Changeset 243209 in webkit

Timestamp:

Mar 20, 2019 9:32:32 AM (5 years ago)

Author:

Simon Fraser

Message:

Explicitly trigger compositing for layers that need to be moved by ScrollingTreePositionedNodes
​https://bugs.webkit.org/show_bug.cgi?id=195710
Source/WebCore:

<rdar://problem/48867502>

Reviewed by Zalan Bujtas.

A position:absolute layer whose containing block is outside an enclosing overflow:scroll, but
whose compositing ancestor is the overflow or is inside it, needs to be composited so that
we can make a Positioning scrolling tree node for it.

Handle this case as a "OverflowScrollPositioning" indirect compositing reason.

Test: compositing/layer-creation/absolute-in-async-overflow-scroll.html

• inspector/agents/InspectorLayerTreeAgent.cpp:

(WebCore::InspectorLayerTreeAgent::reasonsForCompositingLayer):

• rendering/RenderLayer.h:
• rendering/RenderLayerCompositor.cpp:

(WebCore::RenderLayerCompositor::computeCompositingRequirements):
(WebCore::RenderLayerCompositor::requiresOwnBackingStore const):
(WebCore::RenderLayerCompositor::reasonsForCompositing const):
(WebCore::RenderLayerCompositor::logReasonsForCompositing):
(WebCore::RenderLayerCompositor::requiresCompositingForIndirectReason const):
(WebCore::RenderLayerCompositor::layerContainingBlockCrossesCoordinatedScrollingBoundary):
(WebCore::layerContainingBlockCrossesCoordinatedScrollingBoundary): Deleted.

• rendering/RenderLayerCompositor.h: Generalize OverflowScrollingTouch to OverflowScrolling.

LayoutTests:

Reviewed by Zalan Bujtas.

• compositing/layer-creation/absolute-in-async-overflow-scroll-expected.txt: Added.
• compositing/layer-creation/absolute-in-async-overflow-scroll.html: Added.

Location:

trunk

Files:

• LayoutTests/ChangeLog (modified) (1 diff)
• LayoutTests/compositing/layer-creation/absolute-in-async-overflow-scroll-expected.txt (added)
• LayoutTests/compositing/layer-creation/absolute-in-async-overflow-scroll.html (added)
• LayoutTests/platform/ios-wk2/scrollingcoordinator/scrolling-tree/positioned-nodes-expected.txt (modified) (1 diff)
• LayoutTests/scrollingcoordinator/scrolling-tree/positioned-nodes-expected.txt (modified) (1 diff)
• Source/WebCore/ChangeLog (modified) (1 diff)
• Source/WebCore/inspector/agents/InspectorLayerTreeAgent.cpp (modified) (1 diff)
• Source/WebCore/rendering/RenderLayer.h (modified) (1 diff)
• Source/WebCore/rendering/RenderLayerCompositor.cpp (modified) (8 diffs)
• Source/WebCore/rendering/RenderLayerCompositor.h (modified) (2 diffs)

trunk/LayoutTests/ChangeLog

@@ +1 @@
+2019-03-20  Simon Fraser  <simon.fraser@apple.com>
+
+        Explicitly trigger compositing for layers that need to be moved by ScrollingTreePositionedNodes
+        https://bugs.webkit.org/show_bug.cgi?id=195710
+
+        Reviewed by Zalan Bujtas.
+
+        * compositing/layer-creation/absolute-in-async-overflow-scroll-expected.txt: Added.
+        * compositing/layer-creation/absolute-in-async-overflow-scroll.html: Added.
+
 2019-03-20  Devin Rousso  <drousso@apple.com>
 

trunk/LayoutTests/platform/ios-wk2/scrollingcoordinator/scrolling-tree/positioned-nodes-expected.txt

@@ -82 +82 @@
         (vertical scrollbar mode 0)
         (has enabled vertical scrollbar 1))
+      (children 1
+        (Positioned node
+          (layout constraints 
+            (layer-position-at-last-layout (81,30))
+            (positioning-behavior stationary))
+          (related overflow nodes 1)
+        )
+      )
     )
   )

trunk/LayoutTests/scrollingcoordinator/scrolling-tree/positioned-nodes-expected.txt

@@ -83 +83 @@
         (vertical scrollbar mode 0)
         (has enabled vertical scrollbar 1))
+      (children 1
+        (Positioned node
+          (layout constraints 
+            (layer-position-at-last-layout (81,28))
+            (positioning-behavior stationary))
+          (related overflow nodes 1)
+        )
+      )
     )
   )

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2019-03-20  Simon Fraser  <simon.fraser@apple.com>
+
+        Explicitly trigger compositing for layers that need to be moved by ScrollingTreePositionedNodes
+        https://bugs.webkit.org/show_bug.cgi?id=195710
+        <rdar://problem/48867502>
+
+        Reviewed by Zalan Bujtas.
+
+        A position:absolute layer whose containing block is outside an enclosing overflow:scroll, but
+        whose compositing ancestor is the overflow or is inside it, needs to be composited so that
+        we can make a Positioning scrolling tree node for it.
+
+        Handle this case as a "OverflowScrollPositioning" indirect compositing reason.
+
+        Test: compositing/layer-creation/absolute-in-async-overflow-scroll.html
+
+        * inspector/agents/InspectorLayerTreeAgent.cpp:
+        (WebCore::InspectorLayerTreeAgent::reasonsForCompositingLayer):
+        * rendering/RenderLayer.h:
+        * rendering/RenderLayerCompositor.cpp:
+        (WebCore::RenderLayerCompositor::computeCompositingRequirements):
+        (WebCore::RenderLayerCompositor::requiresOwnBackingStore const):
+        (WebCore::RenderLayerCompositor::reasonsForCompositing const):
+        (WebCore::RenderLayerCompositor::logReasonsForCompositing):
+        (WebCore::RenderLayerCompositor::requiresCompositingForIndirectReason const):
+        (WebCore::RenderLayerCompositor::layerContainingBlockCrossesCoordinatedScrollingBoundary):
+        (WebCore::layerContainingBlockCrossesCoordinatedScrollingBoundary): Deleted.
+        * rendering/RenderLayerCompositor.h: Generalize OverflowScrollingTouch to OverflowScrolling.
+
 2019-03-20  Devin Rousso  <drousso@apple.com>
 

trunk/Source/WebCore/inspector/agents/InspectorLayerTreeAgent.cpp

@@ -277 +277 @@
         compositingReasons->setPositionSticky(true);
 
-    if (reasons.contains(CompositingReason::OverflowScrollingTouch))
+    if (reasons.contains(CompositingReason::OverflowScrolling))
         compositingReasons->setOverflowScrollingTouch(true);
+
+    // FIXME: handle OverflowScrollPositioning (webkit.org/b/195985).
 
     if (reasons.contains(CompositingReason::Stacking))

trunk/Source/WebCore/rendering/RenderLayer.h

@@ -1124 +1124 @@
         None,
         Stacking,
+        OverflowScrollPositioning,
         Overlap,
         BackgroundLayer,

trunk/Source/WebCore/rendering/RenderLayerCompositor.cpp

@@ -956 +956 @@
     RenderLayer::IndirectCompositingReason indirectCompositingReason;
     if (!willBeComposited && canBeComposited(layer)
-        && requiresCompositingForIndirectReason(layer.renderer(), childState.subtreeIsCompositing, anyDescendantHas3DTransform, indirectCompositingReason)) {
+        && requiresCompositingForIndirectReason(layer.renderer(), compositingState.compositingAncestor, childState.subtreeIsCompositing, anyDescendantHas3DTransform, indirectCompositingReason)) {
         layer.setIndirectCompositingReason(indirectCompositingReason);
         childState.compositingAncestor = &layer;
@@ -2229 +2229 @@
         RenderLayer::IndirectCompositingReason reason = layer.indirectCompositingReason();
         return reason == RenderLayer::IndirectCompositingReason::Overlap
+            || reason == RenderLayer::IndirectCompositingReason::OverflowScrollPositioning
             || reason == RenderLayer::IndirectCompositingReason::Stacking
             || reason == RenderLayer::IndirectCompositingReason::BackgroundLayer
@@ -2285 +2286 @@
 
     if (requiresCompositingForOverflowScrolling(*renderer.layer(), queryData))
-        reasons.add(CompositingReason::OverflowScrollingTouch);
+        reasons.add(CompositingReason::OverflowScrolling);
 
     switch (renderer.layer()->indirectCompositingReason()) {
@@ -2292 +2293 @@
     case RenderLayer::IndirectCompositingReason::Stacking:
         reasons.add(CompositingReason::Stacking);
+        break;
+    case RenderLayer::IndirectCompositingReason::OverflowScrollPositioning:
+        reasons.add(CompositingReason::OverflowScrollPositioning);
         break;
     case RenderLayer::IndirectCompositingReason::Overlap:
@@ -2375 +2379 @@
         return "position: sticky";
 
-    if (reasons & CompositingReason::OverflowScrollingTouch)
-        return "-webkit-overflow-scrolling: touch";
+    if (reasons & CompositingReason::OverflowScrolling)
+        return "async overflow scrolling";
 
     if (reasons & CompositingReason::Stacking)
@@ -2767 +2771 @@
 
 // FIXME: why doesn't this handle the clipping cases?
-bool RenderLayerCompositor::requiresCompositingForIndirectReason(RenderLayerModelObject& renderer, bool hasCompositedDescendants, bool has3DTransformedDescendants, RenderLayer::IndirectCompositingReason& reason) const
-{
-    auto& layer = *downcast<RenderBoxModelObject>(renderer).layer();
+bool RenderLayerCompositor::requiresCompositingForIndirectReason(RenderLayerModelObject& renderer, const RenderLayer* compositingAncestor, bool hasCompositedDescendants, bool has3DTransformedDescendants, RenderLayer::IndirectCompositingReason& reason) const
+{
+    auto& layer = *renderer.layer();
 
     // When a layer has composited descendants, some effects, like 2d transforms, filters, masks etc must be implemented
@@ -2788 +2792 @@
         if (renderer.style().hasPerspective()) {
             reason = RenderLayer::IndirectCompositingReason::Perspective;
+            return true;
+        }
+    }
+
+    if (renderer.isAbsolutelyPositioned() && compositingAncestor) {
+        if (layerContainingBlockCrossesCoordinatedScrollingBoundary(layer, *compositingAncestor)) {
+            reason = RenderLayer::IndirectCompositingReason::OverflowScrollPositioning;
             return true;
         }
@@ -2893 +2904 @@
 
 // Is this layer's containingBlock an ancestor of scrollable overflow, and is the layer's compositing ancestor inside that overflow?
-static bool layerContainingBlockCrossesCoordinatedScrollingBoundary(const RenderLayer& layer, const RenderLayer& compositedAncestor)
-{
-    ASSERT(layer.isComposited());
-    ASSERT(layer.renderer().style().position() == PositionType::Absolute);
+bool RenderLayerCompositor::layerContainingBlockCrossesCoordinatedScrollingBoundary(const RenderLayer& layer, const RenderLayer& compositedAncestor)
+{
+    ASSERT(layer.renderer().isAbsolutelyPositioned());
 
     bool sawCompositingAncestor = false;

trunk/Source/WebCore/rendering/RenderLayerCompositor.h

@@ -66 +66 @@
     PositionFixed                          = 1 << 9,
     PositionSticky                         = 1 << 10,
-    OverflowScrollingTouch                 = 1 << 11,
+    OverflowScrolling                      = 1 << 11,
     Stacking                               = 1 << 12,
     Overlap                                = 1 << 13,
-    NegativeZIndexChildren                 = 1 << 14,
-    TransformWithCompositedDescendants     = 1 << 15,
-    OpacityWithCompositedDescendants       = 1 << 16,
-    MaskWithCompositedDescendants          = 1 << 17,
-    ReflectionWithCompositedDescendants    = 1 << 18,
-    FilterWithCompositedDescendants        = 1 << 19,
-    BlendingWithCompositedDescendants      = 1 << 20,
-    Perspective                            = 1 << 21,
-    Preserve3D                             = 1 << 22,
-    WillChange                             = 1 << 23,
-    Root                                   = 1 << 24,
-    IsolatesCompositedBlendingDescendants  = 1 << 25,
-    EmbeddedView                           = 1 << 26,
+    OverflowScrollPositioning              = 1 << 14,
+    NegativeZIndexChildren                 = 1 << 15,
+    TransformWithCompositedDescendants     = 1 << 16,
+    OpacityWithCompositedDescendants       = 1 << 17,
+    MaskWithCompositedDescendants          = 1 << 18,
+    ReflectionWithCompositedDescendants    = 1 << 19,
+    FilterWithCompositedDescendants        = 1 << 20,
+    BlendingWithCompositedDescendants      = 1 << 21,
+    Perspective                            = 1 << 22,
+    Preserve3D                             = 1 << 23,
+    WillChange                             = 1 << 24,
+    Root                                   = 1 << 25,
+    IsolatesCompositedBlendingDescendants  = 1 << 26,
+    EmbeddedView                           = 1 << 27,
 };
 
@@ -476 +477 @@
     bool requiresCompositingForOverflowScrolling(const RenderLayer&, RequiresCompositingData&) const;
     bool requiresCompositingForEditableImage(RenderLayerModelObject&) const;
-    bool requiresCompositingForIndirectReason(RenderLayerModelObject&, bool hasCompositedDescendants, bool has3DTransformedDescendants, RenderLayer::IndirectCompositingReason&) const;
+    bool requiresCompositingForIndirectReason(RenderLayerModelObject&, const RenderLayer* compositingAncestor, bool hasCompositedDescendants, bool has3DTransformedDescendants, RenderLayer::IndirectCompositingReason&) const;
+
+    static bool layerContainingBlockCrossesCoordinatedScrollingBoundary(const RenderLayer&, const RenderLayer& compositedAncestor);
 
     static bool styleChangeMayAffectIndirectCompositingReasons(const RenderStyle& oldStyle, const RenderStyle& newStyle);