gboolean gtk_widget_device_is_shadowed ( GtkWidget* widget, GdkDevice* device )
device has been shadowed by a GTK+
device grab on another widget, so it would stop sending
widget. This may be used in the
GtkWidget::grab-notify signal to check for specific
devices. See gtk_device_grab_add().
Available since: 3.0
The data is owned by the caller of the function.