chrome/browser/ui/zoom/chrome_zoom_level_prefs.h

   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_UI_ZOOM_CHROME_ZOOM_LEVEL_PREFS_H_
   6 #define CHROME_BROWSER_UI_ZOOM_CHROME_ZOOM_LEVEL_PREFS_H_
   7
   8 #include "base/callback.h"
   9 #include "base/files/file_path.h"
  10 #include "base/macros.h"
  11 #include "base/memory/ref_counted.h"
  12 #include "base/memory/weak_ptr.h"
  13 #include "base/observer_list.h"
  14 #include "base/prefs/json_pref_store.h"
  15 #include "base/prefs/pref_change_registrar.h"
  16 #include "base/prefs/pref_service.h"
  17 #include "base/prefs/pref_store.h"
  18 #include "content/public/browser/host_zoom_map.h"
  19 #include "content/public/browser/zoom_level_delegate.h"
  20
  21 namespace base {
  22 class DictionaryValue;
  23 }
  24
  25 namespace ui_zoom {
  26 class ZoomEventManager;
  27 }
  28
  29 // A class to manage per-partition default and per-host zoom levels in Chrome's
  30 // preference system. It implements an interface between the content/ zoom
  31 // levels in HostZoomMap and Chrome's preference system. All changes
  32 // to the per-partition default zoom levels from chrome/ flow through this
  33 // class. Any changes to per-host levels are updated when HostZoomMap calls
  34 // OnZoomLevelChanged.
  35 class ChromeZoomLevelPrefs : public content::ZoomLevelDelegate {
  36  public:
  37   typedef base::CallbackList<void(void)>::Subscription
  38       DefaultZoomLevelSubscription;
  39
  40   // Initialize the pref_service and the partition_key via the constructor,
  41   // as these concepts won't be available in the content base class
  42   // ZoomLevelDelegate, which will define the InitHostZoomMap interface.
  43   // |pref_service_| must outlive this class.
  44   ChromeZoomLevelPrefs(
  45       PrefService* pref_service,
  46       const base::FilePath& profile_path,
  47       const base::FilePath& partition_path,
  48       base::WeakPtr<ui_zoom::ZoomEventManager> zoom_event_manager);
  49   ~ChromeZoomLevelPrefs() override;
  50
  51   static std::string GetHashForTesting(const base::FilePath& relative_path);
  52
  53   void SetDefaultZoomLevelPref(double level);
  54   double GetDefaultZoomLevelPref() const;
  55   scoped_ptr<DefaultZoomLevelSubscription> RegisterDefaultZoomLevelCallback(
  56       const base::Closure& callback);
  57
  58   void ExtractPerHostZoomLevels(
  59       const base::DictionaryValue* host_zoom_dictionary,
  60       bool sanitize_partition_host_zoom_levels);
  61
  62   // content::ZoomLevelDelegate
  63   void InitHostZoomMap(content::HostZoomMap* host_zoom_map) override;
  64
  65  private:
  66   // This is a callback function that receives notifications from HostZoomMap
  67   // when per-host zoom levels change. It is used to update the per-host
  68   // zoom levels (if any) managed by this class (for its associated partition).
  69   void OnZoomLevelChanged(const content::HostZoomMap::ZoomLevelChange& change);
  70
  71   PrefService* pref_service_;
  72   base::WeakPtr<ui_zoom::ZoomEventManager> zoom_event_manager_;
  73   content::HostZoomMap* host_zoom_map_;
  74   scoped_ptr<content::HostZoomMap::Subscription> zoom_subscription_;
  75   std::string partition_key_;
  76   base::CallbackList<void(void)> default_zoom_changed_callbacks_;
  77
  78   DISALLOW_COPY_AND_ASSIGN(ChromeZoomLevelPrefs);
  79 };
  80
  81 #endif  // CHROME_BROWSER_UI_ZOOM_CHROME_ZOOM_LEVEL_PREFS_H_