Make basic scrolling work with ui-side compositing on macOS

https://bugs.webkit.org/show_bug.cgi?id=246640 <rdar://problem/101254817> Reviewed by Tim Horton. We already send wheel events to the scrolling tree, but there was no layer movement because we never changed layer positions; this is because with web process scrolling there is coordination with the main thread in the form of scroll synchronization. So add code to manually update layer positions with UI-side compositing. This will be refined as we bring up a scrolling thread in the UI process. * Source/WebKit/UIProcess/RemoteLayerTree/RemoteScrollingCoordinatorProxy.cpp: (WebKit::RemoteScrollingCoordinatorProxy::handleWheelEvent): * Source/WebKit/UIProcess/RemoteLayerTree/RemoteScrollingCoordinatorProxy.h: (WebKit::RemoteScrollingCoordinatorProxy::scrollingTree const): (WebKit::RemoteScrollingCoordinatorProxy::didReceiveWheelEvent): * Source/WebKit/UIProcess/RemoteLayerTree/mac/RemoteScrollingCoordinatorProxyMac.h: * Source/WebKit/UIProcess/RemoteLayerTree/mac/RemoteScrollingCoordinatorProxyMac.mm: (WebKit::RemoteScrollingCoordinatorProxyMac::didReceiveWheelEvent): Canonical link: https://commits.webkit.org/255643@main
WebKit · Oct 17, 2022 · f306cd3 · f306cd3
1 parent d34e00e
commit f306cd3
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diff --git a/Source/WebKit/UIProcess/RemoteLayerTree/RemoteScrollingCoordinatorProxy.cpp b/Source/WebKit/UIProcess/RemoteLayerTree/RemoteScrollingCoordinatorProxy.cpp
@@ -188,6 +188,7 @@ bool RemoteScrollingCoordinatorProxy::handleWheelEvent(const PlatformWheelEvent&
         return false;
 
     auto result = m_scrollingTree->handleWheelEvent(wheelEvent);
+    didReceiveWheelEvent(result.wasHandled);
     return result.wasHandled;
 }
 

diff --git a/Source/WebKit/UIProcess/RemoteLayerTree/RemoteScrollingCoordinatorProxy.h b/Source/WebKit/UIProcess/RemoteLayerTree/RemoteScrollingCoordinatorProxy.h
@@ -117,13 +117,18 @@ class RemoteScrollingCoordinatorProxy : public CanMakeWeakPtr<RemoteScrollingCoo
     const HashSet<WebCore::GraphicsLayer::PlatformLayerID>& fixedScrollingNodeLayerIDs() const { return m_fixedScrollingNodeLayerIDs; }
 #endif
 
+protected:
+    RemoteScrollingTree* scrollingTree() const { return m_scrollingTree.get(); }
+
 private:
     void connectStateNodeLayers(WebCore::ScrollingStateTree&, const RemoteLayerTreeHost&);
     void establishLayerTreeScrollingRelations(const RemoteLayerTreeHost&);
 
     bool shouldSnapForMainFrameScrolling(WebCore::ScrollEventAxis) const;
     std::pair<float, std::optional<unsigned>> closestSnapOffsetForMainFrameScrolling(WebCore::ScrollEventAxis, float currentScrollOffset, WebCore::FloatPoint scrollDestination, float velocity) const;
 
+    virtual void didReceiveWheelEvent(bool /* wasHandled */) { }
+
     void sendUIStateChangedIfNecessary();
     void sendScrollingTreeNodeDidScroll();
     void receivedLastScrollingTreeNodeDidScrollReply();

diff --git a/Source/WebKit/UIProcess/RemoteLayerTree/mac/RemoteScrollingCoordinatorProxyMac.h b/Source/WebKit/UIProcess/RemoteLayerTree/mac/RemoteScrollingCoordinatorProxyMac.h
@@ -34,6 +34,9 @@ namespace WebKit {
 class RemoteScrollingCoordinatorProxyMac final : public RemoteScrollingCoordinatorProxy {
 public:
     explicit RemoteScrollingCoordinatorProxyMac(WebPageProxy&);
+
+private:
+    void didReceiveWheelEvent(bool) override;
 };
 
 } // namespace WebKit

diff --git a/Source/WebKit/UIProcess/RemoteLayerTree/mac/RemoteScrollingCoordinatorProxyMac.mm b/Source/WebKit/UIProcess/RemoteLayerTree/mac/RemoteScrollingCoordinatorProxyMac.mm
@@ -36,6 +36,11 @@
 {
 }
 
+void RemoteScrollingCoordinatorProxyMac::didReceiveWheelEvent(bool /* wasHandled */)
+{
+    scrollingTree()->applyLayerPositions();
+}
+
 } // namespace WebKit
 
 #endif // PLATFORM(MAC) && ENABLE(UI_SIDE_COMPOSITING)