/* set_focus_handler() will cause all button-press events on any
CairoWidget to invoke this slot/functor/function/method/callback.
-
+
We do this because in general, CairoWidgets do not grab
keyboard focus, but a button press on them should
clear focus from any active text entry.
However, derived types can override the behaviour by defining their
own on_button_press_event() handler which returns true under all
- conditions (which will block this handler from being called). If
+ conditions (which will block this handler from being called). If
they wish to invoke any existing focus handler from their own
button press handler, they can just use: focus_handler();
*/