refactor(Cast): Simplify CastProxy internals (#10187)

lib/cast/cast_proxy.js

@@ -93,14 +93,18 @@ shaka.cast.CastProxy = class extends shaka.util.FakeEventTarget {
     /** @private {boolean} */
     this.androidReceiverCompatible_ = androidReceiverCompatible;
 
-    /** @private {!Array<?>} */
-    this.addThumbnailsTrackCalls_ = [];
-
-    /** @private {!Array<?>} */
-    this.addTextTrackAsyncCalls_ = [];
-
-    /** @private {!Array<?>} */
-    this.addChaptersTrackCalls_ = [];
+    /**
+     * @private {{
+     *   addThumbnailsTrack: !Array<?>,
+     *   addTextTrackAsync: !Array<?>,
+     *   addChaptersTrack: !Array<?>,
+     * }}
+     */
+    this.trackedCalls_ = {
+      addThumbnailsTrack: [],
+      addTextTrackAsync: [],
+      addChaptersTrack: [],
+    };
 
     /** @private {!Map} */
     this.playerCompiledToExternNames_ = new Map();
@@ -411,8 +415,12 @@ shaka.cast.CastProxy = class extends shaka.util.FakeEventTarget {
     }
 
     if (COMPILED) {
-      this.mapCompiledToUncompiledPlayerMethodNames_();
-      this.mapCompiledToUncompiledAdManagerMethodNames_();
+      this.mapCompiledToUncompiledMethodNames_(
+          (op) => this.iterateOverPlayerMethods_(op),
+          this.playerCompiledToExternNames_);
+      this.mapCompiledToUncompiledMethodNames_(
+          (op) => this.iterateOverAdManagerMethods_(op),
+          this.adManagerCompiledToExternNames_);
     }
 
     this.videoEventTarget_ = new shaka.util.FakeEventTarget();
@@ -438,53 +446,28 @@ shaka.cast.CastProxy = class extends shaka.util.FakeEventTarget {
 
 
   /**
-   * Maps compiled to uncompiled player names so we can figure out
+   * Maps compiled to uncompiled names for a given object so we can figure out
    * which method to call in compiled build, while casting.
+   * @param {function(function(string, function()))} iterateFn  Accepts an
+   *   operation callback and calls iterateOver*Methods_ with it.
+   * @param {!Map} compiledMap
    * @private
    */
-  mapCompiledToUncompiledPlayerMethodNames_() {
-    // In compiled mode, UI tries to access player methods by their internal
-    // renamed names, but the proxy object doesn't know about those.  See
+  mapCompiledToUncompiledMethodNames_(iterateFn, compiledMap) {
+    // In compiled mode, UI tries to access methods by their internal renamed
+    // names, but the proxy object doesn't know about those.  See
     // https://github.com/shaka-project/shaka-player/issues/2130 for details.
     const methodsToNames = new Map();
-    this.iterateOverPlayerMethods_((name, method) => {
+    iterateFn((name, method) => {
       if (methodsToNames.has(method)) {
-        // If two method names, point to the same method, add them to the
+        // If two method names point to the same method, add them to the
         // map as aliases of each other.
         const name2 = methodsToNames.get(method);
         // Assumes that the compiled name is shorter
         if (name.length < name2.length) {
-          this.playerCompiledToExternNames_.set(name, name2);
+          compiledMap.set(name, name2);
         } else {
-          this.playerCompiledToExternNames_.set(name2, name);
-        }
-      } else {
-        methodsToNames.set(method, name);
-      }
-    });
-  }
-
-
-  /**
-   * Maps compiled to uncompiled ad manager names so we can figure out
-   * which method to call in compiled build, while casting.
-   * @private
-   */
-  mapCompiledToUncompiledAdManagerMethodNames_() {
-    // In compiled mode, UI tries to access ad methods by their internal
-    // renamed names, but the proxy object doesn't know about those.  See
-    // https://github.com/shaka-project/shaka-player/issues/2130 for details.
-    const methodsToNames = new Map();
-    this.iterateOverAdManagerMethods_((name, method) => {
-      if (methodsToNames.has(method)) {
-        // If two method names, point to the same method, add them to the
-        // map as aliases of each other.
-        const name2 = methodsToNames.get(method);
-        // Assumes that the compiled name is shorter
-        if (name.length < name2.length) {
-          this.adManagerCompiledToExternNames_.set(name, name2);
-        } else {
-          this.adManagerCompiledToExternNames_.set(name2, name);
+          compiledMap.set(name2, name);
         }
       } else {
         methodsToNames.set(method, name);
@@ -583,9 +566,9 @@ shaka.cast.CastProxy = class extends shaka.util.FakeEventTarget {
       'manifest': this.localPlayer_.getAssetUri(),
       'startTime': null,
       'mimeType': this.localPlayer_.getMimeType(),
-      'addThumbnailsTrackCalls': this.addThumbnailsTrackCalls_,
-      'addTextTrackAsyncCalls': this.addTextTrackAsyncCalls_,
-      'addChaptersTrackCalls': this.addChaptersTrackCalls_,
+      'addThumbnailsTrackCalls': this.trackedCalls_.addThumbnailsTrack,
+      'addTextTrackAsyncCalls': this.trackedCalls_.addTextTrackAsync,
+      'addChaptersTrackCalls': this.trackedCalls_.addChaptersTrack,
     };
 
     // Pause local playback before capturing state.
@@ -645,9 +628,9 @@ shaka.cast.CastProxy = class extends shaka.util.FakeEventTarget {
       /** @type {Object} */(this.localPlayer_)[setter](value);
     }
 
-    const addThumbnailsTrackCalls = this.addThumbnailsTrackCalls_;
-    const addTextTrackAsyncCalls = this.addTextTrackAsyncCalls_;
-    const addChaptersTrackCalls = this.addChaptersTrackCalls_;
+    const addThumbnailsTrackCalls = this.trackedCalls_.addThumbnailsTrack;
+    const addTextTrackAsyncCalls = this.trackedCalls_.addTextTrackAsync;
+    const addChaptersTrackCalls = this.trackedCalls_.addChaptersTrack;
 
     this.resetExternalTracks();
 
@@ -736,6 +719,33 @@ shaka.cast.CastProxy = class extends shaka.util.FakeEventTarget {
     });
   }
 
+  /**
+   * Returns the local value/method for |name| on |localTarget| when not
+   * casting, or delegates to the sender for the given |targetName|.
+   * Centralises the repeated "use local if not casting" pattern shared by
+   * videoProxyGet_, playerProxyGet_, and adManagerProxyGet_.
+   * @param {!Object} localTarget
+   * @param {string} targetName
+   * @param {string} name
+   * @return {?}
+   * @private
+   */
+  getLocalOrRemote_(localTarget, targetName, name) {
+    if (!this.sender_.isCasting()) {
+      const value = localTarget[name];
+      if (typeof value == 'function') {
+        // eslint-disable-next-line no-restricted-syntax
+        return value.bind(localTarget);
+      }
+      return value;
+    }
+    // getCurrentAd is special: it must return the proxy, not the local ad.
+    if (name == 'getCurrentAd') {
+      return () => this.currentAdProxy_;
+    }
+    return this.sender_.get(targetName, name);
+  }
+
   /**
    * @param {string} name
    * @return {?}
@@ -763,17 +773,8 @@ shaka.cast.CastProxy = class extends shaka.util.FakeEventTarget {
       }
     }
 
-    // Use local values and methods if we are not casting.
-    if (!this.sender_.isCasting()) {
-      let value = this.localVideo_[name];
-      if (typeof value == 'function') {
-        // eslint-disable-next-line no-restricted-syntax
-        value = value.bind(this.localVideo_);
-      }
-      return value;
-    }
-
-    return this.sender_.get('video', name);
+    return this.getLocalOrRemote_(
+        /** @type {!Object} */(this.localVideo_), 'video', name);
   }
 
   /**
@@ -882,21 +883,21 @@ shaka.cast.CastProxy = class extends shaka.util.FakeEventTarget {
     if (!dontRecordCalls) {
       if (name == 'addThumbnailsTrack') {
         return (...args) => {
-          this.addThumbnailsTrackCalls_.push(args);
+          this.trackedCalls_.addThumbnailsTrack.push(args);
           return this.playerProxyGet_(
               name, /* dontRecordCalls= */ true)(...args);
         };
       }
       if (name == 'addTextTrackAsync') {
         return (...args) => {
-          this.addTextTrackAsyncCalls_.push(args);
+          this.trackedCalls_.addTextTrackAsync.push(args);
           return this.playerProxyGet_(
               name, /* dontRecordCalls= */ true)(...args);
         };
       }
       if (name == 'addChaptersTrack') {
         return (...args) => {
-          this.addChaptersTrackCalls_.push(args);
+          this.trackedCalls_.addChaptersTrack.push(args);
           return this.playerProxyGet_(
               name, /* dontRecordCalls= */ true)(...args);
         };
@@ -934,17 +935,8 @@ shaka.cast.CastProxy = class extends shaka.util.FakeEventTarget {
       }
     }
 
-    // Use local getters and methods if we are not casting.
-    if (!this.sender_.isCasting()) {
-      const value = /** @type {Object} */(this.localPlayer_)[name];
-      if (typeof value != 'function') {
-        return value;
-      }
-      // eslint-disable-next-line no-restricted-syntax
-      return value.bind(this.localPlayer_);
-    }
-
-    return this.sender_.get('player', name);
+    return this.getLocalOrRemote_(
+        /** @type {!Object} */(this.localPlayer_), 'player', name);
   }
 
   /**
@@ -985,21 +977,8 @@ shaka.cast.CastProxy = class extends shaka.util.FakeEventTarget {
       };
     }
 
-    // Use local getters and methods if we are not casting.
-    if (!this.sender_.isCasting()) {
-      const value = /** @type {Object} */(this.localAdManager_)[name];
-      if (typeof value != 'function') {
-        return value;
-      }
-      // eslint-disable-next-line no-restricted-syntax
-      return value.bind(this.localAdManager_);
-    }
-
-    if (name == 'getCurrentAd') {
-      return () => this.currentAdProxy_;
-    }
-
-    return this.sender_.get('adManager', name);
+    return this.getLocalOrRemote_(
+        /** @type {!Object} */(this.localAdManager_), 'adManager', name);
   }
 
   /**
@@ -1070,9 +1049,9 @@ shaka.cast.CastProxy = class extends shaka.util.FakeEventTarget {
    * Reset external tracks
    */
   resetExternalTracks() {
-    this.addThumbnailsTrackCalls_ = [];
-    this.addTextTrackAsyncCalls_ = [];
-    this.addChaptersTrackCalls_ = [];
+    this.trackedCalls_.addThumbnailsTrack = [];
+    this.trackedCalls_.addTextTrackAsync = [];
+    this.trackedCalls_.addChaptersTrack = [];
   }
 
   /**

lib/cast/cast_receiver.js

@@ -173,11 +173,7 @@ shaka.cast.CastReceiver = class extends shaka.util.FakeEventTarget {
    * @export
    */
   setContentTitle(title) {
-    if (!this.metadata_) {
-      this.metadata_ = {
-        'metadataType': cast.receiver.media.MetadataType.GENERIC,
-      };
-    }
+    this.ensureMetadata_();
     this.metadata_['title'] = title;
   }
 
@@ -189,11 +185,7 @@ shaka.cast.CastReceiver = class extends shaka.util.FakeEventTarget {
    * @export
    */
   setContentImage(imageUrl) {
-    if (!this.metadata_) {
-      this.metadata_ = {
-        'metadataType': cast.receiver.media.MetadataType.GENERIC,
-      };
-    }
+    this.ensureMetadata_();
     this.metadata_['images'] = [
       {
         'url': imageUrl,
@@ -210,14 +202,24 @@ shaka.cast.CastReceiver = class extends shaka.util.FakeEventTarget {
    * @export
    */
   setContentArtist(artist) {
-    if (!this.metadata_) {
-      this.metadata_ = {};
-    }
+    this.ensureMetadata_();
     this.metadata_['artist'] = artist;
     this.metadata_['metadataType'] =
         cast.receiver.media.MetadataType.MUSIC_TRACK;
   }
 
+  /**
+   * Ensures this.metadata_ exists, initialising it with GENERIC type if not.
+   * @private
+   */
+  ensureMetadata_() {
+    if (!this.metadata_) {
+      this.metadata_ = {
+        'metadataType': cast.receiver.media.MetadataType.GENERIC,
+      };
+    }
+  }
+
   /**
    * Destroys the underlying Player, then terminates the cast receiver app.
    *

lib/cast/cast_sender.js

@@ -347,52 +347,54 @@ shaka.cast.CastSender = class {
         targetName == 'adManager' || targetName == 'currentAd',
     'Unexpected target name');
     const CastUtils = shaka.cast.CastUtils;
-    if (targetName == 'video') {
-      if (CastUtils.VideoVoidMethods.includes(property)) {
-        return (...args) => this.remoteCall_(targetName, property, ...args);
-      }
-    } else if (targetName == 'player') {
-      if (CastUtils.PlayerGetterMethodsThatRequireLive.has(property)) {
-        const isLive = this.get('player', 'isLive')();
-        goog.asserts.assert(isLive,
-            property + ' should be called on a live stream!');
-        // If the property shouldn't exist, return a fake function so that the
-        // user doesn't call an undefined function and get a second error.
-        if (!isLive) {
-          return () => undefined;
-        }
-      }
-      if (CastUtils.PlayerVoidMethods.includes(property)) {
-        return (...args) => this.remoteCall_(targetName, property, ...args);
-      }
-      if (CastUtils.PlayerPromiseMethods.includes(property)) {
-        return (...args) =>
-          this.remoteAsyncCall_(targetName, property, ...args);
-      }
-      if (CastUtils.PlayerGetterMethods.has(property) ||
-          CastUtils.LargePlayerGetterMethods.has(property)) {
-        return () => this.propertyGetter_(targetName, property);
-      }
-    } else if (targetName == 'adManager') {
-      if (CastUtils.AdManagerVoidMethods.includes(property)) {
-        return (...args) => this.remoteCall_(targetName, property, ...args);
-      }
-      if (CastUtils.AdManagerPromiseMethods.includes(property)) {
-        return (...args) =>
-          this.remoteAsyncCall_(targetName, property, ...args);
-      }
-      if (CastUtils.LargeAdManagerGetterMethods.has(property)) {
-        return () => this.propertyGetter_(targetName, property);
-      }
-    } else if (targetName == 'currentAd') {
-      if (CastUtils.CurrentAdVoidMethods.includes(property)) {
-        return (...args) => this.remoteCall_(targetName, property, ...args);
-      }
-      if (CastUtils.CurrentAdGetterMethods.has(property)) {
-        return () => this.propertyGetter_(targetName, property);
+
+    // Config table: for each target, which lists/maps govern dispatch.
+    const config = {
+      'video': {
+        voidMethods: CastUtils.VideoVoidMethods,
+      },
+      'player': {
+        voidMethods: CastUtils.PlayerVoidMethods,
+        promiseMethods: CastUtils.PlayerPromiseMethods,
+        getterMethods: [CastUtils.PlayerGetterMethods,
+          CastUtils.LargePlayerGetterMethods],
+        requiresLiveMap: CastUtils.PlayerGetterMethodsThatRequireLive,
+      },
+      'adManager': {
+        voidMethods: CastUtils.AdManagerVoidMethods,
+        promiseMethods: CastUtils.AdManagerPromiseMethods,
+        getterMethods: [CastUtils.LargeAdManagerGetterMethods],
+      },
+      'currentAd': {
+        voidMethods: CastUtils.CurrentAdVoidMethods,
+        getterMethods: [CastUtils.CurrentAdGetterMethods],
+      },
+    };
+
+    const cfg = config[targetName];
+
+    // Live-only guard (player only).
+    if (cfg.requiresLiveMap && cfg.requiresLiveMap.has(property)) {
+      const isLive = this.get('player', 'isLive')();
+      goog.asserts.assert(isLive,
+          property + ' should be called on a live stream!');
+      if (!isLive) {
+        return () => undefined;
       }
     }
 
+    if (cfg.voidMethods && cfg.voidMethods.includes(property)) {
+      return (...args) => this.remoteCall_(targetName, property, ...args);
+    }
+    if (cfg.promiseMethods && cfg.promiseMethods.includes(property)) {
+      return (...args) =>
+        this.remoteAsyncCall_(targetName, property, ...args);
+    }
+    if (cfg.getterMethods &&
+        cfg.getterMethods.some((map) => map.has(property))) {
+      return () => this.propertyGetter_(targetName, property);
+    }
+
     return this.propertyGetter_(targetName, property);
   }