Capturing the old view transition snapshot includes descendant view-t…

…ransition.

https://bugs.webkit.org/show_bug.cgi?id=270056
<rdar://123606877>

Reviewed by Tim Nguyen.

The 'capture the image' algorithm should skip over descendant elements that
also have a view transition.

This changes snapshotNodeVisualOverflowClippedToViewport to call 'paint' on
the RenderLayer of the element with a view-transition directly rather than
calling it on the root elements Layer (with a subtree painting root set).

It adds a new PaintFlag 'PaintingSkipDescendantViewTransition' which skips descending
into child layers that are being separately captured in a view transition.

* LayoutTests/TestExpectations:
* Source/WebCore/dom/ViewTransition.cpp:
(WebCore::snapshotNodeVisualOverflowClippedToViewport):
(WebCore::ViewTransition::captureOldState):
* Source/WebCore/rendering/RenderLayer.cpp:
(WebCore::RenderLayer::paintList):
* Source/WebCore/rendering/RenderLayer.h:

Canonical link: https://commits.webkit.org/275312@main

LayoutTests/TestExpectations

@@ -6883,16 +6883,12 @@ imported/w3c/web-platform-tests/navigation-api/updateCurrentEntry-method/locatio
 # Reftest failures:
 imported/w3c/web-platform-tests/css/css-view-transitions/3d-transform-incoming.html [ ImageOnlyFailure ]
 imported/w3c/web-platform-tests/css/css-view-transitions/3d-transform-outgoing.html [ ImageOnlyFailure ]
-imported/w3c/web-platform-tests/css/css-view-transitions/animating-new-content-subset.html [ ImageOnlyFailure ]
-imported/w3c/web-platform-tests/css/css-view-transitions/animating-new-content.html [ ImageOnlyFailure ]
 imported/w3c/web-platform-tests/css/css-view-transitions/block-with-overflowing-text.html [ ImageOnlyFailure ]
 imported/w3c/web-platform-tests/css/css-view-transitions/capture-with-offscreen-child-translated.html [ ImageOnlyFailure ]
 imported/w3c/web-platform-tests/css/css-view-transitions/capture-with-visibility-mixed-descendants.html [ ImageOnlyFailure ]
-imported/w3c/web-platform-tests/css/css-view-transitions/content-smaller-than-box-size.html [ ImageOnlyFailure ]
 imported/w3c/web-platform-tests/css/css-view-transitions/content-with-child-with-transparent-background.html [ ImageOnlyFailure ]
 imported/w3c/web-platform-tests/css/css-view-transitions/content-with-clip-root.html [ ImageOnlyFailure ]
 imported/w3c/web-platform-tests/css/css-view-transitions/content-with-transform-old-image.html [ ImageOnlyFailure ]
-imported/w3c/web-platform-tests/css/css-view-transitions/content-with-transparent-background.html [ ImageOnlyFailure ]
 imported/w3c/web-platform-tests/css/css-view-transitions/css-tags-shared-element.html [ ImageOnlyFailure ]
 imported/w3c/web-platform-tests/css/css-view-transitions/dialog-in-top-layer-during-transition-new.html [ ImageOnlyFailure ]
 imported/w3c/web-platform-tests/css/css-view-transitions/element-is-grouping-during-animation.html [ ImageOnlyFailure ]
@@ -6922,10 +6918,8 @@ imported/w3c/web-platform-tests/css/css-view-transitions/object-view-box-new-ima
 imported/w3c/web-platform-tests/css/css-view-transitions/object-view-box-old-image.html [ ImageOnlyFailure ]
 imported/w3c/web-platform-tests/css/css-view-transitions/old-content-captures-clip-path.html [ ImageOnlyFailure ]
 imported/w3c/web-platform-tests/css/css-view-transitions/old-content-captures-different-size.html [ ImageOnlyFailure ]
-imported/w3c/web-platform-tests/css/css-view-transitions/old-content-has-scrollbars.html [ ImageOnlyFailure ]
 imported/w3c/web-platform-tests/css/css-view-transitions/old-content-intrinsic-aspect-ratio.html [ ImageOnlyFailure ]
 imported/w3c/web-platform-tests/css/css-view-transitions/old-content-with-overflow-zoomed.html [ ImageOnlyFailure ]
-imported/w3c/web-platform-tests/css/css-view-transitions/old-root-vertical-writing-mode.html [ ImageOnlyFailure ]
 imported/w3c/web-platform-tests/css/css-view-transitions/root-captured-as-different-tag.html [ ImageOnlyFailure ]
 imported/w3c/web-platform-tests/css/css-view-transitions/root-scrollbar-with-fixed-background.html [ ImageOnlyFailure ]
 imported/w3c/web-platform-tests/css/css-view-transitions/root-style-change-during-animation.html [ ImageOnlyFailure ]
@@ -6935,7 +6929,6 @@ imported/w3c/web-platform-tests/css/css-view-transitions/root-to-shared-animatio
 imported/w3c/web-platform-tests/css/css-view-transitions/snapshot-containing-block-absolute.html [ ImageOnlyFailure ]
 imported/w3c/web-platform-tests/css/css-view-transitions/span-with-overflowing-text-and-box-decorations.html [ ImageOnlyFailure ]
 imported/w3c/web-platform-tests/css/css-view-transitions/span-with-overflowing-text.html [ ImageOnlyFailure ]
-imported/w3c/web-platform-tests/css/css-view-transitions/transform-origin-view-transition-group.html [ ImageOnlyFailure ]
 imported/w3c/web-platform-tests/css/css-view-transitions/view-transition-name-is-grouping.html [ ImageOnlyFailure ]
 imported/w3c/web-platform-tests/css/css-view-transitions/writing-mode-container-resize.html [ ImageOnlyFailure ]
 imported/w3c/web-platform-tests/css/css-view-transitions/capture-with-offscreen-child.html [ ImageOnlyFailure ]
@@ -6976,7 +6969,7 @@ imported/w3c/web-platform-tests/css/css-view-transitions/scroller-child-abspos.h
 imported/w3c/web-platform-tests/css/css-view-transitions/scroller-child.html [ ImageOnlyFailure ]
 imported/w3c/web-platform-tests/css/css-view-transitions/scroller.html [ ImageOnlyFailure ]
 imported/w3c/web-platform-tests/css/css-view-transitions/new-content-element-writing-modes.html [ ImageOnlyFailure ]
-imported/w3c/web-platform-tests/css/css-view-transitions/content-with-clip.html [ ImageOnlyFailure ]
+imported/w3c/web-platform-tests/css/css-view-transitions/massive-element-below-viewport-partially-onscreen-old.html [ ImageOnlyFailure ]
 
 # Timeouts
 imported/w3c/web-platform-tests/css/css-view-transitions/iframe-transition.sub.html [ Skip ]

Source/WebCore/dom/ViewTransition.cpp

@@ -34,6 +34,7 @@
 #include "Document.h"
 #include "DocumentTimeline.h"
 #include "FrameSnapshotting.h"
+#include "HostWindow.h"
 #include "JSDOMPromise.h"
 #include "JSDOMPromiseDeferred.h"
 #include "LayoutRect.h"
@@ -262,32 +263,38 @@ static ExceptionOr<void> checkDuplicateViewTransitionName(const AtomString& name
     return { };
 }
 
-static RefPtr<ImageBuffer> snapshotNodeVisualOverflowClippedToViewport(LocalFrame& frame, Node& node, SnapshotOptions&& options, LayoutRect& oldOverflowRect)
+static RefPtr<ImageBuffer> snapshotNodeVisualOverflowClippedToViewport(LocalFrame& frame, Node& node, LayoutRect& oldOverflowRect)
 {
     if (!node.renderer())
         return nullptr;
 
-    auto paintBehavior = frame.view()->paintBehavior();
-    auto backgroundColor = frame.view()->baseBackgroundColor();
+    ASSERT(node.renderer()->hasLayer());
+    CheckedPtr layerRenderer = downcast<RenderLayerModelObject>(node.renderer());
 
-    options.flags.add(SnapshotFlags::Accelerated);
+    oldOverflowRect = layerRenderer->layer()->localBoundingBox();
+    IntRect paintRect = snappedIntRect(oldOverflowRect);
 
-    frame.view()->setBaseBackgroundColor(Color::transparentBlack);
-    frame.view()->setNodeToDraw(&node);
+    ASSERT(frame.page());
+    float scaleFactor = frame.page()->deviceScaleFactor();
+    if (frame.page()->delegatesScaling())
+        scaleFactor *= frame.page()->pageScaleFactor();
 
-    ASSERT(node.renderer()->hasLayer());
-    CheckedPtr layerRenderer = downcast<RenderLayerModelObject>(node.renderer());
+    ASSERT(frame.document());
+    auto hostWindow = (frame.document()->view() && frame.document()->view()->root()) ? frame.document()->view()->root()->hostWindow() : nullptr;
+
+    auto buffer = ImageBuffer::create(paintRect.size(), RenderingPurpose::Snapshot, scaleFactor, DestinationColorSpace::SRGB(), PixelFormat::BGRA8, { ImageBufferOptions::Accelerated }, hostWindow);
+    if (!buffer)
+        return nullptr;
 
-    IntRect paintRect = layerRenderer->layer()->absoluteBoundingBox();
-    paintRect.intersect(snappedIntRect(frame.view()->layoutViewportRect()));
-    RefPtr result = snapshotFrameRect(frame, paintRect, WTFMove(options));
+    buffer->context().translate(-paintRect.location());
 
-    frame.view()->setPaintBehavior(paintBehavior);
-    frame.view()->setBaseBackgroundColor(backgroundColor);
-    frame.view()->setNodeToDraw(nullptr);
+    auto paintFlags = RenderLayer::paintLayerPaintingCompositingAllPhasesFlags();
+    paintFlags.add(RenderLayer::PaintLayerFlag::TemporaryClipRects);
+    paintFlags.add(RenderLayer::PaintLayerFlag::AppliedTransform);
+    paintFlags.add(RenderLayer::PaintLayerFlag::PaintingSkipDescendantViewTransition);
+    layerRenderer->layer()->paint(buffer->context(), paintRect, LayoutSize(), { PaintBehavior::FlattenCompositingLayers, PaintBehavior::Snapshotting }, nullptr, paintFlags);
 
-    oldOverflowRect = layerRenderer->layer()->localBoundingBox();
-    return result;
+    return buffer;
 }
 
 // This only iterates through elements with a RenderLayer, which is sufficient for View Transitions which force their creation.
@@ -351,7 +358,7 @@ ExceptionOr<void> ViewTransition::captureOldState()
             capture.oldSize = renderBox->size();
         capture.oldProperties = copyElementBaseProperties(element);
         if (m_document->frame())
-            capture.oldImage = snapshotNodeVisualOverflowClippedToViewport(*m_document->frame(), element.get(), { { }, PixelFormat::BGRA8, DestinationColorSpace::SRGB() }, capture.oldOverflowRect);
+            capture.oldImage = snapshotNodeVisualOverflowClippedToViewport(*m_document->frame(), element.get(), capture.oldOverflowRect);
 
         auto transitionName = element->computedStyle()->viewTransitionName();
         m_namedElements.add(transitionName->name, capture);

Source/WebCore/rendering/RenderLayer.cpp

@@ -3520,8 +3520,11 @@ void RenderLayer::paintList(LayerList layerIterator, GraphicsContext& context, c
     LayerListMutationDetector mutationChecker(*this);
 #endif
 
-    for (auto* childLayer : layerIterator)
+    for (auto* childLayer : layerIterator) {
+        if (paintFlags.contains(PaintLayerFlag::PaintingSkipDescendantViewTransition) && childLayer->renderer().capturedInViewTransition())
+            continue;
         childLayer->paintLayer(context, paintingInfo, paintFlags);
+    }
 }
 
 RenderLayer* RenderLayer::enclosingPaginationLayerInSubtree(const RenderLayer* rootLayer, PaginationInclusionMode mode) const

Source/WebCore/rendering/RenderLayer.h

@@ -606,7 +606,7 @@ class RenderLayer : public CanMakeSingleThreadWeakPtr<RenderLayer>, public CanMa
 
     inline int zIndex() const;
 
-    enum class PaintLayerFlag : uint16_t {
+    enum class PaintLayerFlag : uint32_t {
         HaveTransparency                      = 1 << 0,
         AppliedTransform                      = 1 << 1,
         TemporaryClipRects                    = 1 << 2,
@@ -623,6 +623,7 @@ class RenderLayer : public CanMakeSingleThreadWeakPtr<RenderLayer>, public CanMa
         PaintingChildClippingMaskPhase        = 1 << 13,
         PaintingSVGClippingMask               = 1 << 14,
         CollectingEventRegion                 = 1 << 15,
+        PaintingSkipDescendantViewTransition  = 1 << 16,
     };
     static constexpr OptionSet<PaintLayerFlag> paintLayerPaintingCompositingAllPhasesFlags() { return { PaintLayerFlag::PaintingCompositingBackgroundPhase, PaintLayerFlag::PaintingCompositingForegroundPhase }; }