(function() {
// This polyfill fixes the following problems with Edge browser
// (1) Various maplike methods for keystatuses are not supported or suported incorrectly
// (2) Key Ids exposed in keystatuses are incorrect (byte swaps)
if ( navigator.userAgent.toLowerCase().indexOf('edge') > -1 ) {
///////////////////////////////////////////////////////////////////////////////////////////////
// The following function is the core of this JS patch. The rest of this file is infrastructure
// required to enable this function
///////////////////////////////////////////////////////////////////////////////////////////////
function _proxyKeyStatusesChange( event ) {
this._keyStatuses.clear();
var keyStatuses = [];
this._session.keyStatuses.forEach( function( keyId, status ) {
var newKeyId = new Uint8Array( keyId );
function swap( arr, a, b ) { var t = arr[a]; arr[a] = arr[b]; arr[b] = t; }
swap( newKeyId, 0, 3 );
swap( newKeyId, 1, 2 );
swap( newKeyId, 4, 5 );
swap( newKeyId, 6, 7 );
keyStatuses.push( { key: newKeyId, status: status, ord: arrayBufferAsString( newKeyId ) } );
});
function lexicographical( a, b ) { return a < b ? -1 : a === b ? 0 : +1; }
function lexicographicalkey( a, b ) { return lexicographical( a.ord, b.ord ); }
keyStatuses.sort( lexicographicalkey ).forEach( function( obj ) {
this._keyStatuses._set( obj.key, obj.status );
}.bind( this ) );
this.dispatchEvent( event );
};
///////////////////////////////////////////////////////////////////////////////////////////////
// Override MediaKeys.createSession
var _mediaKeysCreateSession = MediaKeys.prototype.createSession;
MediaKeys.prototype.createSession = function ( sessionType ) {
return new MediaKeySession( _mediaKeysCreateSession.call( this, sessionType ) );
};
// MediaKeySession proxy
function MediaKeySession( session ) {
EventTarget.call( this );
this._session = session;
this._keyStatuses = new MediaKeyStatusMap();
this._session.addEventListener("keystatuseschange",this._onKeyStatusesChange.bind(this));
this._session.addEventListener("message",this.dispatchEvent.bind(this));
}
MediaKeySession.prototype = Object.create( EventTarget.prototype );
Object.defineProperties( MediaKeySession.prototype, {
sessionId: { get: function() { return this._session.sessionId; } },
expiration: { get: function() { return this._session.expiration; } },
closed: { get: function() { return this._session.closed; } },
keyStatuses:{ get: function() { return this._keyStatuses; } }
});
[ "generateRequest", "load", "update", "remove", "close" ].forEach( function( fnname ) {
MediaKeySession.prototype[ fnname ] = function() {
return window.MediaKeySession.prototype[ fnname ].apply( this._session, arguments );
}
} );
MediaKeySession.prototype._onKeyStatusesChange = _proxyKeyStatusesChange;
// MediaKeyStatusMap proxy
//
// We need a proxy class to replace the broken MediaKeyStatusMap one. We cannot use a
// regular Map directly because we need get and has methods to compare by value not
// as references.
function MediaKeyStatusMap() { this._map = new Map(); }
Object.defineProperties( MediaKeyStatusMap.prototype, {
size: { get: function() { return this._map.size; } },
forEach: { get: function() { return function( f ) { return this._map.forEach( f ); } } },
entries: { get: function() { return function() { return this._map.entries(); } } },
values: { get: function() { return function() { return this._map.values(); } } },
keys: { get: function() { return function() { return this._map.keys(); } } },
clear: { get: function() { return function() { return this._map.clear(); } } } } );
MediaKeyStatusMap.prototype[ Symbol.iterator ] = function() { return this._map[ Symbol.iterator ]() };
MediaKeyStatusMap.prototype.has = function has( keyId ) {
for ( var k of this._map.keys() ) { if ( arrayBufferEqual( k, keyId ) ) return true; }
return false;
};
MediaKeyStatusMap.prototype.get = function get( keyId ) {
for ( var k of this._map.entries() ) { if ( arrayBufferEqual( k[ 0 ], keyId ) ) return k[ 1 ]; }
};
MediaKeyStatusMap.prototype._set = function _set( keyId, status ) {
this._map.set( new Uint8Array( keyId ), status );
};
function arrayBufferEqual(buf1, buf2)
{
if (buf1.byteLength !== buf2.byteLength) return false;
var a1 = Array.from( new Int8Array(buf1) ), a2 = Array.from( new Int8Array(buf2) );
return a1.every( function( x, i ) { return x === a2[i]; } );
}
// EventTarget
function EventTarget(){
this.listeners = {};
};
EventTarget.prototype.listeners = null;
EventTarget.prototype.addEventListener = function(type, callback){
if(!(type in this.listeners)) {
this.listeners[type] = [];
}
this.listeners[type].push(callback);
};
EventTarget.prototype.removeEventListener = function(type, callback){
if(!(type in this.listeners)) {
return;
}
var stack = this.listeners[type];
for(var i = 0, l = stack.length; i < l; i++){
if(stack[i] === callback){
stack.splice(i, 1);
return this.removeEventListener(type, callback);
}
}
};
EventTarget.prototype.dispatchEvent = function(event){
if(!(event.type in this.listeners)) {
return;
}
var stack = this.listeners[event.type];
event.target = this;
for(var i = 0, l = stack.length; i < l; i++) {
stack[i].call(this, event);
}
};
}
})();
Codebase Browser
chromium