeTracker::ProcessEvent(
+    const PanGestureInput& aEvent, bool aProcessingFirstEvent /* = false */) {
+  // If the fingers have already been lifted or the swipe direction is where
+  // navigation is impossible, don't process this event for swiping.
+  if (!mEventsAreControllingSwipe || !SwipingInAllowedDirection()) {
+    // Return nsEventStatus_eConsumeNoDefault for events from the swipe gesture
+    // and nsEventStatus_eIgnore for events of subsequent scroll gestures.
+    if (aEvent.mType == PanGestureInput::PANGESTURE_MAYSTART ||
+        aEvent.mType == PanGestureInput::PANGESTURE_START) {
+      mEventsHaveStartedNewGesture = true;
+    }
+    return mEventsHaveStartedNewGesture ? nsEventStatus_eIgnore
+                                        : nsEventStatus_eConsumeNoDefault;
+  }
+
+  mDeltaTypeIsPage = aEvent.mDeltaType == PanGestureInput::PANDELTA_PAGE;
+  double delta = [&]() -> double {
+    if (mDeltaTypeIsPage) {
+      return -aEvent.mPanDisplacement.x / StaticPrefs::widget_swipe_page_size();
+    }
+    return -aEvent.mPanDisplacement.x / mWidget.GetDefaultScaleInternal() /
+           StaticPrefs::widget_swipe_pixel_size();
+  }();
+
+  mGestureAmount = ClampToAllowedRange(mGestureAmount + delta);
+  if (aEvent.mType != PanGestureInput::PANGESTURE_END) {
+    if (!aProcessingFirstEvent) {
+      double elapsedSeconds = std::max(
+          0.008, (aEvent.mTimeStamp - mLastEventTimeStamp).ToSeconds());
+      mCurrentVelocity = delta / elapsedSeconds;
+    }
+    mLastEventTimeStamp = aEvent.mTimeStamp;
+  }
+
+  const bool computedSwipeSuccess = ComputeSwipeSuccess();
+  double eventAmount = mGestureAmount;
+  // If ComputeSwipeSuccess returned false because the users fingers were
+  // moving slightly away from the target direction then we do not want to
+  // display the UI as if we were at the success threshold as that would
+  // give a false indication that navigation would happen.
+  if (!computedSwipeSuccess && (eventAmount >= kSwipeSuccessThreshold ||
+                                eventAmount <= -kSwipeSuccessThreshold)) {
+    eventAmount = 0.999 * kSwipeSuccessThreshold;
+    if (mGestureAmount < 0.f) {
+      eventAmount = -eventAmount;
+    }
+  }
+
+  SendSwipeEvent(eSwipeGestureUpdate, 0, eventAmount, aEvent.mTimeStamp);
+
+  if (aEvent.mType == PanGestureInput::PANGESTURE_END) {
+    mEventsAreControllingSwipe = false;
+    if (computedSwipeSuccess) {
+      // Let's use same timestamp as previous event because this is caused by
+      // the preceding event.
+      SendSwipeEvent(eSwipeGesture, mSwipeDirection, 0.0, aEvent.mTimeStamp);
+      UnregisterFromRefreshDriver();
+      NS_DispatchToMainThread(
+          NS_NewRunnableFunction("SwipeTracker::SwipeFinished",
+                                 [swipeTracker = RefPtr<SwipeTracker>(this),
+                                  timeStamp = aEvent.mTimeStamp] {
+                                   swipeTracker->SwipeFinished(timeStamp);
+                                 }));
+    } else {
+      StartAnimating(eventAmount, 0.0);
+    }
+  }
+
+  return nsEventStatus_eConsumeNoDefault;
+}
+
+void SwipeTracker::StartAnimating(double aStartValue, double aTargetValue) {
+  mAxis.SetPosition(aStartValue);
+  mAxis.SetDestination(aTargetValue);
+  mAxis.SetVelocity(mCurrentVelocity);
+
+  mLastAnimationFrameTime = TimeStamp::Now();
+
+  // Add ourselves as a refresh driver observer. The refresh driver
+  // will call WillRefresh for each animation frame until we
+  // unregister ourselves.
+  MOZ_RELEASE_ASSERT(!mRegisteredWithRefreshDriver,
+                     "We only want a single refresh driver registration");
+  if (mRefreshDriver) {
+    mRefreshDriver->AddRefreshObserver(this, FlushType::Style,
+                                       "Swipe animation");
+    mRegisteredWithRefreshDriver = true;
+  }
+}
+
+void SwipeTracker::WillRefresh(TimeStamp aTime) {
+  // FIXME(emilio): shouldn't we be using `aTime`?
+  TimeStamp now = TimeStamp::Now();
+  mAxis.Simulate(now - mLastAnimationFrameTime);
+  mLastAnimationFrameTime = now;
+
+  const double wholeSize = mDeltaTypeIsPage
+                               ? StaticPrefs::widget_swipe_page_size()
+                               : StaticPrefs::widget_swipe_pixel_size();
+  // NOTE(emilio): It's unclear this makes sense for page-based swiping, but
+  // this preserves behavior and all platforms probably will end up converging
+  // in pixel-based pan input, so...
+  const double minIncrement = 1.0 / wholeSize;
+  const bool isFinished = mAxis.IsFinished(minIncrement);
+
+  mGestureAmount = isFinished ? mAxis.GetDestination() : mAxis.GetPosition();
+  SendSwipeEvent(eSwipeGestureUpdate, 0, mGestureAmount, now);
+
+  if (isFinished) {
+    UnregisterFromRefreshDriver();
+    SwipeFinished(now);
+  }
+}
+
+void SwipeTracker::CancelSwipe(const TimeStamp& aTimeStamp) {
+  SendSwipeEvent(eSwipeGestureEnd, 0, 0.0, aTimeStamp);
+}
+
+void SwipeTracker::SwipeFinished(const TimeStamp& aTimeStamp) {
+  SendSwipeEvent(eSwipeGestureEnd, 0, 0.0, aTimeStamp);
+  mWidget.SwipeFinished();
+}
+
+void SwipeTracker::UnregisterFromRefreshDriver() {
+  if (mRegisteredWithRefreshDriver) {
+    MOZ_ASSERT(mRefreshDriver, "How were we able to register, then?");
+    mRefreshDriver->RemoveRefreshObserver(this, FlushType::Style);
+    mRegisteredWithRefreshDriver = false;
+  }
+}
+
+/* static */ WidgetSimpleGestureEvent SwipeTracker::CreateSwipeGestureEvent(
+    EventMessage aMsg, nsIWidget* aWidget,
+    const LayoutDeviceIntPoint& aPosition, const TimeStamp& aTimeStamp) {
+  // XXX Why isn't this initialized with nsCocoaUtils::InitInputEvent()?
+  WidgetSimpleGestureEvent geckoEvent(true, aMsg, aWidget);
+  geckoEvent.mModifiers = 0;
+  // XXX How about geckoEvent.mTime?
+  geckoEvent.mTimeStamp = aTimeStamp;
+  geckoEvent.mRefPoint = aPosition;
+  geckoEvent.mButtons = 0;
+  return geckoEvent;
+}
+
+bool SwipeTracker::SendSwipeEvent(EventMessage aMsg, uint32_t aDirection,
+                                  double aDelta, const TimeStamp& aTimeStamp) {
+  WidgetSimpleGestureEvent geckoEvent =
+      CreateSwipeGestureEvent(aMsg, &mWidget, mEventPosition, aTimeStamp);
+  geckoEvent.mDirection = aDirection;
+  geckoEvent.mDelta = aDelta;
+  geckoEvent.mAllowedDirections = mAllowedDirections;
+  return mWidget.DispatchWindowEvent(geckoEvent);
+}
+
+// static
+bool SwipeTracker::CanTriggerSwipe(const PanGestureInput& aPanInput) {
+  if (StaticPrefs::widget_disable_swipe_tracker()) {
+    return false;
+  }
+
+  if (aPanInput.mType != PanGestureInput::PANGESTURE_START) {
+    return false;
+  }
+
+  // Only initiate horizontal tracking for events whose horizontal element is
+  // at least eight times larger than its vertical element. This minimizes
+  // performance problems with vertical scrolls (by minimizing the possibility
+  // that they'll be misinterpreted as horizontal swipes), while still
+  // tolerating a small vertical element to a true horizontal swipe.  The number
+  // '8' was arrived at by trial and error.
+  return std::abs(aPanInput.mPanDisplacement.x) >
+         std::abs(aPanInput.mPanDisplacement.y) * 8;
+}
+
+}  // namespace mozilla