1 files changed, 68 insertions, 49 deletions

diff --git a/src/gui/kernel/qguiapplication.cpp b/src/gui/kernel/qguiapplication.cpp
index ffd5b04276..445ad6b835 100644
--- a/src/gui/kernel/qguiapplication.cpp
+++ b/src/gui/kernel/qguiapplication.cpp
@@ -236,21 +236,6 @@ static bool qt_detectRTLLanguage()
                          " and Arabic) to get proper widget layout.") == QLatin1String("RTL"));
 }
 
-static void initPalette()
-{
-    if (!QGuiApplicationPrivate::app_pal)
-        if (const QPalette *themePalette = QGuiApplicationPrivate::platformTheme()->palette())
-            QGuiApplicationPrivate::app_pal = new QPalette(*themePalette);
-    if (!QGuiApplicationPrivate::app_pal)
-        QGuiApplicationPrivate::app_pal = new QPalette(Qt::gray);
-}
-
-static inline void clearPalette()
-{
-    delete QGuiApplicationPrivate::app_pal;
-    QGuiApplicationPrivate::app_pal = nullptr;
-}
-
 static void initFontUnlocked()
 {
     if (!QGuiApplicationPrivate::app_font) {
@@ -691,7 +676,7 @@ QGuiApplication::~QGuiApplication()
     d->session_manager = nullptr;
 #endif //QT_NO_SESSIONMANAGER
 
-    clearPalette();
+    QGuiApplicationPrivate::clearPalette();
     QFontDatabase::removeAllApplicationFonts();
 
 #ifndef QT_NO_CURSOR
@@ -1611,7 +1596,7 @@ void QGuiApplicationPrivate::init()
     if (platform_integration == nullptr)
         createPlatformIntegration();
 
-    initPalette();
+    updatePalette();
     QFont::initialize();
     initThemeHints();
 
@@ -3289,46 +3274,97 @@ QClipboard * QGuiApplication::clipboard()
 */
 
 /*!
-    Returns the default application palette.
+    Returns the current application palette.
+
+    Roles that have not been explicitly set will reflect the system's platform theme.
 
     \sa setPalette()
 */
 
 QPalette QGuiApplication::palette()
 {
-    initPalette();
+    if (!QGuiApplicationPrivate::app_pal)
+        QGuiApplicationPrivate::updatePalette();
+
     return *QGuiApplicationPrivate::app_pal;
 }
 
+void QGuiApplicationPrivate::updatePalette()
+{
+    if (app_pal) {
+        if (setPalette(*app_pal) && qGuiApp)
+            qGuiApp->d_func()->handlePaletteChanged();
+    } else {
+        setPalette(QPalette());
+    }
+}
+
+void QGuiApplicationPrivate::clearPalette()
+{
+    delete app_pal;
+    app_pal = nullptr;
+}
+
 /*!
-    Changes the default application palette to \a pal.
+    Changes the application palette to \a pal.
+
+    The color roles from this palette are combined with the system's platform
+    theme to form the application's final palette.
 
     \sa palette()
 */
 void QGuiApplication::setPalette(const QPalette &pal)
 {
-    if (!QGuiApplicationPrivate::setPalette(pal))
-        return;
-
-    QCoreApplication::setAttribute(Qt::AA_SetPalette);
-
-    if (qGuiApp)
-        qGuiApp->d_func()->sendApplicationPaletteChange();
+    if (QGuiApplicationPrivate::setPalette(pal) && qGuiApp)
+        qGuiApp->d_func()->handlePaletteChanged();
 }
 
 bool QGuiApplicationPrivate::setPalette(const QPalette &palette)
 {
-    if (app_pal && palette.isCopyOf(*app_pal))
+    // Resolve the palette against the theme palette, filling in
+    // any missing roles, while keeping the original resolve mask.
+    QPalette basePalette = qGuiApp ? qGuiApp->d_func()->basePalette() : Qt::gray;
+    basePalette.resolve(0); // The base palette only contributes missing colors roles
+    QPalette resolvedPalette = palette.resolve(basePalette);
+
+    if (app_pal && resolvedPalette == *app_pal && resolvedPalette.resolve() == app_pal->resolve())
         return false;
 
     if (!app_pal)
-        app_pal = new QPalette(palette);
+        app_pal = new QPalette(resolvedPalette);
     else
-        *app_pal = palette;
+        *app_pal = resolvedPalette;
+
+    QCoreApplication::setAttribute(Qt::AA_SetPalette, app_pal->resolve() != 0);
 
     return true;
 }
 
+/*
+    Returns the base palette used to fill in missing roles in
+    the current application palette.
+
+    Normally this is the theme palette, but QApplication
+    overrides this for compatibility reasons.
+*/
+QPalette QGuiApplicationPrivate::basePalette() const
+{
+    return platformTheme() ? *platformTheme()->palette() : Qt::gray;
+}
+
+void QGuiApplicationPrivate::handlePaletteChanged(const char *className)
+{
+    if (!className) {
+        Q_ASSERT(app_pal);
+        emit qGuiApp->paletteChanged(*QGuiApplicationPrivate::app_pal);
+    }
+
+    if (is_app_running && !is_app_closing) {
+        QEvent event(QEvent::ApplicationPaletteChange);
+        QGuiApplication::sendEvent(qGuiApp, &event);
+    }
+}
+
 void QGuiApplicationPrivate::applyWindowGeometrySpecificationTo(QWindow *window)
 {
     windowGeometrySpecification.applyTo(window);
@@ -4127,11 +4163,8 @@ QPixmap QGuiApplicationPrivate::getPixmapCursor(Qt::CursorShape cshape)
 
 void QGuiApplicationPrivate::notifyThemeChanged()
 {
-    if (!testAttribute(Qt::AA_SetPalette)) {
-        clearPalette();
-        initPalette();
-        sendApplicationPaletteChange();
-    }
+    updatePalette();
+
     if (!(applicationResourceFlags & ApplicationFontExplicitlySet)) {
         const auto locker = qt_scoped_lock(applicationFontMutex);
         clearFontUnlocked();
@@ -4140,20 +4173,6 @@ void QGuiApplicationPrivate::notifyThemeChanged()
     initThemeHints();
 }
 
-void QGuiApplicationPrivate::sendApplicationPaletteChange(bool toAllWidgets, const char *className)
-{
-    Q_UNUSED(toAllWidgets)
-
-    if (!className)
-        emit qGuiApp->paletteChanged(*QGuiApplicationPrivate::app_pal);
-
-    if (!is_app_running || is_app_closing)
-        return;
-
-    QEvent event(QEvent::ApplicationPaletteChange);
-    QGuiApplication::sendEvent(QGuiApplication::instance(), &event);
-}
-
 #if QT_CONFIG(draganddrop)
 void QGuiApplicationPrivate::notifyDragStarted(const QDrag *drag)
 {