void
WebRenderLayerScrollData::Initialize(WebRenderScrollData& aOwner,
Layer* aLayer,
int32_t aDescendantCount)
{
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(aLayer);
for (uint32_t i = 0; i < aLayer->GetScrollMetadataCount(); i++) {
mScrollIds.AppendElement(aOwner.AddMetadata(aLayer->GetScrollMetadata(i)));
}
mIsScrollInfoLayer = aLayer->AsContainerLayer() && !aLayer->GetFirstChild();
mTransform = aLayer->GetTransform();
mTransformIsPerspective = aLayer->GetTransformIsPerspective();
mEventRegions = aLayer->GetEventRegions();
mReferentId = aLayer->AsRefLayer()
? Some(aLayer->AsRefLayer()->GetReferentId())
: Nothing();
mEventRegionsOverride = aLayer->AsContainerLayer()
? aLayer->AsContainerLayer()->GetEventRegionsOverride()
: EventRegionsOverride::NoOverride;
mScrollThumbData = aLayer->GetScrollThumbData();
mScrollbarTargetContainerId = aLayer->GetScrollbarTargetContainerId();
mIsScrollbarContainer = aLayer->IsScrollbarContainer();
mFixedPosScrollContainerId = aLayer->GetFixedPositionScrollContainerId();
}
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);
asr->mScrollableFrame->NotifyApzTransaction();
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;
}
}
void
WebRenderLayerScrollData::AppendScrollMetadata(WebRenderScrollData& aOwner,
const ScrollMetadata& aData)
{
mScrollIds.AppendElement(aOwner.AddMetadata(aData));
}