QWaylandWindow: Update decoration when application palette/font changes

Ensures the decoration can redraw to adjust for the new colors/font.

Pick-to: 6.7 6.6 6.5
Change-Id: Ib46acde1d14baafda49f379f8279c396bc976bdc
Reviewed-by: David Edmundson <davidedmundson@kde.org>

src/plugins/platforms/wayland/qwaylandwindow.cpp

@@ -1788,6 +1788,17 @@ void QWaylandWindow::reinit()
     }
 }
 
+bool QWaylandWindow::windowEvent(QEvent *event)
+{
+    if (event->type() == QEvent::ApplicationPaletteChange
+        || event->type() == QEvent::ApplicationFontChange) {
+        if (mWindowDecorationEnabled && window()->isVisible())
+            mWindowDecoration->update();
+    }
+
+    return QPlatformWindow::windowEvent(event);
+}
+
 }
 
 QT_END_NAMESPACE

src/plugins/platforms/wayland/qwaylandwindow_p.h

@@ -238,6 +238,8 @@ public:
     virtual void reinit();
     void reset();
 
+    bool windowEvent(QEvent *event) override;
+
 public Q_SLOTS:
     void applyConfigure();