1// Copyright (c) 2013 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.
4//
5// This class enumerates the media transfer protocol (MTP) device objects from
6// a given object entry list.
7
8#ifndef CHROME_BROWSER_MEDIA_GALLERIES_WIN_MTP_DEVICE_OBJECT_ENUMERATOR_H_
9#define CHROME_BROWSER_MEDIA_GALLERIES_WIN_MTP_DEVICE_OBJECT_ENUMERATOR_H_
10
11#include "base/files/file_path.h"
12#include "base/threading/thread_checker.h"
13#include "base/time/time.h"
14#include "chrome/browser/media_galleries/win/mtp_device_object_entry.h"
15
16// MTPDeviceObjectEnumerator is used to enumerate the media transfer protocol
17// (MTP) device objects from a given object entry list.
18// MTPDeviceObjectEnumerator supports MTP device file operations.
19// MTPDeviceObjectEnumerator may only be used on a single thread.
20class MTPDeviceObjectEnumerator {
21 public:
22  explicit MTPDeviceObjectEnumerator(const MTPDeviceObjectEntries& entries);
23  ~MTPDeviceObjectEnumerator();
24
25  base::FilePath Next();
26  int64 Size();
27  bool IsDirectory();
28  base::Time LastModifiedTime();
29
30  // If the current file object entry is valid, returns an non-empty object id.
31  // Returns an empty string otherwise.
32  base::string16 GetObjectId() const;
33
34 private:
35  // Returns true if the enumerator has more entries to traverse, false
36  // otherwise.
37  bool HasMoreEntries() const;
38
39  // Returns true if Next() has been called at least once, and the enumerator
40  // has more entries to traverse.
41  bool IsIndexReadyAndInRange() const;
42
43  // List of directory file object entries.
44  MTPDeviceObjectEntries object_entries_;
45
46  // Index into |object_entries_|.
47  // Should only be used when |is_index_ready_| is true.
48  size_t index_;
49
50  // Initially false. Set to true after Next() has been called.
51  bool is_index_ready_;
52
53  base::ThreadChecker thread_checker_;
54
55  DISALLOW_COPY_AND_ASSIGN(MTPDeviceObjectEnumerator);
56};
57
58#endif  // CHROME_BROWSER_MEDIA_GALLERIES_WIN_MTP_DEVICE_OBJECT_ENUMERATOR_H_
59