// Filename: cInterval.h
// Created by:  drose (27Aug02)
//
////////////////////////////////////////////////////////////////////
//
// PANDA 3D SOFTWARE
// Copyright (c) 2001, Disney Enterprises, Inc.  All rights reserved
//
// All use of this software is subject to the terms of the Panda 3d
// Software license.  You should have received a copy of this license
// along with this source code; you will also find a current copy of
// the license at http://www.panda3d.org/license.txt .
//
// To contact the maintainers of this program write to
// panda3d@yahoogroups.com .
//
////////////////////////////////////////////////////////////////////

#ifndef CINTERVAL_H
#define CINTERVAL_H

#include "directbase.h"
#include "typedReferenceCount.h"
#include "pvector.h"
#include "config_interval.h"

class CIntervalManager;

////////////////////////////////////////////////////////////////////
//       Class : CInterval
// Description : The base class for timeline components.  A CInterval
//               represents a single action, event, or collection of
//               nested intervals that will be performed at some
//               specific time or over a period of time.
//
//               This is essentially similar to the Python "Interval"
//               class, but it is implemented in C++ (hence the name).
//               Intervals that may be implemented in C++ will inherit
//               from this class; Intervals that must be implemented
//               in Python will inherit from the similar Python class.
////////////////////////////////////////////////////////////////////
class EXPCL_DIRECT CInterval : public TypedReferenceCount {
public:
  CInterval(const string &name, double duration, bool open_ended);

PUBLISHED:
  INLINE const string &get_name() const;
  INLINE double get_duration() const;
  INLINE bool get_open_ended() const;

  enum EventType {
    ET_initialize,
    ET_instant,
    ET_step,
    ET_finalize,
    ET_reverse_initialize,
    ET_reverse_instant,
    ET_reverse_finalize,
    ET_interrupt
  };

  enum State {
    S_initial,
    S_started,
    S_paused,
    S_final
  };

  INLINE State get_state() const;
  INLINE bool is_stopped() const;

  INLINE void set_done_event(const string &event);
  INLINE const string &get_done_event() const;

  void set_t(double t);
  INLINE double get_t() const;

  INLINE void set_auto_pause(bool auto_pause);
  INLINE bool get_auto_pause() const;
  INLINE void set_auto_finish(bool auto_finish);
  INLINE bool get_auto_finish() const;

  INLINE void set_wants_t_callback(bool wants_t_callback);
  INLINE bool get_wants_t_callback() const;

  INLINE void set_manager(CIntervalManager *manager);
  INLINE CIntervalManager *get_manager() const;

  void start(double start_t = 0.0, double end_t = -1.0, double play_rate = 1.0);
  void loop(double start_t = 0.0, double end_t = -1.0, double play_rate = 1.0);
  double pause();
  void resume();
  void resume(double start_t);
  void resume_until(double end_t);
  void finish();
  bool is_playing() const;

  // These functions control the actual playback of the interval.
  // Don't call them directly; they're intended to be called from a
  // supervising object, e.g. the Python start() .. finish()
  // interface.

  // These cannot be declared private because they must be accessible
  // to Python, but the method names are prefixed with priv_ to remind
  // you that you probably don't want to be using them directly.
  void priv_do_event(double t, EventType event);
  virtual void priv_initialize(double t);
  virtual void priv_instant();
  virtual void priv_step(double t);
  virtual void priv_finalize();
  virtual void priv_reverse_initialize(double t);
  virtual void priv_reverse_instant();
  virtual void priv_reverse_finalize();
  virtual void priv_interrupt();

  virtual void output(ostream &out) const;
  virtual void write(ostream &out, int indent_level) const;

  void setup_play(double start_time, double end_time, double play_rate,
                  bool do_loop);
  void setup_resume();
  void setup_resume_until(double end_t);
  bool step_play();

public:
  void mark_dirty();
  INLINE bool check_t_callback();

protected:
  void interval_done();

  INLINE void recompute() const;
  virtual void do_recompute();
  INLINE void check_stopped(TypeHandle type, const char *method_name) const;
  INLINE void check_started(TypeHandle type, const char *method_name) const;

  State _state;
  double _curr_t;
  string _name;
  string _done_event;
  double _duration;

  bool _auto_pause;
  bool _auto_finish;
  bool _wants_t_callback;
  double _last_t_callback;
  CIntervalManager *_manager;

  // For setup_play() and step_play().
  double _clock_start;
  double _start_t;
  double _end_t;
  bool _end_t_at_end;
  bool _start_t_at_start;
  double _play_rate;
  bool _do_loop;
  int _loop_count;
  
private:
  bool _open_ended;
  bool _dirty;

  // We keep a record of the "parent" intervals (that is, any
  // CMetaInterval objects that keep a pointer to this one) strictly
  // so we can mark all of our parents dirty when this interval gets
  // dirty.
  typedef pvector<CInterval *> Parents;
  Parents _parents;
  
public:
  static TypeHandle get_class_type() {
    return _type_handle;
  }
  static void init_type() {
    TypedReferenceCount::init_type();
    register_type(_type_handle, "CInterval",
                  TypedReferenceCount::get_class_type());
  }
  virtual TypeHandle get_type() const {
    return get_class_type();
  }
  virtual TypeHandle force_init_type() {init_type(); return get_class_type();}

private:
  static TypeHandle _type_handle;

  friend class CMetaInterval;
};

INLINE ostream &operator << (ostream &out, const CInterval &ival);
ostream &operator << (ostream &out, CInterval::State state);

#include "cInterval.I"

#endif