FUNCTION

MUI has no distinct button class. Instead you can make every object (even groups) behave like a button by setting an input mode for them. Several input modes area available:

MUIV_InputMode_None:

No input, this is not a gadget.

MUIV_InputMode_RelVerify:

For buttons and similar stuff.

MUIV_InputMode_Immediate:

Used e.g. in a radio button object.

MUIV_InputMode_Toggle:

For things like checkmark gadgets.

The input mode setting determines how a user action will trigger the attributes MUIA_Selected, MUIA_Pressed and MUIA_Timer. See their documentation for details.