[Tree] It would be beneficial to separate Tree node selection from node toggling

[vsajip]

Currently, clicking on a Tree node label both selects the node and toggles its expansion state. It would be useful if node expansion was restricted (or restrictable on a per-Tree basis) to clicks on the expansion handle (triangle), and node selection to the label only.

[willmcgugan]

Try auto_expand=False

[davep]

Try auto_expand=False

Unfortunately that seems to stop the ability to expand a tree without the mouse (at least by default -- presumably it's possible for the developer to add their own binding). Is that by design or shall I raise an issue to this effect?

[willmcgugan]

If the dev doesn't want selecting the label to expand the node automatically, then they would need to expand it manually. Unless we have some "expand but don't select" binding.

[davep]

Unless we have some "expand but don't select" binding.

Aye, I'm thinking it might be an idea to split action_select_cursor out a bit so the keyboard binding can always expand, but the _on_click call to action has the desired auto_expand effect? Upshot being that, with auto_expand=False, a mouse click won't expand, but a tap of Enter will, the latter being a bit more deliberate as it's the cursor keys that change selection when in keyboard mode.

At least: playing with the permutations there right now that feels right under my fingers.

[mathman1618]

Upshot being that, with auto_expand=False, a mouse click won't expand, but a tap of Enter will, the latter being a bit more deliberate as it's the cursor keys that change selection when in keyboard mode.

I'm adapting some code to the new Tree widget at present; I find auto_expand=False to work well with an additional binding (Space) for toggling node expansion. I think separating selection and expansion is preferable to having Enter both select and expand a node.

Example use case: I have a tree view tied to a hexdump. Selecting a node (single click or Enter) highlights a corresponding region in the hexdump, while clicking the triangle next to the node label or hitting Space toggles the node. In this scenario I want to be able to select a node without necessarily collapsing its portion of the tree.

(It's also possible to enable a double click to toggle a node by hacking the Driver class a bit.)

[willmcgugan]

Maybe fixed, or possible some other way. To investigate.

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