added double buffering to oxygen-client when compositing is off;

force update of buttons in client->paintEvent();
call _client->paint() from Button, instead of parentWidget()->render();

clients/oxygen/oxygenbutton.cpp

@@ -175,23 +175,36 @@ namespace Oxygen
         if( _client.compositingActive() )
         {
             QPainter painter( this );
-            painter.setClipRect( event->rect() );
+            painter.setRenderHints(QPainter::Antialiasing);
+            painter.setClipRegion( event->region() );
             paint( painter );
 
         } else {
 
+            // create temporary pixmap to avoid flicker
             QPixmap pixmap( size() );
             {
 
+                // create painter
                 QPainter painter( &pixmap );
                 painter.setRenderHints(QPainter::Antialiasing);
-                parentWidget()->render( &painter, QPoint(), geometry(), QWidget::DrawWindowBackground );
+                painter.setClipRect( this->rect().intersected( event->rect() ) );
+
+                // render parent background
+                // parentWidget()->render( &painter, QPoint(), geometry(), QWidget::DrawWindowBackground );
+
+                painter.save();
+                painter.translate( -geometry().topLeft() );
+                _client.paint( painter );
+                painter.restore();
+
+                // render buttons
                 paint( painter );
 
             }
 
             QPainter painter(this);
-            painter.setClipRect( event->rect() );
+            painter.setClipRegion( event->region() );
             painter.drawPixmap( QPoint(), pixmap );
 
         }
@@ -288,6 +301,8 @@ namespace Oxygen
 
         }
 
+        painter.restore();
+
     }
 
     //___________________________________________________

clients/oxygen/oxygenbutton.h

@@ -172,7 +172,7 @@ namespace Oxygen
         private:
 
         //! parent client
-        const Client &_client;
+        Client &_client;
 
         //! helper
         DecoHelper &_helper;

clients/oxygen/oxygenclient.cpp

@@ -1370,15 +1370,47 @@ namespace Oxygen
         // factory
         if(!( _initialized && _factory->initialized() ) ) return;
 
+        if( compositingActive() )
+        {
+            QPainter painter(widget());
+            painter.setRenderHint(QPainter::Antialiasing);
+            painter.setClipRegion( event->region() );
+            paint( painter );
+        } else {
+
+            QPixmap pixmap( widget()->size() );
+            {
+                QPainter painter( &pixmap );
+                painter.setRenderHint(QPainter::Antialiasing);
+                painter.setClipRegion( event->region() );
+                paint( painter );
+            }
+
+            QPainter painter( widget() );
+            painter.setClipRegion( event->region() );
+            painter.drawPixmap( QPoint(), pixmap );
+
+            // update buttons
+            QList<Button*> buttons( widget()->findChildren<Button*>() );
+            foreach( Button* button, buttons )
+            {
+                if( event->rect().intersects( button->geometry() ) )
+                { button->update(); }
+            }
+        }
+
+
+
+    }
+
+    //_________________________________________________________
+    void Client::paint( QPainter& painter )
+    {
+
         // palette
         QPalette palette = widget()->palette();
         palette.setCurrentColorGroup( (isActive() ) ? QPalette::Active : QPalette::Inactive );
 
-        // painter
-        QPainter painter(widget());
-        painter.setRenderHint(QPainter::Antialiasing);
-        painter.setClipRegion( event->region() );
-
         // define frame
         QRect frame = widget()->rect();
 

clients/oxygen/oxygenclient.h

@@ -225,6 +225,8 @@ namespace Oxygen
         //! resize event
         virtual void resizeEvent(QResizeEvent *e);
 
+        virtual void paint( QPainter& );
+
         public slots:
 
         //! triggers widget update in titleRect only