update ThumbnailList's ThumbnailWidgets when changing rendermode.

svn path=/branches/kpdf_experiments/kdegraphics/kpdf/; revision=361149

kpdf/kpdf_part.cpp

@@ -399,7 +399,7 @@ void Part::slotNewConfig()
     // TODO do this only when changing Settings::renderMode()
     m_pageView->updateContents();
     if ( showLeft && m_thumbnailList->isShown() )
-        m_thumbnailList->updateContents();
+        m_thumbnailList->updateWidgets();
 }
 
 void Part::slotPrintPreview()

kpdf/thumbnaillist.cpp

@@ -161,6 +161,25 @@ void ThumbnailList::notifyPixmapChanged( int pageNumber )
 		}
 }
 
+void ThumbnailList::updateWidgets()
+{
+    // find all widgets that intersects the viewport and update them
+    QRect viewportRect( contentsX(), contentsY(), visibleWidth(), visibleHeight() );
+    QValueVector<ThumbnailWidget *>::iterator tIt = m_thumbnails.begin(), tEnd = m_thumbnails.end();
+    for ( ; tIt != tEnd; ++tIt )
+    {
+        ThumbnailWidget * t = *tIt;
+        QRect widgetRect( childX( t ), childY( t ), t->width(), t->height() );
+        if ( viewportRect.intersects( widgetRect ) )
+        {
+            // update only the exposed area of the widget (saves pixels..)
+            QRect relativeRect = viewportRect.intersect( widgetRect );
+            relativeRect.moveBy( -widgetRect.left(), -widgetRect.top() );
+            t->update( relativeRect );
+        }
+    }
+}
+
 void ThumbnailList::dragEnterEvent( QDragEnterEvent * ev )
 {
 	ev->accept();

kpdf/thumbnaillist.h

@@ -42,6 +42,9 @@ Q_OBJECT
 		// redraw thumbnail ( inherited as DocumentObserver )
 		void notifyPixmapChanged( int pageNumber );
 
+        // redraw visible widgets (useful for refreshing contents...)
+        void updateWidgets();
+
 	protected:
 		// scroll up/down the view
 		void keyPressEvent( QKeyEvent * e );