eventboxext.h

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/*
 * Copyright (C) 2017 Robin Gareus <robin@gareus.org>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */
 
#ifndef _WIDGETS_EVENTBOX_EXT_H_
#define _WIDGETS_EVENTBOX_EXT_H_
 
#include <gtkmm/eventbox.h>
 
#include "widgets/visibility.h"
 
namespace ArdourWidgets {
 
class LIBWIDGETS_API EventBoxExt : public Gtk::EventBox
{
public:
        EventBoxExt ();
        virtual ~EventBoxExt () {}
 
protected:
        /* gtk2's gtk/gtkcontainer.c does not
         * unmap child widgets if the container has a window.
         *
         * (this is for historical reasons and optimization
         * because back in the day each GdkWindow was backed by
         * an actual windowing system surface).
         *
         * In Ardour's case an EventBox is used in the Editor's top-level
         * and child-widgets (e.g. Canvas::GtkCanvas never receive an unmap.
         *
         * However, when switching Tabbable pages, we do need to hide overlays
         * such as ArdourCanvasOpenGLView
         *
         */
        void on_unmap () {
                Gtk::EventBox::on_unmap();
                if (get_child ()) {
                        get_child()->unmap();
                }
        }
};
 
} /* namespace */
 
#endif