[Qt-interest] how to make QGraphicsView updated as soon as possible?

[Malyushytsky, Alex]

The only advertised way I know is to call QCoreApplication::processEvent.
Not sure QGraphicsView can do 30 updates per second though.

Alex



From: qt-interest-bounces+alex=wai.com at qt.nokia.com [mailto:qt-interest-bounces+alex=wai.com at qt.nokia.com] On Behalf Of Zhao, Halley
Sent: Friday, February 11, 2011 6:27 PM
To: qt-interest at trolltech.com
Subject: [Qt-interest] how to make QGraphicsView updated as soon as possible?

After QGraphicsItem::update() is executed, there is some delay to QGraphicsItem::paint() is called.
This is not vital for common UI, but for a 30fps video frame update, this delay introduce many issue.

How could I make QGraphicsView updated as soon as possible?
Could I change the event loop to schedule the repaint as soon as possible?


There is also a similar issue for Qt::QueuedConnection, there is visible delay to invoke a method by QMetaObject::invokeMethod(this, method, Qt::QueuedConnection);
Could I reduce the delay?
(I can’t use Qt::DirectConnection because I need some code runs in Qt thread).

thanks
    ZHAO, Halley (Aihua)
    Email: halley.zhao at intel.com
    Tel: +86(21)61166476   iNet: 8821-6476
SSG/OTC/Moblin 3W038 Pole: F4


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