Emit paletteChanged and send ApplicationPaletteChange on theme change

Fixes: QTBUG-72575
Change-Id: I407e081295a456a7bdd36de91ca5bbf74bba6078
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>

4 files changed, 34 insertions, 18 deletions

diff --git a/src/gui/kernel/qguiapplication.cpp b/src/gui/kernel/qguiapplication.cpp
index f4e2dda05a..a63e172461 100644
--- a/src/gui/kernel/qguiapplication.cpp
+++ b/src/gui/kernel/qguiapplication.cpp
@@ -3983,6 +3983,9 @@ void QGuiApplicationPrivate::notifyThemeChanged()
         !QCoreApplication::testAttribute(Qt::AA_SetPalette)) {
         clearPalette();
         initPalette();
+        emit qGuiApp->paletteChanged(*app_pal);
+        if (is_app_running && !is_app_closing)
+            sendApplicationPaletteChange();
     }
     if (!(applicationResourceFlags & ApplicationFontExplicitlySet)) {
         QMutexLocker locker(&applicationFontMutex);
@@ -3991,6 +3994,15 @@ void QGuiApplicationPrivate::notifyThemeChanged()
     }
 }
 
+void QGuiApplicationPrivate::sendApplicationPaletteChange(bool toAllWidgets, const char *className)
+{
+    Q_UNUSED(toAllWidgets)
+    Q_UNUSED(className)
+
+    QEvent event(QEvent::ApplicationPaletteChange);
+    QGuiApplication::sendEvent(QGuiApplication::instance(), &event);
+}
+
 #if QT_CONFIG(draganddrop)
 void QGuiApplicationPrivate::notifyDragStarted(const QDrag *drag)
 {
diff --git a/src/gui/kernel/qguiapplication_p.h b/src/gui/kernel/qguiapplication_p.h
index 79c1a1c820..042a36c31f 100644
--- a/src/gui/kernel/qguiapplication_p.h
+++ b/src/gui/kernel/qguiapplication_p.h
@@ -313,6 +313,7 @@ public:
 
 protected:
     virtual void notifyThemeChanged();
+    virtual void sendApplicationPaletteChange(bool toAllWidgets = false, const char *className = nullptr);
     bool tryCloseRemainingWindows(QWindowList processedWindows);
 #if QT_CONFIG(draganddrop)
     virtual void notifyDragStarted(const QDrag *);
diff --git a/src/widgets/kernel/qapplication.cpp b/src/widgets/kernel/qapplication.cpp
index f9db6155af..6800a51d4b 100644
--- a/src/widgets/kernel/qapplication.cpp
+++ b/src/widgets/kernel/qapplication.cpp
@@ -1420,24 +1420,7 @@ void QApplicationPrivate::setPalette_helper(const QPalette &palette, const char*
 
     if (QApplicationPrivate::is_app_running && !QApplicationPrivate::is_app_closing) {
         // Send ApplicationPaletteChange to qApp itself, and to the widgets.
-        QEvent e(QEvent::ApplicationPaletteChange);
-        QApplication::sendEvent(QApplication::instance(), &e);
-
-        QWidgetList wids = QApplication::allWidgets();
-        for (QWidgetList::ConstIterator it = wids.constBegin(), cend = wids.constEnd(); it != cend; ++it) {
-            QWidget *w = *it;
-            if (all || (!className && w->isWindow()) || w->inherits(className)) // matching class
-                QApplication::sendEvent(w, &e);
-        }
-
-        // Send to all scenes as well.
-#if QT_CONFIG(graphicsview)
-        QList<QGraphicsScene *> &scenes = qApp->d_func()->scene_list;
-        for (QList<QGraphicsScene *>::ConstIterator it = scenes.constBegin();
-             it != scenes.constEnd(); ++it) {
-            QApplication::sendEvent(*it, &e);
-        }
-#endif // QT_CONFIG(graphicsview)
+        qApp->d_func()->sendApplicationPaletteChange(all, className);
     }
     if (!className && (!QApplicationPrivate::sys_pal || !palette.isCopyOf(*QApplicationPrivate::sys_pal))) {
         if (!QApplicationPrivate::set_pal)
@@ -4508,6 +4491,23 @@ void QApplicationPrivate::notifyThemeChanged()
     qt_init_tooltip_palette();
 }
 
+void QApplicationPrivate::sendApplicationPaletteChange(bool toAllWidgets, const char *className)
+{
+    QGuiApplicationPrivate::sendApplicationPaletteChange();
+
+    QEvent event(QEvent::ApplicationPaletteChange);
+    const QWidgetList widgets = QApplication::allWidgets();
+    for (auto widget : widgets) {
+        if (toAllWidgets || (!className && widget->isWindow()) || (className && widget->inherits(className)))
+            QApplication::sendEvent(widget, &event);
+    }
+
+#if QT_CONFIG(graphicsview)
+    for (auto scene : qAsConst(scene_list))
+        QApplication::sendEvent(scene, &event);
+#endif // QT_CONFIG(graphicsview)
+}
+
 #if QT_CONFIG(draganddrop)
 void QApplicationPrivate::notifyDragStarted(const QDrag *drag)
 {
diff --git a/src/widgets/kernel/qapplication_p.h b/src/widgets/kernel/qapplication_p.h
index 05bc2468c1..133279f977 100644
--- a/src/widgets/kernel/qapplication_p.h
+++ b/src/widgets/kernel/qapplication_p.h
@@ -177,6 +177,9 @@ public:
 
 protected:
     void notifyThemeChanged() override;
+    void sendApplicationPaletteChange(bool toAllWidgets = false,
+                                      const char *className = nullptr) override;
+
 #if QT_CONFIG(draganddrop)
     void notifyDragStarted(const QDrag *) override;
 #endif // QT_CONFIG(draganddrop)