using Gtk;

class WindowTest : Gtk.Box{
        private Gdk.Window event_window;
        private Button button = new Button.with_label("Foo");


        public WindowTest() {
                GLib.Object(orientation: Orientation.HORIZONTAL, spacing: 25);
                button.no_show_all = true;
                this.pack_end(new Button.with_label("Bar"));
                this.pack_start(button);

                this.enter_notify_event.connect( ()=> {
                        button.show();
                        message(" IN");
                        return false;
                });
                this.leave_notify_event.connect( () => {
                        button.hide();
                        message("OUT");
                        return false;
                });
        }

        public override void realize() {
                message("realize");
                Allocation alloc;
                Gdk.WindowAttr attr = {};

                this.get_allocation(out alloc);

                this.set_realized(true);


                attr.x = alloc.x;
                attr.y = alloc.y;
                attr.width = alloc.width;
                attr.height = alloc.height;
                attr.window_type = Gdk.WindowType.CHILD;
                attr.event_mask = this.get_events();
                attr.event_mask |= (Gdk.EventMask.ENTER_NOTIFY_MASK |
                                                        Gdk.EventMask.LEAVE_NOTIFY_MASK |
                                                        Gdk.EventMask.EXPOSURE_MASK);

                var attr_type = Gdk.WindowAttributesType.X |
                                Gdk.WindowAttributesType.Y;



                bool visible_window = get_has_window();
                if(visible_window) {
                    error("NOP!");
                }else {
                        var parent = get_parent_window();
                        set_window(parent);

                        attr.wclass = Gdk.WindowWindowClass.INPUT_ONLY;

                        this.event_window = new Gdk.Window(parent, attr, attr_type);
                        this.event_window.set_user_data(this);
                        message("No visible window");

                }

        }

        public override void unrealize() {
                message("unrealize");
                if(this.event_window != null) {
                        this.event_window.set_user_data(null);
                        this.event_window.destroy();
                        this.event_window = null;
                }

                base.unrealize();
        }

        public override void map(){
                message("map");
                base.map();
                if(event_window != null)
                        event_window.show();

        }

        public override void unmap() {
                message("unmap");
                base.unmap();
                if(event_window != null)
                        event_window.hide();
        }

        public override void size_allocate(Allocation alloc) {
                message("size_allocate");
                this.set_allocation(alloc);

                if(this.get_realized()) {
                        if(event_window != null)
                                event_window.move_resize(alloc.x, alloc.y,
                                                         alloc.width, alloc.height);
                }
                base.size_allocate(alloc);
        }



        static void main(string[] args) {
                Gtk.init(ref args);

                var win = new Window();
                win.add(new WindowTest());
                win.resize(200, 200);
                win.show_all();
                Gtk.main();
        }
}