path: root/src/gui/painting
diff options
authorTor Arne Vestbø <>2020-08-24 18:59:54 +0200
committerTor Arne Vestbø <>2020-08-26 16:44:53 +0200
commitb5f972361aa01f55511712016fb2f4f540cdbc66 (patch)
tree45651e80c6e7423c7b6409b471a1f819f5464fac /src/gui/painting
parentc3555fc33d6b7897a36b0176aef68a2e7139d51a (diff)
Introduce QWindow::paintEvent with QPA plumbing
The explicit paint event on QtGui and QPA level allows us to untangle the expose event, which today has at least 3 different meanings. It also allows us to follow the platform more closely in its semantics of when painting can happen. On some platforms a paint can come in before a window is exposed, e.g. to prepare the first frame. On others a paint can come in after a window has been de-exposed, to save a snapshot of the window for use in an application switcher or similar. The expose keeps its semantics of being a barrier signaling that the application can now render at will, for example in a threaded render loop. There are two compatibility code paths in this patch: 1. For platform plugins that do not yet report the PaintEvents capability, QtGui will synthesize paint events on the platform's behalf, based on the existing expose events coming from the platform. 2. For applications that do not yet implement paintEvent, QtGui will send expose events instead, ensuring the same behavior as before. For now none of the platform plugins deliver paint events natively, so the first compatibility code path is always active. Task-numnber: QTBUG-82676 Change-Id: I0fbe0d4cf451d6a1f07f5eab8d376a6c8a53ce8c Reviewed-by: Paul Olav Tvete <>
Diffstat (limited to 'src/gui/painting')
1 files changed, 0 insertions, 7 deletions
diff --git a/src/gui/painting/qbackingstore.cpp b/src/gui/painting/qbackingstore.cpp
index 5bbc03db80..23fc942234 100644
--- a/src/gui/painting/qbackingstore.cpp
+++ b/src/gui/painting/qbackingstore.cpp
@@ -240,13 +240,6 @@ void QBackingStore::flush(const QRegion &region, QWindow *window, const QPoint &
- if (window && window->isTopLevel() && !qt_window_private(window)->receivedExpose) {
- qWarning().nospace() << "QBackingStore::flush() called with non-exposed window "
- << window << ", behavior is undefined";
- }
Q_ASSERT(window == topLevelWindow || topLevelWindow->isAncestorOf(window, QWindow::ExcludeTransients));
handle()->flush(window, QHighDpi::toNativeLocalRegion(region, window),