1 files changed, 197 insertions, 0 deletions
diff --git a/gfx/layers/apz/util/APZCCallbackHelper.h b/gfx/layers/apz/util/APZCCallbackHelper.h
new file mode 100644
index 0000000000..c04bae88d2
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+++ b/gfx/layers/apz/util/APZCCallbackHelper.h
@@ -0,0 +1,197 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* 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/. */
+
+#ifndef mozilla_layers_APZCCallbackHelper_h
+#define mozilla_layers_APZCCallbackHelper_h
+
+#include "InputData.h"
+#include "LayersTypes.h"
+#include "Units.h"
+#include "mozilla/EventForwards.h"
+#include "mozilla/layers/MatrixMessage.h"
+#include "nsRefreshObservers.h"
+
+#include <functional>
+
+class nsIContent;
+class nsIScrollableFrame;
+class nsIWidget;
+class nsPresContext;
+template <class T>
+struct already_AddRefed;
+template <class T>
+class nsCOMPtr;
+
+namespace mozilla {
+
+class PresShell;
+enum class PreventDefaultResult : uint8_t;
+
+namespace layers {
+
+struct RepaintRequest;
+
+/* Refer to documentation on SendSetTargetAPZCNotification for this class */
+class DisplayportSetListener : public ManagedPostRefreshObserver {
+ public:
+  DisplayportSetListener(nsIWidget* aWidget, nsPresContext*,
+                         const uint64_t& aInputBlockId,
+                         nsTArray<ScrollableLayerGuid>&& aTargets);
+  virtual ~DisplayportSetListener();
+  void Register();
+
+ private:
+  RefPtr<nsIWidget> mWidget;
+  uint64_t mInputBlockId;
+  nsTArray<ScrollableLayerGuid> mTargets;
+
+  void OnPostRefresh();
+};
+
+/* This class contains some helper methods that facilitate implementing the
+   GeckoContentController callback interface required by the
+   AsyncPanZoomController. Since different platforms need to implement this
+   interface in similar-but- not-quite-the-same ways, this utility class
+   provides some helpful methods to hold code that can be shared across the
+   different platform implementations.
+ */
+class APZCCallbackHelper {
+  typedef mozilla::layers::ScrollableLayerGuid ScrollableLayerGuid;
+
+ public:
+  static void NotifyLayerTransforms(const nsTArray<MatrixMessage>& aTransforms);
+
+  /* Applies the scroll and zoom parameters from the given RepaintRequest object
+     to the root frame for the given metrics' scrollId. If tiled thebes layers
+     are enabled, this will align the displayport to tile boundaries. Setting
+     the scroll position can cause some small adjustments to be made to the
+     actual scroll position. */
+  static void UpdateRootFrame(const RepaintRequest& aRequest);
+
+  /* Applies the scroll parameters from the given RepaintRequest object to the
+     subframe corresponding to given metrics' scrollId. If tiled thebes
+     layers are enabled, this will align the displayport to tile boundaries.
+     Setting the scroll position can cause some small adjustments to be made
+     to the actual scroll position. */
+  static void UpdateSubFrame(const RepaintRequest& aRequest);
+
+  /* Get the presShellId and view ID for the given content element.
+   * If the view ID does not exist, one is created.
+   * The pres shell ID should generally already exist; if it doesn't for some
+   * reason, false is returned. */
+  static bool GetOrCreateScrollIdentifiers(
+      nsIContent* aContent, uint32_t* aPresShellIdOut,
+      ScrollableLayerGuid::ViewID* aViewIdOut);
+
+  /* Initialize a zero-margin displayport on the root document element of the
+     given presShell. */
+  static void InitializeRootDisplayport(PresShell* aPresShell);
+
+  /* Get the pres context associated with the document enclosing |aContent|. */
+  static nsPresContext* GetPresContextForContent(nsIContent* aContent);
+
+  /* Get the pres shell associated with the root content document enclosing
+   * |aContent|. */
+  static PresShell* GetRootContentDocumentPresShellForContent(
+      nsIContent* aContent);
+
+  /* Dispatch a widget event via the widget stored in the event, if any.
+   * In a child process, allows the BrowserParent event-capture mechanism to
+   * intercept the event. */
+  static nsEventStatus DispatchWidgetEvent(WidgetGUIEvent& aEvent);
+
+  /* Synthesize a mouse event with the given parameters, and dispatch it
+   * via the given widget. */
+  MOZ_CAN_RUN_SCRIPT
+  static nsEventStatus DispatchSynthesizedMouseEvent(
+      EventMessage aMsg, const LayoutDevicePoint& aRefPoint,
+      Modifiers aModifiers, int32_t aClickCount, nsIWidget* aWidget);
+
+  /* Dispatch a mouse event with the given parameters.
+   * Return whether or not any listeners have called preventDefault on the
+   * event.
+   * This is a lightweight wrapper around nsContentUtils::SendMouseEvent()
+   * and as such expects |aPoint| to be in layout coordinates. */
+  MOZ_CAN_RUN_SCRIPT
+  static PreventDefaultResult DispatchMouseEvent(
+      PresShell* aPresShell, const nsString& aType, const CSSPoint& aPoint,
+      int32_t aButton, int32_t aClickCount, int32_t aModifiers,
+      unsigned short aInputSourceArg, uint32_t aPointerId);
+
+  /* Fire a single-tap event at the given point. The event is dispatched
+   * via the given widget. */
+  MOZ_CAN_RUN_SCRIPT
+  static void FireSingleTapEvent(const LayoutDevicePoint& aPoint,
+                                 Modifiers aModifiers, int32_t aClickCount,
+                                 nsIWidget* aWidget);
+
+  /* Perform hit-testing on the touch points of |aEvent| to determine
+   * which scrollable frames they target. If any of these frames don't have
+   * a displayport, set one.
+   *
+   * If any displayports need to be set, this function returns a heap-allocated
+   * object. The caller is responsible for calling Register() on that object.
+   *
+   * The object registers itself as a post-refresh observer on the presShell
+   * and ensures that notifications get sent to APZ correctly after the
+   * refresh.
+   *
+   * Having the caller manage this object is desirable in case they want to
+   * (a) know about the fact that a displayport needs to be set, and
+   * (b) register a post-refresh observer of their own that will run in
+   *     a defined ordering relative to the APZ messages.
+   */
+  static already_AddRefed<DisplayportSetListener> SendSetTargetAPZCNotification(
+      nsIWidget* aWidget, mozilla::dom::Document* aDocument,
+      const WidgetGUIEvent& aEvent, const LayersId& aLayersId,
+      uint64_t aInputBlockId);
+
+  /* Notify content of a mouse scroll testing event. */
+  static void NotifyMozMouseScrollEvent(
+      const ScrollableLayerGuid::ViewID& aScrollId, const nsString& aEvent);
+
+  /* Notify content that the repaint flush is complete. */
+  static void NotifyFlushComplete(PresShell* aPresShell);
+
+  static void NotifyAsyncScrollbarDragInitiated(
+      uint64_t aDragBlockId, const ScrollableLayerGuid::ViewID& aScrollId,
+      ScrollDirection aDirection);
+  static void NotifyAsyncScrollbarDragRejected(
+      const ScrollableLayerGuid::ViewID& aScrollId);
+  static void NotifyAsyncAutoscrollRejected(
+      const ScrollableLayerGuid::ViewID& aScrollId);
+
+  static void CancelAutoscroll(const ScrollableLayerGuid::ViewID& aScrollId);
+  static void NotifyScaleGestureComplete(const nsCOMPtr<nsIWidget>& aWidget,
+                                         float aScale);
+
+  /*
+   * Check if the scrollable frame is currently in the middle of a main thread
+   * async or smooth scroll, or has already requested some other apz scroll that
+   * hasn't been acknowledged by apz.
+   *
+   * We want to discard apz updates to the main-thread scroll offset if this is
+   * true to prevent clobbering higher priority origins.
+   */
+  static bool IsScrollInProgress(nsIScrollableFrame* aFrame);
+
+  /* Notify content of the progress of a pinch gesture that APZ won't do
+   * zooming for (because the apz.allow_zooming pref is false). This function
+   * will dispatch appropriate WidgetSimpleGestureEvent events to gecko.
+   */
+  static void NotifyPinchGesture(PinchGestureInput::PinchGestureType aType,
+                                 const LayoutDevicePoint& aFocusPoint,
+                                 LayoutDeviceCoord aSpanChange,
+                                 Modifiers aModifiers,
+                                 const nsCOMPtr<nsIWidget>& aWidget);
+
+ private:
+  static uint64_t sLastTargetAPZCNotificationInputBlock;
+};
+
+}  // namespace layers
+}  // namespace mozilla
+
+#endif /* mozilla_layers_APZCCallbackHelper_h */