chrome/browser/media_galleries/win/mtp_device_object_enumerator.cc

   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 // MTPDeviceObjectEnumerator implementation.
   6
   7 #include "chrome/browser/media_galleries/win/mtp_device_object_enumerator.h"
   8
   9 #include "base/threading/thread_restrictions.h"
  10 #include "content/public/browser/browser_thread.h"
  11
  12 MTPDeviceObjectEnumerator::MTPDeviceObjectEnumerator(
  13     const MTPDeviceObjectEntries& entries)
  14     : object_entries_(entries),
  15       index_(0U),
  16       is_index_ready_(false) {
  17   base::ThreadRestrictions::AssertIOAllowed();
  18 }
  19
  20 MTPDeviceObjectEnumerator::~MTPDeviceObjectEnumerator() {
  21   DCHECK(thread_checker_.CalledOnValidThread());
  22 }
  23
  24 base::FilePath MTPDeviceObjectEnumerator::Next() {
  25   DCHECK(thread_checker_.CalledOnValidThread());
  26   if (IsIndexReadyAndInRange())
  27     ++index_;  // Normal traversal.
  28   else if (!is_index_ready_)
  29     is_index_ready_ = true;  // First time calling Next().
  30
  31   if (!HasMoreEntries())
  32     return base::FilePath();
  33   return base::FilePath(object_entries_[index_].name);
  34 }
  35
  36 int64 MTPDeviceObjectEnumerator::Size() {
  37   DCHECK(thread_checker_.CalledOnValidThread());
  38   if (!IsIndexReadyAndInRange())
  39     return 0;
  40   return object_entries_[index_].size;
  41 }
  42
  43 bool MTPDeviceObjectEnumerator::IsDirectory() {
  44   DCHECK(thread_checker_.CalledOnValidThread());
  45   if (!IsIndexReadyAndInRange())
  46     return false;
  47   return object_entries_[index_].is_directory;
  48 }
  49
  50 base::Time MTPDeviceObjectEnumerator::LastModifiedTime() {
  51   DCHECK(thread_checker_.CalledOnValidThread());
  52   if (!IsIndexReadyAndInRange())
  53     return base::Time();
  54   return object_entries_[index_].last_modified_time;
  55 }
  56
  57 base::string16 MTPDeviceObjectEnumerator::GetObjectId() const {
  58   DCHECK(thread_checker_.CalledOnValidThread());
  59   if (!IsIndexReadyAndInRange())
  60     return base::string16();
  61   return object_entries_[index_].object_id;
  62 }
  63
  64 bool MTPDeviceObjectEnumerator::HasMoreEntries() const {
  65   return index_ < object_entries_.size();
  66 }
  67
  68 bool MTPDeviceObjectEnumerator::IsIndexReadyAndInRange() const {
  69   return is_index_ready_ && HasMoreEntries();
  70 }