/*
  timeline-track.hpp  -  Declaration of the timeline group track object
 
  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 widgets/timeline/timeline-track.hpp
 ** This file contains the definition of timeline track object
 */

#include "../../gtk-lumiera.hpp"
#include "../../model/track.hpp"
#include "../menu-button.hpp"
#include "timeline-header-container.hpp"
#include "timeline-header-widget.hpp"

#ifndef TIMELINE_TRACK_HPP
#define TIMELINE_TRACK_HPP

namespace gui {
namespace widgets { 
namespace timeline {
  
class TimelineViewWindow;

/**
 * Timeline tracks are created by the timeline widget to correspond to
 * model tracks. Timeline tracks are used to store UI specific state
 * data.
 **/
class Track : public sigc::trackable
{
public:
  
  /**
   * An enum used by the branch expand/collapse animation.
   * ExpandDirection represents whether the branch us being expanded or
   * collapsed, or neither.
   **/ 
  enum ExpandDirection
  {
    None,
    Expand,
    Collapse
  };
  
public:
  Track(TimelineWidget &timeline_widget,
    boost::shared_ptr<model::Track> track);
  
  Gtk::Widget& get_header_widget();
  
  boost::shared_ptr<model::Track> get_model_track() const;
  
  int get_height() const;
  
  /**
   * Gets whether the descendant tracks are expanded or collapsed.
   * @return Returns true if the branch is expanded, false if it's
   * collapsed.
   * @see expand_collapse
   **/
  bool get_expanded() const;
  
  /**
   * Expands or collapses this branch.
   * @param direction Specifies whether this branch should be expanded
   * or collapse. direction must not equal None
   **/
  void expand_collapse(ExpandDirection direction);
  
  /**
   * The current expand state.
   * @return Returns the expand state value, this value is a number
   * between 0 and 1.0, and is recalculated by tick_expand_animation().
   * @remarks A value of 1.0 is given when the branch is fully expanded
   * (and animating), 0.0 is given when the branch is fully collapsed
   * (and animating). When the branch is not animating this value has
   * an indeterminate value.
   * @see tick_expand_animation
   **/
  float get_expand_animation_state() const;
  
  /**
   * Gets whether the branch is animation.
   * @return Returns true if the branch is animating, false if not.
   **/
  bool is_expand_animating() const;
  
  /**
   * When this track is being animated, tick_expand_animation must be
   * called repeatedly to cause the animation to progress.
   **/ 
  void tick_expand_animation();
  
  /**
   * Calculates the expander style, given the animation state.
   **/
  Gtk::ExpanderStyle get_expander_style() const;
  
  void show_header_context_menu(guint button, guint32 time);

  virtual void draw_track(Cairo::RefPtr<Cairo::Context> cairo,
    TimelineViewWindow* const window)
    const = 0;
    
public:
  //----- Constants -----//
  
  /**
   * Specifies the period of the expand animation in seconds.
   **/
  static const float ExpandAnimationPeriod;

private:
  //----- Internals -----//
  void update_name();
  
private:

  //----- Event Handlers -----//
  void on_set_name();

  void on_remove_track();
  
protected:

  TimelineWidget &timelineWidget;
  boost::shared_ptr<model::Track> model_track;

private:

  /**
   * This bool is true if this branch is expanded. false if it is
   * collapsed.
   **/
  bool expanded;
  
  /**
   * This enum specifies which direction the expand/collapse animation
   * is moving - if any.
   * @remarks If no animation is occuring, expandDirection is set to
   * None.
   **/
  ExpandDirection expandDirection;
  
  /**
   * The current expand state.
   * @remarks This value is a number between 0 and 1.0,
   * and is recalculated by tick_expand_animation(). This variable is
   * set to 1.0 when the branch is fully expanded (and animating) and
   * 0.0 when the branch is fully collapsed (and animating). When the
   * branch is not animating this value has an indeterminate value.
   * @see tick_expand_animation
   **/
  double expandAnimationState;
  
  /**
   * An internal timer used for the expand/collapse animation.
   **/
  boost::scoped_ptr<Glib::Timer> expand_timer;

  //----- Header Widgets ------//
  
  timeline::TimelineHeaderWidget headerWidget;
  
  Gtk::VBox headerBox;
  
  MenuButton titleMenuButton;
  
  Gtk::ToolButton enableButton;
  Gtk::ToolButton lockButton;
  
  Gtk::Entry titleBox;
  Gtk::Toolbar buttonBar;
  
  Gtk::Menu contextMenu;
  
  friend class TimelineHeaderWidget;
};


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

#endif // TIMELINE_TRACK_HPP