void gtk_widget_grab_default ( GtkWidget* widget )
widget to become the default widget.
widget must be able to be
a default widget; typically you would ensure this yourself
gtk_widget_set_can_default() with a
The default widget is activated when
the user presses Enter in a window. Default widgets must be
activatable, that is,
gtk_widget_activate() should affect them. Note
GtkEntry widgets require the “activates-default” property
TRUE before they activate the default widget when Enter
is pressed and the
GtkEntry is focused.