[Qt-interest] Have any recommendations of enhance the GUI speed of using GraphiscView/Scene/Items ?

[Schimkowitsch Robert]

Hi,

when moving lots of items, updating the bsp tree for fast item lookup can be expensive.
You might want to check QGraphicsScene::setItemIndexMethod and QGraphicsScene::setBspTreeDepth.

Also, you might run it on Linux using valgrind - it's very easy to use nowadays, with the integration in Creator.

Kind regards

Robert Schimkowitsch


-----Original Message-----
From: qt-interest-bounces+robert.schimkowitsch=andritz.com at qt.nokia.com on behalf of Duan,Lin
Sent: Fri 10/28/2011 11:45 AM
To: qt-interest at qt.nokia.com
Subject: [Qt-interest] Have any recommendations of enhance the GUI speed of using GraphiscView/Scene/Items ?
 
I am performing a task of building a GraphicsView based GUI application. But I found that when I RubberBand-select about 20 Items,then Drag them together within the unique GraphicsView/Scene,it seems need I wait it for redraw (very very slow).
( there were many GraphicsPathItems connected the items, then moving the items together , the GraphicsPathItem redraw in the GraphicsPathItem::mouseMoveEvent()).



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