[Media Router] Assign each route a current cast mode if possible

chrome/browser/resources/media_router/elements/route_details/route_details.js

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // This Polymer element shows information from media that is currently cast
 // to a device.
 Polymer({
   is: 'route-details',
 
   properties: {
     /**
      * The text for the current casting activity status.
      * @private {string|undefined}
      */
     activityStatus_: {
       type: String,
     },
 
     /**
-     * Bitmask of available cast modes compatible with the sink of the current
-     * route.
-     * @type {number}
-     */
-    availableCastModes: {
-      type: Number,
-      value: 0,
-    },
-
-    /**
      * Whether the external container will accept replace-route-click events.
-     * @type {boolean}
+     * @private {boolean}
      */
-    replaceRouteAvailable: {
+    replaceRouteAvailable_: {
       type: Boolean,
-      value: true,
+      computed: 'computeReplaceRouteAvailable_(route, sink,' +
+                    'sinkCurrentlyLaunching, shownCastModeValue)',
     },
 
     /**
      * The route to show.
      * @type {?media_router.Route|undefined}
      */
     route: {
       type: Object,
       observer: 'maybeLoadCustomController_',
     },
 
     /**
+     * The cast mode shown to the user. Initially set to auto mode. (See
+     * media_router.CastMode documentation for details on auto mode.)
+     * @type {number}
+     */
+    shownCastModeValue: {
+      type: Number,
+      value: media_router.AUTO_CAST_MODE.type,
+    },
+
+    /**
+     * Sink associated with |route|.
+     * @type {?media_router.Sink}
+     */
+    sink: {
+      type: Object,
+      value: null,
+    },
+
+    /**
+     * Whether a sink is currently launching in the container.
+     * @type {boolean}
+     */
+    sinkCurrentlyLaunching: {

[apacible, 2016/06/07 12:13:42]

nit: Rename as something like, |isAnySinkCurrentlyLaunching|.

It makes more sense with the comments in route-details but this would make it
more obvious that |sinkCurrentlyLaunching| and |sink| don't refer to the same
sink in media-router-container.

[btolsch, 2016/06/07 19:45:34]

Done.

+      type: Boolean,
+      value: false,
+    },
+
+    /**
      * Whether the custom controller should be hidden.
      * A custom controller is shown iff |route| specifies customControllerPath
      * and the view can be loaded.
      * @private {boolean}
      */
     isCustomControllerHidden_: {
       type: Boolean,
       value: true,
     },
   },
 
   behaviors: [
     I18nBehavior,
   ],
 
   /**
    * Fires a close-route event. This is called when the button to close
    * the current route is clicked.
    *
    * @private
    */
   closeRoute_: function() {
     this.fire('close-route', {route: this.route});
   },
 
   /**
    * @param {?media_router.Route|undefined} route
-   * @param {number} availableCastModes
    * @param {boolean} replaceRouteAvailable
    * @return {boolean} Whether to show the button that allows casting to the
    *     current route or the current route's sink.
    */
-  computeCastButtonHidden_: function(
-      route, availableCastModes, replaceRouteAvailable) {
-    return !((route && route.canJoin) ||
-             (availableCastModes && replaceRouteAvailable));
+  computeCastButtonHidden_: function(route, replaceRouteAvailable) {
+    return !((route && route.canJoin) || replaceRouteAvailable);
   },
 
   /**
+   * @param {?media_router.Route|undefined} route The current route for the
+   *     route details view.
+   * @param {?media_router.Sink|undefined} sink Sink associated with |route|.
+   * @param {boolean} sinkCurrentlyLaunching Whether a sink is launching now.
+   * @param {number} shownCastModeValue Currently selected cast mode value or
+   *     AUTO if no value has been explicitly selected.
+   * @return {boolean} Whether the replace route function should be available
+   *     when displaying |currentRoute| in the route details view. Replace route
+   *     should not be available when the source that would be cast from when
+   *     creating a new route would be the same as the route's current source.
+   * @private
+   */
+  computeReplaceRouteAvailable_: function(
+      route, sink, sinkCurrentlyLaunching, shownCastModeValue) {
+    if (sinkCurrentlyLaunching || !route || !sink) {
+      return false;
+    }
+    if (!route.currentCastMode) {
+      return true;
+    }
+    var selectedCastMode = shownCastModeValue;
+    if (selectedCastMode == media_router.CastModeType.AUTO) {
+      selectedCastMode = sink.castModes & -sink.castModes;
+    }
+    return (selectedCastMode & sink.castModes) &&
+        (selectedCastMode != route.currentCastMode);
+  },
+
+  /**
    * Fires a join-route-click event if the current route is joinable, otherwise
    * it fires a replace-route-click event, which stops the current route and
    * immediately launches a new route to the same sink. This is called when the
    * button to start casting to the current route is clicked.
    *
    * @private
    */
   startCastingToRoute_: function() {
     if (this.route.canJoin) {
       this.fire('join-route-click', {route: this.route});
@@ skipping 32 matching lines @@
     extensionview.load(this.route.customControllerPath)
     .then(function() {
       // Load was successful; show the custom controller.
       that.isCustomControllerHidden_ = false;
     }, function() {
       // Load was unsuccessful; fall back to default view.
       that.isCustomControllerHidden_ = true;
     });
   },
 });