Question

I have to design a GUI using Qt. I would like to draw multiple lines depicting relationships between two objects. It’s the same idea as matching a word with a definition by drawing a straight line (which might be a diagonal) between the two.

In my case it is an a label (with image inside of it) that needs to be matched with another label.

So we have something like this – http://dl.dropbox.com/u/46437808/DrawLines.png

And I want to add lines to make it look something like this http://dl.dropbox.com/u/46437808/DrawLines2.png

I need to do this in run time because the relationship will be changing based on different factors.

Thanks!

Answer 1

Do you need interaction or is this just an image that the user needs to see based on other information? If it’s just a static image, I would simply draw it onto a QImage and show it. That way you have complete control over how things are drawn. So you can either cache the relationship diagrams you need ahead of time, or just draw them on the fly onto the QImage based on the relationship that needs to be displayed at the time. You can look at Qt’s painting example for some ideas on how to accomplish what you need.

If you need interactivity, I would probably go with the Graphics View Framework. This way if you need push buttons, check boxes, etc. for any reason you can use the QGraphicsProxyWidget to get them, or you can just make your own from QGraphicsItem subclasses.