Implement multitouch in BaseButton to supersede TouchScreenButton

[Calinou]

• Related to Implement pass-by pressing in BaseButton #3030.

Describe the project you are working on

The Godot editor 🙂

Describe the problem or limitation you are having in your project

Since Godot's early days, Godot has two main button nodes:

• BaseButton¹, which extends from Control. Does not support multitouch, and is therefore not suited to mobile controls.
• TouchScreenButton, which extends from Node2D. Supports multitouch, but does not support Control's anchors, margins and containers system. This makes them difficult to place in specific corners of the screen unless you make them a child of a Control node.

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

Add multitouch support to BaseButton to supersede TouchScreenButton.

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

• Implement multitouch for BaseButton.
  • This should preferably include support for displaying pressed styles on multiple buttons at once.
• Add a Touchscreen Only boolean property to BaseButton (similar to TouchScreenButton's existing property).
• Deprecate TouchScreenButton as BaseButton (and its derived nodes) will supersede it for all intents and purposes.

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

No.

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

This is a compatibility-breaking change, and it's about improving usability when developing mobile games.

Footnotes

1. BaseButton is the parent class for Button, TextureButton, LinkButton, CheckBox, CheckButton, and more. ↩

[roalyr]

What are the chances of backporting it to 3.x if / when it is implemented? Or does compatibility break deny it?

[Calinou]

What are the chances of backporting it to 3.x if / when it is implemented? Or does compatibility break deny it?

This is a compatibility-breaking change, but multitouch support could be added to BaseButton without removing TouchScreenButton in 3.x. However, the chances that this feature is implemented before 3.5 is released is slim.

[roalyr]

As long as it can arrive within few years I am fine.

[madmiraal]

godotengine/godot#49215 and it's original 3.x version godotengine/godot#34383 by @NoFr1ends provide support for multi touch in _gui_input().

Note: These PRs only enable multi-touch support in the GUI. They provide the basis for, but do not implement multi-touch in BaseButton.

[Atem1995]

godotengine/godot#49215 and it's original 3.x version godotengine/godot#34383 by @NoFr1ends provide support for multi touch in _gui_input().

Note: These PRs only enable multi-touch support in the GUI. They provide the basis for, but do not implement multi-touch in BaseButton.

@madmiraal sir,hava you tested it on varsion 3.4?

[grayhaze]

While this proposal is a good start, I'd like to see touch supported on all Control nodes. Currently if a project requires multitouch support (e.g. pinch zoom), usage of any Control nodes which at present offer mouse interaction (e.g. SplitContainer) is impossible. This effectively removes most of the UI functionality Godot provides on touch devices unless multitouch is disabled.

[Calinou]

While this proposal is a good start, I'd like to see touch supported on all Control nodes.

This can be done separately from this proposal, as handling native (non-emulated) touch events in Control nodes not inheriting from BaseButton can be implemented independently.