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 #include "url/gurl.h"
  17
  18 namespace content {
  19
  20 class NavigationEntry;
  21 class BrowserContext;
  22 class ResourceContext;
  23 class SiteInstance;
  24 class WebContents;
  25
  26 // Maps hostnames to custom zoom levels.  Written on the UI thread and read on
  27 // any thread.  One instance per browser context. Must be created on the UI
  28 // thread, and it'll delete itself on the UI thread as well.
  29 // Zoom can be defined at three levels: default zoom, zoom for host, and zoom
  30 // for host with specific scheme. Setting any of the levels leaves settings
  31 // for other settings intact. Getting the zoom level starts at the most
  32 // specific setting and progresses to the less specific: first the zoom for the
  33 // host and scheme pair is checked, secondly the zoom for the host only and
  34 // lastly default zoom.
  35
  36 class HostZoomMap {
  37  public:
  38   // Enum that indicates what was the scope of zoom level change.
  39   enum ZoomLevelChangeMode {
  40     ZOOM_CHANGED_FOR_HOST,            // Zoom level changed for host.
  41     ZOOM_CHANGED_FOR_SCHEME_AND_HOST, // Zoom level changed for scheme/host
  42                                       // pair.
  43     ZOOM_CHANGED_TEMPORARY_ZOOM,      // Temporary zoom change for specific
  44                                       // renderer, no scheme/host is specified.
  45   };
  46
  47   // Structure used to notify about zoom changes. Host and/or scheme are empty
  48   // if not applicable to |mode|.
  49   struct ZoomLevelChange {
  50     ZoomLevelChangeMode mode;
  51     std::string host;
  52     std::string scheme;
  53     double zoom_level;
  54   };
  55
  56   typedef std::vector<ZoomLevelChange> ZoomLevelVector;
  57
  58   // Extracts the URL from NavigationEntry, substituting the error page
  59   // URL in the event that the error page is showing.
  60   CONTENT_EXPORT static GURL GetURLFromEntry(const NavigationEntry* entry);
  61
  62   CONTENT_EXPORT static HostZoomMap* GetDefaultForBrowserContext(
  63       BrowserContext* browser_context);
  64
  65   // Returns the HostZoomMap associated with this SiteInstance. The SiteInstance
  66   // may serve multiple WebContents, and the HostZoomMap is the same for all of
  67   // these WebContents.
  68   CONTENT_EXPORT static HostZoomMap* Get(SiteInstance* instance);
  69
  70   // Returns the HostZoomMap associated with this WebContent's main frame. If
  71   // multiple WebContents share the same SiteInstance, then they share a single
  72   // HostZoomMap.
  73   CONTENT_EXPORT static HostZoomMap* GetForWebContents(
  74       const WebContents* contents);
  75
  76   // Returns the current zoom level for the specified WebContents. May be
  77   // temporary or host-specific.
  78   CONTENT_EXPORT static double GetZoomLevel(const WebContents* web_contents);
  79
  80   // Sets the current zoom level for the specified WebContents. The level may
  81   // be temporary or host-specific depending on the particular WebContents.
  82   CONTENT_EXPORT static void SetZoomLevel(const WebContents* web_contents,
  83                                           double level);
  84
  85   // Send an IPC to refresh any displayed error page's zoom levels. Needs to
  86   // be called since error pages don't get loaded via the normal channel.
  87   CONTENT_EXPORT static void SendErrorPageZoomLevelRefresh(
  88       const WebContents* web_contents);
  89
  90   // Copy the zoom levels from the given map. Can only be called on the UI
  91   // thread.
  92   virtual void CopyFrom(HostZoomMap* copy) = 0;
  93
  94   // Here |host| is the host portion of URL, or (in the absence of a host)
  95   // the complete spec of the URL.
  96   // Returns the zoom for the specified |scheme| and |host|. See class
  97   // description for details.
  98   //
  99   // This may be called on any thread.
 100   virtual double GetZoomLevelForHostAndScheme(
 101       const std::string& scheme,
 102       const std::string& host) const = 0;
 103
 104   // Returns true if the specified |scheme| and/or |host| has a zoom level
 105   // currently set.
 106   //
 107   // This may be called on any thread.
 108   virtual bool HasZoomLevel(const std::string& scheme,
 109                             const std::string& host) const = 0;
 110
 111   // Returns all non-temporary zoom levels. Can be called on any thread.
 112   virtual ZoomLevelVector GetAllZoomLevels() const = 0;
 113
 114   // Here |host| is the host portion of URL, or (in the absence of a host)
 115   // the complete spec of the URL.
 116   // Sets the zoom level for the |host| to |level|.  If the level matches the
 117   // current default zoom level, the host is erased from the saved preferences;
 118   // otherwise the new value is written out.
 119   // Zoom levels specified for both scheme and host are not affected.
 120   //
 121   // This should only be called on the UI thread.
 122   virtual void SetZoomLevelForHost(const std::string& host, double level) = 0;
 123
 124   // Here |host| is the host portion of URL, or (in the absence of a host)
 125   // the complete spec of the URL.
 126   // Sets the zoom level for the |scheme|/|host| pair to |level|. No values
 127   // will be erased during this operation, and this value will not be stored in
 128   // the preferences.
 129   //
 130   // This should only be called on the UI thread.
 131   virtual void SetZoomLevelForHostAndScheme(const std::string& scheme,
 132                                             const std::string& host,
 133                                             double level) = 0;
 134
 135   // Returns whether the view manages its zoom level independently of other
 136   // views displaying content from the same host.
 137   virtual bool UsesTemporaryZoomLevel(int render_process_id,
 138                                       int render_view_id) const = 0;
 139
 140   // Sets the temporary zoom level that's only valid for the lifetime of this
 141   // WebContents.
 142   //
 143   // This should only be called on the UI thread.
 144   virtual void SetTemporaryZoomLevel(int render_process_id,
 145                                      int render_view_id,
 146                                      double level) = 0;
 147
 148   // Clears the temporary zoom level stored for this WebContents.
 149   //
 150   // This should only be called on the UI thread.
 151   virtual void ClearTemporaryZoomLevel(int render_process_id,
 152                                        int render_view_id) = 0;
 153
 154   // Get/Set the default zoom level for pages that don't override it.
 155   virtual double GetDefaultZoomLevel() const = 0;
 156   virtual void SetDefaultZoomLevel(double level) = 0;;
 157
 158   typedef base::Callback<void(const ZoomLevelChange&)> ZoomLevelChangedCallback;
 159   typedef base::CallbackList<void(const ZoomLevelChange&)>::Subscription
 160       Subscription;
 161   // Add and remove zoom level changed callbacks.
 162   virtual scoped_ptr<Subscription> AddZoomLevelChangedCallback(
 163       const ZoomLevelChangedCallback& callback) = 0;
 164
 165  protected:
 166   virtual ~HostZoomMap() {}
 167 };
 168
 169 }  // namespace content
 170
 171 #endif  // CONTENT_PUBLIC_BROWSER_HOST_ZOOM_MAP_H_