content/browser/host_zoom_map_impl.h

   1 // Copyright (c) 2012 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 CONTENT_BROWSER_HOST_ZOOM_MAP_IMPL_H_
   6 #define CONTENT_BROWSER_HOST_ZOOM_MAP_IMPL_H_
   7
   8 #include <map>
   9 #include <string>
  10 #include <vector>
  11
  12 #include "base/compiler_specific.h"
  13 #include "base/sequenced_task_runner_helpers.h"
  14 #include "base/supports_user_data.h"
  15 #include "base/synchronization/lock.h"
  16 #include "content/public/browser/host_zoom_map.h"
  17 #include "content/public/browser/notification_observer.h"
  18 #include "content/public/browser/notification_registrar.h"
  19
  20 namespace content {
  21
  22 // HostZoomMap needs to be deleted on the UI thread because it listens
  23 // to notifications on there (and holds a NotificationRegistrar).
  24 class CONTENT_EXPORT HostZoomMapImpl : public NON_EXPORTED_BASE(HostZoomMap),
  25                                        public NotificationObserver,
  26                                        public base::SupportsUserData::Data {
  27  public:
  28   HostZoomMapImpl();
  29   virtual ~HostZoomMapImpl();
  30
  31   // HostZoomMap implementation:
  32   virtual void CopyFrom(HostZoomMap* copy) OVERRIDE;
  33   virtual double GetZoomLevelForHostAndScheme(
  34       const std::string& scheme,
  35       const std::string& host) const OVERRIDE;
  36   virtual void SetZoomLevelForHost(
  37       const std::string& host,
  38       double level) OVERRIDE;
  39   virtual void SetZoomLevelForHostAndScheme(
  40       const std::string& scheme,
  41       const std::string& host,
  42       double level) OVERRIDE;
  43   virtual double GetDefaultZoomLevel() const OVERRIDE;
  44   virtual void SetDefaultZoomLevel(double level) OVERRIDE;
  45   virtual scoped_ptr<Subscription> AddZoomLevelChangedCallback(
  46       const ZoomLevelChangedCallback& callback) OVERRIDE;
  47
  48   // Returns the temporary zoom level that's only valid for the lifetime of
  49   // the given WebContents (i.e. isn't saved and doesn't affect other
  50   // WebContentses) if it exists, the default zoom level otherwise.
  51   //
  52   // This may be called on any thread.
  53   double GetTemporaryZoomLevel(int render_process_id,
  54                                int render_view_id) const;
  55
  56   // Sets the temporary zoom level that's only valid for the lifetime of this
  57   // WebContents.
  58   //
  59   // This should only be called on the UI thread.
  60   void SetTemporaryZoomLevel(int render_process_id,
  61                              int render_view_id,
  62                              double level);
  63
  64   // NotificationObserver implementation.
  65   virtual void Observe(int type,
  66                        const NotificationSource& source,
  67                        const NotificationDetails& details) OVERRIDE;
  68
  69  private:
  70   double GetZoomLevelForHost(const std::string& host) const;
  71
  72   typedef std::map<std::string, double> HostZoomLevels;
  73   typedef std::map<std::string, HostZoomLevels> SchemeHostZoomLevels;
  74
  75   // Callbacks called when zoom level changes.
  76   base::CallbackList<void(const ZoomLevelChange&)>
  77       zoom_level_changed_callbacks_;
  78
  79   // Copy of the pref data, so that we can read it on the IO thread.
  80   HostZoomLevels host_zoom_levels_;
  81   SchemeHostZoomLevels scheme_host_zoom_levels_;
  82   double default_zoom_level_;
  83
  84   struct TemporaryZoomLevel {
  85     int render_process_id;
  86     int render_view_id;
  87     double zoom_level;
  88   };
  89
  90   // Don't expect more than a couple of tabs that are using a temporary zoom
  91   // level, so vector is fine for now.
  92   std::vector<TemporaryZoomLevel> temporary_zoom_levels_;
  93
  94   // Used around accesses to |host_zoom_levels_|, |default_zoom_level_| and
  95   // |temporary_zoom_levels_| to guarantee thread safety.
  96   mutable base::Lock lock_;
  97
  98   NotificationRegistrar registrar_;
  99
 100   DISALLOW_COPY_AND_ASSIGN(HostZoomMapImpl);
 101 };
 102
 103 }  // namespace content
 104
 105 #endif  // CONTENT_BROWSER_HOST_ZOOM_MAP_IMPL_H_