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      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/prefs/pref_member.h"
     11 #include "content/public/browser/host_zoom_map.h"
     12 #include "content/public/browser/web_contents_observer.h"
     13 #include "content/public/browser/web_contents_user_data.h"
     14 
     15 class ZoomObserver;
     16 
     17 namespace content {
     18 class WebContents;
     19 }
     20 
     21 // Per-tab class to manage the Omnibox zoom icon.
     22 class ZoomController : public content::WebContentsObserver,
     23                        public content::WebContentsUserData<ZoomController> {
     24  public:
     25   virtual ~ZoomController();
     26 
     27   int zoom_percent() const { return zoom_percent_; }
     28 
     29   // Convenience method to quickly check if the tab's at default zoom.
     30   bool IsAtDefaultZoom() const;
     31 
     32   // Returns which image should be loaded for the current zoom level.
     33   int GetResourceForZoomLevel() const;
     34 
     35   void set_observer(ZoomObserver* observer) { observer_ = observer; }
     36 
     37   // content::WebContentsObserver overrides:
     38   virtual void DidNavigateMainFrame(
     39       const content::LoadCommittedDetails& details,
     40       const content::FrameNavigateParams& params) OVERRIDE;
     41 
     42  private:
     43   explicit ZoomController(content::WebContents* web_contents);
     44   friend class content::WebContentsUserData<ZoomController>;
     45   friend class ZoomControllerTest;
     46 
     47   void OnZoomLevelChanged(const content::HostZoomMap::ZoomLevelChange& change);
     48 
     49   // Updates the zoom icon and zoom percentage based on current values and
     50   // notifies the observer if changes have occurred. |host| may be empty,
     51   // meaning the change should apply to ~all sites. If it is not empty, the
     52   // change only affects sites with the given host.
     53   void UpdateState(const std::string& host);
     54 
     55   // The current zoom percentage.
     56   int zoom_percent_;
     57 
     58   // Used to access the default zoom level preference.
     59   DoublePrefMember default_zoom_level_;
     60 
     61   // Observer receiving notifications on state changes.
     62   ZoomObserver* observer_;
     63 
     64   content::BrowserContext* browser_context_;
     65 
     66   scoped_ptr<content::HostZoomMap::Subscription> zoom_subscription_;
     67 
     68   DISALLOW_COPY_AND_ASSIGN(ZoomController);
     69 };
     70 
     71 #endif  // CHROME_BROWSER_UI_ZOOM_ZOOM_CONTROLLER_H_
     72