Add support for PTZ via VISCA.

extensions/browser/api/webcam_private/visca_webcam.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_BROWSER_API_WEBCAM_PRIVATE_VISCA_WEBCAM_H_
+#define EXTENSIONS_BROWSER_API_WEBCAM_PRIVATE_VISCA_WEBCAM_H_
+
+#include <deque>
+
+#include "base/callback.h"
+#include "base/memory/weak_ptr.h"
+#include "extensions/browser/api/webcam_private/webcam.h"
+#include "extensions/common/api/serial.h"
+
+namespace extensions {
+
+class SerialConnection;
+
+class ViscaWebcam : public Webcam, public base::SupportsWeakPtr<ViscaWebcam> {
+ public:
+  ViscaWebcam(const std::string& path, const std::string& extension_id);
+  ~ViscaWebcam() override;
+
+  typedef base::Callback<void(bool)> OpenCallback;
+  void Open(const OpenCallback& callback);
+
+ private:
+  typedef base::Callback<void(bool, const std::vector<char>&)>
+      CommandCompleteCallback;
+
+  void OpenOnIOThread(const OpenCallback& callback);
+  void OnConnected(const OpenCallback& callback, bool success);
+  void OnClearAllComplete(const OpenCallback& callback,
+                          bool success, const std::vector<char>& data);
+
+  void Send(const std::vector<char>& data,
+            const CommandCompleteCallback& callback);
+  void OnSendComplete(const CommandCompleteCallback& callback,
+                      int bytes_sent, core_api::serial::SendError error);
+  void ReceiveLoop();
+  void OnReceiveComplete(const std::vector<char>& data,
+                         core_api::serial::ReceiveError error);
+
+  // Webcam:
+  void Reset(bool pan, bool tilt, bool zoom) override;
+  bool GetPan(int* value) override;
+  bool GetTilt(int* value) override;
+  bool GetZoom(int* value) override;
+  bool SetPan(int value) override;
+  bool SetTilt(int value) override;
+  bool SetZoom(int value) override;
+  bool SetPanDirection(PanDirection direction) override;
+  bool SetTiltDirection(TiltDirection direction) override;
+
+  const std::string path_;
+  const std::string extension_id_;
+
+  scoped_ptr<SerialConnection> serial_connection_;
+
+  std::deque<char> data_buffer_;
+  std::deque<std::pair<std::vector<char>, CommandCompleteCallback>> commands_;
+
+  DISALLOW_COPY_AND_ASSIGN(ViscaWebcam);
+};
+
+
+}  // namespace extensions
+
+#endif  // EXTENSIONS_BROWSER_API_WEBCAM_PRIVATE_VISCA_WEBCAM_H_