gboolean gtk_widget_child_focus ( GtkWidget* widget, GtkDirectionType direction )
This function is used by custom widget implementations; if you’re
writing an app, you’d use
gtk_widget_grab_focus() to move the focus
to a particular widget, and
change the focus tab order. So you may want to investigate those
gtk_widget_child_focus() is called by containers as the user moves
around the window using keyboard shortcuts.
what kind of motion is taking place (up, down, left, right, tab
forward, tab backward).
gtk_widget_child_focus() emits the
GtkWidget::focus signal; widgets override the default handler
for this signal in order to implement appropriate focus behavior.
The default ::focus handler for a widget should return
direction left the focus on a focusable location inside
that widget, and
FALSE if moving in
direction moved the focus
outside the widget. If returning
TRUE, widgets normally
gtk_widget_grab_focus() to place the focus accordingly;
FALSE, they don’t modify the current focus location.
Direction of focus movement.