QGtkStyle: Fix styling and palette issues related to combo box

Well actually this change is a bit bigger than just that.

*We no longer override the palette you provide in polish so it should
be a bit more frienly toward custom application changes.

* Another issue  was that we  would generate the palette information
when we got the style callback from gtkButton but then the line edits might not yet have been
polished. Hence we now return from the callback and instead post the
update for later.

* We had to modify the PE_Frame entry to draw a raised menu when the
custom combo box delegate was used.

* We now simply ignore custom
qtconfig palette entries when using GtkStyle since they only cause
trouble with it.

Task-number: 250142
Reviewed-by: nrc

1 files changed, 38 insertions, 30 deletions

diff --git a/src/gui/styles/gtksymbols.cpp b/src/gui/styles/gtksymbols.cpp
index f60c980..8123d32 100644
--- a/src/gui/styles/gtksymbols.cpp
+++ b/src/gui/styles/gtksymbols.cpp
@@ -75,6 +75,7 @@
 QT_BEGIN_NAMESPACE
 
 static bool displayDepth  =  -1;
+Q_GLOBAL_STATIC(QGtkStyleUpdateScheduler, styleScheduler)
 
 typedef QHash<QString, GtkWidget*> WidgetMap;
 Q_GLOBAL_STATIC(WidgetMap, gtkWidgetMap)
@@ -486,11 +487,11 @@ static void init_gtk_menu()
 }
 
 // Updates window/windowtext palette based on the indicated gtk widget
-static void ensureWidgetPalette(QWidget* widget, const QString &gtkWidgetName)
+static QPalette gtkWidgetPalette(const QString &gtkWidgetName)
 {
     GtkWidget *gtkWidget = QGtk::gtkWidget(gtkWidgetName);
     Q_ASSERT(gtkWidget);
-    QPalette pal = widget->palette();
+    QPalette pal = QApplication::palette();
     GdkColor gdkBg = gtkWidget->style->bg[GTK_STATE_NORMAL];
     GdkColor gdkText = gtkWidget->style->fg[GTK_STATE_NORMAL];
     GdkColor gdkDisabledText = gtkWidget->style->fg[GTK_STATE_INSENSITIVE];
@@ -503,8 +504,14 @@ static void ensureWidgetPalette(QWidget* widget, const QString &gtkWidgetName)
     pal.setBrush(QPalette::Disabled, QPalette::WindowText, disabledTextColor);
     pal.setBrush(QPalette::All, QPalette::ButtonText, textColor);
     pal.setBrush(QPalette::Disabled, QPalette::ButtonText, disabledTextColor);
-    widget->setPalette(pal);
-    widget->setAttribute(Qt::WA_SetPalette, false);
+    if (gtkWidgetName == QLS("GtkMenu")) {
+        // This really applies to the combo box rendering since
+        // QComboBox copies the palette from a QMenu
+        GdkColor gdkBg = gtkWidget->style->bg[GTK_STATE_NORMAL];
+        QColor bgColor(gdkBg.red>>8, gdkBg.green>>8, gdkBg.blue>>8);
+        pal.setBrush(QPalette::Base, bgColor);
+    }
+    return pal;
 }
 
 bool QGtk::isKDE4Session()
@@ -515,44 +522,45 @@ bool QGtk::isKDE4Session()
     return (version == 4);
 }
 
-// Maps a Gtk widget palettes to a Qt widget
-void QGtk::applyGtkSystemPalette(QWidget *widget)
+void QGtk::applyCustomPaletteHash()
 {
-    // Do not apply if the widget has a custom palette;
-    if (widget->testAttribute(Qt::WA_SetPalette))
-        return;
+    QPalette menuPal = gtkWidgetPalette(QLS("GtkMenu"));
+    GdkColor gdkBg = QGtk::gtkWidget(QLS("GtkMenu"))->style->bg[GTK_STATE_NORMAL];
+    QColor bgColor(gdkBg.red>>8, gdkBg.green>>8, gdkBg.blue>>8);
+    menuPal.setBrush(QPalette::Base, bgColor);
+    qApp->setPalette(menuPal, "QMenu");
 
-    QPalette pal;
-    if (QStatusBar *statusbar = qobject_cast<QStatusBar*> (widget))
-        ensureWidgetPalette(statusbar, QLS("GtkStatusbar"));
-    else if (QMenuBar *menubar = qobject_cast<QMenuBar*> (widget))
-        ensureWidgetPalette(menubar, QLS("GtkMenuBar"));
-    else if (QToolBar *toolbar = qobject_cast<QToolBar*> (widget))
-        ensureWidgetPalette(toolbar, QLS("GtkToolbar"));
-    else if (QMenu *menu = qobject_cast<QMenu*> (widget)) {
-        // This really applies to the combo box rendering since
-        // QComboBox copies the palette from a QMenu
-        QPalette pal = widget->palette();
-        GdkColor gdkBg = QGtk::gtkWidget(QLS("GtkMenu"))->style->bg[GTK_STATE_NORMAL];
-        QColor bgColor(gdkBg.red>>8, gdkBg.green>>8, gdkBg.blue>>8);
-        pal.setBrush(QPalette::Base, bgColor);
-        menu->setPalette(pal);
-    }
-    widget->setAttribute(Qt::WA_SetPalette, false);
+    QPalette toolbarPal = gtkWidgetPalette(QLS("GtkToolbar"));
+    qApp->setPalette(toolbarPal, "QToolBar");
+
+    QPalette menuBarPal = gtkWidgetPalette(QLS("GtkMenuBar"));
+    qApp->setPalette(menuBarPal, "QMenuBar");
 }
 
 static void gtkStyleSetCallback(GtkWidget*, GtkStyle*, void*)
 {
+    // We have to let this function return and complete the event
+    // loop to ensure that all gtk widgets have been styled before
+    // updating
+    QMetaObject::invokeMethod(styleScheduler(), "updateTheme", Qt::QueuedConnection);
+}
+
+void QGtkStyleUpdateScheduler::updateTheme()
+{
     static QString oldTheme(QLS("qt_not_set"));
     QPixmapCache::clear();
-    qApp->setFont(QGtk::getThemeFont());
-    QGtk::initGtkWidgets();
     if (oldTheme != getThemeName()) {
         oldTheme = getThemeName();
-        QApplicationPrivate::setSystemPalette(qApp->style()->standardPalette());
+        qApp->setFont(QGtk::getThemeFont());
+        QPalette newPalette = qApp->style()->standardPalette();
+        QApplicationPrivate::setSystemPalette(newPalette);
+        QApplication::setPalette(newPalette);
+        QGtk::applyCustomPaletteHash();
         QList<QWidget*> widgets = QApplication::allWidgets();
+        // Notify all widgets that size metrics might have changed
         foreach (QWidget *widget, widgets) {
-            QGtk::applyGtkSystemPalette(widget);
+            QEvent e(QEvent::StyleChange);
+            QApplication::sendEvent(widget, &e);
         }
     }
 }