chrome/browser/media_galleries/fileapi/iapps_data_provider.h

   1 // Copyright 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 #ifndef CHROME_BROWSER_MEDIA_GALLERIES_FILEAPI_IAPPS_DATA_PROVIDER_H_
   6 #define CHROME_BROWSER_MEDIA_GALLERIES_FILEAPI_IAPPS_DATA_PROVIDER_H_
   7
   8 #include <map>
   9 #include <set>
  10 #include <string>
  11
  12 #include "base/basictypes.h"
  13 #include "base/callback_forward.h"
  14 #include "base/files/file_path.h"
  15 #include "base/files/file_path_watcher.h"
  16 #include "base/memory/weak_ptr.h"
  17
  18 namespace iapps {
  19
  20 // This class is the holder for iTunes parsed data. Given a path to the iTunes
  21 // library XML file it will read it in, parse the data, and provide convenient
  22 // methods to access it.  When the file changes, it will update the data.
  23 // It is not thread safe, but can be run on any thread with IO access.
  24 class IAppsDataProvider {
  25  public:
  26   typedef base::Callback<void(bool)> ReadyCallback;
  27
  28   explicit IAppsDataProvider(const base::FilePath& library_path);
  29   virtual ~IAppsDataProvider();
  30
  31   // Ask the data provider to refresh the data if necessary. |ready_callback|
  32   // will be called with the result; false if unable to parse the XML file.
  33   virtual void RefreshData(const ReadyCallback& ready_callback);
  34
  35   // Get the platform path for the library XML file.
  36   const base::FilePath& library_path() const;
  37
  38  protected:
  39   bool valid() const;
  40
  41   // Subclass should set this to true if the last parse succeeded.
  42   void set_valid(bool valid);
  43
  44   // Signal to subclass to parse the |library_path|. The |ready_callback|
  45   // should be called when parsing has finished.
  46   virtual void DoParseLibrary(const base::FilePath& library_path,
  47                               const ReadyCallback& ready_callback) = 0;
  48
  49   // Called when |library_path_| has changed. Virtual for testing.
  50   virtual void OnLibraryChanged(const base::FilePath& path, bool error);
  51
  52  private:
  53   // Called when the FilePathWatcher for |library_path_| has tried to add an
  54   // watch.
  55   void OnLibraryWatchStarted(scoped_ptr<base::FilePathWatcher> library_watcher);
  56
  57   // Path to the library XML file.
  58   const base::FilePath library_path_;
  59
  60   // True if the data needs to be refreshed from disk.
  61   bool needs_refresh_;
  62
  63   // True if |library_| contains valid data. False at construction and if
  64   // reading or parsing the XML file fails.
  65   bool is_valid_;
  66
  67   // A watcher on the library xml file.
  68   scoped_ptr<base::FilePathWatcher> library_watcher_;
  69
  70   base::WeakPtrFactory<IAppsDataProvider> weak_factory_;
  71
  72   DISALLOW_COPY_AND_ASSIGN(IAppsDataProvider);
  73 };
  74
  75 }  // namespace iapps
  76
  77 #endif  // CHROME_BROWSER_MEDIA_GALLERIES_FILEAPI_IAPPS_DATA_PROVIDER_H_