Tone.js/Tone/core/Timeline.js
2017-04-25 23:08:57 -04:00

382 lines
No EOL
10 KiB
JavaScript

define(["Tone/core/Tone"], function (Tone) {
"use strict";
/**
* @class A Timeline class for scheduling and maintaining state
* along a timeline. All events must have a "time" property.
* Internally, events are stored in time order for fast
* retrieval.
* @extends {Tone}
* @param {Positive} [memory=Infinity] The number of previous events that are retained.
*/
Tone.Timeline = function(){
var options = Tone.defaults(arguments, ["memory"], Tone.Timeline);
Tone.call(this);
/**
* The array of scheduled timeline events
* @type {Array}
* @private
*/
this._timeline = [];
/**
* An array of items to remove from the list.
* @type {Array}
* @private
*/
this._toRemove = [];
/**
* Flag if the timeline is mid iteration
* @private
* @type {Boolean}
*/
this._iterating = false;
/**
* The memory of the timeline, i.e.
* how many events in the past it will retain
* @type {Positive}
*/
this.memory = options.memory;
};
Tone.extend(Tone.Timeline);
/**
* the default parameters
* @static
* @const
*/
Tone.Timeline.defaults = {
"memory" : Infinity
};
/**
* The number of items in the timeline.
* @type {Number}
* @memberOf Tone.Timeline#
* @name length
* @readOnly
*/
Object.defineProperty(Tone.Timeline.prototype, "length", {
get : function(){
return this._timeline.length;
}
});
/**
* Insert an event object onto the timeline. Events must have a "time" attribute.
* @param {Object} event The event object to insert into the
* timeline.
* @returns {Tone.Timeline} this
*/
Tone.Timeline.prototype.add = function(event){
//the event needs to have a time attribute
if (this.isUndef(event.time)){
throw new Error("Tone.Timeline: events must have a time attribute");
}
if (this._timeline.length){
var index = this._search(event.time);
this._timeline.splice(index + 1, 0, event);
} else {
this._timeline.push(event);
}
//if the length is more than the memory, remove the previous ones
if (this.length > this.memory){
var diff = this.length - this.memory;
this._timeline.splice(0, diff);
}
return this;
};
/**
* Remove an event from the timeline.
* @param {Object} event The event object to remove from the list.
* @returns {Tone.Timeline} this
*/
Tone.Timeline.prototype.remove = function(event){
if (this._iterating){
this._toRemove.push(event);
} else {
var index = this._timeline.indexOf(event);
if (index !== -1){
this._timeline.splice(index, 1);
}
}
return this;
};
/**
* Get the nearest event whose time is less than or equal to the given time.
* @param {Number} time The time to query.
* @returns {Object} The event object set after that time.
*/
Tone.Timeline.prototype.get = function(time){
var index = this._search(time);
if (index !== -1){
return this._timeline[index];
} else {
return null;
}
};
/**
* Return the first event in the timeline without removing it
* @returns {Object} The first event object
*/
Tone.Timeline.prototype.peek = function(){
return this._timeline[0];
};
/**
* Return the first event in the timeline and remove it
* @returns {Object} The first event object
*/
Tone.Timeline.prototype.shift = function(){
return this._timeline.shift();
};
/**
* Get the event which is scheduled after the given time.
* @param {Number} time The time to query.
* @returns {Object} The event object after the given time
*/
Tone.Timeline.prototype.getAfter = function(time){
var index = this._search(time);
if (index + 1 < this._timeline.length){
return this._timeline[index + 1];
} else {
return null;
}
};
/**
* Get the event before the event at the given time.
* @param {Number} time The time to query.
* @returns {Object} The event object before the given time
*/
Tone.Timeline.prototype.getBefore = function(time){
var len = this._timeline.length;
//if it's after the last item, return the last item
if (len > 0 && this._timeline[len - 1].time < time){
return this._timeline[len - 1];
}
var index = this._search(time);
if (index - 1 >= 0){
return this._timeline[index - 1];
} else {
return null;
}
};
/**
* Cancel events after the given time
* @param {Number} time The time to query.
* @returns {Tone.Timeline} this
*/
Tone.Timeline.prototype.cancel = function(after){
if (this._timeline.length > 1){
var index = this._search(after);
if (index >= 0){
if (this._timeline[index].time === after){
//get the first item with that time
for (var i = index; i >= 0; i--){
if (this._timeline[i].time === after){
index = i;
} else {
break;
}
}
this._timeline = this._timeline.slice(0, index);
} else {
this._timeline = this._timeline.slice(0, index + 1);
}
} else {
this._timeline = [];
}
} else if (this._timeline.length === 1){
//the first item's time
if (this._timeline[0].time >= after){
this._timeline = [];
}
}
return this;
};
/**
* Cancel events before or equal to the given time.
* @param {Number} time The time to cancel before.
* @returns {Tone.Timeline} this
*/
Tone.Timeline.prototype.cancelBefore = function(time){
if (this._timeline.length){
var index = this._search(time);
if (index >= 0){
this._timeline = this._timeline.slice(index + 1);
}
}
return this;
};
/**
* Does a binary serach on the timeline array and returns the
* nearest event index whose time is after or equal to the given time.
* If a time is searched before the first index in the timeline, -1 is returned.
* If the time is after the end, the index of the last item is returned.
* @param {Number} time
* @return {Number} the index in the timeline array
* @private
*/
Tone.Timeline.prototype._search = function(time){
var beginning = 0;
var len = this._timeline.length;
var end = len;
if (len > 0 && this._timeline[len - 1].time <= time){
return len - 1;
}
while (beginning < end){
// calculate the midpoint for roughly equal partition
var midPoint = Math.floor(beginning + (end - beginning) / 2);
var event = this._timeline[midPoint];
var nextEvent = this._timeline[midPoint + 1];
if (event.time === time){
//choose the last one that has the same time
for (var i = midPoint; i < this._timeline.length; i++){
var testEvent = this._timeline[i];
if (testEvent.time === time){
midPoint = i;
}
}
return midPoint;
} else if (event.time < time && nextEvent.time > time){
return midPoint;
} else if (event.time > time){
//search lower
end = midPoint;
} else if (event.time < time){
//search upper
beginning = midPoint + 1;
}
}
return -1;
};
/**
* Internal iterator. Applies extra safety checks for
* removing items from the array.
* @param {Function} callback
* @param {Number=} lowerBound
* @param {Number=} upperBound
* @private
*/
Tone.Timeline.prototype._iterate = function(callback, lowerBound, upperBound){
this._iterating = true;
lowerBound = this.defaultArg(lowerBound, 0);
upperBound = this.defaultArg(upperBound, this._timeline.length - 1);
for (var i = lowerBound; i <= upperBound; i++){
callback.call(this, this._timeline[i]);
}
this._iterating = false;
if (this._toRemove.length > 0){
for (var j = 0; j < this._toRemove.length; j++){
var index = this._timeline.indexOf(this._toRemove[j]);
if (index !== -1){
this._timeline.splice(index, 1);
}
}
this._toRemove = [];
}
};
/**
* Iterate over everything in the array
* @param {Function} callback The callback to invoke with every item
* @returns {Tone.Timeline} this
*/
Tone.Timeline.prototype.forEach = function(callback){
this._iterate(callback);
return this;
};
/**
* Iterate over everything in the array at or before the given time.
* @param {Number} time The time to check if items are before
* @param {Function} callback The callback to invoke with every item
* @returns {Tone.Timeline} this
*/
Tone.Timeline.prototype.forEachBefore = function(time, callback){
//iterate over the items in reverse so that removing an item doesn't break things
var upperBound = this._search(time);
if (upperBound !== -1){
this._iterate(callback, 0, upperBound);
}
return this;
};
/**
* Iterate over everything in the array after the given time.
* @param {Number} time The time to check if items are before
* @param {Function} callback The callback to invoke with every item
* @returns {Tone.Timeline} this
*/
Tone.Timeline.prototype.forEachAfter = function(time, callback){
//iterate over the items in reverse so that removing an item doesn't break things
var lowerBound = this._search(time);
this._iterate(callback, lowerBound + 1);
return this;
};
/**
* Iterate over everything in the array at or after the given time. Similar to
* forEachAfter, but includes the item(s) at the given time.
* @param {Number} time The time to check if items are before
* @param {Function} callback The callback to invoke with every item
* @returns {Tone.Timeline} this
*/
Tone.Timeline.prototype.forEachFrom = function(time, callback){
//iterate over the items in reverse so that removing an item doesn't break things
var lowerBound = this._search(time);
//work backwards until the event time is less than time
while (lowerBound >= 0 && this._timeline[lowerBound].time >= time){
lowerBound--;
}
this._iterate(callback, lowerBound + 1);
return this;
};
/**
* Iterate over everything in the array at the given time
* @param {Number} time The time to check if items are before
* @param {Function} callback The callback to invoke with every item
* @returns {Tone.Timeline} this
*/
Tone.Timeline.prototype.forEachAtTime = function(time, callback){
//iterate over the items in reverse so that removing an item doesn't break things
var upperBound = this._search(time);
if (upperBound !== -1){
this._iterate(function(event){
if (event.time === time){
callback.call(this, event);
}
}, 0, upperBound);
}
return this;
};
/**
* Clean up.
* @return {Tone.Timeline} this
*/
Tone.Timeline.prototype.dispose = function(){
Tone.prototype.dispose.call(this);
this._timeline = null;
this._toRemove = null;
return this;
};
return Tone.Timeline;
});