LibGUI: Use of REGISTER_*_PROPERTY with custom getter or setter names should be minimized

[timschumi]

The discrepancies between the registered getter/setter names and the name of the function that they end up calling are an ongoing source of confusion when converting applications from the runtime GML interpreter, which uses the registered properties, to the GML compiler, which doesn't use registered properties (#20518).

The following should be evaluated:

• Convert REGISTER_*_PROPERTY calls to be strictly of the format REGISTER_*_PROPERTY(<name>, <name>, set_<name>, ...) where possible
• Determine a better way to model read- or write-only properties (e.g. for GUI::Widget::dummy_fixed_*)
• Remove the ability to provide custom getter and setter names completely

[AtkinsSJ]

An alternative idea I've been toying with, (but haven't worked on,) is to move the property definitions into a JSON file, and use that in the GML compiler, widget initialization, and Playground's autocomplete. The benefits would be:

• Static type checking in the compiler.
• Playground would know what type to expect, and could autocomplete enum values.
• The method names could be completely arbitrary but still work when compiled.
• Replace the REGISTER_*_PROPERTY() macros with a call to a generated register_properties(qualified_class_name); function.
• We could maybe generate some of the Widget manpages with this too?

But yeah, haven't actually started on it. 😅

[kleinesfilmroellchen]

An alternative idea I've been toying with, (but haven't worked on,) is to move the property definitions into a JSON file, and use that in the GML compiler, widget initialization, and Playground's autocomplete. The benefits would be:

* Static type checking in the compiler.

* Playground would know what type to expect, and could autocomplete enum values.

* The method names could be completely arbitrary but still work when compiled.

* Replace the `REGISTER_*_PROPERTY()` macros with a call to a generated `register_properties(qualified_class_name);` function.

* We could maybe generate some of the Widget manpages with this too?

But yeah, haven't actually started on it. 😅

+1 for this idea

[kleinesfilmroellchen]

#22920