GtkWindow::activate_focus
int activate_focus(void);
activate_focus() is a method
that will emit the activate signal from the child widget having
focus at the point that the method is called. In GTK+, each widget
has one signal which has activate signal status; the signal with this
status has the ability to respond to events generated from the keyboard.
If you do not have that widget-specific activate signal connected to
the widget with focus, nothing will be fired.
The widget that is most likely to be used in this situation is probably
GtkButton, which has
"clicked" as its activate
signal.
If this method is part of a callback called from another widget, that
widget will have focus at the time that the callback is run and PHP
will - understandably - crash. It needs to be called from an event
signal in order to work.
See also: Signals and Events
in the PHP-GTK userguide,
activate_default() ,
set_focus() ,
"activate".