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.
1. battery.hpp - added local bool variable. Force to print warnings the
only once in order to warn user about wrong battery configuraion. And
does not bring a mess when the battery is turned off (gamepads, etc.)
2. dir_name is an object which takes a part in comparison. So converted to the string.
Speedup battery state update by only updating the battery list when we
get a CREATE/DELETE event in the directory or whenever we do a full
refresh on the interval.
