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 class WebContentsImpl;
  23
  24 // HostZoomMap needs to be deleted on the UI thread because it listens
  25 // to notifications on there (and holds a NotificationRegistrar).
  26 class CONTENT_EXPORT HostZoomMapImpl : public NON_EXPORTED_BASE(HostZoomMap),
  27                                        public NotificationObserver,
  28                                        public base::SupportsUserData::Data {
  29  public:
  30   HostZoomMapImpl();
  31   virtual ~HostZoomMapImpl();
  32
  33   // HostZoomMap implementation:
  34   virtual void CopyFrom(HostZoomMap* copy) OVERRIDE;
  35   virtual double GetZoomLevelForHostAndScheme(
  36       const std::string& scheme,
  37       const std::string& host) const OVERRIDE;
  38   // TODO(wjmaclean) Should we use a GURL here? crbug.com/384486
  39   virtual bool HasZoomLevel(const std::string& scheme,
  40                             const std::string& host) const OVERRIDE;
  41   virtual ZoomLevelVector GetAllZoomLevels() const OVERRIDE;
  42   virtual void SetZoomLevelForHost(
  43       const std::string& host,
  44       double level) OVERRIDE;
  45   virtual void SetZoomLevelForHostAndScheme(
  46       const std::string& scheme,
  47       const std::string& host,
  48       double level) OVERRIDE;
  49   virtual bool UsesTemporaryZoomLevel(int render_process_id,
  50                                       int render_view_id) const OVERRIDE;
  51   virtual void SetTemporaryZoomLevel(int render_process_id,
  52                                      int render_view_id,
  53                                      double level) OVERRIDE;
  54
  55   virtual void ClearTemporaryZoomLevel(int render_process_id,
  56                                        int render_view_id) OVERRIDE;
  57   virtual double GetDefaultZoomLevel() const OVERRIDE;
  58   virtual void SetDefaultZoomLevel(double level) OVERRIDE;
  59   virtual scoped_ptr<Subscription> AddZoomLevelChangedCallback(
  60       const ZoomLevelChangedCallback& callback) OVERRIDE;
  61
  62   // Returns the current zoom level for the specified WebContents. This may
  63   // be a temporary zoom level, depending on UsesTemporaryZoomLevel().
  64   double GetZoomLevelForWebContents(
  65       const WebContentsImpl& web_contents_impl) const;
  66
  67   // Sets the zoom level for this WebContents. If this WebContents is using
  68   // a temporary zoom level, then level is only applied to this WebContents.
  69   // Otherwise, the level will be applied on a host level.
  70   void SetZoomLevelForWebContents(const WebContentsImpl& web_contents_impl,
  71                                   double level);
  72
  73   // Sets the zoom level for the specified view. The level may be set for only
  74   // this view, or for the host, depending on UsesTemporaryZoomLevel().
  75   void SetZoomLevelForView(int render_process_id,
  76                            int render_view_id,
  77                            double level,
  78                            const std::string& host);
  79
  80   // Returns the temporary zoom level that's only valid for the lifetime of
  81   // the given WebContents (i.e. isn't saved and doesn't affect other
  82   // WebContentses) if it exists, the default zoom level otherwise.
  83   //
  84   // This may be called on any thread.
  85   double GetTemporaryZoomLevel(int render_process_id,
  86                                int render_view_id) const;
  87
  88   // NotificationObserver implementation.
  89   virtual void Observe(int type,
  90                        const NotificationSource& source,
  91                        const NotificationDetails& details) OVERRIDE;
  92
  93  private:
  94   typedef std::map<std::string, double> HostZoomLevels;
  95   typedef std::map<std::string, HostZoomLevels> SchemeHostZoomLevels;
  96
  97   struct RenderViewKey {
  98     int render_process_id;
  99     int render_view_id;
 100     RenderViewKey(int render_process_id, int render_view_id)
 101         : render_process_id(render_process_id),
 102           render_view_id(render_view_id) {}
 103     bool operator<(const RenderViewKey& other) const {
 104       return render_process_id < other.render_process_id ||
 105              ((render_process_id == other.render_process_id) &&
 106               (render_view_id < other.render_view_id));
 107     }
 108   };
 109
 110   typedef std::map<RenderViewKey, double> TemporaryZoomLevels;
 111
 112   double GetZoomLevelForHost(const std::string& host) const;
 113
 114   // Notifies the renderers from this browser context to change the zoom level
 115   // for the specified host and scheme.
 116   // TODO(wjmaclean) Should we use a GURL here? crbug.com/384486
 117   void SendZoomLevelChange(const std::string& scheme,
 118                            const std::string& host,
 119                            double level);
 120
 121   // Callbacks called when zoom level changes.
 122   base::CallbackList<void(const ZoomLevelChange&)>
 123       zoom_level_changed_callbacks_;
 124
 125   // Copy of the pref data, so that we can read it on the IO thread.
 126   HostZoomLevels host_zoom_levels_;
 127   SchemeHostZoomLevels scheme_host_zoom_levels_;
 128   double default_zoom_level_;
 129
 130   // Don't expect more than a couple of tabs that are using a temporary zoom
 131   // level, so vector is fine for now.
 132   TemporaryZoomLevels temporary_zoom_levels_;
 133
 134   // Used around accesses to |host_zoom_levels_|, |default_zoom_level_| and
 135   // |temporary_zoom_levels_| to guarantee thread safety.
 136   mutable base::Lock lock_;
 137
 138   NotificationRegistrar registrar_;
 139
 140   DISALLOW_COPY_AND_ASSIGN(HostZoomMapImpl);
 141 };
 142
 143 }  // namespace content
 144
 145 #endif  // CONTENT_BROWSER_HOST_ZOOM_MAP_IMPL_H_