| // Copyright 2014 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #ifndef COMPONENTS_ZOOM_ZOOM_EVENT_MANAGER_H_ |
| #define COMPONENTS_ZOOM_ZOOM_EVENT_MANAGER_H_ |
| |
| #include <memory> |
| |
| #include "base/callback_list.h" |
| #include "base/macros.h" |
| #include "base/memory/weak_ptr.h" |
| #include "base/observer_list.h" |
| #include "base/supports_user_data.h" |
| #include "content/public/browser/host_zoom_map.h" |
| |
| namespace content { |
| class BrowserContext; |
| } // namespace content |
| |
| namespace zoom { |
| |
| class ZoomEventManagerObserver; |
| |
| // This class serves as a target for event notifications from all ZoomController |
| // objects. Classes that need to know about browser-specific zoom events (e.g. |
| // manual-mode zoom) should subscribe here. |
| class ZoomEventManager : public base::SupportsUserData::Data { |
| public: |
| ZoomEventManager(); |
| ~ZoomEventManager() override; |
| |
| // Returns the ZoomEventManager for the specified BrowserContext. This |
| // function creates the ZoomEventManager if it hasn't been created already. |
| static ZoomEventManager* GetForBrowserContext( |
| content::BrowserContext* context); |
| |
| // Called by ZoomControllers when changes are made to zoom levels in manual |
| // mode in order that browser listeners can be notified. |
| void OnZoomLevelChanged(const content::HostZoomMap::ZoomLevelChange& change); |
| |
| // Add and remove zoom level changed callbacks. |
| // TODO(wjmaclean): Convert this callback mechanism to use |
| // ZoomEventManagerObserver instead. |
| std::unique_ptr<content::HostZoomMap::Subscription> |
| AddZoomLevelChangedCallback( |
| const content::HostZoomMap::ZoomLevelChangedCallback& callback); |
| |
| // Called by ZoomLevelDelegates when changes are made to the default zoom |
| // level for their associated HostZoomMap. |
| void OnDefaultZoomLevelChanged(); |
| |
| // Add and remove observers. |
| void AddZoomEventManagerObserver(ZoomEventManagerObserver* observer); |
| void RemoveZoomEventManagerObserver(ZoomEventManagerObserver* observer); |
| |
| // Get a weak ptr to be used by clients who may themselves be UserData for |
| // the context, since the order of destruction is undefined between the client |
| // and this class. |
| base::WeakPtr<ZoomEventManager> GetWeakPtr() { |
| return weak_ptr_factory_.GetWeakPtr(); |
| } |
| |
| private: |
| base::CallbackList<void(const content::HostZoomMap::ZoomLevelChange&)> |
| zoom_level_changed_callbacks_; |
| base::ObserverList<ZoomEventManagerObserver> observers_; |
| base::WeakPtrFactory<ZoomEventManager> weak_ptr_factory_; |
| |
| DISALLOW_COPY_AND_ASSIGN(ZoomEventManager); |
| }; |
| |
| } // namespace zoom |
| |
| #endif // COMPONENTS_ZOOM_ZOOM_EVENT_MANAGER_H_ |