Performance problems with overlapping qgraphicsitems

[Gopala Krishna]

Hello, i eperimented performances problem with graphicsview and
found a workaround wich can perhaps help,
try it, it is very easy, you only have to reimplement paintEvent function like this
in a subclass :

class MyFasterGraphicView :public QGraphicsView
{
 	Q_OBJECT
public:
	MyFasterGraphicView( ...);
protected:
	...
	void paintEvent ( QPaintEvent * event );
	...
};
 
void MyFasterGraphicView::paintEvent ( QPaintEvent * event )
{
	QPaintEvent *newEvent=new QPaintEvent(event->region().boundingRect());
	QGraphicsView::paintEvent(newEvent);
	delete newEvent;
}

class MyFasterGraphicView :public QGraphicsView
{
 	Q_OBJECT
public:
	MyFasterGraphicView( ...);
protected:
	...
	void paintEvent ( QPaintEvent * event );
	...
};

void MyFasterGraphicView::paintEvent ( QPaintEvent * event )
{
	QPaintEvent *newEvent=new QPaintEvent(event->region().boundingRect());
	QGraphicsView::paintEvent(newEvent);
	delete newEvent;
}

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I can explain the reason, is someone is interrested,

Have fun,

CyrBa

Indeed the performance is better. Can somebody explain how this improves?