Add an @export annotation for InputMap actions

[Sulfrix]

Describe the project you are working on

Input glyph displays for a 2D game that show control hints on screen

Describe the problem or limitation you are having in your project

I have a resource that exports a StringName property corresponding to the action in the InputMap that should be displayed as a button glyph. This works fine, but I feel that it would help to have a way to select an action from a dropdown, reducing the chance of mistyping an action name, and reducing trips to the Input Map project settings in case one forgets the correct name. In addition, the built-in TouchScreenButton node also simply has a StringName property that should correspond to an action in the InputMap.

Describe the feature / enhancement and how it helps to overcome the problem or limitation

I think an @export_action annotation, similar to other annotations that use project context like @export_file, would provide a nice experience for specifying InputMap actions for nodes/resources that require one.

Describe how your proposal will work, with code, pseudo-code, mock-ups, and/or diagrams

The inspector would display the property similar to @export_enum, allowing the user to pick from a list of actions defined in the project settings' InputMap.

This would be used in GDScript as follows:

@export_action var hint_action: StringName = &"run"

This could also be applied to the TouchScreenButton node so that an action can be quickly selected.
If TouchScreenButton does use this action dropdown, there is possibility for a regression if a project uses dynamically created actions since the default inspector enum behavior does not allow the user to type in a value manually, so it should probably use PROPERTY_HINT_ENUM_SUGGESTION.

If this enhancement will not be used often, can it be worked around with a few lines of script?

As far as I'm aware, @export_enum nor @export_custom allow a dynamic list of options, like options taken from project settings, so they are not suitable for this. You could possibly implement this using get_property_list() but this seems rather inconvenient.

Is there a reason why this should be core and not an add-on in the asset library?

Currently GDScript does not support custom annotations (#1316) so an add-on could not implement it. In addition, this change could also improve the built-in node TouchScreenButton.

[AThousandShips]

See:

• Idea: export variable as input action #7559
• Add PROPERTY_HINT_INPUT_NAME for use with @export_custom to allow using  godot#96611