How to get the Index of a binding.DataItem

[udelledo]

I have a list with databinding that is supposed to draw buttons with a description.

In case the description is too long I have a function that wraps it to a fixed width, and I'm trying to render it properly.

So far I got to this snippte of code:

      // ...
      var recentTasksBinding = binding.NewUntypedList()
      var taskList *widget.List

	taskList = widget.NewListWithData(recentTasksBinding, func() fyne.CanvasObject {
		return widget.NewButton(strings.Repeat("*", 50), nil)
	}, func(item binding.DataItem, object fyne.CanvasObject) {
		button := object.(*widget.Button)
		value, err := item.(binding.Untyped).Get()
		if err != nil {
			return
		}
		record := value.(api.Record)
		button.SetText(wrapString(record.Description, 50))
		button.OnTapped = func() { updateTaskEntry(record) }

         // I'm not able to find how to get the index of the item, and I would like to avoid looping the whole list comparing with the item to find the ID. Is there a different option?
         // taskList.SetItemHeight(item, button.MinSize().Height)
	})

As a different workaround I used this "hack", but I was wondering if there's a better, and more idiomatic way in Fyne to achieve my goal:

func ResizableListWithData(data binding.DataList, createItem func() fyne.CanvasObject, updateItem func(binding.DataItem, fyne.CanvasObject), shouldResize func(item binding.DataItem) bool) *widget.List {
	var l *widget.List
	l = widget.NewList(
		data.Length,
		createItem,
		func(i widget.ListItemID, o fyne.CanvasObject) {
			item, err := data.GetItem(i)
			if err != nil {
				fyne.LogError(fmt.Sprintf("Error getting data item %d", i), err)
				return
			}
			updateItem(item, o)
			if shouldResize(item) {
				l.SetItemHeight(i, o.MinSize().Height)
			}
		})

	data.AddListener(binding.NewDataListener(l.Refresh))
	return l
}

[andydotxyz]

Currently there is no direct way - you need to choose between data list or indexed list.
Your workaround is a reasonable one. If you can think if a good API that would support the ID lookup when using data that could be cool - but I've not thought of how that would work. Or how we can set the height for a DataItem row?

[udelledo]

mhm, it's not exactly the approach you were asking, but off the top of my head maybe a simple yet effective API would be to have a DataListItem that would be based off DataItem, and include a GetIndex() method.

But I'm not still clear on how it could be added to the list elements with backward compatibility for the current existing signatures.

Maybe a widger.NewListWithIndexedData that would use the updateItem with the DataListItem instead of the plain DataItem

P.S.
I'm not entirely sure the lookup of the id from the DataItem is really a viable option, because this would implicitly prevent any list with duplicated values.