I think you're kinda thinking about it wrong.
First, there is QGraphicsItemGroup, which would probably do what you want, and
automatically provides a boundingRect() as the unsion of all child bounding
rects.
When custom drawing your item always draw it "native" resolution. let the Scene
work out the scaling and scaled bounding rect. You only need to worry about
yourself at 1:1 scaling.
HTH
________________________________
From: BRM <bm_witn...@yahoo.com>
To: Interests Qt <interest@qt-project.org>
Sent: Tuesday, August 7, 2012 12:36 PM
Subject: [Interest] Questions about QGraphicsWidget
I'm working on a QGraphicsWidget version of something I already have a QWidget
version of; namely because I need to add some features where I need to overlay
items, lines, and text in a way that QWidget does not support (namely the
addition of the text information) - presently I'm just focused on getting to
the point of equivalence with what I had under QWidget. In doing so I have
taken my one QWidget and converted it into a series of QGraphicsWidgets, and
added a parent QGraphicsWidget that will contain at most two of the sub-widgets
- the data being drawn, and its ideal overlay. (I originally had just one
QGraphicsWidget but found it simplified things if I split stuff out. I figured
this would be an advantage since I can overlay stuff in QGraphics* where I
could not under QWidget.)
Question #1: The parent widget has two widgets within it. At this time I'm not
using a QGraphicsLayout of any sort as none seem to match doing the overlay I
need - that is, the two widgets will be in different Z-levels (1 and 2), and if
both are visible then they will be nearly the same coordinates in their parent
coordinate system. Or am I missing something and this would be supported by one
of the existing QGraphicsLayouts? Do I really even need a QGraphicsLayout to
manage these, or is there a simpler way to do it? I'm thinking the geometry
would be that of the farthest extremities of the combination of the two widgets
when both are visible, or just the one widget when only one is visible. The
parent widget will likely sit in a QGraphicsLayout of some sort when I am done.
Question #2: I'm having an issue with scaling of the drawing. If I understand
QTransform::scale() correctly, then it maps the coordinates being used from one
coordinate system to another. I am trying to keep the drawing within the
boundaries of the widget itself, but using the
boundingRect().contains(pointToDraw) does not keep any points from being drawn
when the leave the boundingRect(). I didn't have to worry about this with
QWidget as QWidget clipped what was being drawn (or at least displayed) on the
boundaries of the widget; while QGraphicsWidget doesn't do that - it'll gladly
leave artifacts. Am I missing an easy way to keep it from leaving artifacts?
TIA,
Ben
_______________________________________________
Interest mailing list
Interest@qt-project.org
http://lists.qt-project.org/mailman/listinfo/interest
_______________________________________________
Interest mailing list
Interest@qt-project.org
http://lists.qt-project.org/mailman/listinfo/interest
