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.
4
5#ifndef CHROME_BROWSER_MEDIA_GALLERIES_MEDIA_FOLDER_FINDER_H_
6#define CHROME_BROWSER_MEDIA_GALLERIES_MEDIA_FOLDER_FINDER_H_
7
8#include <map>
9#include <vector>
10
11#include "base/callback.h"
12#include "base/files/file_path.h"
13#include "base/memory/ref_counted.h"
14#include "base/memory/weak_ptr.h"
15#include "base/sequenced_task_runner.h"
16#include "chrome/browser/media_galleries/media_scan_types.h"
17
18// MediaFolderFinder scans local hard drives and look for folders that contain
19// media files.
20class MediaFolderFinder {
21 public:
22  // Key: path to a folder
23  // Value: scan results for that folder, non-recursive.
24  typedef std::map<base::FilePath, MediaGalleryScanResult>
25      MediaFolderFinderResults;
26
27  // |results| never contains entries for |graylisted_folders_| or parent
28  // directories of |graylisted_folders_|.
29  typedef base::Callback<void(bool /*success*/,
30                              const MediaFolderFinderResults& /*results*/)>
31      MediaFolderFinderResultsCallback;
32
33  // |callback| will get called when the scan finishes. If the object is deleted
34  // before it finishes, the scan will stop and |callback| will get called with
35  // success = false.
36  // MediaFolderFinder has a default set of per-platform paths to scan.
37  // Override in tests with SetRootsForTesting().
38  explicit MediaFolderFinder(const MediaFolderFinderResultsCallback& callback);
39  virtual ~MediaFolderFinder();
40
41  // Start the scan.
42  virtual void StartScan();
43
44  const std::vector<base::FilePath>& graylisted_folders() const;
45
46 private:
47  friend class MediaFolderFinderTest;
48  friend class MediaGalleriesPlatformAppBrowserTest;
49
50  class Worker;
51  struct WorkerReply {
52    WorkerReply();
53    ~WorkerReply();
54
55    MediaGalleryScanResult scan_result;
56    std::vector<base::FilePath> new_folders;
57  };
58
59  enum ScanState {
60    SCAN_STATE_NOT_STARTED,
61    SCAN_STATE_STARTED,
62    SCAN_STATE_FINISHED,
63  };
64
65  void SetRootsForTesting(const std::vector<base::FilePath>& roots);
66
67  void OnInitialized(const std::vector<base::FilePath>& roots);
68
69  // Scan a folder from |folders_to_scan_|.
70  void ScanFolder();
71
72  // Callback that handles the |reply| from |worker_| for a scanned |path|.
73  void GotScanResults(const base::FilePath& path, const WorkerReply& reply);
74
75  const MediaFolderFinderResultsCallback results_callback_;
76  MediaFolderFinderResults results_;
77
78  std::vector<base::FilePath> graylisted_folders_;
79  std::vector<base::FilePath> folders_to_scan_;
80  ScanState scan_state_;
81
82  scoped_refptr<base::SequencedTaskRunner> worker_task_runner_;
83
84  // Owned by MediaFolderFinder, but lives on |worker_task_runner_|.
85  Worker* worker_;
86
87  // Set of roots to scan for testing.
88  bool has_roots_for_testing_;
89  std::vector<base::FilePath> roots_for_testing_;
90
91  base::WeakPtrFactory<MediaFolderFinder> weak_factory_;
92
93  DISALLOW_COPY_AND_ASSIGN(MediaFolderFinder);
94};
95
96#endif  // CHROME_BROWSER_MEDIA_GALLERIES_MEDIA_FOLDER_FINDER_H_
97