[Media Router] Custom Controls 2 - add MediaRouter::GetRouteController()

chrome/browser/media/router/mojo/media_router.mojom

 // 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.
 
 module media_router.mojom;
 
+import "chrome/browser/media/router/mojo/media_controller.mojom";
+import "chrome/browser/media/router/mojo/media_status.mojom";
 import "mojo/common/time.mojom";
 import "net/interfaces/ip_address.mojom";
 import "url/mojo/origin.mojom";
 import "url/mojo/url.mojom";
 
 // Represents an output sink to which media can be routed.
 struct MediaSink {
   enum IconType {
     CAST,
     CAST_AUDIO,
@@ skipping 55 matching lines @@
 
 // Should be kept in sync with media_route.h.
 struct MediaRoute {
   // The ID of this media route, e.g. "r_PR1O_blkC9dsKp-tb1ti8qurOo".
   string media_route_id;
   // The ID of the media source being sent through this media route.
   // May be missing if route is not local.
   string? media_source;
   // The ID of sink that is rendering the media content.
   string media_sink_id;
-  // Human readable description of this route, e.g.
-  // "Tab casting".
+  // Human readable description of this route, e.g. "Tab casting".
   string description;
   // Specifies that the route is requested locally.
   bool is_local;
   // An optional path to an HTML page bundled bundled with the media router
   // component extension. When set, the route can have custom route detail as
   // well as its own route controls in the media router dialog.
   string? custom_controller_path;
   // Set to true if this route should be displayed for |media_sink_id| in UI.
   bool for_display;
   // Set to true if this route was created by an incognito profile.
@@ skipping 262 matching lines @@
   // Indicates that the Media Router is interested in finding a sink that
   // matches |search_criteria| and is compatible with the source urn
   // |media_source|. |search_criteria| should contain an exact copy of the user
   // input. The user's current domain is also used to search.  The domain is the
   // hosted domain of the user's signed-in identity, or empty if the user has no
   // domain or is not signed in.
   SearchSinks(string sink_id,
               string media_source,
               SinkSearchCriteria search_criteria) =>
                   (string sink_id);
+
+  // Creates a controller for the media route with given |route_id| and binds it
+  // to |media_controller| for receiving media commands. This method returns
+  // false if such a media route doesn't exist, a controller already exists
+  // for it, or there was an error while creating a controller.
+  // |media_controller| becomes invalid when the media route is terminated. The
+  // created controller is destroyed when |media_controller| becomes invalid.
+  // TODO(takumif): Consider returning an enum instead of a bool to distinguish
+  // between error conditions for metrics/debugging.
+  CreateMediaRouteController(string route_id,
+                             MediaController& media_controller) =>
+                                 (bool success);

[dcheng, 2017/03/27 22:15:26]

Out of curiosity, would it make sense to just have this return a
MediaController? directly? Then I think we might not need Invalidate()

[imcheng, 2017/03/28 01:18:38]

We still need a way to invalidate the MediaRouteController, if it encounters a
Mojo connection error in the MediaController / MediaStatusObserver message
pipes.

Functionally, there is no big difference between this API, and one where a
MediaController is returned. One advantage of this API is that the message pipe
is created and bound in the browser, which means clients can begin using
MediaController without waiting for the implementation to be bound in the
extension side first.

+
+  // Sets the observer to be notified whenever there is a change in the status
+  // of a media route. A media route can have at most one observer at a time,
+  // and it will be overwritten each time this method is called with the same
+  // |route_id|.
+  SetMediaRouteStatusObserver(string route_id, MediaStatusObserver observer);
 };
 
 // Interface for a service which observes state changes across media
 // sources, sinks, and issues.
 interface MediaRouter {
 
   // Represents overall media sink availability states.
   // UNAVAILABLE - No sinks are available.
   // PER_SOURCE - Sinks are available, but are only compatible with specific
   //              media sources.
@@ skipping 55 matching lines @@
 
   // Called when the a batch of messages arrives from the media sink for the
   // route given by |route_id|.
   // |StartListeningForRouteMessages| must be called first in order to receive
   // messages.
   // |route_id|: ID of route of the messages.
   // |messages|: A non-empty list of messages received.
   OnRouteMessagesReceived(string route_id,
                           array<RouteMessage> messages);
 };