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Diffstat (limited to 'gfx/layers/apz/src/HitTestingTreeNode.h')
| -rw-r--r-- | gfx/layers/apz/src/HitTestingTreeNode.h | 166 |
1 files changed, 166 insertions, 0 deletions
diff --git a/gfx/layers/apz/src/HitTestingTreeNode.h b/gfx/layers/apz/src/HitTestingTreeNode.h new file mode 100644 index 000000000..442751a8d --- /dev/null +++ b/gfx/layers/apz/src/HitTestingTreeNode.h @@ -0,0 +1,166 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* vim: set sw=2 ts=8 et 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 "APZUtils.h" // for HitTestResult +#include "FrameMetrics.h" // for ScrollableLayerGuid +#include "Layers.h" +#include "mozilla/gfx/Matrix.h" // for Matrix4x4 +#include "mozilla/layers/LayersTypes.h" // for EventRegions +#include "mozilla/Maybe.h" // for Maybe +#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 + * LayerMetrics tree (see documentation in LayerMetricsWrapper.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. + */ +class HitTestingTreeNode { + NS_INLINE_DECL_THREADSAFE_REFCOUNTING(HitTestingTreeNode); + +private: + ~HitTestingTreeNode(); +public: + HitTestingTreeNode(AsyncPanZoomController* aApzc, bool aIsPrimaryHolder, + uint64_t aLayersId); + void RecycleWith(AsyncPanZoomController* aApzc, uint64_t aLayersId); + void Destroy(); + + /* 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; + + /* APZC related methods */ + + AsyncPanZoomController* GetApzc() const; + AsyncPanZoomController* GetNearestContainingApzc() const; + bool IsPrimaryHolder() const; + uint64_t GetLayersId() const; + + /* Hit test related methods */ + + void SetHitTestData(const EventRegions& aRegions, + const CSSTransformMatrix& aTransform, + const Maybe<ParentLayerIntRegion>& aClipRegion, + const EventRegionsOverride& aOverride); + bool IsOutsideClip(const ParentLayerPoint& aPoint) const; + + /* Scrollbar info */ + + void SetScrollbarData(FrameMetrics::ViewID aScrollViewId, + Layer::ScrollDirection aDir, + int32_t aScrollSize, + bool aIsScrollContainer); + bool MatchesScrollDragMetrics(const AsyncDragMetrics& aDragMetrics) const; + int32_t GetScrollSize() const; + bool IsScrollbarNode() const; + + /* Fixed pos info */ + + void SetFixedPosData(FrameMetrics::ViewID aFixedPosTarget); + FrameMetrics::ViewID GetFixedPosTarget() const; + + /* Convert aPoint into the LayerPixel space for the layer corresponding to + * this node. */ + Maybe<LayerPoint> Untransform(const ParentLayerPoint& aPoint) const; + /* Assuming aPoint is inside the clip region for this node, check which of the + * event region spaces it falls inside. */ + HitTestResult HitTest(const ParentLayerPoint& aPoint) const; + /* Returns the mOverride flag. */ + EventRegionsOverride GetEventRegionsOverride() const; + + /* Debug helpers */ + void Dump(const char* aPrefix = "") const; + +private: + void SetApzcParent(AsyncPanZoomController* aApzc); + + RefPtr<HitTestingTreeNode> mLastChild; + RefPtr<HitTestingTreeNode> mPrevSibling; + RefPtr<HitTestingTreeNode> mParent; + + RefPtr<AsyncPanZoomController> mApzc; + bool mIsPrimaryApzcHolder; + + uint64_t mLayersId; + + FrameMetrics::ViewID mScrollViewId; + Layer::ScrollDirection mScrollDir; + int32_t mScrollSize; + bool mIsScrollbarContainer; + + FrameMetrics::ViewID mFixedPosTarget; + + /* Let {L,M} be the {layer, scrollable metrics} pair that this node + * corresponds to in the layer tree. mEventRegions contains the event regions + * from L, in the case where event-regions are enabled. If event-regions are + * disabled, it will contain the visible region of L, which we use as an + * approximation to the hit region for the purposes of obscuring other layers. + * This value is in L's LayerPixels. + */ + EventRegions mEventRegions; + + /* This is the transform from layer L. This does NOT include any async + * transforms. */ + CSSTransformMatrix mTransform; + + /* This is clip rect for L that we wish to use for hit-testing purposes. Note + * that this may not be exactly the same as the clip rect on layer L because + * of the touch-sensitive region provided by the GeckoContentController, or + * because we may use the composition bounds of the layer if the clip is not + * present. This value is in L's ParentLayerPixels. */ + Maybe<ParentLayerIntRegion> mClipRegion; + + /* Indicates whether or not the event regions on this node need to be + * overridden in a certain way. */ + EventRegionsOverride mOverride; +}; + +} // namespace layers +} // namespace mozilla + +#endif // mozilla_layers_HitTestingTreeNode_h |