chrome/browser/ui/zoom/zoom_controller.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 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_