Models and Delegates

[wysota]

The docs and examples I have read clearly say you can use data() in the model or paint() in the delegate.

It's not "or", it's "and". Always both routines are used. You can't choose between the two, you always use both.

I believe I understand what you are saying. My issue was if there is a preferred place to make the alterations of what is displayed. As a test I was able to make the changes in both methods. So this seems to be a matter of preference.

More like a matter of effect you wish to obtain. When you change the way the model returns data you affect all places where the data is used. When you change the delegate you only affect the view the delegate is installed on. Imagine you have two views showing the same data. If you modify the "looks" of the data in the model, both views will display the same thing, if you install two different delegates on each of the views, the display will differ. Also some things can't be done by changing the model - i.e. try making it display some text and two icons besides it (one on the left of the text and the other on the right of the text).

I am impressed at how much flexibility the model / delegate classes provide.

They are fine when dealing with simple situations but at some point you start stumbling against the wall. The architecture is already reaching its limits but hopefully it will be replaced (or complemented) by ItemViewsNG within a year or so.

[aamer4yu]

I can put color information in the data() method.

But simply having color information wont paint it in that color ! Unless your delegate knows about it. But still its the delegate that actually draws things.

I can put color information in the data() method. What I really believe is going on, is that paint() in the delegate asks the model for information.

You are getting it right. The model is the data provider, delegate the painter.