pass QS_POSTMESSAGE to GetQueueStatus() instead of QS_ALLINPUT.

walker0643 · walker0643 · commit dbfb04a6ec30 · 2018-01-29T18:12:50.000-05:00
QS_ALLINPUT is a meta-flag that includes QS_POINTER and QS_TOUCH, both of which can cause GetQueueStatus() to return 0 even when there are pending messages. fixes #4
diff --git a/src/lib/platform/MSWindowsEventQueueBuffer.cpp b/src/lib/platform/MSWindowsEventQueueBuffer.cpp
@@ -62,7 +62,7 @@ MSWindowsEventQueueBuffer::waitForEvent(double timeout)
     // MsgWaitForMultipleObjects() will block even if the queue isn't
     // empty if the messages in the queue were there before the last
     // call to GetMessage()/PeekMessage().
-    if (HIWORD(GetQueueStatus(QS_ALLINPUT)) != 0) {
+    if (!isEmpty()) {
         return;
     }
 
@@ -128,7 +128,9 @@ MSWindowsEventQueueBuffer::addEvent(UInt32 dataID)
 bool
 MSWindowsEventQueueBuffer::isEmpty() const
 {
-    return (HIWORD(GetQueueStatus(QS_ALLINPUT)) == 0);
+    // don't use QS_POINTER, QS_TOUCH, or any meta-flags that include them (like QS_ALLINPUT)
+    // because they can cause GetQueueStatus() to always return 0 and we miss events
+    return (HIWORD(GetQueueStatus(QS_POSTMESSAGE)) == 0);
 }
 
 EventQueueTimer*

Original file line number	Diff line number	Diff line change
`@@ -62,7 +62,7 @@ MSWindowsEventQueueBuffer::waitForEvent(double timeout)`
`62`	`62`	`// MsgWaitForMultipleObjects() will block even if the queue isn't`
`63`	`63`	`// empty if the messages in the queue were there before the last`
`64`	`64`	`// call to GetMessage()/PeekMessage().`
`65`		`- if (HIWORD(GetQueueStatus(QS_ALLINPUT)) != 0) {`
	`65`	`+ if (!isEmpty()) {`
`66`	`66`	`return;`
`67`	`67`	`}`
`68`	`68`
`@@ -128,7 +128,9 @@ MSWindowsEventQueueBuffer::addEvent(UInt32 dataID)`
`128`	`128`	`bool`
`129`	`129`	`MSWindowsEventQueueBuffer::isEmpty() const`
`130`	`130`	`{`
`131`		`- return (HIWORD(GetQueueStatus(QS_ALLINPUT)) == 0);`
	`131`	`+ // don't use QS_POINTER, QS_TOUCH, or any meta-flags that include them (like QS_ALLINPUT)`
	`132`	`+ // because they can cause GetQueueStatus() to always return 0 and we miss events`
	`133`	`+ return (HIWORD(GetQueueStatus(QS_POSTMESSAGE)) == 0);`
`132`	`134`	`}`
`133`	`135`
`134`	`136`	`EventQueueTimer*`