chrome.displaySource custom bindings

extensions/renderer/api/display_source/display_source_session.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 EXTENSIONS_RENDERER_API_DISPLAY_SOURCE_DISPLAY_SOURCE_SESSION_H_
+#define EXTENSIONS_RENDERER_API_DISPLAY_SOURCE_DISPLAY_SOURCE_SESSION_H_
+
+#include "base/callback.h"
+#include "base/macros.h"
+#include "extensions/common/api/display_source.h"
+#include "third_party/WebKit/public/web/WebDOMMediaStreamTrack.h"
+
+namespace extensions {
+
+using DisplaySourceAuthInfo = api::display_source::AuthenticationInfo;
+using DisplaySourceErrorType = api::display_source::ErrorType;
+
+// This class represents a generic display source session interface.
+class DisplaySourceSession {
+ public:
+  using SinkIdCallback = base::Callback<void(int)>;
+  using ErrorCallback =
+      base::Callback<void(int, DisplaySourceErrorType, const std::string&)>;

[asargent_no_longer_on_chrome, 2015/12/07 21:47:49]

nit: please add comments or variable names so that it's clear what the meaning
of each parameter is in SinkIdCallback and ErrorCallback, e.g.


using Foo = base::Callback<void(int requestId)>;

or

// Callback for passing back a request id.
using Foo = base::Callback<void(int)>;

[Mikhail, 2015/12/08 07:44:43]

Done.

+
+  // State flow is ether:
+  // 'Idle' -> 'Establishing' -> 'Established' -> 'Terminating' -> 'Idle'
+  // (terminated by Terminate() call)
+  //  or
+  // 'Idle' -> 'Establishing' -> 'Established' -> 'Idle'
+  // (terminated from sink device or due to an error)
+  enum State {
+    Idle,
+    Establishing,
+    Established,
+    Terminating
+  };
+
+  virtual ~DisplaySourceSession();
+
+  // Starts the session.
+  // The session state should be set to 'Establishing' immediately after this
+  // method is called.
+  virtual void Start() = 0;
+
+  // Terminates the session.
+  // The session state should be set to 'Terminating' immediately after this
+  // method is called.
+  virtual void Terminate() = 0;
+
+  State state() const { return state_; }
+
+  // Sets the callbacks invoked to inform about the session's state changes

[asargent_no_longer_on_chrome, 2015/12/07 21:47:49]

suggestion: It might be helpful to document somewhere whether it's required or
optional to call SetCallbacks before calling Start().

[Mikhail, 2015/12/08 07:44:42]

Done.

+  // |started_callback| : Called when the session was actually started (state
+  //                      should be set to 'Established')
+  // |terminated_callback| : Called when the session was actually started (state
+  //                         should be set to 'Idle')
+  // |error_callback| : Called if a fatal error has occured and the session
+  //                    either cannot be started (if was invoked in
+  //                    'Establishing' state) or will be terminated soon for
+  //                    emergency reasons (if was invoked in 'Established'
+  //                    state).
+  void SetCallbacks(const SinkIdCallback& started_callback,
+                    const SinkIdCallback& terminated_callback,
+                    const ErrorCallback& error_callback);
+
+ protected:
+  DisplaySourceSession();
+
+  State state_;
+  SinkIdCallback started_callback_;
+  SinkIdCallback terminated_callback_;
+  ErrorCallback error_callback_;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(DisplaySourceSession);
+};
+
+class DisplaySourceSessionFactory {
+ public:
+  static scoped_ptr<DisplaySourceSession> CreateSession(
+      int sink_id,
+      const blink::WebMediaStreamTrack& video_track,
+      const blink::WebMediaStreamTrack& audio_track,
+      scoped_ptr<DisplaySourceAuthInfo> auth_info);
+ private:
+  DISALLOW_COPY_AND_ASSIGN(DisplaySourceSessionFactory);
+};
+
+}  // namespace extensions
+
+#endif  // EXTENSIONS_RENDERER_API_DISPLAY_SOURCE_DISPLAY_SOURCE_SESSION_H_