[Development] QGView and deprecated indirect painting

[Christian Gagneraud]

Hi Trolls!

Note: I'm sending this email to qt-dev not to qt-interest because it 
deals with deprecated features and API changes of the Qt Graphics View 
framework.

QGraphicsView has an optimisation flag called "IndirectPainting", which 
when set "restore the old painting algorithm that calls 
QGraphicsView::drawItems() and QGraphicsScene::drawItems()." and is 
marked as "To be used only for compatibility with old code."

I would like to use this feature to achieve per view painting controls 
such as:
- item transparency and colors (effect)
- drawing order

In my context, there is one main view (the working view) and other 
auxiliary views (typically in dock widgets), a picture being worth a 
thousand word, here is an example of the sort of things I'm after: 
http://techdocs.altium.com/display/ADOH/Working+with+the+Board+Insight+System#WorkingwiththeBoardInsightSystem-SingleLayerMode

So, my question is: Do you guys plan to remove this feature, and if yes 
(which seems likely to me), how could I then control colors, opacity and 
drawing order on a per view basis?

I think it is a very good feature to allow the view to take control of 
painting over the QGItems and the QGScene. (on the side, i think as well 
that it is way better to let the view handle mouse and keyboard events 
instead of the scene or the items)

Thanks,
Krys