| (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); |
| } |
| }; |
| } |
| })(); |