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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-28 14:29:10 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-28 14:29:10 +0000 |
commit | 2aa4a82499d4becd2284cdb482213d541b8804dd (patch) | |
tree | b80bf8bf13c3766139fbacc530efd0dd9d54394c /gfx/layers/wr/WebRenderScrollDataWrapper.h | |
parent | Initial commit. (diff) | |
download | firefox-upstream.tar.xz firefox-upstream.zip |
Adding upstream version 86.0.1.upstream/86.0.1upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | gfx/layers/wr/WebRenderScrollDataWrapper.h | 424 |
1 files changed, 424 insertions, 0 deletions
diff --git a/gfx/layers/wr/WebRenderScrollDataWrapper.h b/gfx/layers/wr/WebRenderScrollDataWrapper.h new file mode 100644 index 0000000000..1f681a7cff --- /dev/null +++ b/gfx/layers/wr/WebRenderScrollDataWrapper.h @@ -0,0 +1,424 @@ +/* -*- 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 GFX_WEBRENDERSCROLLDATAWRAPPER_H +#define GFX_WEBRENDERSCROLLDATAWRAPPER_H + +#include "FrameMetrics.h" +#include "mozilla/layers/CompositorBridgeParent.h" +#include "mozilla/layers/WebRenderBridgeParent.h" +#include "mozilla/layers/WebRenderScrollData.h" + +namespace mozilla { +namespace layers { + +/* + * This class is a wrapper to walk through a WebRenderScrollData object, with + * an exposed API that is template-compatible to LayerMetricsWrapper. This + * allows APZ to walk through both layer trees and WebRender scroll metadata + * structures without a lot of code duplication. (Note that not all functions + * from LayerMetricsWrapper are implemented here, only the ones we've needed in + * APZ code so far.) + * + * A WebRenderScrollData object is basically a flattened layer tree, with a + * number of WebRenderLayerScrollData objects that have a 1:1 correspondence + * to layers in a layer tree. Therefore the mLayer pointer in this class can + * be considered equivalent to the mLayer pointer in the LayerMetricsWrapper. + * There are some extra fields (mData, mLayerIndex, mContainingSubtreeLastIndex) + * to move around between these "layers" given the flattened representation. + * The mMetadataIndex field in this class corresponds to the mIndex field in + * LayerMetricsWrapper, as both classes also need to manage walking through + * "virtual" container layers implied by the list of ScrollMetadata objects. + * + * One important note here is that this class holds a pointer to the "owning" + * WebRenderScrollData. The caller must ensure that this class does not outlive + * the owning WebRenderScrollData, or this may result in use-after-free errors. + * This class being declared a MOZ_STACK_CLASS should help with that. + * + * Refer to LayerMetricsWrapper.h for actual documentation on the exposed API. + */ +class MOZ_STACK_CLASS WebRenderScrollDataWrapper final { + public: + // Basic constructor for external callers. Starts the walker at the root of + // the tree. + explicit WebRenderScrollDataWrapper( + const APZUpdater& aUpdater, const WebRenderScrollData* aData = nullptr) + : mUpdater(&aUpdater), + mData(aData), + mLayerIndex(0), + mContainingSubtreeLastIndex(0), + mLayer(nullptr), + mMetadataIndex(0) { + if (!mData) { + return; + } + mLayer = mData->GetLayerData(mLayerIndex); + if (!mLayer) { + return; + } + + // sanity check on the data + MOZ_ASSERT(mData->GetLayerCount() == + (size_t)(1 + mLayer->GetDescendantCount())); + mContainingSubtreeLastIndex = mData->GetLayerCount(); + + // See documentation in LayerMetricsWrapper.h about this. mMetadataIndex + // in this class is equivalent to mIndex in that class. + mMetadataIndex = mLayer->GetScrollMetadataCount(); + if (mMetadataIndex > 0) { + mMetadataIndex--; + } + } + + private: + // Internal constructor for walking from one WebRenderLayerScrollData to + // another. In this case we need to recompute the mMetadataIndex to be the + // "topmost" scroll metadata on the new layer. + WebRenderScrollDataWrapper(const APZUpdater* aUpdater, + const WebRenderScrollData* aData, + size_t aLayerIndex, + size_t aContainingSubtreeLastIndex) + : mUpdater(aUpdater), + mData(aData), + mLayerIndex(aLayerIndex), + mContainingSubtreeLastIndex(aContainingSubtreeLastIndex), + mLayer(nullptr), + mMetadataIndex(0) { + MOZ_ASSERT(mData); + mLayer = mData->GetLayerData(mLayerIndex); + MOZ_ASSERT(mLayer); + + // See documentation in LayerMetricsWrapper.h about this. mMetadataIndex + // in this class is equivalent to mIndex in that class. + mMetadataIndex = mLayer->GetScrollMetadataCount(); + if (mMetadataIndex > 0) { + mMetadataIndex--; + } + } + + // Internal constructor for walking from one metadata to another metadata on + // the same WebRenderLayerScrollData. + WebRenderScrollDataWrapper(const APZUpdater* aUpdater, + const WebRenderScrollData* aData, + size_t aLayerIndex, + size_t aContainingSubtreeLastIndex, + const WebRenderLayerScrollData* aLayer, + uint32_t aMetadataIndex) + : mUpdater(aUpdater), + mData(aData), + mLayerIndex(aLayerIndex), + mContainingSubtreeLastIndex(aContainingSubtreeLastIndex), + mLayer(aLayer), + mMetadataIndex(aMetadataIndex) { + MOZ_ASSERT(mData); + MOZ_ASSERT(mLayer); + MOZ_ASSERT(mLayer == mData->GetLayerData(mLayerIndex)); + MOZ_ASSERT(mMetadataIndex == 0 || + mMetadataIndex < mLayer->GetScrollMetadataCount()); + } + + public: + bool IsValid() const { return mLayer != nullptr; } + + explicit operator bool() const { return IsValid(); } + + WebRenderScrollDataWrapper GetLastChild() const { + MOZ_ASSERT(IsValid()); + + if (!AtBottomLayer()) { + // If we're still walking around in the virtual container layers created + // by the ScrollMetadata array, we just need to update the metadata index + // and that's it. + return WebRenderScrollDataWrapper(mUpdater, mData, mLayerIndex, + mContainingSubtreeLastIndex, mLayer, + mMetadataIndex - 1); + } + + // Otherwise, we need to walk to a different WebRenderLayerScrollData in + // mData. + + // Since mData contains the layer in depth-first, last-to-first order, + // the index after mLayerIndex must be mLayerIndex's last child, if it + // has any children (indicated by GetDescendantCount() > 0). Furthermore + // we compute the first index outside the subtree rooted at this node + // (in |subtreeLastIndex|) and pass that in to the child wrapper to use as + // its mContainingSubtreeLastIndex. + if (mLayer->GetDescendantCount() > 0) { + size_t prevSiblingIndex = mLayerIndex + 1 + mLayer->GetDescendantCount(); + size_t subtreeLastIndex = + std::min(mContainingSubtreeLastIndex, prevSiblingIndex); + return WebRenderScrollDataWrapper(mUpdater, mData, mLayerIndex + 1, + subtreeLastIndex); + } + + // We've run out of descendants. But! If the original layer was a RefLayer, + // then it connects to another layer tree and we need to traverse that too. + // So return a WebRenderScrollDataWrapper for the root of the child layer + // tree. + if (mLayer->GetReferentId()) { + return WebRenderScrollDataWrapper( + *mUpdater, mUpdater->GetScrollData(*mLayer->GetReferentId())); + } + + return WebRenderScrollDataWrapper(*mUpdater); + } + + WebRenderScrollDataWrapper GetPrevSibling() const { + MOZ_ASSERT(IsValid()); + + if (!AtTopLayer()) { + // The virtual container layers don't have siblings + return WebRenderScrollDataWrapper(*mUpdater); + } + + // Skip past the descendants to get to the previous sibling. However, we + // might be at the last sibling already. + size_t prevSiblingIndex = mLayerIndex + 1 + mLayer->GetDescendantCount(); + if (prevSiblingIndex < mContainingSubtreeLastIndex) { + return WebRenderScrollDataWrapper(mUpdater, mData, prevSiblingIndex, + mContainingSubtreeLastIndex); + } + return WebRenderScrollDataWrapper(*mUpdater); + } + + const ScrollMetadata& Metadata() const { + MOZ_ASSERT(IsValid()); + + if (mMetadataIndex >= mLayer->GetScrollMetadataCount()) { + return *ScrollMetadata::sNullMetadata; + } + return mLayer->GetScrollMetadata(*mData, mMetadataIndex); + } + + const FrameMetrics& Metrics() const { return Metadata().GetMetrics(); } + + AsyncPanZoomController* GetApzc() const { return nullptr; } + + void SetApzc(AsyncPanZoomController* aApzc) const {} + + const char* Name() const { return "WebRenderScrollDataWrapper"; } + + gfx::Matrix4x4 GetTransform() const { + MOZ_ASSERT(IsValid()); + + // See WebRenderLayerScrollData::Initialize for more context. The ancestor + // transform is associated with the "topmost" layer, and the transform is + // associated with the "bottommost" layer. If there is only one + // scrollmetadata on the layer, then it is both "topmost" and "bottommost" + // and we combine the two transforms. + + gfx::Matrix4x4 transform; + if (AtTopLayer()) { + transform = mLayer->GetAncestorTransform(); + } + if (AtBottomLayer()) { + transform = transform * mLayer->GetTransform(); + } + return transform; + } + + CSSTransformMatrix GetTransformTyped() const { + return ViewAs<CSSTransformMatrix>(GetTransform()); + } + + bool TransformIsPerspective() const { + MOZ_ASSERT(IsValid()); + + if (AtBottomLayer()) { + return mLayer->GetTransformIsPerspective(); + } + return false; + } + + EventRegions GetEventRegions() const { + MOZ_ASSERT(IsValid()); + + if (AtBottomLayer()) { + return mLayer->GetEventRegions(); + } + return EventRegions(); + } + + LayerIntRegion GetVisibleRegion() const { + MOZ_ASSERT(IsValid()); + + if (AtBottomLayer()) { + return mLayer->GetVisibleRegion(); + } + + return ViewAs<LayerPixel>( + TransformBy(mLayer->GetTransformTyped(), mLayer->GetVisibleRegion()), + PixelCastJustification::MovingDownToChildren); + } + + LayerIntSize GetRemoteDocumentSize() const { + MOZ_ASSERT(IsValid()); + + if (mLayer->GetReferentId().isNothing()) { + return LayerIntSize(); + } + + if (AtBottomLayer()) { + return mLayer->GetRemoteDocumentSize(); + } + + return ViewAs<LayerPixel>(mLayer->GetRemoteDocumentSize(), + PixelCastJustification::MovingDownToChildren); + } + + Maybe<LayersId> GetReferentId() const { + MOZ_ASSERT(IsValid()); + + if (AtBottomLayer()) { + return mLayer->GetReferentId(); + } + return Nothing(); + } + + Maybe<ParentLayerIntRect> GetClipRect() const { + // TODO + return Nothing(); + } + + EventRegionsOverride GetEventRegionsOverride() const { + MOZ_ASSERT(IsValid()); + // Only ref layers can have an event regions override. + if (GetReferentId()) { + return mLayer->GetEventRegionsOverride(); + } + return EventRegionsOverride::NoOverride; + } + + const ScrollbarData& GetScrollbarData() const { + MOZ_ASSERT(IsValid()); + return mLayer->GetScrollbarData(); + } + + Maybe<uint64_t> GetScrollbarAnimationId() const { + MOZ_ASSERT(IsValid()); + return mLayer->GetScrollbarAnimationId(); + } + + Maybe<uint64_t> GetFixedPositionAnimationId() const { + MOZ_ASSERT(IsValid()); + + if (AtBottomLayer()) { + return mLayer->GetFixedPositionAnimationId(); + } + return Nothing(); + } + + ScrollableLayerGuid::ViewID GetFixedPositionScrollContainerId() const { + MOZ_ASSERT(IsValid()); + + if (AtBottomLayer()) { + return mLayer->GetFixedPositionScrollContainerId(); + } + return ScrollableLayerGuid::NULL_SCROLL_ID; + } + + SideBits GetFixedPositionSides() const { + MOZ_ASSERT(IsValid()); + + if (AtBottomLayer()) { + return mLayer->GetFixedPositionSides(); + } + return SideBits::eNone; + } + + ScrollableLayerGuid::ViewID GetStickyScrollContainerId() const { + MOZ_ASSERT(IsValid()); + + if (AtBottomLayer()) { + return mLayer->GetStickyPositionScrollContainerId(); + } + return ScrollableLayerGuid::NULL_SCROLL_ID; + } + + const LayerRectAbsolute& GetStickyScrollRangeOuter() const { + MOZ_ASSERT(IsValid()); + + if (AtBottomLayer()) { + return mLayer->GetStickyScrollRangeOuter(); + } + + static const LayerRectAbsolute empty; + return empty; + } + + const LayerRectAbsolute& GetStickyScrollRangeInner() const { + MOZ_ASSERT(IsValid()); + + if (AtBottomLayer()) { + return mLayer->GetStickyScrollRangeInner(); + } + + static const LayerRectAbsolute empty; + return empty; + } + + Maybe<uint64_t> GetStickyPositionAnimationId() const { + MOZ_ASSERT(IsValid()); + + if (AtBottomLayer()) { + return mLayer->GetStickyPositionAnimationId(); + } + return Nothing(); + } + + Maybe<uint64_t> GetZoomAnimationId() const { + MOZ_ASSERT(IsValid()); + return mLayer->GetZoomAnimationId(); + } + + bool IsBackfaceHidden() const { + // This is only used by APZCTM hit testing, and WR does its own + // hit testing, so no need to implement this. + return false; + } + + bool IsAsyncZoomContainer() const { + MOZ_ASSERT(IsValid()); + return mLayer->IsAsyncZoomContainer(); + } + + const void* GetLayer() const { + MOZ_ASSERT(IsValid()); + return mLayer; + } + + private: + bool AtBottomLayer() const { return mMetadataIndex == 0; } + + bool AtTopLayer() const { + return mLayer->GetScrollMetadataCount() == 0 || + mMetadataIndex == mLayer->GetScrollMetadataCount() - 1; + } + + private: + const APZUpdater* mUpdater; + const WebRenderScrollData* mData; + // The index (in mData->mLayerScrollData) of the WebRenderLayerScrollData this + // wrapper is pointing to. + size_t mLayerIndex; + // The upper bound on the set of valid indices inside the subtree rooted at + // the parent of this "layer". That is, any layer index |i| in the range + // mLayerIndex <= i < mContainingSubtreeLastIndex is guaranteed to point to + // a layer that is a descendant of "parent", where "parent" is the parent + // layer of the layer at mLayerIndex. This is needed in order to implement + // GetPrevSibling() correctly. + size_t mContainingSubtreeLastIndex; + // The WebRenderLayerScrollData this wrapper is pointing to. + const WebRenderLayerScrollData* mLayer; + // The index of the scroll metadata within mLayer that this wrapper is + // pointing to. + uint32_t mMetadataIndex; +}; + +} // namespace layers +} // namespace mozilla + +#endif /* GFX_WEBRENDERSCROLLDATAWRAPPER_H */ |