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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 COMPONENTS_UI_ZOOM_ZOOM_EVENT_MANAGER_H_ | |
6 #define COMPONENTS_UI_ZOOM_ZOOM_EVENT_MANAGER_H_ | |
7 | |
8 #include <memory> | |
9 | |
10 #include "base/callback_list.h" | |
11 #include "base/macros.h" | |
12 #include "base/memory/weak_ptr.h" | |
13 #include "base/observer_list.h" | |
14 #include "base/supports_user_data.h" | |
15 #include "content/public/browser/host_zoom_map.h" | |
16 | |
17 namespace content { | |
18 class BrowserContext; | |
19 } // namespace content | |
20 | |
21 namespace ui_zoom { | |
22 | |
23 class ZoomEventManagerObserver; | |
24 | |
25 // This class serves as a target for event notifications from all ZoomController | |
26 // objects. Classes that need to know about browser-specific zoom events (e.g. | |
27 // manual-mode zoom) should subscribe here. | |
28 class ZoomEventManager : public base::SupportsUserData::Data { | |
29 public: | |
30 ZoomEventManager(); | |
31 ~ZoomEventManager() override; | |
32 | |
33 // Returns the ZoomEventManager for the specified BrowserContext. This | |
34 // function creates the ZoomEventManager if it hasn't been created already. | |
35 static ZoomEventManager* GetForBrowserContext( | |
36 content::BrowserContext* context); | |
37 | |
38 // Called by ZoomControllers when changes are made to zoom levels in manual | |
39 // mode in order that browser listeners can be notified. | |
40 void OnZoomLevelChanged(const content::HostZoomMap::ZoomLevelChange& change); | |
41 | |
42 // Add and remove zoom level changed callbacks. | |
43 // TODO(wjmaclean): Convert this callback mechanism to use | |
44 // ZoomEventManagerObserver instead. | |
45 std::unique_ptr<content::HostZoomMap::Subscription> | |
46 AddZoomLevelChangedCallback( | |
47 const content::HostZoomMap::ZoomLevelChangedCallback& callback); | |
48 | |
49 // Called by ZoomLevelDelegates when changes are made to the default zoom | |
50 // level for their associated HostZoomMap. | |
51 void OnDefaultZoomLevelChanged(); | |
52 | |
53 // Add and remove observers. | |
54 void AddZoomEventManagerObserver(ZoomEventManagerObserver* observer); | |
55 void RemoveZoomEventManagerObserver(ZoomEventManagerObserver* observer); | |
56 | |
57 // Get a weak ptr to be used by clients who may themselves be UserData for | |
58 // the context, since the order of destruction is undefined between the client | |
59 // and this class. | |
60 base::WeakPtr<ZoomEventManager> GetWeakPtr() { | |
61 return weak_ptr_factory_.GetWeakPtr(); | |
62 } | |
63 | |
64 private: | |
65 base::CallbackList<void(const content::HostZoomMap::ZoomLevelChange&)> | |
66 zoom_level_changed_callbacks_; | |
67 base::ObserverList<ZoomEventManagerObserver> observers_; | |
68 base::WeakPtrFactory<ZoomEventManager> weak_ptr_factory_; | |
69 | |
70 DISALLOW_COPY_AND_ASSIGN(ZoomEventManager); | |
71 }; | |
72 | |
73 } // namespace ui_zoom | |
74 | |
75 #endif // COMPONENTS_UI_ZOOM_ZOOM_EVENT_MANAGER_H_ | |
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