Changeset 271508 in webkit

Timestamp:

Jan 14, 2021 9:12:47 PM (18 months ago)

Author:

Simon Fraser

Message:

[Async scrolling] Slow-scrolling reasons should not propagate across frame boundaries
​https://bugs.webkit.org/show_bug.cgi?id=220635

Reviewed by Tim Horton.

Source/WebCore:

We should be able to do fast scrolling of the main frame when a subframe has background-attachment:fixed
content in it, but currently we propagate the "slow scrolling reasons" up to the root of
the scrolling tree, which crosses frame boundaries.

This is a partial fix for the problem; ThreadedScrollingTree::canUpdateLayersOnScrollingThread()
is still consulting tree-wide state.

Test: scrollingcoordinator/mac/fixed-backgrounds/fixed-background-in-overflow-in-iframe.html

• page/scrolling/ScrollingStateFrameScrollingNode.cpp:

(WebCore::ScrollingStateFrameScrollingNode::dumpProperties const):

• page/scrolling/ThreadedScrollingTree.cpp:

(WebCore::ThreadedScrollingTree::propagateSynchronousScrollingReasons):
(WebCore::ThreadedScrollingTree::canUpdateLayersOnScrollingThread const):

• page/scrolling/ThreadedScrollingTree.h:

LayoutTests:

• scrollingcoordinator/mac/fixed-backgrounds/fixed-background-in-overflow-in-iframe-expected.txt: Added.
• scrollingcoordinator/mac/fixed-backgrounds/fixed-background-in-overflow-in-iframe.html: Added.

Location:

trunk

Files:

• LayoutTests/ChangeLog (modified) (1 diff)
• LayoutTests/scrollingcoordinator/mac/fixed-backgrounds/fixed-background-in-overflow-in-iframe-expected.txt (added)
• LayoutTests/scrollingcoordinator/mac/fixed-backgrounds/fixed-background-in-overflow-in-iframe.html (added)
• Source/WebCore/ChangeLog (modified) (1 diff)
• Source/WebCore/page/scrolling/ScrollingStateFrameScrollingNode.cpp (modified) (1 diff)
• Source/WebCore/page/scrolling/ThreadedScrollingTree.cpp (modified) (3 diffs)
• Source/WebCore/page/scrolling/ThreadedScrollingTree.h (modified) (1 diff)

trunk/LayoutTests/ChangeLog

@@ +1 @@
+2021-01-14  Simon Fraser  <simon.fraser@apple.com>
+
+        [Async scrolling] Slow-scrolling reasons should not propagate across frame boundaries
+        https://bugs.webkit.org/show_bug.cgi?id=220635
+
+        Reviewed by Tim Horton.
+
+        * scrollingcoordinator/mac/fixed-backgrounds/fixed-background-in-overflow-in-iframe-expected.txt: Added.
+        * scrollingcoordinator/mac/fixed-backgrounds/fixed-background-in-overflow-in-iframe.html: Added.
+
 2021-01-14  Aditya Keerthi  <akeerthi@apple.com>
 

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2021-01-14  Simon Fraser  <simon.fraser@apple.com>
+
+        [Async scrolling] Slow-scrolling reasons should not propagate across frame boundaries
+        https://bugs.webkit.org/show_bug.cgi?id=220635
+
+        Reviewed by Tim Horton.
+
+        We should be able to do fast scrolling of the main frame when a subframe has background-attachment:fixed
+        content in it, but currently we propagate the "slow scrolling reasons" up to the root of
+        the scrolling tree, which crosses frame boundaries.
+
+        This is a partial fix for the problem; ThreadedScrollingTree::canUpdateLayersOnScrollingThread()
+        is still consulting tree-wide state.
+
+        Test: scrollingcoordinator/mac/fixed-backgrounds/fixed-background-in-overflow-in-iframe.html
+
+        * page/scrolling/ScrollingStateFrameScrollingNode.cpp:
+        (WebCore::ScrollingStateFrameScrollingNode::dumpProperties const):
+        * page/scrolling/ThreadedScrollingTree.cpp:
+        (WebCore::ThreadedScrollingTree::propagateSynchronousScrollingReasons):
+        (WebCore::ThreadedScrollingTree::canUpdateLayersOnScrollingThread const):
+        * page/scrolling/ThreadedScrollingTree.h:
+
 2021-01-14  Aditya Keerthi  <akeerthi@apple.com>
 

trunk/Source/WebCore/page/scrolling/ScrollingStateFrameScrollingNode.cpp

@@ -318 +318 @@
     if (behavior & ScrollingStateTreeAsTextBehaviorIncludeLayerIDs) {
         ts.dumpProperty("root contents layer ID", m_rootContentsLayer.layerID());
-        ts.dumpProperty("counter scrolling layer ID", m_counterScrollingLayer.layerID());
-        ts.dumpProperty("inset clip layer ID", m_insetClipLayer.layerID());
-        ts.dumpProperty("content shadow layer ID", m_contentShadowLayer.layerID());
-        ts.dumpProperty("header layer ID", m_headerLayer.layerID());
-        ts.dumpProperty("footer layer ID", m_footerLayer.layerID());
+        if (m_counterScrollingLayer.layerID())
+            ts.dumpProperty("counter scrolling layer ID", m_counterScrollingLayer.layerID());
+        if (m_insetClipLayer.layerID())
+            ts.dumpProperty("inset clip layer ID", m_insetClipLayer.layerID());
+        if (m_contentShadowLayer.layerID())
+            ts.dumpProperty("content shadow layer ID", m_contentShadowLayer.layerID());
+        if (m_headerLayer.layerID())
+            ts.dumpProperty("header layer ID", m_headerLayer.layerID());
+        if (m_footerLayer.layerID())
+            ts.dumpProperty("footer layer ID", m_footerLayer.layerID());
     }
 

trunk/Source/WebCore/page/scrolling/ThreadedScrollingTree.cpp

@@ -169 +169 @@
                 continue;
             }
+            
+            if (is<ScrollingTreeFrameScrollingNode>(currNode))
+                break;
 
             currNode = currNode->parent();
@@ -174 +177 @@
     };
 
+    m_hasNodesWithSynchronousScrollingReasons = !synchronousScrollingNodes.isEmpty();
+
     for (auto nodeID : synchronousScrollingNodes) {
         if (auto node = nodeForID(nodeID))
@@ -182 +187 @@
 bool ThreadedScrollingTree::canUpdateLayersOnScrollingThread() const
 {
-    auto* rootNode = this->rootNode();
-    return !(rootNode && rootNode->hasSynchronousScrollingReasons());
+    return m_hasNodesWithSynchronousScrollingReasons;
 }
 

trunk/Source/WebCore/page/scrolling/ThreadedScrollingTree.h

@@ -114 +114 @@
 
     bool m_scrollAnimatorEnabled { false };
+    bool m_hasNodesWithSynchronousScrollingReasons { false };
 };