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_BASE_MODELS_LIST_SELECTION_MODEL_H_ 6 #define UI_BASE_MODELS_LIST_SELECTION_MODEL_H_ 7 8 #include <vector> 9 10 #include "base/basictypes.h" 11 #include "ui/base/ui_base_export.h" 12 13 namespace ui { 14 15 // Selection model represented as a list of ints. Used by the TabStrip. In 16 // addition to the set of selected indices ListSelectionModel maintains the 17 // following: 18 // active: the index of the currently visible tab in the tab strip. 19 // anchor: the index of the last tab the user clicked on. Extending the 20 // selection extends it from this index. 21 // 22 // Typically there is only one selected item, in which case the anchor and 23 // active index correspond to the same thing. 24 class UI_BASE_EXPORT ListSelectionModel { 25 public: 26 typedef std::vector<int> SelectedIndices; 27 28 // Used to identify no selection. 29 static const int kUnselectedIndex; 30 31 ListSelectionModel(); 32 ~ListSelectionModel(); 33 34 // See class description for details of the anchor. set_anchor(int anchor)35 void set_anchor(int anchor) { anchor_ = anchor; } anchor()36 int anchor() const { return anchor_; } 37 38 // See class description for details of active. set_active(int active)39 void set_active(int active) { active_ = active; } active()40 int active() const { return active_; } 41 42 // True if nothing is selected. empty()43 bool empty() const { return selected_indices_.empty(); } 44 45 // Number of selected indices. size()46 size_t size() const { return selected_indices_.size(); } 47 48 // Increments all indices >= |index|. For example, if the selection consists 49 // of [0, 1, 5] and this is invoked with 1, it results in [0, 2, 6]. This also 50 // updates the anchor and active indices. 51 // This is used when a new tab is inserted into the tabstrip. 52 void IncrementFrom(int index); 53 54 // Shifts all indices > |index| down by 1. If |index| is selected, it is 55 // removed. For example, if the selection consists of [0, 1, 5] and this is 56 // invoked with 1, it results in [0, 4]. This is used when a tab is removed 57 // from the tabstrip. 58 void DecrementFrom(int index); 59 60 // Sets the anchor, active and selection to |index|. 61 void SetSelectedIndex(int index); 62 63 // Returns true if |index| is selected. 64 bool IsSelected(int index) const; 65 66 // Adds |index| to the selection. This does not change the active or anchor 67 // indices. 68 void AddIndexToSelection(int index); 69 70 // Removes |index| from the selection. This does not change the active or 71 // anchor indices. 72 void RemoveIndexFromSelection(int index); 73 74 // Extends the selection from the anchor to |index|. If the anchor is empty, 75 // this sets the anchor, selection and active indices to |index|. 76 void SetSelectionFromAnchorTo(int index); 77 78 // Makes sure the indices from the anchor to |index| are selected. This only 79 // adds to the selection. 80 void AddSelectionFromAnchorTo(int index); 81 82 // Invoked when an item moves. |from| is the original index, and |to| the 83 // target index. 84 // NOTE: this matches the TabStripModel API. If moving to a greater index, 85 // |to| should be the index *after* removing |from|. For example, consider 86 // three tabs 'A B C', to move A to the end of the list, this should be 87 // invoked with '0, 2'. 88 void Move(int from, int to); 89 90 // Sets the anchor and active to kUnselectedIndex, and removes all the 91 // selected indices. 92 void Clear(); 93 94 // Returns the selected indices. The selection is always ordered in acending 95 // order. selected_indices()96 const SelectedIndices& selected_indices() const { return selected_indices_; } 97 98 // Copies the selection from |source| to this. 99 void Copy(const ListSelectionModel& source); 100 101 // Compares this selection with |rhs|. 102 bool Equals(const ListSelectionModel& rhs) const; 103 104 private: 105 SelectedIndices selected_indices_; 106 107 int active_; 108 109 int anchor_; 110 111 DISALLOW_COPY_AND_ASSIGN(ListSelectionModel); 112 }; 113 114 } // namespace ui 115 116 #endif // UI_BASE_MODELS_LIST_SELECTION_MODEL_H_ 117