void grab_focus ( GtkWidget* widget )
widget to have the keyboard focus for the
widget must be a focusable widget, such as a
GtkFrame won’t work.
More precisely, it must have the
GTK_CAN_FOCUS flag set. Use
gtk_widget_set_can_focus() to modify that flag.
The widget also needs to be realized and mapped. This is indicated by the related signals. Grabbing the focus immediately after creating the widget will likely fail and cause critical warnings.