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     PAGE_SCALE_IS_ONE_CHANGED,         // Page scale factor equal to one changed
  46                                        // for a host.
  47   };
  48
  49   // Structure used to notify about zoom changes. Host and/or scheme are empty
  50   // if not applicable to |mode|.
  51   struct ZoomLevelChange {
  52     ZoomLevelChangeMode mode;
  53     std::string host;
  54     std::string scheme;
  55     double zoom_level;
  56   };
  57
  58   typedef std::vector<ZoomLevelChange> ZoomLevelVector;
  59
  60   // Extracts the URL from NavigationEntry, substituting the error page
  61   // URL in the event that the error page is showing.
  62   CONTENT_EXPORT static GURL GetURLFromEntry(const NavigationEntry* entry);
  63
  64   CONTENT_EXPORT static HostZoomMap* GetDefaultForBrowserContext(
  65       BrowserContext* browser_context);
  66
  67   // Returns the HostZoomMap associated with this SiteInstance. The SiteInstance
  68   // may serve multiple WebContents, and the HostZoomMap is the same for all of
  69   // these WebContents.
  70   CONTENT_EXPORT static HostZoomMap* Get(SiteInstance* instance);
  71
  72   // Returns the HostZoomMap associated with this WebContent's main frame. If
  73   // multiple WebContents share the same SiteInstance, then they share a single
  74   // HostZoomMap.
  75   CONTENT_EXPORT static HostZoomMap* GetForWebContents(
  76       const WebContents* contents);
  77
  78   // Returns the current zoom level for the specified WebContents. May be
  79   // temporary or host-specific.
  80   CONTENT_EXPORT static double GetZoomLevel(const WebContents* web_contents);
  81
  82   // Returns true if the page scale factor for the WebContents is one.
  83   CONTENT_EXPORT static bool PageScaleFactorIsOne(
  84       const WebContents* web_contents);
  85
  86   // Sets the current zoom level for the specified WebContents. The level may
  87   // be temporary or host-specific depending on the particular WebContents.
  88   CONTENT_EXPORT static void SetZoomLevel(const WebContents* web_contents,
  89                                           double level);
  90
  91   // Send an IPC to refresh any displayed error page's zoom levels. Needs to
  92   // be called since error pages don't get loaded via the normal channel.
  93   CONTENT_EXPORT static void SendErrorPageZoomLevelRefresh(
  94       const WebContents* web_contents);
  95
  96   // Set or clear whether or not the page scale factor for a view is one.
  97   virtual void SetPageScaleFactorIsOneForView(
  98       int render_process_id, int render_view_id, bool is_one) = 0;
  99   virtual void ClearPageScaleFactorIsOneForView(
 100       int render_process_id, int render_view_id) = 0;
 101
 102   // Copy the zoom levels from the given map. Can only be called on the UI
 103   // thread.
 104   virtual void CopyFrom(HostZoomMap* copy) = 0;
 105
 106   // Here |host| is the host portion of URL, or (in the absence of a host)
 107   // the complete spec of the URL.
 108   // Returns the zoom for the specified |scheme| and |host|. See class
 109   // description for details.
 110   //
 111   // This may be called on any thread.
 112   virtual double GetZoomLevelForHostAndScheme(
 113       const std::string& scheme,
 114       const std::string& host) const = 0;
 115
 116   // Returns true if the specified |scheme| and/or |host| has a zoom level
 117   // currently set.
 118   //
 119   // This may be called on any thread.
 120   virtual bool HasZoomLevel(const std::string& scheme,
 121                             const std::string& host) const = 0;
 122
 123   // Returns all non-temporary zoom levels. Can be called on any thread.
 124   virtual ZoomLevelVector GetAllZoomLevels() const = 0;
 125
 126   // Here |host| is the host portion of URL, or (in the absence of a host)
 127   // the complete spec of the URL.
 128   // Sets the zoom level for the |host| to |level|.  If the level matches the
 129   // current default zoom level, the host is erased from the saved preferences;
 130   // otherwise the new value is written out.
 131   // Zoom levels specified for both scheme and host are not affected.
 132   //
 133   // This should only be called on the UI thread.
 134   virtual void SetZoomLevelForHost(const std::string& host, double level) = 0;
 135
 136   // Here |host| is the host portion of URL, or (in the absence of a host)
 137   // the complete spec of the URL.
 138   // Sets the zoom level for the |scheme|/|host| pair to |level|. No values
 139   // will be erased during this operation, and this value will not be stored in
 140   // the preferences.
 141   //
 142   // This should only be called on the UI thread.
 143   virtual void SetZoomLevelForHostAndScheme(const std::string& scheme,
 144                                             const std::string& host,
 145                                             double level) = 0;
 146
 147   // Returns whether the view manages its zoom level independently of other
 148   // views displaying content from the same host.
 149   virtual bool UsesTemporaryZoomLevel(int render_process_id,
 150                                       int render_view_id) const = 0;
 151
 152   // Sets the temporary zoom level that's only valid for the lifetime of this
 153   // WebContents.
 154   //
 155   // This should only be called on the UI thread.
 156   virtual void SetTemporaryZoomLevel(int render_process_id,
 157                                      int render_view_id,
 158                                      double level) = 0;
 159
 160   // Clears the temporary zoom level stored for this WebContents.
 161   //
 162   // This should only be called on the UI thread.
 163   virtual void ClearTemporaryZoomLevel(int render_process_id,
 164                                        int render_view_id) = 0;
 165
 166   // Get/Set the default zoom level for pages that don't override it.
 167   virtual double GetDefaultZoomLevel() const = 0;
 168   virtual void SetDefaultZoomLevel(double level) = 0;;
 169
 170   typedef base::Callback<void(const ZoomLevelChange&)> ZoomLevelChangedCallback;
 171   typedef base::CallbackList<void(const ZoomLevelChange&)>::Subscription
 172       Subscription;
 173   // Add and remove zoom level changed callbacks.
 174   virtual scoped_ptr<Subscription> AddZoomLevelChangedCallback(
 175       const ZoomLevelChangedCallback& callback) = 0;
 176
 177  protected:
 178   virtual ~HostZoomMap() {}
 179 };
 180
 181 }  // namespace content
 182
 183 #endif  // CONTENT_PUBLIC_BROWSER_HOST_ZOOM_MAP_H_