The AButton class is designed as full a substitute to ALabel. The
GtkButton attribute 'button_' is initialized with a label. This
label can the be referenced by the subsequent inheritors of AButton
instead of the GtkLabel attribute 'label_' of ALabel.
For convenience a GtkLabel* 'label_' attribute is added to AButton.
If the button cannot be clicked it is disabled, effectively acting
like its label predecessor.
GtkButton seems to catch one-click mouse events regardless of the
flags set on it. Therefore, 'signal_pressed' is connected to a
function creating a fake GdkEventButton* and calling 'handleToggle'
(for details on this possible bug in GTK see:
https://stackoverflow.com/questions/45334911 )
In accordance with other GtkButtons (i.e. the sway/workspace ones)
set_relief(Gtk::RELIEF_NONE) is called on the 'button_' instance.
When adding a custom module with a name, e.g.:
```jsonc
{
...,
"custom/foo#bar": { },
...
}
```
The custom module does not retain the `bar` class as it should, because
all the classes are replaced with the runtime output:
1b4a7b02f4/src/modules/custom.cpp (L141-L147)
Avoid removing the module instance name class so css class behavior is
consistent between all modules.
This commit allows custom modules (json only) to set a percentage. This can be displayed either by using {percentage} or by using {icon} with format-icons set.