How to resize QListView row to index widget size

[sm4ll-3gg]

I have custom model(ListModel), which contains AbstractModel*. From the AbstractModel are inherited 3 models : User, Group and Chat. Each of the models have own view (***View). I need to set my model(ListModel) and set for each item(index for QListView) own view. But when I set view (QListView::setIndexWidget) row height remains default.

How to make the height of the row equal to the height of its view(views can resize dynamically)?

QListView have sizeHintForRow method, but it never calls.
From Qt docs: "Note that to control the height of a row, you must reimplement the QAbstractItemDelegate::sizeHint() function". But I can't get access to index widget from delegate.

What I can do?

[VRonin]

@sm4ll-3gg said in How to resize QListView row to index widget size:

QAbstractItemDelegate::sizeHint() function". But I can't get access to index widget from delegate.

The index is the second argument of sizehint... http://doc.qt.io/qt-5/qabstractitemdelegate.html#sizeHint

[sm4ll-3gg]

@VRonin yes ,I can get a model by index, but I can not get a view by index or model. I need view because I can get item widget only when I call view-> indexWidget(), isn't it?.

[VRonin]

Nope, the delegate replaces the indexWidget completely.

What kind of widgets are you using? are they simple Qt widgets or are they composite?

[sm4ll-3gg]

@VRonin I'm using composite custom widgets. Yep, you right, delegate replaces indexWidget, but I don't understand how show my custom widget for display, not for edit.
I.e., I need to all widgets are always visible, not only when edit requested

Actually, I do not need editing at all. I need only show widgets and use them

Please tell me how this can be done, if you know. Because I google it for 3 days. And I didn't find the right answer. The createEditor method shows the widget only for editing.

[VRonin]

It's not a trivial task. If your model is not huge you could use something like this: https://pastebin.com/XrppLZ3m but, in general, you'd have to manually handle the painting

[sm4ll-3gg]

@VRonin Ty, it's works, what I should read to better understand Model / View / Delegate programming? I read all the documentaition on qt.io about this theme, but I did not see anything even remotely resembling such an approach.

P.S. It is normal to set new delegate for each item if I need to show heterogeneous data in list?

[VRonin]

@sm4ll-3gg said in How to resize QListView row to index widget size:

what I should read to better understand Model / View / Delegate programming?

Basically everything I know comes from Advanced Qt Prgramming: Creating Great Software with C++ and Qt4

It is normal to set new delegate for each item if I need to show heterogeneous data in list?

No. What I would do is create a QStackedWidget with the possible combinations, use that as base and display the correct page based on the data in the index