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 UI_VIEWS_FOCUS_VIEW_STORAGE_H_ 6 #define UI_VIEWS_FOCUS_VIEW_STORAGE_H_ 7 8 #include <map> 9 #include <vector> 10 11 #include "base/basictypes.h" 12 #include "ui/views/views_export.h" 13 14 template <typename T> struct DefaultSingletonTraits; 15 16 // This class is a simple storage place for storing/retrieving views. It is 17 // used for example in the FocusManager to store/restore focused views when the 18 // main window becomes active/inactive. 19 // It automatically removes a view from the storage if the view is removed from 20 // the tree hierarchy or when the view is destroyed, which ever comes first. 21 // 22 // To use it, you first need to create a view storage id that can then be used 23 // to store/retrieve views. 24 25 namespace views { 26 class View; 27 28 class VIEWS_EXPORT ViewStorage { 29 public: 30 // Returns the global ViewStorage instance. 31 // It is guaranted to be non NULL. 32 static ViewStorage* GetInstance(); 33 34 // Returns a unique storage id that can be used to store/retrieve views. 35 int CreateStorageID(); 36 37 // Associates |view| with the specified |storage_id|. 38 void StoreView(int storage_id, View* view); 39 40 // Returns the view associated with |storage_id| if any, NULL otherwise. 41 View* RetrieveView(int storage_id); 42 43 // Removes the view associated with |storage_id| if any. 44 void RemoveView(int storage_id); 45 46 // Notifies the ViewStorage that a view was removed from its parent somewhere. 47 void ViewRemoved(View* removed); 48 view_count()49 size_t view_count() const { return view_to_ids_.size(); } 50 51 private: 52 friend struct DefaultSingletonTraits<ViewStorage>; 53 54 ViewStorage(); 55 ~ViewStorage(); 56 57 // Removes the view associated with |storage_id|. If |remove_all_ids| is true, 58 // all other mapping pointing to the same view are removed as well. 59 void EraseView(int storage_id, bool remove_all_ids); 60 61 // Next id for the view storage. 62 int view_storage_next_id_; 63 64 // The association id to View used for the view storage. 65 std::map<int, View*> id_to_view_; 66 67 // Association View to id, used to speed up view notification removal. 68 std::map<View*, std::vector<int>*> view_to_ids_; 69 70 DISALLOW_COPY_AND_ASSIGN(ViewStorage); 71 }; 72 73 } // namespace views 74 75 #endif // UI_VIEWS_FOCUS_VIEW_STORAGE_H_ 76