winamp/Src/Wasabi/api/core/sequence.h

//PORTABLE
#ifndef _SEQUENCE_H
#define _SEQUENCE_H

#include <bfc/dispatch.h>
#include <bfc/depend.h>

// abstracted version of a playback order
class ItemSequencer : public Dispatchable {
public:
  api_dependent *getDependencyPtr();

  const char *getNextPlayItem();
  int getCurrentPlaybackNumber();	// 0-based, -1 if you don't know
  int getNumItems();	// -1 if you don't know
  int rewind();
  int forward();

  int onNotify(int msg, int param1=0, int param2=0);

protected:
  enum {
    GETNEXTPLAYITEM=100,
    GETCURRENTPLAYBACKNUMBER=101,
    GETNUMITEMS=102,
    REWIND=200,
    FORWARD=210,
    ONNOTIFY=300,
    GETDEPENDENCYPTR=400,
  };
};

inline api_dependent *ItemSequencer::getDependencyPtr() {
  return _call(GETDEPENDENCYPTR, (api_dependent*)NULL);
}

inline const char *ItemSequencer::getNextPlayItem() {
  return _call(GETNEXTPLAYITEM, (const char *)NULL);
}

inline
int ItemSequencer::getCurrentPlaybackNumber() {
  return _call(GETCURRENTPLAYBACKNUMBER, -1);
}

inline
int ItemSequencer::getNumItems() {
  return _call(GETNUMITEMS, -1);
}

inline int ItemSequencer::rewind() {
  return _call(REWIND, 0);
}

inline int ItemSequencer::forward() {
  return _call(FORWARD, 0);
}

inline int ItemSequencer::onNotify(int msg, int param1, int param2) {
  return _call(ONNOTIFY, 0, msg, param1, param2);
}

#define SEQNOTIFY_ONREGISTER	10
#define SEQNOTIFY_ONDEREGISTER	20
#define SEQNOTIFY_ONNEXTFILE	30
#define SEQNOTIFY_ONTITLECHANGE	40
#define SEQNOTIFY_ONSTARTED	50
#define SEQNOTIFY_ONSTOPPED	60
#define SEQNOTIFY_ONPAUSED	70
#define SEQNOTIFY_ONUNPAUSED	80

// override this one
class ItemSequencerI : public ItemSequencer, public DependentI {
public:
  api_dependent *getDependencyPtr() { return this; }

  virtual int rewind()=0;
  virtual int forward()=0;
  virtual const char *getNextPlayItem()=0;
  virtual int getCurrentPlaybackNumber() { return -1; }
  virtual int getNumItems() { return -1; }

  // these are optional callbacks
  virtual int onRegister() { return 0; };
  virtual int onDeregister() { return 0; };
  virtual int onNextFile() { return 0; }// on transition
  virtual int onTitleChange() { return 0; }
  virtual int onStarted() { return 0; }
  virtual int onStopped() { return 0; }
  virtual int onPaused() { return 0; }
  virtual int onUnpaused() { return 0; }

protected:
  // default implementation calls above callback methods based on msg
  virtual int onNotify(int msg, int param1, int param2);

  RECVS_DISPATCH;
};

// also somewhat abstract, but implements playing through some arbitrary
// list. just override the protected stuff
class ListSequencer : public ItemSequencerI {
public:
  virtual const char *getNextPlayItem();
  virtual int rewind();
  virtual int forward();

protected:
  // override these 4 only
  virtual int getNumEntries()=0;
  virtual const char *enumItem(int pos)=0;
  virtual int getCurrent()=0;
  virtual int setCurrent(int cur)=0;

protected:
  virtual int loop() { return 0; }	// override as necessary

private:
  virtual int getNumItems();	// calls getNumEntries()
};

#endif