/*
  timeline-header-widget.hpp  -  Declaration of the timeline
  header widget

  Copyright (C)         Lumiera.org
    2008,               Joel Holdsworth <joel@airwebreathe.org.uk>

  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., 675 Mass Ave, Cambridge, MA 02139, USA.

*/
/** @file timeline-header-widget.hpp
 ** This file contains the definition of the header widget
 */

#ifndef HEADER_WIDGET_HPP
#define HEADER_WIDGET_HPP

#include "gui/gtk-lumiera.hpp"

namespace gui {  
namespace widgets {
namespace timeline {

class Track;

/**
 * TimelineHeaderWidget is the base implementation of all header widgets
 * and acts as a containers for the header controls.
 */
class TimelineHeaderWidget : public Gtk::Container
{
public:
  /**
   * Constructor
   * @param timeline_track The timeline track that owns this header
   * widget
   */
  TimelineHeaderWidget(timeline::Track &timeline_track);
  
  void set_child_widget(Widget& child);

private:
  /* ===== Overrides ===== */

  /**
   * An event handler for the window realized signal.
   */
  void on_realize();
  
  /**
   * An event handler for the window unrealized signal.
   */
  void on_unrealize();

  /**
   * An event handler that is called to offer an allocation to this
   * widget.
   * @param requisition The area offered for this widget.
   */
  void on_size_request(Gtk::Requisition* requisition);
  
  /**
   * An event handler that is called to notify this widget to allocate
   * a given area for itself.
   * @param allocation The area to allocate for this widget.
   */
  void on_size_allocate(Gtk::Allocation& allocation);
  
  /**
   * An event handler for when the window must be redrawn.
   */
  bool on_expose_event(GdkEventExpose *event);
  
  /**
   * An event handler for mouse button press events.
   * @param event The GDK event containing details of the event.
   */
  bool on_button_press_event (GdkEventButton* event);
  
  /**
   * An event handler for mouse button release events.
   * @param event The GDK event containing details of the event.
   */
  bool on_button_release_event (GdkEventButton* event);
  
  /**
   * An event handler for mouse movement events.
   * @param event The GDK event containing details of the event.
   */
  bool on_motion_notify_event (GdkEventMotion* event);

  /**
   * Applies a given function to all the widgets in the container.
   */
  void forall_vfunc(gboolean include_internals, GtkCallback callback,
    gpointer callback_data);

  /**
   * A notification of when a widget is added to this container.
   */
  void on_add(Gtk::Widget* child);
  
  /**
   * A notification of when a widget is removed to this container.
   */
  void on_remove(Gtk::Widget* child);
  
  /**
   * An implementation of the a container function that specifies the
   * types of child widget that this widget will accept.
   */
  GtkType child_type_vfunc() const;

  /**
   * Registers all the styles that this class will respond to.
   */
  void register_styles() const;
  
  /**
   * Reads styles from the present stylesheet.
   */
  void read_styles();

private:

  /**
   * A reference to the timeline track that owns this widget.
   */
  timeline::Track &track;

  /**
   * The widget placed inside this container.
   * @remarks This value is set to NULL if the container is empty
   */
  Gtk::Widget* widget;
  
  /**
   * This value is true if the mouse hovering over the expander.
   * @remarks This value is updated by on_motion_notify_event
   */
  bool hoveringExpander;
  
  /**
   * This value is true if the mouse button is depressed over the
   * expander.
   * @remarks This value is updated by on_button_press_event and
   * on_button_release_event
   */
  bool clickedExpander;
  
  /**
   * The widget's window object. 
   */
  Glib::RefPtr<Gdk::Window> gdkWindow;
  
  //----- Style Values -----//
  
  /**
   * The style value which indicates the amount of padding around each
   * header pixels.
   */
  int margin;
  
  /**
   * The style value which indicates the size to draw the expand button
   * in pixels.
   */
  int expand_button_size;
};

}   // namespace timeline
}   // namespace widgets
}   // namespace gui

#endif // HEADER_WIDGET_HPP