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1 // Copyright 2016 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 ASH_COMMON_WM_WINDOW_USER_DATA_H_ | |
6 #define ASH_COMMON_WM_WINDOW_USER_DATA_H_ | |
7 | |
8 #include <map> | |
9 #include <memory> | |
10 #include <utility> | |
11 | |
12 #include "ash/common/wm_window.h" | |
13 #include "base/macros.h" | |
14 #include "ui/aura/window.h" | |
15 #include "ui/aura/window_observer.h" | |
16 | |
17 namespace ash { | |
18 | |
19 // WmWindowUserData provides a way to associate arbitrary objects with a | |
20 // WmWindow. WmWindowUserData owns the data, deleting it either when | |
21 // WmWindowUserData is deleted, or when the window the data is associated with | |
22 // is destroyed (from aura::WindowObserver::OnWindowDestroying()). | |
23 template <typename UserData> | |
24 class WmWindowUserData : public aura::WindowObserver { | |
25 public: | |
26 WmWindowUserData() {} | |
27 | |
28 ~WmWindowUserData() override { clear(); } | |
29 | |
30 void clear() { | |
31 for (auto& pair : window_to_data_) | |
32 pair.first->aura_window()->RemoveObserver(this); | |
33 window_to_data_.clear(); | |
34 } | |
35 | |
36 // Sets the data associated with window. This destroys any existing data. | |
37 // |data| may be null. | |
38 void Set(WmWindow* window, std::unique_ptr<UserData> data) { | |
39 if (!data) { | |
40 if (window_to_data_.erase(window)) | |
41 window->aura_window()->RemoveObserver(this); | |
42 return; | |
43 } | |
44 if (window_to_data_.count(window) == 0u) | |
45 window->aura_window()->AddObserver(this); | |
46 window_to_data_[window] = std::move(data); | |
47 } | |
48 | |
49 // Returns the data associated with the window, or null if none set. The | |
50 // returned object is owned by WmWindowUserData. | |
51 UserData* Get(WmWindow* window) { | |
52 auto it = window_to_data_.find(window); | |
53 return it == window_to_data_.end() ? nullptr : it->second.get(); | |
54 } | |
55 | |
56 // Returns the set of windows with data associated with them. | |
57 std::set<WmWindow*> GetWindows() { | |
58 std::set<WmWindow*> windows; | |
59 for (auto& pair : window_to_data_) | |
60 windows.insert(pair.first); | |
61 return windows; | |
62 } | |
63 | |
64 private: | |
65 // aura::WindowObserver: | |
66 void OnWindowDestroying(aura::Window* window) override { | |
67 window->RemoveObserver(this); | |
68 window_to_data_.erase(WmWindow::Get(window)); | |
69 } | |
70 | |
71 std::map<WmWindow*, std::unique_ptr<UserData>> window_to_data_; | |
72 | |
73 DISALLOW_COPY_AND_ASSIGN(WmWindowUserData); | |
74 }; | |
75 | |
76 } // namespace ash | |
77 | |
78 #endif // ASH_COMMON_WM_WINDOW_USER_DATA_H_ | |
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