| // Copyright 2014 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 DEVICE_HID_HID_SERVICE_H_ |
| #define DEVICE_HID_HID_SERVICE_H_ |
| |
| #include <map> |
| #include <string> |
| #include <vector> |
| |
| #include "base/bind_helpers.h" |
| #include "base/memory/ref_counted.h" |
| #include "base/observer_list.h" |
| #include "base/single_thread_task_runner.h" |
| #include "base/threading/thread_checker.h" |
| #include "device/hid/hid_device_info.h" |
| |
| namespace device { |
| |
| class HidConnection; |
| |
| // The HidService keeps track of human interface devices connected to the |
| // system. Call HidService::GetInstance to get the singleton instance. |
| class HidService { |
| public: |
| class Observer { |
| public: |
| virtual void OnDeviceAdded(scoped_refptr<HidDeviceInfo> info); |
| // Notifies all observers that a device is being removed, called before |
| // removing the device from HidService. Observers should not depend on the |
| // order in which they are notified of the OnDeviceRemove event. |
| virtual void OnDeviceRemoved(scoped_refptr<HidDeviceInfo> info); |
| // Notifies all observers again, after having first notified all observers |
| // with OnDeviceRemoved and removed the device from internal structures. |
| // Each observer must not depend on any other observers' awareness of the |
| // device as they could be cleaned up in any order. |
| virtual void OnDeviceRemovedCleanup(scoped_refptr<HidDeviceInfo> info); |
| }; |
| |
| typedef base::Callback<void(const std::vector<scoped_refptr<HidDeviceInfo>>&)> |
| GetDevicesCallback; |
| typedef base::Callback<void(scoped_refptr<HidConnection> connection)> |
| ConnectCallback; |
| |
| // This function should be called on a thread with a MessageLoopForUI and be |
| // passed the task runner for a thread with a MessageLoopForIO. |
| static scoped_ptr<HidService> Create( |
| scoped_refptr<base::SingleThreadTaskRunner> file_task_runner); |
| |
| virtual ~HidService(); |
| |
| // Enumerates available devices. The provided callback will always be posted |
| // to the calling thread's task runner. |
| virtual void GetDevices(const GetDevicesCallback& callback); |
| |
| void AddObserver(Observer* observer); |
| void RemoveObserver(Observer* observer); |
| |
| // Fills in a DeviceInfo struct with info for the given device_id. |
| // Returns |nullptr| if |device_id| is invalid. |
| scoped_refptr<HidDeviceInfo> GetDeviceInfo( |
| const HidDeviceId& device_id) const; |
| |
| // Opens a connection to a device. The callback will be run with null on |
| // failure. |
| virtual void Connect(const HidDeviceId& device_id, |
| const ConnectCallback& callback) = 0; |
| |
| protected: |
| friend class HidConnectionTest; |
| |
| typedef std::map<HidDeviceId, scoped_refptr<HidDeviceInfo>> DeviceMap; |
| |
| HidService(); |
| |
| void AddDevice(scoped_refptr<HidDeviceInfo> info); |
| void RemoveDevice(const HidDeviceId& device_id); |
| void FirstEnumerationComplete(); |
| |
| const DeviceMap& devices() const { return devices_; } |
| |
| base::ThreadChecker thread_checker_; |
| |
| private: |
| DeviceMap devices_; |
| bool enumeration_ready_; |
| std::vector<GetDevicesCallback> pending_enumerations_; |
| base::ObserverList<Observer, true> observer_list_; |
| |
| DISALLOW_COPY_AND_ASSIGN(HidService); |
| }; |
| |
| } // namespace device |
| |
| #endif // DEVICE_HID_HID_SERVICE_H_ |