Add ICU message format support
[chromium-blink-merge.git] / device / usb / usb_service.h
blobb18524115826594867d6dce6de763a3671e849a8
1 // Copyright 2014 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
5 #ifndef DEVICE_USB_USB_SERVICE_H_
6 #define DEVICE_USB_USB_SERVICE_H_
8 #include <string>
9 #include <vector>
11 #include "base/bind_helpers.h"
12 #include "base/memory/ref_counted.h"
13 #include "base/memory/scoped_ptr.h"
14 #include "base/observer_list.h"
15 #include "base/threading/non_thread_safe.h"
17 namespace base {
18 class SequencedTaskRunner;
21 namespace device {
23 class UsbDevice;
25 // The USB service handles creating and managing an event handler thread that is
26 // used to manage and dispatch USB events. It is also responsible for device
27 // discovery on the system, which allows it to re-use device handles to prevent
28 // competition for the same USB device.
29 class UsbService : public base::NonThreadSafe {
30 public:
31 using GetDevicesCallback =
32 base::Callback<void(const std::vector<scoped_refptr<UsbDevice>>&)>;
34 class Observer {
35 public:
36 // These events are delivered from the thread on which the UsbService object
37 // was created.
38 virtual void OnDeviceAdded(scoped_refptr<UsbDevice> device);
39 virtual void OnDeviceRemoved(scoped_refptr<UsbDevice> device);
40 // For observers that need to process device removal after others have run.
41 // Should not depend on any other service's knowledge of connected devices.
42 virtual void OnDeviceRemovedCleanup(scoped_refptr<UsbDevice> device);
45 // The file task runner reference is used for blocking I/O operations.
46 // Returns NULL when initialization fails.
47 static UsbService* GetInstance(
48 scoped_refptr<base::SequencedTaskRunner> blocking_task_runner);
50 virtual scoped_refptr<UsbDevice> GetDevice(const std::string& guid) = 0;
52 // Enumerates available devices.
53 virtual void GetDevices(const GetDevicesCallback& callback) = 0;
55 void AddObserver(Observer* observer);
56 void RemoveObserver(Observer* observer);
58 protected:
59 UsbService();
60 virtual ~UsbService();
62 void NotifyDeviceAdded(scoped_refptr<UsbDevice> device);
63 void NotifyDeviceRemoved(scoped_refptr<UsbDevice> device);
65 base::ObserverList<Observer, true> observer_list_;
67 private:
68 friend void base::DeletePointer<UsbService>(UsbService* service);
70 DISALLOW_COPY_AND_ASSIGN(UsbService);
73 } // namespace device
75 #endif // DEVICE_USB_USB_SERVICE_H_