[PresentationAPI] Implementing send() from WebPresentationClient to the PresentationService.

content/renderer/presentation/presentation_dispatcher.h

 // 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.
 
 #ifndef CONTENT_RENDERER_PRESENTATION_PRESENTATION_DISPATCHER_H_
 #define CONTENT_RENDERER_PRESENTATION_PRESENTATION_DISPATCHER_H_
 
 #include "base/compiler_specific.h"
+#include "base/containers/hash_tables.h"
+#include "base/memory/linked_ptr.h"
 #include "base/memory/scoped_vector.h"
 #include "content/common/content_export.h"
 #include "content/common/presentation/presentation_service.mojom.h"
 #include "content/public/renderer/render_frame_observer.h"
 #include "content/renderer/presentation/presentation_session_dispatcher.h"
 #include "third_party/WebKit/public/platform/modules/presentation/WebPresentationClient.h"
 
 namespace blink {
 class WebString;
 }  // namespace blink
 
 namespace content {
 
 // PresentationDispatcher is a delegate for Presentation API messages used by
 // Blink. It forwards the calls to the Mojo PresentationService.
 class CONTENT_EXPORT PresentationDispatcher
     : public RenderFrameObserver,
       public NON_EXPORTED_BASE(blink::WebPresentationClient) {
  public:
   explicit PresentationDispatcher(RenderFrame* render_frame);
   ~PresentationDispatcher() override;
 
  private:
+
+  // postMessage request from a presentation session.
+  struct CONTENT_EXPORT PostMessageRequest {
+    PostMessageRequest(const std::string& presentation_url,
+                       const std::string& presentation_id,
+                       const std::string& message);
+    ~PostMessageRequest();
+
+    const std::string presentation_url;
+    const std::string presentation_id;
+    const std::string message;
+
+    // Need to handle ArrayBuffer/View and Blob data also

[imcheng, 2015/04/02 23:57:24]

Please add a TODO here.

[USE s.singapati at gmail.com, 2015/04/07 17:45:16]

Done.

+    //presentation::MessageType message_type;
+    //presentation::BinaryType binary_type;
+  };
+
   // WebPresentationClient implementation.
   virtual void setController(
       blink::WebPresentationController* controller);
   virtual void updateAvailableChangeWatched(bool watched);
   virtual void startSession(
       const blink::WebString& presentationUrl,
       const blink::WebString& presentationId,
       blink::WebPresentationSessionClientCallbacks* callback);
   virtual void joinSession(
       const blink::WebString& presentationUrl,
       const blink::WebString& presentationId,
       blink::WebPresentationSessionClientCallbacks* callback);
+  virtual void postMessage(
+      const blink::WebString& presentationUrl,
+      const blink::WebString& presentationId,
+      const blink::WebString& message);
+  virtual void postMessage(
+      const blink::WebString& presentationUrl,
+      const blink::WebString& presentationId,
+      const char* data,
+      size_t length);
   virtual void closeSession(
       const blink::WebString& presentationUrl,
       const blink::WebString& presentationId);
 
   // RenderFrameObserver
   void DidChangeDefaultPresentation() override;
 
   void OnScreenAvailabilityChanged(
       const std::string& presentation_url,
       bool available);
   void OnSessionCreated(
       blink::WebPresentationSessionClientCallbacks* callback,
       presentation::PresentationSessionInfoPtr session_info,
       presentation::PresentationErrorPtr error);
   void OnDefaultSessionStarted(
       presentation::PresentationSessionInfoPtr session_info);
 
   void ConnectToPresentationServiceIfNeeded();
 
   void DoUpdateAvailableChangeWatched(
       const std::string& presentation_url,
       bool watched);
 
+  void PostMessagesOfFirstSession();
+
+  void HandlePostMessageRequests();
+
+  void DoPostMessages(
+      const std::string& presentation_url,
+      const std::string& presentation_id,
+      std::vector<std::string> string_messages);
+
+  void RemovePostMessageRequestsOfFirstSession();
+
   // Used as a weak reference. Can be null since lifetime is bound to the frame.
   blink::WebPresentationController* controller_;
   presentation::PresentationServicePtr presentation_service_;
 
   // Wrappers around the PresentationSessionPtr corresponding to each Javascript
   // PresentationSession object passed back to the frame.
   // TODO(avayvod): Switch to base::IDMap when the lookup by presentation id is
   // needed.
   using PresentationSessionDispatchers =
       ScopedVector<PresentationSessionDispatcher>;
   PresentationSessionDispatchers presentation_session_dispatchers_;
+
+  // Map of presentation ID to its postMessage requests.
+  typedef std::vector<linked_ptr<PostMessageRequest>> PostMessageVector;

[imcheng, 2015/04/02 23:57:24]

using PostMessageVector = std::vector<linked_ptr<PostMessageRequest>>;

Same for PostMessageRequestMap.

[USE s.singapati at gmail.com, 2015/04/07 17:45:16]

Done.

+  typedef base::hash_map<std::string, linked_ptr<PostMessageVector>>
+      PostMessageRequestMap;
+
+  PostMessageRequestMap post_message_requests_map_;

[imcheng, 2015/04/02 23:57:24]

If we are sending 1 message per mojo call (I think that's what mark is
suggesting), then we can consider using a queue<PostMessageRequest> as it's
simpler?

[USE s.singapati at gmail.com, 2015/04/07 17:45:16]

Acknowledged. Simple queuing approach in new patch:
https://codereview.chromium.org/1061363002/. (Need to merge that with current
patch based review). Also with this approach all message types can be sent
individually in order to presentation_service_impl, for eg., send(struct
MessageRequest) or send(.., .., Messagetype, BinaryType) overloads.

 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_PRESENTATION_PRESENTATION_DISPATCHER_H_