Adding upstream version 115.7.0esr.upstream/115.7.0esr

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

1 files changed, 270 insertions, 0 deletions

diff --git a/gfx/layers/apz/src/HitTestingTreeNode.h b/gfx/layers/apz/src/HitTestingTreeNode.h
new file mode 100644
index 0000000000..ed20f9f561
--- /dev/null
+++ b/gfx/layers/apz/src/HitTestingTreeNode.h
@@ -0,0 +1,270 @@
+/* -*- 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/. */
+
+#ifndef mozilla_layers_HitTestingTreeNode_h
+#define mozilla_layers_HitTestingTreeNode_h
+
+#include "mozilla/gfx/CompositorHitTestInfo.h"
+#include "mozilla/gfx/Matrix.h"                  // for Matrix4x4
+#include "mozilla/layers/LayersTypes.h"          // for EventRegions
+#include "mozilla/layers/ScrollableLayerGuid.h"  // for ScrollableLayerGuid
+#include "mozilla/layers/ScrollbarData.h"        // for ScrollbarData
+#include "mozilla/Maybe.h"                       // for Maybe
+#include "mozilla/RecursiveMutex.h"              // for RecursiveMutexAutoLock
+#include "mozilla/RefPtr.h"                      // for nsRefPtr
+namespace mozilla {
+namespace layers {
+
+class AsyncDragMetrics;
+class AsyncPanZoomController;
+
+/**
+ * This class represents a node in a tree that is used by the APZCTreeManager
+ * to do hit testing. The tree is roughly a copy of the layer tree, but will
+ * contain multiple nodes in cases where the layer has multiple FrameMetrics.
+ * In other words, the structure of this tree should be identical to the
+ * WebRenderScrollDataWrapper tree (see documentation in
+ * WebRenderScrollDataWrapper.h).
+ *
+ * Not all HitTestingTreeNode instances will have an APZC associated with them;
+ * only HitTestingTreeNodes that correspond to layers with scrollable metrics
+ * have APZCs.
+ * Multiple HitTestingTreeNode instances may share the same underlying APZC
+ * instance if the layers they represent share the same scrollable metrics (i.e.
+ * are part of the same animated geometry root). If this happens, exactly one of
+ * the HitTestingTreeNode instances will be designated as the "primary holder"
+ * of the APZC. When this primary holder is destroyed, it will destroy the APZC
+ * along with it; in contrast, destroying non-primary-holder nodes will not
+ * destroy the APZC.
+ * Code should not make assumptions about which of the nodes will be the
+ * primary holder, only that that there will be exactly one for each APZC in
+ * the tree.
+ *
+ * The reason this tree exists at all is so that we can do hit-testing on the
+ * thread that we receive input on (referred to the as the controller thread in
+ * APZ terminology), which may be different from the compositor thread.
+ * Accessing the compositor layer tree can only be done on the compositor
+ * thread, and so it is simpler to make a copy of the hit-testing related
+ * properties into a separate tree.
+ *
+ * The tree pointers on the node (mLastChild, etc.) can only be manipulated
+ * while holding the APZ tree lock. Any code that wishes to use a
+ * HitTestingTreeNode outside of holding the tree lock should do so by using
+ * the HitTestingTreeNodeAutoLock wrapper, which prevents the node from
+ * being recycled (and also holds a RefPtr to the node to prevent it from
+ * getting freed).
+ */
+class HitTestingTreeNode {
+  NS_INLINE_DECL_THREADSAFE_REFCOUNTING(HitTestingTreeNode);
+
+ private:
+  ~HitTestingTreeNode();
+
+ public:
+  HitTestingTreeNode(AsyncPanZoomController* aApzc, bool aIsPrimaryHolder,
+                     LayersId aLayersId);
+  void RecycleWith(const RecursiveMutexAutoLock& aProofOfTreeLock,
+                   AsyncPanZoomController* aApzc, LayersId aLayersId);
+  // Clears the tree pointers on the node, thereby breaking RefPtr cycles. This
+  // can trigger free'ing of this and other HitTestingTreeNode instances.
+  void Destroy();
+
+  // Returns true if and only if the node is available for recycling as part
+  // of a hit-testing tree update. Note that this node can have Destroy() called
+  // on it whether or not it is recyclable.
+  bool IsRecyclable(const RecursiveMutexAutoLock& aProofOfTreeLock);
+
+  /* Tree construction methods */
+
+  void SetLastChild(HitTestingTreeNode* aChild);
+  void SetPrevSibling(HitTestingTreeNode* aSibling);
+  void MakeRoot();
+
+  /* Tree walking methods. GetFirstChild is O(n) in the number of children. The
+   * other tree walking methods are all O(1). */
+
+  HitTestingTreeNode* GetFirstChild() const;
+  HitTestingTreeNode* GetLastChild() const;
+  HitTestingTreeNode* GetPrevSibling() const;
+  HitTestingTreeNode* GetParent() const;
+
+  bool IsAncestorOf(const HitTestingTreeNode* aOther) const;
+
+  /* APZC related methods */
+
+  AsyncPanZoomController* GetApzc() const;
+  AsyncPanZoomController* GetNearestContainingApzc() const;
+  bool IsPrimaryHolder() const;
+  LayersId GetLayersId() const;
+
+  /* Hit test related methods */
+
+  void SetHitTestData(
+      const LayerIntRegion& aVisibleRegion,
+      const LayerIntSize& aRemoteDocumentSize,
+      const CSSTransformMatrix& aTransform,
+      const EventRegionsOverride& aOverride,
+      const Maybe<ScrollableLayerGuid::ViewID>& aAsyncZoomContainerId);
+
+  /* Scrollbar info */
+
+  void SetScrollbarData(const Maybe<uint64_t>& aScrollbarAnimationId,
+                        const ScrollbarData& aScrollbarData);
+  bool MatchesScrollDragMetrics(const AsyncDragMetrics& aDragMetrics,
+                                LayersId aLayersId) const;
+  bool IsScrollbarNode() const;  // Scroll thumb or scrollbar container layer.
+  bool IsScrollbarContainerNode() const;  // Scrollbar container layer.
+  // This can only be called if IsScrollbarNode() is true
+  ScrollDirection GetScrollbarDirection() const;
+  bool IsScrollThumbNode() const;  // Scroll thumb container layer.
+  ScrollableLayerGuid::ViewID GetScrollTargetId() const;
+  const ScrollbarData& GetScrollbarData() const;
+  Maybe<uint64_t> GetScrollbarAnimationId() const;
+
+  /* Fixed pos info */
+
+  void SetFixedPosData(ScrollableLayerGuid::ViewID aFixedPosTarget,
+                       SideBits aFixedPosSides,
+                       const Maybe<uint64_t>& aFixedPositionAnimationId);
+  ScrollableLayerGuid::ViewID GetFixedPosTarget() const;
+  SideBits GetFixedPosSides() const;
+  Maybe<uint64_t> GetFixedPositionAnimationId() const;
+
+  /* Sticky pos info */
+  void SetStickyPosData(ScrollableLayerGuid::ViewID aStickyPosTarget,
+                        const LayerRectAbsolute& aScrollRangeOuter,
+                        const LayerRectAbsolute& aScrollRangeInner,
+                        const Maybe<uint64_t>& aStickyPositionAnimationId);
+  ScrollableLayerGuid::ViewID GetStickyPosTarget() const;
+  const LayerRectAbsolute& GetStickyScrollRangeOuter() const;
+  const LayerRectAbsolute& GetStickyScrollRangeInner() const;
+  Maybe<uint64_t> GetStickyPositionAnimationId() const;
+
+  /* Returns the mOverride flag. */
+  EventRegionsOverride GetEventRegionsOverride() const;
+  const CSSTransformMatrix& GetTransform() const;
+  /* This is similar to APZCTreeManager::GetApzcToGeckoTransform but without
+   * the async bits. It's used on the main-thread for transforming coordinates
+   * across a BrowserParent/BrowserChild interface.*/
+  LayerToScreenMatrix4x4 GetTransformToGecko() const;
+  const LayerIntRegion& GetVisibleRegion() const;
+
+  /* Returns the screen coordinate rectangle of remote iframe corresponding to
+   * this node. The rectangle is the result of clipped by ancestor async
+   * scrolling. */
+  ScreenRect GetRemoteDocumentScreenRect() const;
+
+  Maybe<ScrollableLayerGuid::ViewID> GetAsyncZoomContainerId() const;
+
+  /* Debug helpers */
+  void Dump(const char* aPrefix = "") const;
+
+ private:
+  friend class HitTestingTreeNodeAutoLock;
+  // Functions that are private but called from HitTestingTreeNodeAutoLock
+  void Lock(const RecursiveMutexAutoLock& aProofOfTreeLock);
+  void Unlock(const RecursiveMutexAutoLock& aProofOfTreeLock);
+
+  void SetApzcParent(AsyncPanZoomController* aApzc);
+
+  RefPtr<HitTestingTreeNode> mLastChild;
+  RefPtr<HitTestingTreeNode> mPrevSibling;
+  RefPtr<HitTestingTreeNode> mParent;
+
+  RefPtr<AsyncPanZoomController> mApzc;
+  bool mIsPrimaryApzcHolder;
+  int mLockCount;
+
+  LayersId mLayersId;
+
+  // This is only set if WebRender is enabled, and only for HTTNs
+  // where IsScrollThumbNode() returns true. It holds the animation id that we
+  // use to move the thumb node to reflect async scrolling.
+  Maybe<uint64_t> mScrollbarAnimationId;
+
+  // This is set for scrollbar Container and Thumb layers.
+  ScrollbarData mScrollbarData;
+
+  // This is only set if WebRender is enabled. It holds the animation id that
+  // we use to adjust fixed position content for the toolbar.
+  Maybe<uint64_t> mFixedPositionAnimationId;
+
+  ScrollableLayerGuid::ViewID mFixedPosTarget;
+  SideBits mFixedPosSides;
+
+  ScrollableLayerGuid::ViewID mStickyPosTarget;
+  LayerRectAbsolute mStickyScrollRangeOuter;
+  LayerRectAbsolute mStickyScrollRangeInner;
+  // This is only set if WebRender is enabled. It holds the animation id that
+  // we use to adjust sticky position content for the toolbar.
+  Maybe<uint64_t> mStickyPositionAnimationId;
+
+  LayerIntRegion mVisibleRegion;
+
+  /* The size of remote iframe on the corresponding layer coordinate.
+   * It's empty if this node is not for remote iframe. */
+  LayerIntSize mRemoteDocumentSize;
+
+  /* This is the transform from layer L. This does NOT include any async
+   * transforms. */
+  CSSTransformMatrix mTransform;
+
+  /* If the layer is the async zoom container layer then this will hold the id.
+   */
+  Maybe<ScrollableLayerGuid::ViewID> mAsyncZoomContainerId;
+
+  /* Indicates whether or not the event regions on this node need to be
+   * overridden in a certain way. */
+  EventRegionsOverride mOverride;
+};
+
+/**
+ * A class that allows safe usage of a HitTestingTreeNode outside of the APZ
+ * tree lock. In general, this class should be Initialize()'d inside the tree
+ * lock (enforced by the proof-of-lock to Initialize), and then can be returned
+ * to a scope outside the tree lock and used safely. Upon destruction or
+ * Clear() being called, it unlocks the underlying node at which point it can
+ * be recycled or freed.
+ */
+class HitTestingTreeNodeAutoLock final {
+ public:
+  HitTestingTreeNodeAutoLock();
+  ~HitTestingTreeNodeAutoLock();
+  // Make it move-only. Note that the default implementations of the move
+  // constructor and assignment operator are correct: they'll call the
+  // move constructor of mNode, which will null out mNode on the moved-from
+  // object, and Clear() will early-exit when the moved-from object's
+  // destructor is called.
+  HitTestingTreeNodeAutoLock(HitTestingTreeNodeAutoLock&&) = default;
+  HitTestingTreeNodeAutoLock& operator=(HitTestingTreeNodeAutoLock&&) = default;
+
+  void Initialize(const RecursiveMutexAutoLock& aProofOfTreeLock,
+                  already_AddRefed<HitTestingTreeNode> aNode,
+                  RecursiveMutex& aTreeMutex);
+  void Clear();
+
+  // Convenience operators to simplify the using code.
+  explicit operator bool() const { return !!mNode; }
+  bool operator!() const { return !mNode; }
+  HitTestingTreeNode* operator->() const { return mNode.get(); }
+
+  // Allow getting back a raw pointer to the node, but only inside the scope
+  // of the tree lock. The caller is responsible for ensuring that they do not
+  // use the raw pointer outside that scope.
+  HitTestingTreeNode* Get(
+      mozilla::RecursiveMutexAutoLock& aProofOfTreeLock) const {
+    return mNode.get();
+  }
+
+ private:
+  RefPtr<HitTestingTreeNode> mNode;
+  RecursiveMutex* mTreeMutex;
+};
+
+}  // namespace layers
+}  // namespace mozilla
+
+#endif  // mozilla_layers_HitTestingTreeNode_h