Handle theme change in QApplication/QGuiApplication.

Re-initialize palette and fonts.

Change-Id: Ib312747886a31e8370f8d99536d52cbcf8afe8a4
Reviewed-by: Morten Johan Sørvig <morten.sorvig@nokia.com>

src/gui/kernel/qguiapplication.cpp

@@ -99,6 +99,14 @@ QPlatformTheme *QGuiApplicationPrivate::platform_theme = 0;
 
 QList<QObject *> QGuiApplicationPrivate::generic_plugin_list;
 
+enum ApplicationResourceFlags
+{
+    ApplicationPaletteExplicitlySet = 0x1,
+    ApplicationFontExplicitlySet = 0x2
+};
+
+static unsigned applicationResourceFlags = 0;
+
 bool QGuiApplicationPrivate::app_do_modal = false;
 
 QPalette *QGuiApplicationPrivate::app_pal = 0;        // default application palette
@@ -144,6 +152,33 @@ 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::black);
+}
+
+static inline void clearPalette()
+{
+    delete QGuiApplicationPrivate::app_pal;
+    QGuiApplicationPrivate::app_pal = 0;
+}
+
+static void initFontUnlocked()
+{
+    if (!QGuiApplicationPrivate::app_font)
+        QGuiApplicationPrivate::app_font =
+            new QFont(QGuiApplicationPrivate::platformIntegration()->fontDatabase()->defaultFont());
+}
+
+static inline void clearFontUnlocked()
+{
+    delete QGuiApplicationPrivate::app_font;
+    QGuiApplicationPrivate::app_font = 0;
+}
 
 /*!
     \class QGuiApplication
@@ -312,8 +347,7 @@ QGuiApplication::~QGuiApplication()
     delete QGuiApplicationPrivate::qt_clipboard;
     QGuiApplicationPrivate::qt_clipboard = 0;
 
-    delete QGuiApplicationPrivate::app_pal;
-    QGuiApplicationPrivate::app_pal = 0;
+    clearPalette();
 
     qUnregisterGuiVariant();
 
@@ -671,8 +705,8 @@ QGuiApplicationPrivate::~QGuiApplicationPrivate()
         delete generic_plugin_list.at(i);
     generic_plugin_list.clear();
 
-    delete app_font;
-    app_font = 0;
+    clearFontUnlocked();
+
     QFont::cleanup();
 
 #ifndef QT_NO_CURSOR
@@ -1090,6 +1124,8 @@ void QGuiApplicationPrivate::processWindowStateChangedEvent(QWindowSystemInterfa
 
 void QGuiApplicationPrivate::processThemeChanged(QWindowSystemInterfacePrivate::ThemeChangeEvent *tce)
 {
+    if (self)
+        self->notifyThemeChanged();
     if (QWindow *window  = tce->window.data()) {
         QEvent e(QEvent::ThemeChange);
         QGuiApplication::sendSpontaneousEvent(window, &e);
@@ -1579,13 +1615,10 @@ QClipboard * QGuiApplication::clipboard()
 
     \sa setPalette()
 */
+
 QPalette QGuiApplication::palette()
 {
-    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::black);
+    initPalette();
     return *QGuiApplicationPrivate::app_pal;
 }
 
@@ -1602,6 +1635,7 @@ void QGuiApplication::setPalette(const QPalette &pal)
         QGuiApplicationPrivate::app_pal = new QPalette(pal);
     else
         *QGuiApplicationPrivate::app_pal = pal;
+    applicationResourceFlags |= ApplicationPaletteExplicitlySet;
 }
 
 /*!
@@ -1612,9 +1646,7 @@ void QGuiApplication::setPalette(const QPalette &pal)
 QFont QGuiApplication::font()
 {
     QMutexLocker locker(&applicationFontMutex);
-    if (!QGuiApplicationPrivate::app_font)
-        QGuiApplicationPrivate::app_font =
-            new QFont(QGuiApplicationPrivate::platformIntegration()->fontDatabase()->defaultFont());
+    initFontUnlocked();
     return *QGuiApplicationPrivate::app_font;
 }
 
@@ -1630,6 +1662,7 @@ void QGuiApplication::setFont(const QFont &font)
         QGuiApplicationPrivate::app_font = new QFont(font);
     else
         *QGuiApplicationPrivate::app_font = font;
+    applicationResourceFlags |= ApplicationFontExplicitlySet;
 }
 
 /*!
@@ -2034,4 +2067,17 @@ QPixmap QGuiApplicationPrivate::getPixmapCursor(Qt::CursorShape cshape)
     return QPixmap();
 }
 
+void QGuiApplicationPrivate::notifyThemeChanged()
+{
+    if (!(applicationResourceFlags & ApplicationPaletteExplicitlySet)) {
+        clearPalette();
+        initPalette();
+    }
+    if (!(applicationResourceFlags & ApplicationFontExplicitlySet)) {
+        QMutexLocker locker(&applicationFontMutex);
+        clearFontUnlocked();
+        initFontUnlocked();
+    }
+}
+
 QT_END_NAMESPACE

src/gui/kernel/qguiapplication_p.h

@@ -200,6 +200,9 @@ public:
     };
     QHash<QWindow *, SynthesizedMouseData> synthesizedMousePoints;
 
+protected:
+    virtual void notifyThemeChanged();
+
 private:
     void init();
 

src/plugins/platforms/windows/qwindowstheme.cpp

@@ -52,6 +52,7 @@
 #include <QtCore/QSysInfo>
 #include <QtGui/QPalette>
 #include <QtGui/QGuiApplication>
+#include <QtGui/QWindowSystemInterface>
 
 QT_BEGIN_NAMESPACE
 
@@ -265,10 +266,10 @@ QPlatformDialogHelper *QWindowsTheme::createPlatformDialogHelper(DialogType type
     return QWindowsDialogs::createHelper(type);
 }
 
-void QWindowsTheme::windowsThemeChanged(QWindow * /* window */)
+void QWindowsTheme::windowsThemeChanged(QWindow * window)
 {
     refresh();
-    // QWindowSystemInterface::handleThemeChange(window);
+    QWindowSystemInterface::handleThemeChange(window);
 }
 
 QT_END_NAMESPACE

src/widgets/kernel/qapplication.cpp

@@ -128,6 +128,21 @@ Q_CORE_EXPORT void qt_call_post_routines();
 
 QApplicationPrivate *QApplicationPrivate::self = 0;
 
+static void initSystemPalette()
+{
+    if (!QApplicationPrivate::sys_pal)
+        if (const QPalette *themePalette = QGuiApplicationPrivate::platformTheme()->palette())
+            QApplicationPrivate::setSystemPalette(*themePalette);
+    if (!QApplicationPrivate::sys_pal && QApplicationPrivate::app_style)
+        QApplicationPrivate::setSystemPalette(QApplicationPrivate::app_style->standardPalette());
+}
+
+static void clearSystemPalette()
+{
+    delete QApplicationPrivate::sys_pal;
+    QApplicationPrivate::sys_pal = 0;
+}
+
 #ifdef Q_OS_WINCE
 int QApplicationPrivate::autoMaximizeThreshold = -1;
 bool QApplicationPrivate::autoSipEnabled = false;
@@ -365,6 +380,7 @@ QString QApplicationPrivate::styleSheet;           // default application styles
 QPointer<QWidget> QApplicationPrivate::leaveAfterRelease = 0;
 
 int QApplicationPrivate::app_cspec = QApplication::NormalColor;
+
 QPalette *QApplicationPrivate::sys_pal = 0;        // default system palette
 QPalette *QApplicationPrivate::set_pal = 0;        // default palette set by programmer
 
@@ -783,8 +799,7 @@ QApplication::~QApplication()
 
     delete QApplicationPrivate::app_pal;
     QApplicationPrivate::app_pal = 0;
-    delete QApplicationPrivate::sys_pal;
-    QApplicationPrivate::sys_pal = 0;
+    clearSystemPalette();
     delete QApplicationPrivate::set_pal;
     QApplicationPrivate::set_pal = 0;
     app_palettes()->clear();
@@ -1084,11 +1099,8 @@ QStyle *QApplication::style()
     // take ownership of the style
     QApplicationPrivate::app_style->setParent(qApp);
 
-    if (!QApplicationPrivate::sys_pal)
-        if (const QPalette *themePalette = QGuiApplicationPrivate::platformTheme()->palette())
-            QApplicationPrivate::setSystemPalette(*themePalette);
-    if (!QApplicationPrivate::sys_pal)
-        QApplicationPrivate::setSystemPalette(QApplicationPrivate::app_style->standardPalette());
+    initSystemPalette();
+
     if (QApplicationPrivate::set_pal) // repolish set palette with the new style
         QApplication::setPalette(*QApplicationPrivate::set_pal);
 
@@ -4631,6 +4643,13 @@ void QApplicationPrivate::translateTouchCancel(QTouchDevice *device, ulong times
     }
 }
 
+void QApplicationPrivate::notifyThemeChanged()
+{
+    QGuiApplicationPrivate::notifyThemeChanged();
+    clearSystemPalette();
+    initSystemPalette();
+}
+
 #ifndef QT_NO_GESTURES
 QGestureManager* QGestureManager::instance()
 {

src/widgets/kernel/qapplication_p.h

@@ -260,7 +260,9 @@ public:
     static QPalette *sys_pal;
     static QPalette *set_pal;
 
-private:
+protected:
+    void notifyThemeChanged();
+
 public:
     static QFont *sys_font;
     static QFont *set_font;