Bt: Fix regression in the Embedded dialogs example

We had to revert an earlier fix since it obviously did
not work correctly. However since we do not really need to propagate the
palette on the viewContainer _before_ it is created, we can simply avoid
the issue alltogether as it would happen because we implicitly added
a child widget during the polish of the combo box.

Reviewed-by: nrc

2 files changed, 22 insertions, 13 deletions

diff --git a/demos/embeddeddialogs/customproxy.cpp b/demos/embeddeddialogs/customproxy.cpp
index 56a0548..ed2fc76 100644
--- a/demos/embeddeddialogs/customproxy.cpp
+++ b/demos/embeddeddialogs/customproxy.cpp
@@ -111,8 +111,15 @@ bool CustomProxy::sceneEventFilter(QGraphicsItem *watched, QEvent *event)
 
 QVariant CustomProxy::itemChange(GraphicsItemChange change, const QVariant &value)
 {
-    if (change == ItemChildRemovedChange)
-        removeSceneEventFilter(this);
+    if (change == ItemChildAddedChange || change == ItemChildRemovedChange) {
+        QGraphicsItem *item = qVariantValue<QGraphicsItem *>(value);
+        if (change == ItemChildAddedChange) {
+            item->setCacheMode(ItemCoordinateCache);
+            item->installSceneEventFilter(this);
+        } else {
+            item->removeSceneEventFilter(this);
+        }
+    }
     return QGraphicsProxyWidget::itemChange(change, value);
 }
 
diff --git a/src/gui/widgets/qcombobox.cpp b/src/gui/widgets/qcombobox.cpp
index 09a51fe..b9dbc62 100644
--- a/src/gui/widgets/qcombobox.cpp
+++ b/src/gui/widgets/qcombobox.cpp
@@ -2572,19 +2572,21 @@ void QComboBox::changeEvent(QEvent *e)
             hidePopup();
         break;
     case QEvent::PaletteChange: {
-        QStyleOptionComboBox opt;
-        initStyleOption(&opt);
+        if (d->container) {
+            QStyleOptionComboBox opt;
+            initStyleOption(&opt);
 #ifndef QT_NO_MENU
-        if (style()->styleHint(QStyle::SH_ComboBox_Popup, &opt, this)) {
-            QMenu menu;
-            menu.ensurePolished();
-            d->viewContainer()->setPalette(menu.palette());
-            d->viewContainer()->setWindowOpacity(menu.windowOpacity());
-        } else
+            if (style()->styleHint(QStyle::SH_ComboBox_Popup, &opt, this)) {
+                QMenu menu;
+                menu.ensurePolished();
+                d->viewContainer()->setPalette(menu.palette());
+                d->viewContainer()->setWindowOpacity(menu.windowOpacity());
+            } else
 #endif
-        {
-            d->viewContainer()->setPalette(palette());
-            d->viewContainer()->setWindowOpacity(1.0);
+            {
+                d->viewContainer()->setPalette(palette());
+                d->viewContainer()->setWindowOpacity(1.0);
+            }
         }
         break;
     }