MIDI.js/inc/WebMIDIAPI.js

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2013-01-23 09:46:35 +01:00
/// http://cwilso.github.com/WebMIDIAPIShim
// Initialize the MIDI library.
(function (global, exports, perf) {
'use strict';
var midiIO,
debug = false;
if (debug) {
window.console.warn('Debuggin enabled');
}
//init: create plugin
if (!window.navigator.requestMIDIAccess) {
window.navigator.requestMIDIAccess = _requestMIDIAccess;
if (!window.navigator.getMIDIAccess)
window.navigator.getMIDIAccess = _getMIDIAccess;
}
function _JazzInstance() {
this.inputInUse = false;
this.outputInUse = false;
// load the Jazz plugin
var o1 = document.createElement("object");
o1.style.cssText = "top: -500px; position: absolute;";
2013-01-23 09:46:35 +01:00
o1.id = "_Jazz" + Math.random() + "ie";
o1.classid = "CLSID:1ACE1618-1C7D-4561-AEE1-34842AA85E90";
this.activeX = o1;
var o2 = document.createElement("object");
o2.id = "_Jazz" + Math.random;
o2.type="audio/x-jazz";
o1.appendChild(o2);
this.objRef = o2;
var e = document.createElement("p");
e.appendChild(document.createTextNode("This page requires the "));
var a = document.createElement("a");
a.appendChild(document.createTextNode("Jazz plugin"));
a.href = "http://jazz-soft.net/";
e.appendChild(a);
e.appendChild(document.createTextNode("."));
o2.appendChild(e);
var insertionPoint = document.getElementById("MIDIPlugin");
if (!insertionPoint)
insertionPoint = document.body;
insertionPoint.appendChild(o1);
if (this.objRef.isJazz)
this._Jazz = this.objRef;
else if (this.activeX.isJazz)
this._Jazz = this.activeX;
else
this._Jazz = null;
if (this._Jazz) {
this._Jazz._jazzTimeZero = this._Jazz.Time();
this._Jazz._perfTimeZero = window.performance.now();
}
}
function _requestMIDIAccess( successCallback, errorCallback ) {
new MIDIAccess( successCallback, errorCallback );
}
function _getMIDIAccess( successCallback, errorCallback ) {
var message = "getMIDIAccess has been renamed to requestMIDIAccess. Please update your code.";
if (console.warn)
console.warn( message );
else
console.log( message );
new MIDIAccess( successCallback, errorCallback );
}
// API Methods
function MIDIAccess( successCallback, errorCallback ) {
this._jazzInstances = new Array();
this._jazzInstances.push( new _JazzInstance() );
if (this._jazzInstances[0]._Jazz) {
this._Jazz = this._jazzInstances[0]._Jazz;
this._successCallback = successCallback;
window.setTimeout( _onReady.bind(this), 3 );
} else {
if (errorCallback)
errorCallback( { code: 1 } );
}
}
function _onReady() {
if (this._successCallback)
this._successCallback( this );
}
MIDIAccess.prototype.getInputs = function( ) {
if (!this._Jazz)
return null;
var list=this._Jazz.MidiInList();
var inputs = new Array( list.length );
for ( var i=0; i<list.length; i++ ) {
inputs[i] = new MIDIPort( this, list[i], i, "input" );
}
return inputs;
}
MIDIAccess.prototype.getOutputs = function( ) {
if (!this._Jazz)
return null;
var list=this._Jazz.MidiOutList();
var outputs = new Array( list.length );
for ( var i=0; i<list.length; i++ ) {
outputs[i] = new MIDIPort( this, list[i], i, "output" );
}
return outputs;
}
// TODO: remove these versions
MIDIAccess.prototype.enumerateInputs = function( ) {
var message = "MIDIAccess.enumerateInputs has been renamed to MIDIAccess.getInputs. Please update your code.";
if (console.warn)
console.warn( message );
else
console.log( message );
return this.getInputs();
}
MIDIAccess.prototype.enumerateOutputs = function( ) {
var message = "MIDIAccess.enumerateOutputs has been renamed to MIDIAccess.getOutputs. Please update your code.";
if (console.warn)
console.warn( message );
else
console.log( message );
return this.getOutputs();
}
MIDIAccess.prototype.getInput = function( target ) {
if (target==null)
return null;
return new MIDIInput( this, target );
}
MIDIAccess.prototype.getOutput = function( target ) {
if (target==null)
return null;
return new MIDIOutput( this, target );
}
function MIDIPort( midi, port, index, type ) {
this._index = index;
this._midi = midi;
this.type = type;
// Can't get manu/version from Jazz
this.name = port;
this.manufacturer = "<manufacturer unknown>";
this.version = "<version not supported>";
this.fingerprint = "" + index + "." + this.name;
}
MIDIPort.prototype.toString = function() {
return ("type: "+ this.type + "name: '" + this.name + "' manufacturer: '" +
this.manufacturer + "' version: " + this.version + " fingerprint: '" + this.fingerprint + "'" );
}
function MIDIInput( midiAccess, target ) {
this.onmessage = null;
this._listeners = [];
this._midiAccess = midiAccess;
var inputInstance = null;
for (var i=0; (i<midiAccess._jazzInstances.length)&&(!inputInstance); i++) {
if (!midiAccess._jazzInstances[i].inputInUse)
inputInstance=midiAccess._jazzInstances[i];
}
if (!inputInstance) {
inputInstance = new _JazzInstance();
midiAccess._jazzInstances.push( inputInstance );
}
inputInstance.inputInUse = true;
this._jazzInstance = inputInstance._Jazz;
// target can be a MIDIPort or DOMString
if ( target instanceof MIDIPort ) {
this._deviceName = target.name;
this._index = target._index;
} else if (typeof target === "number") { // target is numerical index
this._index = target;
var list=this._jazzInstance.MidiInList();
this._deviceName = list[target];
} else if ( target.isString() ) { // fingerprint
var dot = target.indexOf(".");
this._index = parseInt( target.slice( 0, dot ) );
this._deviceName = target.slice( dot + 1 );
}
this._input = this._jazzInstance.MidiInOpen( this._index, _midiProc.bind(this) );
}
// Introduced in DOM Level 2:
MIDIInput.prototype.addEventListener = function (type, listener, useCapture ) {
if (type != "message")
return;
for (var i=0; i<this._listeners.length; i++)
if (this._listeners[i] == listener)
return;
this._listeners.push( listener );
}
MIDIInput.prototype.removeEventListener = function (type, listener, useCapture ) {
if (type != "message")
return;
for (var i=0; i<this._listeners.length; i++)
if (this._listeners[i] == listener) {
this._listeners.splice( i, 1 ); //remove it
return;
}
}
MIDIInput.prototype.preventDefault = function() {
this._pvtDef = true;
}
MIDIInput.prototype.dispatchEvent = function (evt) {
this._pvtDef = false;
// dispatch to listeners
for (var i=0; i<this._listeners.length; i++)
if (this._listeners[i].handleEvent)
this._listeners[i].handleEvent.bind(this)( evt );
else
this._listeners[i].bind(this)( evt );
if (this.onmessage)
this.onmessage( evt );
return this._pvtDef;
}
function _midiProc( timestamp, data ) {
var evt = new CustomEvent( "message" );
evt.timestamp = parseFloat( timestamp.toString()) + this._jazzInstance._perfTimeZero;
var length = 0;
var i,j;
// Jazz sometimes passes us multiple messages at once, so we need to parse them out
// and pass them one at a time.
for (i=0; i<data.length; i+=length) {
switch (data[i] & 0xF0) {
case 0x80: // note off
case 0x90: // note on
case 0xA0: // polyphonic aftertouch
case 0xB0: // control change
case 0xE0: // channel mode
length = 3;
break;
case 0xC0: // program change
case 0xD0: // channel aftertouch
length = 2;
break;
case 0xF0:
switch (data[i]) {
case 0xf0: // variable-length sysex.
// count the length;
length = -1;
for (j=i+1; (j<data.length) && (data[j] != 0xF7); j++)
;
length = j-i+1;
break;
case 0xF1: // MTC quarter frame
case 0xF3: // song select
length = 2;
break;
case 0xF2: // song position pointer
length = 3;
break;
default:
length = 1;
break;
}
break;
}
evt.data = new Uint8Array(data.slice(i, length+i));
this.dispatchEvent( evt );
}
}
function MIDIOutput( midiAccess, target ) {
this._midiAccess = midiAccess;
var outputInstance = null;
for (var i=0; (i<midiAccess._jazzInstances.length)&&(!outputInstance); i++) {
if (!midiAccess._jazzInstances[i].outputInUse)
outputInstance=midiAccess._jazzInstances[i];
}
if (!outputInstance) {
outputInstance = new _JazzInstance();
midiAccess._jazzInstances.push( outputInstance );
}
outputInstance.outputInUse = true;
this._jazzInstance = outputInstance._Jazz;
// target can be a MIDIPort or DOMString
if ( target instanceof MIDIPort ) {
this._deviceName = target.name;
this._index = target._index;
} else if (typeof target === "number") { // target is numerical index
this._index = target;
var list=this._jazzInstance.MidiOutList();
this._deviceName = list[target];
} else if ( target.isString() ) { // fingerprint
var dot = target.indexOf(".");
this._index = parseInt( target.slice( 0, dot ) );
this._deviceName = target.slice( dot + 1 );
}
this._jazzInstance.MidiOutOpen(this._deviceName);
}
function _sendLater() {
this.jazz.MidiOutLong( this.data ); // handle send as sysex
}
MIDIOutput.prototype.send = function( data, timestamp ) {
var delayBeforeSend = 0;
if (data.length==0)
return false;
if (timestamp)
delayBeforeSend = Math.floor( timestamp - window.performance.now() );
if (timestamp && (delayBeforeSend>1)) {
var sendObj = new Object;
sendObj.jazz = this._jazzInstance;
sendObj.data = data;
window.setTimeout( _sendLater.bind(sendObj), delayBeforeSend );
} else {
this._jazzInstance.MidiOutLong( data );
}
return true;
}
}(window));
// Polyfill window.performance.now() if necessary.
(function (exports) {
var perf = {},
props;
function findAlt() {
var prefix = "moz,webkit,opera,ms".split(","),
i = prefix.length,
//worst case, we use Date.now()
props = {
value: function (start) {
return function () {
return Date.now() - start;
}
}(Date.now())
};
//seach for vendor prefixed version
for (; i >= 0; i--) {
if ((prefix[i] + "Now") in exports.performance) {
props.value = function (method) {
return function () {
exports.performance[method]();
}
}(prefix[i] + "Now");
return props;
}
}
//otherwise, try to use connectionStart
if ("timing" in exports.performance &&
"connectStart" in exports.performance.timing) {
//this pretty much approximates performance.now() to the millisecond
props.value = function (start) {
return function(){Date.now() - start;}
}(exports.performance.timing.connectStart);
}
return props;
}
//if already defined, bail
if (("performance" in exports) && ("now" in exports.performance)) {
return;
}
if (!("performance" in exports)) {
Object.defineProperty(exports, "performance", {
get: function () {
return perf;
}
});
//otherwise, perforance is there, but not "now()"
}
props = findAlt();
Object.defineProperty(exports.performance, "now", props);
}(window));