On Thu, 5 Nov 2009 06:28:36 -0800 Daniel Burrows <dburr...@algebraicthunk.net> wrote: > > I have what's probably a simple GTK+ problem, and I was wondering if > anyone could give me a tip. > > I'm trying to write a custom widget (in GTK--) that would benefit > from knowing whether it's currently visible or not. It seems pretty > easy to detect when a widget becomes visible for the first time by > hooking into the "expose" signal, but I can't for the life of me find > any way of detecting when a widget becomes invisible. (for instance, > when the user switches away from its tab in a notebook or scrolls past > it in a TextView) > > The most promising thing I found was the "visibility notify event", > but it never seems to get delivered to my widget. I've also tried to > use is_viewable() and get_visible_region() on the GDK window, but even > if these work (they don't seem to so far, but I could be doing it > wrong) I need a signal or event so that I know when to test them.
You need to add the GDK_VISIBILITY_NOTIFY_MASK for the widget with gtk_widget_add_events() in order to get visibility notify events on it. Also test GTK_WIDGET_VISIBLE() if you might call hide() on the widget (eg when in the system tray), because hiding a widget for some reason does not count as a change of visibility status. Depending on what you are after, you may also want to track window state events for cases where a window is iconified (minimised). In other words, a lot depends on what you mean by "visible". Your meaning many not be the same as GDK's meaning. If you test for all of the conditions I have mentioned it will probably do what you want. Chris _______________________________________________ gtk-app-devel-list mailing list gtk-app-devel-list@gnome.org http://mail.gnome.org/mailman/listinfo/gtk-app-devel-list
