Changeset 107467 in webkit

Timestamp:

Feb 10, 2012 6:33:17 PM (12 years ago)

Author:

andersca@apple.com

Message:

Always update the scroll position through the scrolling coordinator
​https://bugs.webkit.org/show_bug.cgi?id=78403

Reviewed by Sam Weinig.

To get correct behavior, we always want to update the scrolling layer position
on the scrolling thread. Do this by allowing the scrolling coordinator to intercept
scroll position update requests and send them to the scrolling tree.

• page/FrameView.cpp:

(WebCore::FrameView::requestScrollPositionUpdate):
Let the scrolling coordinator have a go at updating the scroll position for this frame view.

• page/scrolling/ScrollingCoordinator.cpp:

(WebCore::ScrollingCoordinator::requestScrollPositionUpdate):
If it's a frame view we're coordinating scrolling for, tell the scrolling tree to update
the scroll position.

• page/scrolling/ScrollingTree.cpp:

(WebCore::ScrollingTree::setMainFrameScrollPosition):
Call through to the scrolling tree node.

• page/scrolling/ScrollingTreeNode.h:

Add a new pure virtual setScrollPosition member function.

(WebCore::ScrollingTreeNodeMac::setScrollPosition):
Move most of the code from scrollBy here.

(WebCore::ScrollingTreeNodeMac::setScrollLayerPosition):
Rename this member function from setScrollPosition to avoid conflicts.

(WebCore::ScrollingTreeNodeMac::scrollBy):
Just call setScsrollPosition.

• platform/ScrollableArea.cpp:

(WebCore::ScrollableArea::setScrollOffsetFromAnimation):
Call requestScrollPositionUpdate, which allows subclasses of scrollable area to intercept
the scroll operation and call it asynchronously.

Location:

trunk/Source/WebCore

Files:

• ChangeLog (modified) (1 diff)
• page/FrameView.cpp (modified) (1 diff)
• page/FrameView.h (modified) (1 diff)
• page/scrolling/ScrollingCoordinator.cpp (modified) (1 diff)
• page/scrolling/ScrollingCoordinator.h (modified) (1 diff)
• page/scrolling/ScrollingTree.cpp (modified) (1 diff)
• page/scrolling/ScrollingTree.h (modified) (1 diff)
• page/scrolling/ScrollingTreeNode.h (modified) (1 diff)
• page/scrolling/mac/ScrollingTreeNodeMac.h (modified) (2 diffs)
• page/scrolling/mac/ScrollingTreeNodeMac.mm (modified) (3 diffs)
• platform/ScrollableArea.cpp (modified) (1 diff)
• platform/ScrollableArea.h (modified) (1 diff)

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2012-02-10  Anders Carlsson  <andersca@apple.com>
+
+        Always update the scroll position through the scrolling coordinator
+        https://bugs.webkit.org/show_bug.cgi?id=78403
+
+        Reviewed by Sam Weinig.
+
+        To get correct behavior, we always want to update the scrolling layer position
+        on the scrolling thread. Do this by allowing the scrolling coordinator to intercept
+        scroll position update requests and send them to the scrolling tree.
+
+        * page/FrameView.cpp:
+        (WebCore::FrameView::requestScrollPositionUpdate):
+        Let the scrolling coordinator have a go at updating the scroll position for this frame view.
+
+        * page/scrolling/ScrollingCoordinator.cpp:
+        (WebCore::ScrollingCoordinator::requestScrollPositionUpdate):
+        If it's a frame view we're coordinating scrolling for, tell the scrolling tree to update 
+        the scroll position.
+
+        * page/scrolling/ScrollingTree.cpp:
+        (WebCore::ScrollingTree::setMainFrameScrollPosition):
+        Call through to the scrolling tree node.
+
+        * page/scrolling/ScrollingTreeNode.h:
+        Add a new pure virtual setScrollPosition member function.
+
+        (WebCore::ScrollingTreeNodeMac::setScrollPosition):
+        Move most of the code from scrollBy here.
+
+        (WebCore::ScrollingTreeNodeMac::setScrollLayerPosition):
+        Rename this member function from setScrollPosition to avoid conflicts.
+
+        (WebCore::ScrollingTreeNodeMac::scrollBy):
+        Just call setScsrollPosition.
+
+        * platform/ScrollableArea.cpp:
+        (WebCore::ScrollableArea::setScrollOffsetFromAnimation):
+        Call requestScrollPositionUpdate, which allows subclasses of scrollable area to intercept
+        the scroll operation and call it asynchronously.
+
 2012-02-10  Anders Carlsson  <andersca@apple.com>
 

trunk/Source/WebCore/page/FrameView.cpp

@@ -1760 +1760 @@
 }
 
+bool FrameView::requestScrollPositionUpdate(const IntPoint& position)
+{
+#if ENABLE(THREADED_SCROLLING)
+    if (Page* page = m_frame->page()) {
+        if (ScrollingCoordinator* scrollingCoordinator = page->scrollingCoordinator())
+            return scrollingCoordinator->requestScrollPositionUpdate(this, position);
+    }
+#endif
+
+    return false;
+}
+
 HostWindow* FrameView::hostWindow() const
 {

trunk/Source/WebCore/page/FrameView.h

@@ -170 +170 @@
     virtual void repaintFixedElementsAfterScrolling();
     virtual bool shouldRubberBandInDirection(ScrollDirection) const;
+    virtual bool requestScrollPositionUpdate(const IntPoint&) OVERRIDE;
 
     virtual void zoomAnimatorTransformChanged(float, float, float, ZoomAnimationState);

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

@@ -159 +159 @@
 }
 
+bool ScrollingCoordinator::requestScrollPositionUpdate(FrameView* frameView, const IntPoint& scrollPosition)
+{
+    ASSERT(isMainThread());
+    ASSERT(m_page);
+
+    if (!coordinatesScrollingForFrameView(frameView))
+        return false;
+
+    ScrollingThread::dispatch(bind(&ScrollingTree::setMainFrameScrollPosition, m_scrollingTree.get(), scrollPosition));
+    return true;
+}
+
 void ScrollingCoordinator::updateMainFrameScrollPosition(const IntPoint& scrollPosition)
 {

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

@@ -84 +84 @@
     void frameViewVerticalScrollbarLayerDidChange(FrameView*, GraphicsLayer* verticalScrollbarLayer);
 
+    // Requests that the scrolling coordinator updates the scroll position of the given frame view. If this function returns true, it means that the
+    // position will be updated asynchronously. If it returns false, the caller should update the scrolling position itself.
+    bool requestScrollPositionUpdate(FrameView*, const IntPoint&);
+
     // Dispatched by the scrolling tree whenever the main frame scroll position changes.
     void updateMainFrameScrollPosition(const IntPoint&);

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

@@ -83 +83 @@
 }
 
+void ScrollingTree::setMainFrameScrollPosition(const IntPoint& scrollPosition)
+{
+    ASSERT(ScrollingThread::isCurrentThread());
+
+    m_rootNode->setScrollPosition(scrollPosition);
+}
+
 void ScrollingTree::invalidate()
 {

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

@@ -61 +61 @@
     void handleWheelEvent(const PlatformWheelEvent&);
 
+    void setMainFrameScrollPosition(const IntPoint&);
+
     void invalidate();
     void commitNewTreeState(PassOwnPtr<ScrollingTreeState>);

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

@@ -46 +46 @@
     virtual void update(ScrollingTreeState*);
     virtual void handleWheelEvent(const PlatformWheelEvent&) = 0;
+    virtual void setScrollPosition(const IntPoint&) = 0;
 
 protected:

trunk/Source/WebCore/page/scrolling/mac/ScrollingTreeNodeMac.h

@@ -45 +45 @@
     virtual void update(ScrollingTreeState*) OVERRIDE;
     virtual void handleWheelEvent(const PlatformWheelEvent&) OVERRIDE;
+    virtual void setScrollPosition(const IntPoint&) OVERRIDE;
 
     // ScrollElasticityController member functions.
@@ -61 +62 @@
 
     IntPoint scrollPosition() const;
-    void setScrollPosition(const IntPoint&);
+    void setScrollLayerPosition(const IntPoint&);
 
     void scrollBy(const IntSize&);

trunk/Source/WebCore/page/scrolling/mac/ScrollingTreeNodeMac.mm

@@ -57 +57 @@
     // FXIME: This needs to handle rubberbanding.
     scrollBy(IntSize(-wheelEvent.deltaX(), -wheelEvent.deltaY()));
+}
+
+void ScrollingTreeNodeMac::setScrollPosition(const IntPoint& scrollPosition)
+{
+    if (shouldUpdateScrollLayerPositionOnMainThread()) {
+        scrollingTree()->updateMainFrameScrollPositionAndScrollLayerPosition(scrollPosition);
+        return;
+    }
+
+    setScrollLayerPosition(scrollPosition);
+    scrollingTree()->updateMainFrameScrollPosition(scrollPosition);
 }
 
@@ -133 +144 @@
 }
 
-void ScrollingTreeNodeMac::setScrollPosition(const IntPoint& position)
+void ScrollingTreeNodeMac::setScrollLayerPosition(const IntPoint& position)
 {
     ASSERT(!shouldUpdateScrollLayerPositionOnMainThread());
@@ -142 +153 @@
 void ScrollingTreeNodeMac::scrollBy(const IntSize& offset)
 {
-    IntPoint newScrollPosition = scrollPosition() + offset;
-
-    if (shouldUpdateScrollLayerPositionOnMainThread()) {
-        scrollingTree()->updateMainFrameScrollPositionAndScrollLayerPosition(newScrollPosition);
-        return;
-    }
-
-    setScrollPosition(newScrollPosition);
-    scrollingTree()->updateMainFrameScrollPosition(newScrollPosition);
+    setScrollPosition(scrollPosition() + offset);
 }
 

trunk/Source/WebCore/platform/ScrollableArea.cpp

@@ -177 +177 @@
 void ScrollableArea::setScrollOffsetFromAnimation(const IntPoint& offset)
 {
+    if (requestScrollPositionUpdate(offset))
+        return;
+
     notifyScrollPositionChanged(offset);
 }

trunk/Source/WebCore/platform/ScrollableArea.h

@@ -53 +53 @@
     void notifyScrollPositionChanged(const IntPoint&);
 
+    // Allows subclasses to handle scroll position updates themselves. If this member function
+    // returns true, the scrollable area won't actually update the scroll position and instead
+    // expect it to happen sometime in the future.
+    virtual bool requestScrollPositionUpdate(const IntPoint&) { return false; }
+
     virtual void zoomAnimatorTransformChanged(float, float, float, ZoomAnimationState);