Allow shortcuts to have any number of input events assigned to them.

[EricEzaM]

Closes godotengine/godot-proposals#2875
Supersedes / Closes #48009

This is based on discussion on Rocket chat as well as feedback in the above proposal and PR.

Summary:

• One Shortcut can now have many InputEvents assigned to it (related; Shortcut: Rename shortcut property to event #51215)
• Relevant methods and properties changed, as well as the way Editor shortcuts are serialised as it is now an array.
• The EditorSettings Shortcuts editor finally has the same user interface for Built-In actions and other editor actions! 🎉🎉 (see below). A lot of the changes were to do with the changes made to the editor settings dialog.
• I had to made one minor modification to drag & drop logic, where the drag and drop forward target can now just be a Node rather than being a Control. This is because EditorSettingsDialog needed to be the node which the Tree drag was forwarded to, but as Window is not a Control, I had to change this to Node.

The the editor settings shows up to 2 shortcuts in-line, and the additional amount in parentheses. The next tree level then shows all shortcuts, where they can be edited or removed. The user can drag and drop shortcuts to determine which one is the "primary" one. The primary shortcut is what is displayed in the UI, for example in PopupMenus with items that have shortcuts, or in Button tooltips, as shown in the video. In the video, any shortcut (E, Ctrl+R, Ctrl+Shit+T) could be used to select the rotate mode.

shortcut_changing.mp4

For users, the shortcuts resource now includes an array, which accepts any InputEvent derived resource. Please note when editing this in the inspector, this is affected by the new "inspector refresh" system, as described here: #49817. To test this PR properly and be able to drop down the array item selector, change your inspector refresh interval in your settings to a high value (e.g. 5 seconds). P.S. yes, the button in the video should say "press S", its just a typo :)

shortcuts.showcase.mp4

And for serialization of shortcut editor settings, a bit simpler now:

shortcuts = [{
"name": "canvas_item_editor/rotate_mode",
"shortcuts": [SubResource( "InputEventKey_5ftl2" ), SubResource( "InputEventKey_nudrv" ), SubResource( "InputEventKey_ffuxw" )]
}, {
"name": "tiles_editor/paint_tool",
"shortcuts": [SubResource( "InputEventKey_nlk4p" )]
}]

[EricEzaM]

I am not sure if #51215 should be merged before or after this... Probably before?

[akien-mga]

I am not sure if #51215 should be merged before or after this... Probably before?

Either way works for me, but I'd need someone to approve it to merge ;)

[akien-mga]

Needs a rebase.

[EricEzaM]

Rebased.

Also had to make some changes to fix the inspector refresh bug. I follow what was done in #52082, which is basically just making the backing field and Array instead of List<Ref<InputEvent>> *. This kind of sucks since we lose the typing but... otherwise it is completely unusable in resources/inspector, so it needs to be done. Not sure if Vector<> can be used for this, or TypedArray<>, but the PR I mentioned above just uses Array so that's what I went with, and it's fine. The positive is that we can remove the auxiliary methods which just set/get the list as an array, so there is compatibility with the properties and functions system.

Anyway, it all appears to be working as expected.

[Paulb23]

Looks good to me, couple small nitpicks but nothing major.

[akien-mga]

Thanks!