Win: QLineEdit not updating correctly when embedded in Graphics View

Updates triggered by the line edit itself, i.e. cursor blinking, are not
processed after the top-level is resized. This is yet another problem
caused by the event dispatcher on Windows (Qt posted events are not sent
during top-level resize, task 146849). We added a work-around for that
particular case by posting an event via Windows, but the widget is not
visible on the screen (hidden from Windows' POV) so it'll never be posted.
And of course then we'll never receive it and the backing store is not
synced. This work-around is therefore useless for widgets that are
not visible on the screen.

However, not receiving update requests while resizing the top-level
(in this case QGraphicsView), is not a problem for embedded widgets
because all items and hence the proxied widgets are repainted by
graphics view anyways.

Task-number: 252400
Reviewed-by: Olivier

1 files changed, 2 insertions, 1 deletions

diff --git a/src/gui/painting/qbackingstore.cpp b/src/gui/painting/qbackingstore.cpp
index 8fb7a12..0a3a8dd 100644
--- a/src/gui/painting/qbackingstore.cpp
+++ b/src/gui/painting/qbackingstore.cpp
@@ -492,7 +492,8 @@ static inline void sendUpdateRequest(QWidget *widget, bool updateImmediately)
         return;
 
 #if defined(Q_WS_WIN) && !defined(Q_OS_WINCE)
-    if (QApplicationPrivate::inSizeMove && widget->internalWinId() && !updateImmediately) {
+    if (QApplicationPrivate::inSizeMove && widget->internalWinId() && !updateImmediately
+        && !widget->testAttribute(Qt::WA_DontShowOnScreen)) {
         // Tell Windows to send us a paint event if we're in WM_SIZE/WM_MOVE; posted events
         // are blocked until the mouse button is released. See task 146849.
         const QRegion rgn(qt_dirtyRegion(widget));