chrome/browser/ui/zoom/chrome_zoom_level_prefs.cc

   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 #include "chrome/browser/ui/zoom/chrome_zoom_level_prefs.h"
   6
   7 #include "base/bind.h"
   8 #include "base/prefs/json_pref_store.h"
   9 #include "base/prefs/pref_filter.h"
  10 #include "base/prefs/pref_registry_simple.h"
  11 #include "base/prefs/pref_service_factory.h"
  12 #include "base/prefs/scoped_user_pref_update.h"
  13 #include "base/strings/string_number_conversions.h"
  14 #include "base/values.h"
  15 #include "chrome/common/chrome_constants.h"
  16 #include "chrome/common/pref_names.h"
  17 #include "components/ui/zoom/zoom_event_manager.h"
  18 #include "content/public/browser/browser_thread.h"
  19 #include "content/public/browser/host_zoom_map.h"
  20 #include "content/public/common/page_zoom.h"
  21
  22 namespace {
  23
  24 std::string GetHash(const base::FilePath& relative_path) {
  25   size_t int_key = BASE_HASH_NAMESPACE::hash<base::FilePath>()(relative_path);
  26   return base::SizeTToString(int_key);
  27 }
  28
  29 }  // namespace
  30
  31 ChromeZoomLevelPrefs::ChromeZoomLevelPrefs(
  32     PrefService* pref_service,
  33     const base::FilePath& profile_path,
  34     const base::FilePath& partition_path,
  35     base::WeakPtr<ui_zoom::ZoomEventManager> zoom_event_manager)
  36     : pref_service_(pref_service),
  37       zoom_event_manager_(zoom_event_manager),
  38       host_zoom_map_(nullptr) {
  39   DCHECK(pref_service_);
  40
  41   DCHECK(!partition_path.empty());
  42   DCHECK((partition_path == profile_path) ||
  43          profile_path.IsParent(partition_path));
  44   // Create a partition_key string with no '.'s in it. For the default
  45   // StoragePartition, this string will always be "0".
  46   base::FilePath partition_relative_path;
  47   profile_path.AppendRelativePath(partition_path, &partition_relative_path);
  48   partition_key_ = GetHash(partition_relative_path);
  49
  50 }
  51
  52 ChromeZoomLevelPrefs::~ChromeZoomLevelPrefs() {
  53 }
  54
  55 std::string ChromeZoomLevelPrefs::GetHashForTesting(
  56     const base::FilePath& relative_path) {
  57   return GetHash(relative_path);
  58 }
  59
  60 void ChromeZoomLevelPrefs::SetDefaultZoomLevelPref(double level) {
  61   if (content::ZoomValuesEqual(level, host_zoom_map_->GetDefaultZoomLevel()))
  62     return;
  63
  64   DictionaryPrefUpdate update(pref_service_, prefs::kPartitionDefaultZoomLevel);
  65   update->SetDouble(partition_key_, level);
  66   // For unregistered paths, OnDefaultZoomLevelChanged won't be called, so
  67   // set this manually.
  68   host_zoom_map_->SetDefaultZoomLevel(level);
  69   default_zoom_changed_callbacks_.Notify();
  70   if (zoom_event_manager_)
  71     zoom_event_manager_->OnDefaultZoomLevelChanged();
  72 }
  73
  74 double ChromeZoomLevelPrefs::GetDefaultZoomLevelPref() const {
  75   double default_zoom_level = 0.0;
  76
  77   const base::DictionaryValue* default_zoom_level_dictionary =
  78       pref_service_->GetDictionary(prefs::kPartitionDefaultZoomLevel);
  79   // If no default has been previously set, the default returned is the
  80   // value used to initialize default_zoom_level in this function.
  81   default_zoom_level_dictionary->GetDouble(partition_key_, &default_zoom_level);
  82   return default_zoom_level;
  83 }
  84
  85 scoped_ptr<ChromeZoomLevelPrefs::DefaultZoomLevelSubscription>
  86 ChromeZoomLevelPrefs::RegisterDefaultZoomLevelCallback(
  87     const base::Closure& callback) {
  88   return default_zoom_changed_callbacks_.Add(callback);
  89 }
  90
  91 void ChromeZoomLevelPrefs::OnZoomLevelChanged(
  92     const content::HostZoomMap::ZoomLevelChange& change) {
  93   // If there's a manager to aggregate ZoomLevelChanged events, pass this event
  94   // along. Since we already hold a subscription to our associated HostZoomMap,
  95   // we don't need to create a separate subscription for this.
  96   if (zoom_event_manager_)
  97     zoom_event_manager_->OnZoomLevelChanged(change);
  98
  99   if (change.mode != content::HostZoomMap::ZOOM_CHANGED_FOR_HOST)
 100     return;
 101   double level = change.zoom_level;
 102   DictionaryPrefUpdate update(pref_service_,
 103                               prefs::kPartitionPerHostZoomLevels);
 104   base::DictionaryValue* host_zoom_dictionaries = update.Get();
 105   DCHECK(host_zoom_dictionaries);
 106
 107   bool modification_is_removal =
 108       content::ZoomValuesEqual(level, host_zoom_map_->GetDefaultZoomLevel());
 109
 110   base::DictionaryValue* host_zoom_dictionary = nullptr;
 111   if (!host_zoom_dictionaries->GetDictionary(partition_key_,
 112                                              &host_zoom_dictionary)) {
 113     host_zoom_dictionary = new base::DictionaryValue();
 114     host_zoom_dictionaries->Set(partition_key_, host_zoom_dictionary);
 115   }
 116
 117   if (modification_is_removal)
 118     host_zoom_dictionary->RemoveWithoutPathExpansion(change.host, nullptr);
 119   else
 120     host_zoom_dictionary->SetDoubleWithoutPathExpansion(change.host, level);
 121 }
 122
 123 // TODO(wjmaclean): Remove the dictionary_path once the migration code is
 124 // removed. crbug.com/420643
 125 void ChromeZoomLevelPrefs::ExtractPerHostZoomLevels(
 126     const base::DictionaryValue* host_zoom_dictionary,
 127     bool sanitize_partition_host_zoom_levels) {
 128   std::vector<std::string> keys_to_remove;
 129   scoped_ptr<base::DictionaryValue> host_zoom_dictionary_copy =
 130       host_zoom_dictionary->DeepCopyWithoutEmptyChildren();
 131   for (base::DictionaryValue::Iterator i(*host_zoom_dictionary_copy);
 132        !i.IsAtEnd();
 133        i.Advance()) {
 134     const std::string& host(i.key());
 135     double zoom_level = 0;
 136
 137     bool has_valid_zoom_level = i.value().GetAsDouble(&zoom_level);
 138
 139     // Filter out A) the empty host, B) zoom levels equal to the default; and
 140     // remember them, so that we can later erase them from Prefs.
 141     // Values of type A and B could have been stored due to crbug.com/364399.
 142     // Values of type B could further have been stored before the default zoom
 143     // level was set to its current value. In either case, SetZoomLevelForHost
 144     // will ignore type B values, thus, to have consistency with HostZoomMap's
 145     // internal state, these values must also be removed from Prefs.
 146     if (host.empty() || !has_valid_zoom_level ||
 147         content::ZoomValuesEqual(zoom_level,
 148                                  host_zoom_map_->GetDefaultZoomLevel())) {
 149       keys_to_remove.push_back(host);
 150       continue;
 151     }
 152
 153     host_zoom_map_->SetZoomLevelForHost(host, zoom_level);
 154   }
 155
 156   // We don't bother sanitizing non-partition dictionaries as they will be
 157   // discarded in the migration process. Note: since the structure of partition
 158   // per-host zoom level dictionaries is different from the legacy profile
 159   // per-host zoom level dictionaries, the following code will fail if run
 160   // on the legacy dictionaries.
 161   if (!sanitize_partition_host_zoom_levels)
 162     return;
 163
 164   // Sanitize prefs to remove entries that match the default zoom level and/or
 165   // have an empty host.
 166   {
 167     DictionaryPrefUpdate update(pref_service_,
 168                                 prefs::kPartitionPerHostZoomLevels);
 169     base::DictionaryValue* host_zoom_dictionaries = update.Get();
 170     base::DictionaryValue* host_zoom_dictionary = nullptr;
 171     host_zoom_dictionaries->GetDictionary(partition_key_,
 172                                           &host_zoom_dictionary);
 173     for (const std::string& s : keys_to_remove)
 174       host_zoom_dictionary->RemoveWithoutPathExpansion(s, nullptr);
 175   }
 176 }
 177
 178 void ChromeZoomLevelPrefs::InitHostZoomMap(
 179     content::HostZoomMap* host_zoom_map) {
 180   // This init function must be called only once.
 181   DCHECK(!host_zoom_map_);
 182   DCHECK(host_zoom_map);
 183   host_zoom_map_ = host_zoom_map;
 184
 185   // Initialize the default zoom level.
 186   host_zoom_map_->SetDefaultZoomLevel(GetDefaultZoomLevelPref());
 187
 188   // Initialize the HostZoomMap with per-host zoom levels from the persisted
 189   // zoom-level preference values.
 190   const base::DictionaryValue* host_zoom_dictionaries =
 191       pref_service_->GetDictionary(prefs::kPartitionPerHostZoomLevels);
 192   const base::DictionaryValue* host_zoom_dictionary = nullptr;
 193   if (host_zoom_dictionaries->GetDictionary(partition_key_,
 194                                             &host_zoom_dictionary)) {
 195     // Since we're calling this before setting up zoom_subscription_ below we
 196     // don't need to worry that host_zoom_dictionary is indirectly affected
 197     // by calls to HostZoomMap::SetZoomLevelForHost().
 198     ExtractPerHostZoomLevels(host_zoom_dictionary,
 199                              true /* sanitize_partition_host_zoom_levels */);
 200   }
 201   zoom_subscription_ = host_zoom_map_->AddZoomLevelChangedCallback(base::Bind(
 202       &ChromeZoomLevelPrefs::OnZoomLevelChanged, base::Unretained(this)));
 203 }