Changeset 277482 in webkit

Timestamp:

May 13, 2021, 10:52:46 PM (5 years ago)

Author:

Carlos Garcia Campos

Message:

[GTK] Wrong smooth animation sometimes with non-async scrolling
​https://bugs.webkit.org/show_bug.cgi?id=225764

Reviewed by Adrian Perez de Castro.

This is happening because sometimes when the scrollbars are added to the scroll view, the contents size hasn't
been updated yet, so that values saved by ScrollAnimationSmooth::updateVisibleLengths() are 0x0. After that the
updateVisibleLengths() is not called again when the contents size is updated, so scroll happens with the wrong
visible lengths. This doesn't happen with async scrolling because updateVisibleLengths() is called every time
layers are repositioned. For non-async scrolling it should be enough to update visible lengths when he contents
size changes.

• platform/ScrollAnimator.cpp:

(WebCore::ScrollAnimator::contentsResized const):

• platform/ScrollAnimator.h:

(WebCore::ScrollAnimator::ScrollAnimator::contentsResized const):

Location:

trunk/Source/WebCore

Files:

• ChangeLog (modified) (1 diff)
• platform/ScrollAnimator.cpp (modified) (1 diff)
• platform/ScrollAnimator.h (modified) (1 diff)

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2021-05-13  Carlos Garcia Campos  <cgarcia@igalia.com>
+
+        [GTK] Wrong smooth animation sometimes with non-async scrolling
+        https://bugs.webkit.org/show_bug.cgi?id=225764
+
+        Reviewed by Adrian Perez de Castro.
+
+        This is happening because sometimes when the scrollbars are added to the scroll view, the contents size hasn't
+        been updated yet, so that values saved by ScrollAnimationSmooth::updateVisibleLengths() are 0x0. After that the
+        updateVisibleLengths() is not called again when the contents size is updated, so scroll happens with the wrong
+        visible lengths. This doesn't happen with async scrolling because updateVisibleLengths()  is called every time
+        layers are repositioned. For non-async scrolling it should be enough to update visible lengths when he contents
+        size changes.
+
+        * platform/ScrollAnimator.cpp:
+        (WebCore::ScrollAnimator::contentsResized const):
+        * platform/ScrollAnimator.h:
+        (WebCore::ScrollAnimator::ScrollAnimator::contentsResized const):
+
 2021-05-13  Devin Rousso  <drousso@apple.com>
 

trunk/Source/WebCore/platform/ScrollAnimator.cpp

@@ -380 +380 @@
 }
 
+void ScrollAnimator::contentsResized() const
+{
+    m_scrollAnimation->updateVisibleLengths();
+}
+
 void ScrollAnimator::willEndLiveResize()
 {

trunk/Source/WebCore/platform/ScrollAnimator.h

@@ -112 +112 @@
     virtual void mouseIsDownInScrollbar(Scrollbar*, bool) const { }
     virtual void willStartLiveResize() { }
-    virtual void contentsResized() const { }
+    virtual void contentsResized() const;
     virtual void willEndLiveResize();
     virtual void contentAreaDidShow() { }