Changeset 286631 in webkit

Timestamp:

Dec 7, 2021, 4:44:05 PM (5 years ago)

Author:

Simon Fraser

Message:

[Scroll Momentum Generator] Pages lose ability to momentum scroll after dragging between displays
​https://bugs.webkit.org/show_bug.cgi?id=233948
rdar://86110813

Reviewed by Tim Horton.

This is a conservative fix for the bug. When a view moves to a new screen, WebPageProxy
needs to unregister for full speed updates using the old displayID, and register
using the new one.

Longer term, it would be better if "full speed updates" was a per-observer concept,
but that would mean registering an observer while wheel events are being received,
which needs a bit more thought.

• UIProcess/WebPageProxy.cpp:

(WebKit::WebPageProxy::windowScreenDidChange):

Location:

trunk/Source/WebKit

Files:

• ChangeLog (modified) (1 diff)
• UIProcess/WebPageProxy.cpp (modified) (2 diffs)

trunk/Source/WebKit/ChangeLog

@@ +1 @@
+2021-12-07  Simon Fraser  <simon.fraser@apple.com>
+
+        [Scroll Momentum Generator] Pages lose ability to momentum scroll after dragging between displays
+        https://bugs.webkit.org/show_bug.cgi?id=233948
+        rdar://86110813
+
+        Reviewed by Tim Horton.
+
+        This is a conservative fix for the bug. When a view moves to a new screen, WebPageProxy
+        needs to unregister for full speed updates using the old displayID, and register 
+        using the new one.
+
+        Longer term, it would be better if "full speed updates" was a per-observer concept,
+        but that would mean registering an observer while wheel events are being received,
+        which needs a bit more thought.
+
+        * UIProcess/WebPageProxy.cpp:
+        (WebKit::WebPageProxy::windowScreenDidChange):
+
 2021-12-07  Cameron McCormack  <heycam@apple.com>
 

trunk/Source/WebKit/UIProcess/WebPageProxy.cpp

@@ -3959 +3959 @@
 void WebPageProxy::windowScreenDidChange(PlatformDisplayID displayID, std::optional<unsigned> nominalFramesPerSecond)
 {
+#if HAVE(CVDISPLAYLINK)
+    if (hasRunningProcess() && m_displayID && m_registeredForFullSpeedUpdates)
+        process().processPool().setDisplayLinkForDisplayWantsFullSpeedUpdates(*m_process->connection(), *m_displayID, false);
+
+    m_registeredForFullSpeedUpdates = false;
+#endif
+
     m_displayID = displayID;
 
@@ -3966 +3973 @@
     send(Messages::EventDispatcher::PageScreenDidChange(m_webPageID, displayID));
     send(Messages::WebPage::WindowScreenDidChange(displayID, nominalFramesPerSecond));
+#if HAVE(CVDISPLAYLINK)
+    updateDisplayLinkFrequency();
+#endif
 }