1 files changed, 371 insertions, 0 deletions
diff --git a/gfx/layers/wr/WebRenderScrollData.cpp b/gfx/layers/wr/WebRenderScrollData.cpp
new file mode 100644
index 0000000000..424e6b03d5
--- /dev/null
+++ b/gfx/layers/wr/WebRenderScrollData.cpp
@@ -0,0 +1,371 @@
+/* -*- 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 "mozilla/layers/WebRenderScrollData.h"
+
+#include <ostream>
+
+#include "Layers.h"
+#include "mozilla/layers/LayersMessageUtils.h"
+#include "mozilla/layers/WebRenderLayerManager.h"
+#include "mozilla/ToString.h"
+#include "mozilla/Unused.h"
+#include "nsDisplayList.h"
+#include "nsTArray.h"
+#include "UnitTransforms.h"
+
+namespace mozilla {
+namespace layers {
+
+WebRenderLayerScrollData::WebRenderLayerScrollData()
+    : mDescendantCount(-1),
+      mTransformIsPerspective(false),
+      mEventRegionsOverride(EventRegionsOverride::NoOverride),
+      mFixedPositionSides(mozilla::SideBits::eNone),
+      mFixedPosScrollContainerId(ScrollableLayerGuid::NULL_SCROLL_ID),
+      mStickyPosScrollContainerId(ScrollableLayerGuid::NULL_SCROLL_ID) {}
+
+WebRenderLayerScrollData::~WebRenderLayerScrollData() = default;
+
+void WebRenderLayerScrollData::InitializeRoot(int32_t aDescendantCount) {
+  mDescendantCount = aDescendantCount;
+}
+
+void WebRenderLayerScrollData::Initialize(
+    WebRenderScrollData& aOwner, nsDisplayItem* aItem, int32_t aDescendantCount,
+    const ActiveScrolledRoot* aStopAtAsr,
+    const Maybe<gfx::Matrix4x4>& aAncestorTransform) {
+  MOZ_ASSERT(aDescendantCount >= 0);  // Ensure value is valid
+  MOZ_ASSERT(mDescendantCount ==
+             -1);  // Don't allow re-setting an already set value
+  mDescendantCount = aDescendantCount;
+
+  MOZ_ASSERT(aItem);
+  aItem->UpdateScrollData(&aOwner, this);
+
+  const ActiveScrolledRoot* asr = aItem->GetActiveScrolledRoot();
+  if (ActiveScrolledRoot::IsAncestor(asr, aStopAtAsr)) {
+    // If the item's ASR is an ancestor of the stop-at ASR, then we don't need
+    // any more metrics information because we'll end up duplicating what the
+    // ancestor WebRenderLayerScrollData already has.
+    asr = nullptr;
+  }
+
+  while (asr && asr != aStopAtAsr) {
+    MOZ_ASSERT(aOwner.GetManager());
+    ScrollableLayerGuid::ViewID scrollId = asr->GetViewId();
+    if (Maybe<size_t> index = aOwner.HasMetadataFor(scrollId)) {
+      mScrollIds.AppendElement(index.ref());
+    } else {
+      Maybe<ScrollMetadata> metadata =
+          asr->mScrollableFrame->ComputeScrollMetadata(
+              aOwner.GetManager(), aItem->ReferenceFrame(), Nothing(), nullptr);
+      aOwner.GetBuilder()->AddScrollFrameToNotify(asr->mScrollableFrame);
+      if (metadata) {
+        MOZ_ASSERT(metadata->GetMetrics().GetScrollId() == scrollId);
+        mScrollIds.AppendElement(aOwner.AddMetadata(metadata.ref()));
+      } else {
+        MOZ_ASSERT_UNREACHABLE("Expected scroll metadata to be available!");
+      }
+    }
+    asr = asr->mParent;
+  }
+
+  // See the comments on StackingContextHelper::mDeferredTransformItem for an
+  // overview of what deferred transforms are.
+  // aAncestorTransform, if present, is the transform from a deferred transform
+  // item that is an ancestor of |aItem|. We store this transform value
+  // separately from mTransform because in the case where we have multiple
+  // scroll metadata on this layer item, the mAncestorTransform is associated
+  // with the "topmost" scroll metadata, and the mTransform is associated with
+  // the "bottommost" scroll metadata. The code in
+  // WebRenderScrollDataWrapper::GetTransform() is responsible for combining
+  // these transforms and exposing them appropriately. Also, we don't save the
+  // ancestor transform for thumb layers, because those are a special case in
+  // APZ; we need to keep the ancestor transform for the scrollable content that
+  // the thumb scrolls, but not for the thumb itself, as it will result in
+  // incorrect visual positioning of the thumb.
+  if (aAncestorTransform &&
+      mScrollbarData.mScrollbarLayerType != ScrollbarLayerType::Thumb) {
+    mAncestorTransform = *aAncestorTransform;
+  }
+}
+
+int32_t WebRenderLayerScrollData::GetDescendantCount() const {
+  MOZ_ASSERT(mDescendantCount >= 0);  // check that it was set
+  return mDescendantCount;
+}
+
+size_t WebRenderLayerScrollData::GetScrollMetadataCount() const {
+  return mScrollIds.Length();
+}
+
+void WebRenderLayerScrollData::AppendScrollMetadata(
+    WebRenderScrollData& aOwner, const ScrollMetadata& aData) {
+  mScrollIds.AppendElement(aOwner.AddMetadata(aData));
+}
+
+const ScrollMetadata& WebRenderLayerScrollData::GetScrollMetadata(
+    const WebRenderScrollData& aOwner, size_t aIndex) const {
+  MOZ_ASSERT(aIndex < mScrollIds.Length());
+  return aOwner.GetScrollMetadata(mScrollIds[aIndex]);
+}
+
+CSSTransformMatrix WebRenderLayerScrollData::GetTransformTyped() const {
+  return ViewAs<CSSTransformMatrix>(GetTransform());
+}
+
+void WebRenderLayerScrollData::Dump(std::ostream& aOut,
+                                    const WebRenderScrollData& aOwner) const {
+  aOut << "WebRenderLayerScrollData(" << this
+       << "), descendantCount=" << mDescendantCount;
+  for (size_t i = 0; i < mScrollIds.Length(); i++) {
+    aOut << ", metadata" << i << "=" << aOwner.GetScrollMetadata(mScrollIds[i]);
+  }
+  if (!mAncestorTransform.IsIdentity()) {
+    aOut << ", ancestorTransform=" << mAncestorTransform;
+  }
+  if (!mTransform.IsIdentity()) {
+    aOut << ", transform=" << mTransform;
+    if (mTransformIsPerspective) {
+      aOut << ", transformIsPerspective";
+    }
+  }
+  aOut << ", visible=" << mVisibleRegion;
+  if (mReferentId) {
+    aOut << ", refLayersId=" << *mReferentId;
+  }
+  if (mEventRegionsOverride) {
+    aOut << std::hex << ", eventRegionsOverride=0x"
+         << (int)mEventRegionsOverride << std::dec;
+  }
+  if (mScrollbarData.mScrollbarLayerType != ScrollbarLayerType::None) {
+    aOut << ", scrollbarType=" << (int)mScrollbarData.mScrollbarLayerType
+         << std::hex << ", scrollbarAnimationId=0x"
+         << mScrollbarAnimationId.valueOr(0) << std::dec;
+  }
+  if (mFixedPosScrollContainerId != ScrollableLayerGuid::NULL_SCROLL_ID) {
+    aOut << ", fixedContainer=" << mFixedPosScrollContainerId << std::hex
+         << ", fixedAnimation=0x" << mFixedPositionAnimationId.valueOr(0)
+         << ", sideBits=0x" << (int)mFixedPositionSides << std::dec;
+  }
+  if (mStickyPosScrollContainerId != ScrollableLayerGuid::NULL_SCROLL_ID) {
+    aOut << ", stickyContainer=" << mStickyPosScrollContainerId << std::hex
+         << ", stickyAnimation=" << mStickyPositionAnimationId.valueOr(0)
+         << std::dec << ", stickyInner=" << mStickyScrollRangeInner
+         << ", stickyOuter=" << mStickyScrollRangeOuter;
+  }
+}
+
+WebRenderScrollData::WebRenderScrollData()
+    : mManager(nullptr), mIsFirstPaint(false), mPaintSequenceNumber(0) {}
+
+WebRenderScrollData::WebRenderScrollData(WebRenderLayerManager* aManager,
+                                         nsDisplayListBuilder* aBuilder)
+    : mManager(aManager),
+      mBuilder(aBuilder),
+      mIsFirstPaint(false),
+      mPaintSequenceNumber(0) {}
+
+WebRenderLayerManager* WebRenderScrollData::GetManager() const {
+  return mManager;
+}
+
+nsDisplayListBuilder* WebRenderScrollData::GetBuilder() const {
+  return mBuilder;
+}
+
+size_t WebRenderScrollData::AddMetadata(const ScrollMetadata& aMetadata) {
+  ScrollableLayerGuid::ViewID scrollId = aMetadata.GetMetrics().GetScrollId();
+  auto p = mScrollIdMap.lookupForAdd(scrollId);
+  if (!p) {
+    // It's a scrollId we hadn't seen before
+    bool ok = mScrollIdMap.add(p, scrollId, mScrollMetadatas.Length());
+    MOZ_RELEASE_ASSERT(ok);
+    mScrollMetadatas.AppendElement(aMetadata);
+  }  // else we didn't insert, because it already existed
+  return p->value();
+}
+
+size_t WebRenderScrollData::AddLayerData(
+    const WebRenderLayerScrollData& aData) {
+  mLayerScrollData.AppendElement(aData);
+  return mLayerScrollData.Length() - 1;
+}
+
+size_t WebRenderScrollData::GetLayerCount() const {
+  return mLayerScrollData.Length();
+}
+
+const WebRenderLayerScrollData* WebRenderScrollData::GetLayerData(
+    size_t aIndex) const {
+  if (aIndex >= mLayerScrollData.Length()) {
+    return nullptr;
+  }
+  return &(mLayerScrollData.ElementAt(aIndex));
+}
+
+const ScrollMetadata& WebRenderScrollData::GetScrollMetadata(
+    size_t aIndex) const {
+  MOZ_ASSERT(aIndex < mScrollMetadatas.Length());
+  return mScrollMetadatas[aIndex];
+}
+
+Maybe<size_t> WebRenderScrollData::HasMetadataFor(
+    const ScrollableLayerGuid::ViewID& aScrollId) const {
+  auto ptr = mScrollIdMap.lookup(aScrollId);
+  return (ptr ? Some(ptr->value()) : Nothing());
+}
+
+void WebRenderScrollData::SetIsFirstPaint() { mIsFirstPaint = true; }
+
+bool WebRenderScrollData::IsFirstPaint() const { return mIsFirstPaint; }
+
+void WebRenderScrollData::SetPaintSequenceNumber(
+    uint32_t aPaintSequenceNumber) {
+  mPaintSequenceNumber = aPaintSequenceNumber;
+}
+
+uint32_t WebRenderScrollData::GetPaintSequenceNumber() const {
+  return mPaintSequenceNumber;
+}
+
+void WebRenderScrollData::ApplyUpdates(ScrollUpdatesMap&& aUpdates,
+                                       uint32_t aPaintSequenceNumber) {
+  for (auto it = aUpdates.Iter(); !it.Done(); it.Next()) {
+    if (Maybe<size_t> index = HasMetadataFor(it.Key())) {
+      mScrollMetadatas[*index].UpdatePendingScrollInfo(std::move(it.Data()));
+    }
+  }
+  mPaintSequenceNumber = aPaintSequenceNumber;
+}
+
+void WebRenderScrollData::DumpSubtree(std::ostream& aOut, size_t aIndex,
+                                      const std::string& aIndent) const {
+  aOut << aIndent;
+  mLayerScrollData.ElementAt(aIndex).Dump(aOut, *this);
+  aOut << std::endl;
+
+  int32_t descendants = mLayerScrollData.ElementAt(aIndex).GetDescendantCount();
+  if (descendants == 0) {
+    return;
+  }
+
+  // Build a stack of indices at which this aIndex's children live. We do
+  // this because we want to dump them first-to-last but they are stored
+  // last-to-first.
+  std::stack<size_t> childIndices;
+  size_t childIndex = aIndex + 1;
+  while (descendants > 0) {
+    childIndices.push(childIndex);
+    // "1" for the child itelf, plus whatever descendants it has
+    int32_t subtreeSize =
+        1 + mLayerScrollData.ElementAt(childIndex).GetDescendantCount();
+    childIndex += subtreeSize;
+    descendants -= subtreeSize;
+    MOZ_ASSERT(descendants >= 0);
+  }
+
+  std::string indent = aIndent + "    ";
+  while (!childIndices.empty()) {
+    size_t child = childIndices.top();
+    childIndices.pop();
+    DumpSubtree(aOut, child, indent);
+  }
+}
+
+std::ostream& operator<<(std::ostream& aOut, const WebRenderScrollData& aData) {
+  aOut << "--- WebRenderScrollData (firstPaint=" << aData.mIsFirstPaint
+       << ") ---" << std::endl;
+
+  if (aData.mLayerScrollData.Length() > 0) {
+    aData.DumpSubtree(aOut, 0, std::string());
+  }
+  return aOut;
+}
+
+bool WebRenderScrollData::RepopulateMap() {
+  MOZ_ASSERT(mScrollIdMap.empty());
+  for (size_t i = 0; i < mScrollMetadatas.Length(); i++) {
+    ScrollableLayerGuid::ViewID scrollId =
+        mScrollMetadatas[i].GetMetrics().GetScrollId();
+    bool ok = mScrollIdMap.putNew(scrollId, i);
+    MOZ_RELEASE_ASSERT(ok);
+  }
+  return true;
+}
+
+}  // namespace layers
+}  // namespace mozilla
+
+namespace IPC {
+
+void ParamTraits<mozilla::layers::WebRenderLayerScrollData>::Write(
+    Message* aMsg, const paramType& aParam) {
+  WriteParam(aMsg, aParam.mDescendantCount);
+  WriteParam(aMsg, aParam.mScrollIds);
+  WriteParam(aMsg, aParam.mAncestorTransform);
+  WriteParam(aMsg, aParam.mTransform);
+  WriteParam(aMsg, aParam.mTransformIsPerspective);
+  WriteParam(aMsg, aParam.mVisibleRegion);
+  WriteParam(aMsg, aParam.mRemoteDocumentSize);
+  WriteParam(aMsg, aParam.mReferentId);
+  WriteParam(aMsg, aParam.mEventRegionsOverride);
+  WriteParam(aMsg, aParam.mScrollbarData);
+  WriteParam(aMsg, aParam.mScrollbarAnimationId);
+  WriteParam(aMsg, aParam.mFixedPositionAnimationId);
+  WriteParam(aMsg, aParam.mFixedPositionSides);
+  WriteParam(aMsg, aParam.mFixedPosScrollContainerId);
+  WriteParam(aMsg, aParam.mStickyPosScrollContainerId);
+  WriteParam(aMsg, aParam.mStickyScrollRangeOuter);
+  WriteParam(aMsg, aParam.mStickyScrollRangeInner);
+  WriteParam(aMsg, aParam.mStickyPositionAnimationId);
+  WriteParam(aMsg, aParam.mZoomAnimationId);
+  WriteParam(aMsg, aParam.mAsyncZoomContainerId);
+}
+
+bool ParamTraits<mozilla::layers::WebRenderLayerScrollData>::Read(
+    const Message* aMsg, PickleIterator* aIter, paramType* aResult) {
+  return ReadParam(aMsg, aIter, &aResult->mDescendantCount) &&
+         ReadParam(aMsg, aIter, &aResult->mScrollIds) &&
+         ReadParam(aMsg, aIter, &aResult->mAncestorTransform) &&
+         ReadParam(aMsg, aIter, &aResult->mTransform) &&
+         ReadParam(aMsg, aIter, &aResult->mTransformIsPerspective) &&
+         ReadParam(aMsg, aIter, &aResult->mVisibleRegion) &&
+         ReadParam(aMsg, aIter, &aResult->mRemoteDocumentSize) &&
+         ReadParam(aMsg, aIter, &aResult->mReferentId) &&
+         ReadParam(aMsg, aIter, &aResult->mEventRegionsOverride) &&
+         ReadParam(aMsg, aIter, &aResult->mScrollbarData) &&
+         ReadParam(aMsg, aIter, &aResult->mScrollbarAnimationId) &&
+         ReadParam(aMsg, aIter, &aResult->mFixedPositionAnimationId) &&
+         ReadParam(aMsg, aIter, &aResult->mFixedPositionSides) &&
+         ReadParam(aMsg, aIter, &aResult->mFixedPosScrollContainerId) &&
+         ReadParam(aMsg, aIter, &aResult->mStickyPosScrollContainerId) &&
+         ReadParam(aMsg, aIter, &aResult->mStickyScrollRangeOuter) &&
+         ReadParam(aMsg, aIter, &aResult->mStickyScrollRangeInner) &&
+         ReadParam(aMsg, aIter, &aResult->mStickyPositionAnimationId) &&
+         ReadParam(aMsg, aIter, &aResult->mZoomAnimationId) &&
+         ReadParam(aMsg, aIter, &aResult->mAsyncZoomContainerId);
+}
+
+void ParamTraits<mozilla::layers::WebRenderScrollData>::Write(
+    Message* aMsg, const paramType& aParam) {
+  WriteParam(aMsg, aParam.mScrollMetadatas);
+  WriteParam(aMsg, aParam.mLayerScrollData);
+  WriteParam(aMsg, aParam.mIsFirstPaint);
+  WriteParam(aMsg, aParam.mPaintSequenceNumber);
+}
+
+bool ParamTraits<mozilla::layers::WebRenderScrollData>::Read(
+    const Message* aMsg, PickleIterator* aIter, paramType* aResult) {
+  return ReadParam(aMsg, aIter, &aResult->mScrollMetadatas) &&
+         ReadParam(aMsg, aIter, &aResult->mLayerScrollData) &&
+         ReadParam(aMsg, aIter, &aResult->mIsFirstPaint) &&
+         ReadParam(aMsg, aIter, &aResult->mPaintSequenceNumber) &&
+         aResult->RepopulateMap();
+}
+
+}  // namespace IPC