content/public/browser/host_zoom_map.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_PUBLIC_BROWSER_HOST_ZOOM_MAP_H_
   6 #define CONTENT_PUBLIC_BROWSER_HOST_ZOOM_MAP_H_
   7
   8 #include <map>
   9 #include <string>
  10 #include <vector>
  11
  12 #include "base/basictypes.h"
  13 #include "base/callback.h"
  14 #include "base/callback_list.h"
  15 #include "content/common/content_export.h"
  16
  17 namespace content {
  18
  19 class BrowserContext;
  20 class ResourceContext;
  21 class WebContents;
  22
  23 // Maps hostnames to custom zoom levels.  Written on the UI thread and read on
  24 // any thread.  One instance per browser context. Must be created on the UI
  25 // thread, and it'll delete itself on the UI thread as well.
  26 // Zoom can be defined at three levels: default zoom, zoom for host, and zoom
  27 // for host with specific scheme. Setting any of the levels leaves settings
  28 // for other settings intact. Getting the zoom level starts at the most
  29 // specific setting and progresses to the less specific: first the zoom for the
  30 // host and scheme pair is checked, secondly the zoom for the host only and
  31 // lastly default zoom.
  32
  33 class HostZoomMap {
  34  public:
  35   // Enum that indicates what was the scope of zoom level change.
  36   enum ZoomLevelChangeMode {
  37     ZOOM_CHANGED_FOR_HOST,            // Zoom level changed for host.
  38     ZOOM_CHANGED_FOR_SCHEME_AND_HOST, // Zoom level changed for scheme/host
  39                                       // pair.
  40     ZOOM_CHANGED_TEMPORARY_ZOOM,      // Temporary zoom change for specific
  41                                       // renderer, no scheme/host is specified.
  42   };
  43
  44   // Structure used to notify about zoom changes. Host and/or scheme are empty
  45   // if not applicable to |mode|.
  46   struct ZoomLevelChange {
  47     ZoomLevelChangeMode mode;
  48     std::string host;
  49     std::string scheme;
  50     double zoom_level;
  51   };
  52
  53   typedef std::vector<ZoomLevelChange> ZoomLevelVector;
  54
  55   CONTENT_EXPORT static HostZoomMap* GetDefaultForBrowserContext(
  56       BrowserContext* browser_context);
  57
  58   // Returns the current zoom level for the specified WebContents. May be
  59   // temporary or host-specific.
  60   CONTENT_EXPORT static double GetZoomLevel(const WebContents* web_contents);
  61
  62   // Sets the current zoom level for the specified WebContents. The level may
  63   // be temporary or host-specific depending on the particular WebContents.
  64   CONTENT_EXPORT static void SetZoomLevel(const WebContents* web_contents,
  65                                           double level);
  66
  67   // Copy the zoom levels from the given map. Can only be called on the UI
  68   // thread.
  69   virtual void CopyFrom(HostZoomMap* copy) = 0;
  70
  71   // Here |host| is the host portion of URL, or (in the absence of a host)
  72   // the complete spec of the URL.
  73   // Returns the zoom for the specified |scheme| and |host|. See class
  74   // description for details.
  75   //
  76   // This may be called on any thread.
  77   virtual double GetZoomLevelForHostAndScheme(
  78       const std::string& scheme,
  79       const std::string& host) const = 0;
  80
  81   // Returns true if the specified |scheme| and/or |host| has a zoom level
  82   // currently set.
  83   //
  84   // This may be called on any thread.
  85   virtual bool HasZoomLevel(const std::string& scheme,
  86                             const std::string& host) const = 0;
  87
  88   // Returns all non-temporary zoom levels. Can be called on any thread.
  89   virtual ZoomLevelVector GetAllZoomLevels() const = 0;
  90
  91   // Here |host| is the host portion of URL, or (in the absence of a host)
  92   // the complete spec of the URL.
  93   // Sets the zoom level for the |host| to |level|.  If the level matches the
  94   // current default zoom level, the host is erased from the saved preferences;
  95   // otherwise the new value is written out.
  96   // Zoom levels specified for both scheme and host are not affected.
  97   //
  98   // This should only be called on the UI thread.
  99   virtual void SetZoomLevelForHost(const std::string& host, double level) = 0;
 100
 101   // Here |host| is the host portion of URL, or (in the absence of a host)
 102   // the complete spec of the URL.
 103   // Sets the zoom level for the |scheme|/|host| pair to |level|. No values
 104   // will be erased during this operation, and this value will not be stored in
 105   // the preferences.
 106   //
 107   // This should only be called on the UI thread.
 108   virtual void SetZoomLevelForHostAndScheme(const std::string& scheme,
 109                                             const std::string& host,
 110                                             double level) = 0;
 111
 112   // Returns whether the view manages its zoom level independently of other
 113   // views displaying content from the same host.
 114   virtual bool UsesTemporaryZoomLevel(int render_process_id,
 115                                       int render_view_id) const = 0;
 116
 117   // Sets the temporary zoom level that's only valid for the lifetime of this
 118   // WebContents.
 119   //
 120   // This should only be called on the UI thread.
 121   virtual void SetTemporaryZoomLevel(int render_process_id,
 122                                      int render_view_id,
 123                                      double level) = 0;
 124
 125   // Clears the temporary zoom level stored for this WebContents.
 126   //
 127   // This should only be called on the UI thread.
 128   virtual void ClearTemporaryZoomLevel(int render_process_id,
 129                                        int render_view_id) = 0;
 130
 131   // Get/Set the default zoom level for pages that don't override it.
 132   virtual double GetDefaultZoomLevel() const = 0;
 133   virtual void SetDefaultZoomLevel(double level) = 0;;
 134
 135   typedef base::Callback<void(const ZoomLevelChange&)> ZoomLevelChangedCallback;
 136   typedef base::CallbackList<void(const ZoomLevelChange&)>::Subscription
 137       Subscription;
 138   // Add and remove zoom level changed callbacks.
 139   virtual scoped_ptr<Subscription> AddZoomLevelChangedCallback(
 140       const ZoomLevelChangedCallback& callback) = 0;
 141
 142  protected:
 143   virtual ~HostZoomMap() {}
 144 };
 145
 146 }  // namespace content
 147
 148 #endif  // CONTENT_PUBLIC_BROWSER_HOST_ZOOM_MAP_H_