web-audio-scheduler/build/web-audio-scheduler.js

Event Scheduler for Web Audio API

(function(f){if(typeof exports==="object"&&typeof module!=="undefined"){module.exports=f()}else if(typeof define==="function"&&define.amd){define([],f)}else{var g;if(typeof window!=="undefined"){g=window}else if(typeof global!=="undefined"){g=global}else if(typeof self!=="undefined"){g=self}else{g=this}g.WebAudioScheduler = f()}})(function(){var define,module,exports;return (function e(t,n,r){function s(o,u){if(!n[o]){if(!t[o]){var a=typeof require=="function"&&require;if(!u&&a)return a(o,!0);if(i)return i(o,!0);var f=new Error("Cannot find module '"+o+"'");throw f.code="MODULE_NOT_FOUND",f}var l=n[o]={exports:{}};t[o][0].call(l.exports,function(e){var n=t[o][1][e];return s(n?n:e)},l,l.exports,e,t,n,r)}return n[o].exports}var i=typeof require=="function"&&require;for(var o=0;o<r.length;o++)s(r[o]);return s})({1:[function(require,module,exports){
// Copyright Joyent, Inc. and other Node contributors.
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to permit
// persons to whom the Software is furnished to do so, subject to the
// following conditions:
//
// The above copyright notice and this permission notice shall be included
// in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
// USE OR OTHER DEALINGS IN THE SOFTWARE.

function EventEmitter() {
  this._events = this._events || {};
  this._maxListeners = this._maxListeners || undefined;
}
module.exports = EventEmitter;

// Backwards-compat with node 0.10.x
EventEmitter.EventEmitter = EventEmitter;

EventEmitter.prototype._events = undefined;
EventEmitter.prototype._maxListeners = undefined;

// By default EventEmitters will print a warning if more than 10 listeners are
// added to it. This is a useful default which helps finding memory leaks.
EventEmitter.defaultMaxListeners = 10;

// Obviously not all Emitters should be limited to 10. This function allows
// that to be increased. Set to zero for unlimited.
EventEmitter.prototype.setMaxListeners = function(n) {
  if (!isNumber(n) || n < 0 || isNaN(n))
    throw TypeError('n must be a positive number');
  this._maxListeners = n;
  return this;
};

EventEmitter.prototype.emit = function(type) {
  var er, handler, len, args, i, listeners;

  if (!this._events)
    this._events = {};

  // If there is no 'error' event listener then throw.
  if (type === 'error') {
    if (!this._events.error ||
        (isObject(this._events.error) && !this._events.error.length)) {
      er = arguments[1];
      if (er instanceof Error) {
        throw er; // Unhandled 'error' event
      } else {
        // At least give some kind of context to the user
        var err = new Error('Uncaught, unspecified "error" event. (' + er + ')');
        err.context = er;
        throw err;
      }
    }
  }

  handler = this._events[type];

  if (isUndefined(handler))
    return false;

  if (isFunction(handler)) {
    switch (arguments.length) {
      // fast cases
      case 1:
        handler.call(this);
        break;
      case 2:
        handler.call(this, arguments[1]);
        break;
      case 3:
        handler.call(this, arguments[1], arguments[2]);
        break;
      // slower
      default:
        args = Array.prototype.slice.call(arguments, 1);
        handler.apply(this, args);
    }
  } else if (isObject(handler)) {
    args = Array.prototype.slice.call(arguments, 1);
    listeners = handler.slice();
    len = listeners.length;
    for (i = 0; i < len; i++)
      listeners[i].apply(this, args);
  }

  return true;
};

EventEmitter.prototype.addListener = function(type, listener) {
  var m;

  if (!isFunction(listener))
    throw TypeError('listener must be a function');

  if (!this._events)
    this._events = {};

  // To avoid recursion in the case that type === "newListener"! Before
  // adding it to the listeners, first emit "newListener".
  if (this._events.newListener)
    this.emit('newListener', type,
              isFunction(listener.listener) ?
              listener.listener : listener);

  if (!this._events[type])
    // Optimize the case of one listener. Don't need the extra array object.
    this._events[type] = listener;
  else if (isObject(this._events[type]))
    // If we've already got an array, just append.
    this._events[type].push(listener);
  else
    // Adding the second element, need to change to array.
    this._events[type] = [this._events[type], listener];

  // Check for listener leak
  if (isObject(this._events[type]) && !this._events[type].warned) {
    if (!isUndefined(this._maxListeners)) {
      m = this._maxListeners;
    } else {
      m = EventEmitter.defaultMaxListeners;
    }

    if (m && m > 0 && this._events[type].length > m) {
      this._events[type].warned = true;
      console.error('(node) warning: possible EventEmitter memory ' +
                    'leak detected. %d listeners added. ' +
                    'Use emitter.setMaxListeners() to increase limit.',
                    this._events[type].length);
      if (typeof console.trace === 'function') {
        // not supported in IE 10
        console.trace();
      }
    }
  }

  return this;
};

EventEmitter.prototype.on = EventEmitter.prototype.addListener;

EventEmitter.prototype.once = function(type, listener) {
  if (!isFunction(listener))
    throw TypeError('listener must be a function');

  var fired = false;

  function g() {
    this.removeListener(type, g);

    if (!fired) {
      fired = true;
      listener.apply(this, arguments);
    }
  }

  g.listener = listener;
  this.on(type, g);

  return this;
};

// emits a 'removeListener' event iff the listener was removed
EventEmitter.prototype.removeListener = function(type, listener) {
  var list, position, length, i;

  if (!isFunction(listener))
    throw TypeError('listener must be a function');

  if (!this._events || !this._events[type])
    return this;

  list = this._events[type];
  length = list.length;
  position = -1;

  if (list === listener ||
      (isFunction(list.listener) && list.listener === listener)) {
    delete this._events[type];
    if (this._events.removeListener)
      this.emit('removeListener', type, listener);

  } else if (isObject(list)) {
    for (i = length; i-- > 0;) {
      if (list[i] === listener ||
          (list[i].listener && list[i].listener === listener)) {
        position = i;
        break;
      }
    }

    if (position < 0)
      return this;

    if (list.length === 1) {
      list.length = 0;
      delete this._events[type];
    } else {
      list.splice(position, 1);
    }

    if (this._events.removeListener)
      this.emit('removeListener', type, listener);
  }

  return this;
};

EventEmitter.prototype.removeAllListeners = function(type) {
  var key, listeners;

  if (!this._events)
    return this;

  // not listening for removeListener, no need to emit
  if (!this._events.removeListener) {
    if (arguments.length === 0)
      this._events = {};
    else if (this._events[type])
      delete this._events[type];
    return this;
  }

  // emit removeListener for all listeners on all events
  if (arguments.length === 0) {
    for (key in this._events) {
      if (key === 'removeListener') continue;
      this.removeAllListeners(key);
    }
    this.removeAllListeners('removeListener');
    this._events = {};
    return this;
  }

  listeners = this._events[type];

  if (isFunction(listeners)) {
    this.removeListener(type, listeners);
  } else if (listeners) {
    // LIFO order
    while (listeners.length)
      this.removeListener(type, listeners[listeners.length - 1]);
  }
  delete this._events[type];

  return this;
};

EventEmitter.prototype.listeners = function(type) {
  var ret;
  if (!this._events || !this._events[type])
    ret = [];
  else if (isFunction(this._events[type]))
    ret = [this._events[type]];
  else
    ret = this._events[type].slice();
  return ret;
};

EventEmitter.prototype.listenerCount = function(type) {
  if (this._events) {
    var evlistener = this._events[type];

    if (isFunction(evlistener))
      return 1;
    else if (evlistener)
      return evlistener.length;
  }
  return 0;
};

EventEmitter.listenerCount = function(emitter, type) {
  return emitter.listenerCount(type);
};

function isFunction(arg) {
  return typeof arg === 'function';
}

function isNumber(arg) {
  return typeof arg === 'number';
}

function isObject(arg) {
  return typeof arg === 'object' && arg !== null;
}

function isUndefined(arg) {
  return arg === void 0;
}

},{}],2:[function(require,module,exports){
(function (global){
"use strict";

var _createClass = function () { function defineProperties(target, props) { for (var i = 0; i < props.length; i++) { var descriptor = props[i]; descriptor.enumerable = descriptor.enumerable || false; descriptor.configurable = true; if ("value" in descriptor) descriptor.writable = true; Object.defineProperty(target, descriptor.key, descriptor); } } return function (Constructor, protoProps, staticProps) { if (protoProps) defineProperties(Constructor.prototype, protoProps); if (staticProps) defineProperties(Constructor, staticProps); return Constructor; }; }();

function _classCallCheck(instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } }

function _possibleConstructorReturn(self, call) { if (!self) { throw new ReferenceError("this hasn't been initialised - super() hasn't been called"); } return call && (typeof call === "object" || typeof call === "function") ? call : self; }

function _inherits(subClass, superClass) { if (typeof superClass !== "function" && superClass !== null) { throw new TypeError("Super expression must either be null or a function, not " + typeof superClass); } subClass.prototype = Object.create(superClass && superClass.prototype, { constructor: { value: subClass, enumerable: false, writable: true, configurable: true } }); if (superClass) Object.setPrototypeOf ? Object.setPrototypeOf(subClass, superClass) : subClass.__proto__ = superClass; }

var events = require("events");
var defaults = require("./utils/defaults");
var defaultContext = require("./defaultContext");

var WebAudioScheduler = function (_events$EventEmitter) {
  _inherits(WebAudioScheduler, _events$EventEmitter);

  function WebAudioScheduler(opts) {
    _classCallCheck(this, WebAudioScheduler);

    opts = opts || /* istanbul ignore next */{};

    var _this = _possibleConstructorReturn(this, (WebAudioScheduler.__proto__ || Object.getPrototypeOf(WebAudioScheduler)).call(this));

    _this.context = defaults(opts.context, defaultContext);
    _this.interval = defaults(opts.interval, 0.025);
    _this.aheadTime = defaults(opts.aheadTime, 0.1);
    _this.timerAPI = defaults(opts.timerAPI, global);
    _this.playbackTime = _this.currentTime;

    _this._timerId = 0;
    _this._schedId = 0;
    _this._scheds = [];
    return _this;
  }

  _createClass(WebAudioScheduler, [{
    key: "start",
    value: function start(callback, args) {
      var loop = this.process.bind(this);

      if (this._timerId === 0) {
        this._timerId = this.timerAPI.setInterval(loop, this.interval * 1000);

        this.emit("start");

        if (callback) {
          this.insert(this.context.currentTime, callback, args);
          loop();
        }
      } else if (callback) {
        this.insert(this.context.currentTime, callback, args);
      }

      return this;
    }
  }, {
    key: "stop",
    value: function stop() {
      var reset = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : true;

      if (this._timerId !== 0) {
        this.timerAPI.clearInterval(this._timerId);
        this._timerId = 0;

        this.emit("stop");
      }

      if (reset) {
        this._scheds.splice(0);
      }

      return this;
    }
  }, {
    key: "insert",
    value: function insert(time, callback, args) {
      var id = ++this._schedId;
      var event = { id: id, time: time, callback: callback, args: args };
      var scheds = this._scheds;

      if (scheds.length === 0 || scheds[scheds.length - 1].time <= time) {
        scheds.push(event);
      } else {
        for (var i = 0, imax = scheds.length; i < imax; i++) {
          if (time < scheds[i].time) {
            scheds.splice(i, 0, event);
            break;
          }
        }
      }

      return id;
    }
  }, {
    key: "nextTick",
    value: function nextTick(time, callback, args) {
      if (typeof time === "function") {
        args = callback;
        callback = time;
        time = this.playbackTime;
      }

      return this.insert(time + this.aheadTime, callback, args);
    }
  }, {
    key: "remove",
    value: function remove(schedId) {
      var scheds = this._scheds;

      if (typeof schedId === "number") {
        for (var i = 0, imax = scheds.length; i < imax; i++) {
          if (schedId === scheds[i].id) {
            scheds.splice(i, 1);
            break;
          }
        }
      }

      return schedId;
    }
  }, {
    key: "removeAll",
    value: function removeAll() {
      this._scheds.splice(0);
    }
  }, {
    key: "process",
    value: function process() {
      var t0 = this.context.currentTime;
      var t1 = t0 + this.aheadTime;

      this._process(t0, t1);
    }
  }, {
    key: "_process",
    value: function _process(t0, t1) {
      var scheds = this._scheds;
      var playbackTime = t0;

      this.playbackTime = playbackTime;
      this.emit("process", { playbackTime: playbackTime });

      while (scheds.length && scheds[0].time < t1) {
        var event = scheds.shift();
        var _playbackTime = event.time;
        var args = event.args;

        this.playbackTime = _playbackTime;

        event.callback({ playbackTime: _playbackTime, args: args });
      }

      this.playbackTime = playbackTime;
      this.emit("processed", { playbackTime: playbackTime });
    }
  }, {
    key: "state",
    get: function get() {
      return this._timerId !== 0 ? "running" : "suspended";
    }
  }, {
    key: "currentTime",
    get: function get() {
      return this.context.currentTime;
    }
  }, {
    key: "events",
    get: function get() {
      return this._scheds.slice();
    }
  }]);

  return WebAudioScheduler;
}(events.EventEmitter);

module.exports = WebAudioScheduler;

}).call(this,typeof global !== "undefined" ? global : typeof self !== "undefined" ? self : typeof window !== "undefined" ? window : {})
},{"./defaultContext":3,"./utils/defaults":4,"events":1}],3:[function(require,module,exports){
"use strict";

module.exports = {
  get currentTime() {
    return Date.now() / 1000;
  }
};

},{}],4:[function(require,module,exports){
"use strict";

function defaults(value, defaultValue) {
  return value !== undefined ? value : defaultValue;
}

module.exports = defaults;

},{}],5:[function(require,module,exports){
"use strict";

module.exports = require("./WebAudioScheduler");

},{"./WebAudioScheduler":2}]},{},[5])(5)
});