chrome/browser/ui/zoom/zoom_event_manager.h

   1 // Copyright 2014 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_EVENT_MANAGER_H_
   6 #define CHROME_BROWSER_UI_ZOOM_ZOOM_EVENT_MANAGER_H_
   7
   8 #include "base/callback_list.h"
   9 #include "base/supports_user_data.h"
  10 #include "content/public/browser/host_zoom_map.h"
  11
  12 namespace content {
  13 class BrowserContext;
  14 }  // namespace content
  15
  16 // This class serves as a target for event notifications from all ZoomController
  17 // objects. Classes that need to know about browser-specific zoom events (e.g.
  18 // manual-mode zoom) should subscribe here.
  19 class ZoomEventManager : public base::SupportsUserData::Data {
  20  public:
  21   ZoomEventManager();
  22   virtual ~ZoomEventManager();
  23
  24   // Returns the ZoomEventManager for the specified BrowserContext. This
  25   // function creates the ZoomEventManager if it hasn't been created already.
  26   static ZoomEventManager* GetForBrowserContext(
  27       content::BrowserContext* context);
  28
  29   // Called by ZoomControllers when changes are made to zoom levels in manual
  30   // mode in order that browser listeners can be notified.
  31   void OnZoomLevelChanged(const content::HostZoomMap::ZoomLevelChange& change);
  32
  33   // Add and remove zoom level changed callbacks.
  34   scoped_ptr<content::HostZoomMap::Subscription> AddZoomLevelChangedCallback(
  35       const content::HostZoomMap::ZoomLevelChangedCallback& callback);
  36
  37  private:
  38   base::CallbackList<void(const content::HostZoomMap::ZoomLevelChange&)>
  39       zoom_level_changed_callbacks_;
  40
  41   DISALLOW_COPY_AND_ASSIGN(ZoomEventManager);
  42 };
  43
  44 #endif  // CHROME_BROWSER_UI_ZOOM_ZOOM_EVENT_MANAGER_H_