Expose SceneTreeDialog and PropertySelector via EditorInterface

[nlupugla]

Allows users to create SceneTreeDialog and PropertySelector dialogs via the EditorInterface. Lays the groundwork for adding similar dialogs in the future as needed.

The API is

EditorInterface.popup_dialog_scene_tree(callback: Callable, valid_types: Array[StringName] = [])
EditorInterface.popup_dialog_property_selector(object: Object, callback: Callable, type_filter: PackedIntArray = [])

Example usage

@tool
extends Node
class_name Main


func _ready() -> void:
	if Engine.is_editor_hint():
		EditorInterface.popup_dialog_scene_tree(_on_node_selected, [&"Button"])

func _on_node_selected(node_path : NodePath) -> void:
	if node_path == ^"":
		print("scene tree dialog canceled")
	else:
		EditorInterface.popup_dialog_property_selector(get_node(node_path), func(x) : print(x), [TYPE_BOOL])

Closes godotengine/godot-proposals#7635.
Closes godotengine/godot-proposals#7636.

Supersedes #81488.
Supersedes #81489.

Related: godotengine/godot-proposals#300.

Edit 2023-Oct-05 12:45:
I have only implemented PropertySelector::select_property_from_instance, but there are several related methods: select_property_from_base_type, select_property_from_script, and select_property_from_basic_type. Should I implement these now or wait until the need arises?

Edit 2023-Dec-09 19:06:
Edited example usage to reflect new API that uses a single NodePath instead of an array of NodePaths.

[nlupugla]

Why the callbacks use arrays of NodePaths as arguments if the dialog itself returns NodePath?

Thanks for the review @KoBeWi, I'm learning a lot from your comments!

I grateful you asked about using an Array because it's a decision I want some feedback on. I have two reasons for using an Array.

1. It reduces the number of signals that need to be added to EditorInterfaceAPI. An empty Array can be interpreted as a "cancelled" event, which means there doesn't need to be seperate cancelled signals for each dialog, e.g. dialog_scene_tree_cancelled.
2. It will make it easier to support multi-select in the future. I hope to add multi-select select to these dialogs soon: Add support for multiple selection in EditorPropertySelector and SceneTreeDialog godot-proposals#7676.

[KoBeWi]

Left some code suggestions, but the functionality itself looks fine now.

[nlupugla]

Awesome, thanks for all the help KoBeWi :)

Just pushed the minor change you suggested of Vector -> PackedInt32Array.

[YuriSizov]

Overall, this looks good to me and seems useful. Once the comments are addressed, this can be merged. Thank you for waiting :)

[nlupugla]

Awesome, thanks Yuri <3

Hopefully I'll have time to commit these changes and test them soon :)

[nlupugla]

Made the requested changes :)

I reran it with my test project and it still works fine. I haven't done any testing of the edge cases that removing signals and removing from tree before deleting the dialog nodes would address: presumably when the user attempts to popup the same dialog twice in one frame. Should I submit a unit test for that? A test project? Or is that all overboard for this PR?

[YuriSizov]

You need to rebase on the current master, we had an issue with macOS builds which will fail your CI.

[akien-mga]

Thanks! And congrats for your first merged Godot contribution 🎉