How to set pen for a QgraphicsView and let my items use them from painter received ?

[tonnot]

I have a - QgraphicsView- QgraphicsScene - QgraphicsItems schema.
I have a painter object at QgraphicsView and other at QgraphicsView, I think that it must be the same of course.

Can I set-use the pen of this *painter at my qgraphicsitem paint() or at graphicsview background event ?
I tried to set the pen inside my graphicsview background event, but it seems to be 'volatile' .

Any idea ?

[wysota]

I'm not sure I understand what you mean but if you mean that you want to set painter properties in drawBackground() and expect them to persist until some item's paint() call then it won't.

[tonnot]

As drawbackground paints the background before the items be drawed, I think it can be a good place to say to the painter the global pen width. Depending of the 'zoom' I need to set how many meters have 1 pixel, to draw the width of my polylines rightly. (variable width) (Yes I know the meaning of setwidth to zero and the 'cosmetic' function).
I need a 'global' way to setup the pen width (and maybe other painter-draw properties). I would not want to set this inside every graphic item.
So, ....., is there any way to do this ?
Thanks

[wysota]

As drawbackground paints the background before the items be drawed, I think it can be a good place to say to the painter the global pen width.
No, because each item can have a different pen, brush and a bunch of other things. You can override this behaviour by setting DontSavePainterState on the view but then you will have to keep the painter clean yourself.


I need a 'global' way to setup the pen width (and maybe other painter-draw properties). I would not want to set this inside every graphic item.
You're lazy. Do it properly.

[tonnot]

No, it is not a lazy problem.
If I have 1 million of items, I think it would be better to set the pen width for the whole million than setting the pen 1 miilion times.
Thanks.

[wysota]

The zoom should determine the transform for the pen size, there should be no need to alter it per item.