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 CHROME_BROWSER_UI_ZOOM_ZOOM_CONTROLLER_H_ 6 #define CHROME_BROWSER_UI_ZOOM_ZOOM_CONTROLLER_H_ 7 8 #include "base/basictypes.h" 9 #include "base/compiler_specific.h" 10 #include "base/memory/scoped_ptr.h" 11 #include "base/observer_list.h" 12 #include "base/prefs/pref_member.h" 13 #include "content/public/browser/host_zoom_map.h" 14 #include "content/public/browser/web_contents_observer.h" 15 #include "content/public/browser/web_contents_user_data.h" 16 17 class ZoomObserver; 18 19 namespace content { 20 class WebContents; 21 } 22 23 namespace extensions { 24 class Extension; 25 } // namespace extensions 26 27 // Per-tab class to manage zoom changes and the Omnibox zoom icon. 28 class ZoomController : public content::WebContentsObserver, 29 public content::WebContentsUserData<ZoomController> { 30 public: 31 // Defines how zoom changes are handled. 32 enum ZoomMode { 33 // Results in default zoom behavior, i.e. zoom changes are handled 34 // automatically and on a per-origin basis, meaning that other tabs 35 // navigated to the same origin will also zoom. 36 ZOOM_MODE_DEFAULT, 37 // Results in zoom changes being handled automatically, but on a per-tab 38 // basis. Tabs in this zoom mode will not be affected by zoom changes in 39 // other tabs, and vice versa. 40 ZOOM_MODE_ISOLATED, 41 // Overrides the automatic handling of zoom changes. The |onZoomChange| 42 // event will still be dispatched, but the page will not actually be zoomed. 43 // These zoom changes can be handled manually by listening for the 44 // |onZoomChange| event. Zooming in this mode is also on a per-tab basis. 45 ZOOM_MODE_MANUAL, 46 // Disables all zooming in this tab. The tab will revert to default (100%) 47 // zoom, and all attempted zoom changes will be ignored. 48 ZOOM_MODE_DISABLED, 49 }; 50 51 struct ZoomChangedEventData { 52 ZoomChangedEventData(content::WebContents* web_contents, 53 double old_zoom_level, 54 double new_zoom_level, 55 ZoomController::ZoomMode zoom_mode, 56 bool can_show_bubble) 57 : web_contents(web_contents), 58 old_zoom_level(old_zoom_level), 59 new_zoom_level(new_zoom_level), 60 zoom_mode(zoom_mode), 61 can_show_bubble(can_show_bubble) {} 62 content::WebContents* web_contents; 63 double old_zoom_level; 64 double new_zoom_level; 65 ZoomController::ZoomMode zoom_mode; 66 bool can_show_bubble; 67 }; 68 69 virtual ~ZoomController(); 70 71 ZoomMode zoom_mode() const { return zoom_mode_; } 72 73 // Convenience method to get default zoom level. Implemented here for 74 // inlining. 75 double GetDefaultZoomLevel() const { 76 // TODO(wjmaclean) Make this refer to the webcontents-specific HostZoomMap 77 // when that becomes available. 78 return content::HostZoomMap::GetDefaultForBrowserContext(browser_context_)-> 79 GetDefaultZoomLevel(); 80 } 81 82 // Convenience method to quickly check if the tab's at default zoom. 83 bool IsAtDefaultZoom() const; 84 85 // Returns which image should be loaded for the current zoom level. 86 int GetResourceForZoomLevel() const; 87 88 const extensions::Extension* last_extension() const { 89 return last_extension_.get(); 90 } 91 92 void AddObserver(ZoomObserver* observer); 93 void RemoveObserver(ZoomObserver* observer); 94 95 // Used to set whether the zoom notification bubble can be shown when the 96 // zoom level is changed for this controller. Default behavior is to show 97 // the bubble. 98 void SetShowsNotificationBubble(bool can_show_bubble) { 99 can_show_bubble_ = can_show_bubble; 100 } 101 102 // Gets the current zoom level by querying HostZoomMap (if not in manual zoom 103 // mode) or from the ZoomController local value otherwise. 104 double GetZoomLevel() const; 105 // Calls GetZoomLevel() then converts the returned value to a percentage 106 // zoom factor. 107 // Virtual for testing. 108 virtual int GetZoomPercent() const; 109 110 // Sets the zoom level through HostZoomMap. 111 // Returns true on success. 112 bool SetZoomLevel(double zoom_level); 113 114 // Sets the zoom level via HostZoomMap (or stores it locally if in manual zoom 115 // mode), and attributes the zoom to |extension|. Returns true on success. 116 bool SetZoomLevelByExtension( 117 double zoom_level, 118 const scoped_refptr<const extensions::Extension>& extension); 119 120 // Sets the zoom mode, which defines zoom behavior (see enum ZoomMode). 121 void SetZoomMode(ZoomMode zoom_mode); 122 123 // content::WebContentsObserver overrides: 124 virtual void DidNavigateMainFrame( 125 const content::LoadCommittedDetails& details, 126 const content::FrameNavigateParams& params) OVERRIDE; 127 virtual void WebContentsDestroyed() OVERRIDE; 128 129 protected: 130 // Protected for testing. 131 explicit ZoomController(content::WebContents* web_contents); 132 133 private: 134 friend class content::WebContentsUserData<ZoomController>; 135 friend class ZoomControllerTest; 136 137 void OnZoomLevelChanged(const content::HostZoomMap::ZoomLevelChange& change); 138 139 // Updates the zoom icon and zoom percentage based on current values and 140 // notifies the observer if changes have occurred. |host| may be empty, 141 // meaning the change should apply to ~all sites. If it is not empty, the 142 // change only affects sites with the given host. 143 void UpdateState(const std::string& host); 144 145 // True if changes to zoom level can trigger the zoom notification bubble. 146 bool can_show_bubble_; 147 148 // The current zoom mode. 149 ZoomMode zoom_mode_; 150 151 // Current zoom level. 152 double zoom_level_; 153 154 scoped_ptr<ZoomChangedEventData> event_data_; 155 156 // Keeps track of the extension (if any) that initiated the last zoom change 157 // that took effect. 158 scoped_refptr<const extensions::Extension> last_extension_; 159 160 // Observer receiving notifications on state changes. 161 ObserverList<ZoomObserver> observers_; 162 163 content::BrowserContext* browser_context_; 164 165 scoped_ptr<content::HostZoomMap::Subscription> zoom_subscription_; 166 167 DISALLOW_COPY_AND_ASSIGN(ZoomController); 168 }; 169 170 #endif // CHROME_BROWSER_UI_ZOOM_ZOOM_CONTROLLER_H_ 171
