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 #include "ui/base/models/list_selection_model.h" 6 7 #include <algorithm> 8 #include <valarray> 9 10 #include "base/logging.h" 11 12 namespace ui { 13 14 // static 15 const int ListSelectionModel::kUnselectedIndex = -1; 16 17 static void IncrementFromImpl(int index, int* value) { 18 if (*value >= index) 19 (*value)++; 20 } 21 22 static bool DecrementFromImpl(int index, int* value) { 23 if (*value == index) { 24 *value = ListSelectionModel::kUnselectedIndex; 25 return true; 26 } 27 if (*value > index) 28 (*value)--; 29 return false; 30 } 31 32 ListSelectionModel::ListSelectionModel() 33 : active_(kUnselectedIndex), 34 anchor_(kUnselectedIndex) { 35 } 36 37 ListSelectionModel::~ListSelectionModel() { 38 } 39 40 void ListSelectionModel::IncrementFrom(int index) { 41 // Shift the selection to account for the newly inserted tab. 42 for (SelectedIndices::iterator i = selected_indices_.begin(); 43 i != selected_indices_.end(); ++i) { 44 IncrementFromImpl(index, &(*i)); 45 } 46 IncrementFromImpl(index, &anchor_); 47 IncrementFromImpl(index, &active_); 48 } 49 50 void ListSelectionModel::DecrementFrom(int index) { 51 for (SelectedIndices::iterator i = selected_indices_.begin(); 52 i != selected_indices_.end(); ) { 53 if (DecrementFromImpl(index, &(*i))) 54 i = selected_indices_.erase(i); 55 else 56 ++i; 57 } 58 DecrementFromImpl(index, &anchor_); 59 DecrementFromImpl(index, &active_); 60 } 61 62 void ListSelectionModel::SetSelectedIndex(int index) { 63 anchor_ = active_ = index; 64 selected_indices_.clear(); 65 if (index != kUnselectedIndex) 66 selected_indices_.push_back(index); 67 } 68 69 bool ListSelectionModel::IsSelected(int index) const { 70 return std::find(selected_indices_.begin(), selected_indices_.end(), index) != 71 selected_indices_.end(); 72 } 73 74 void ListSelectionModel::AddIndexToSelection(int index) { 75 if (!IsSelected(index)) { 76 selected_indices_.push_back(index); 77 std::sort(selected_indices_.begin(), selected_indices_.end()); 78 } 79 } 80 81 void ListSelectionModel::RemoveIndexFromSelection(int index) { 82 SelectedIndices::iterator i = std::find(selected_indices_.begin(), 83 selected_indices_.end(), index); 84 if (i != selected_indices_.end()) 85 selected_indices_.erase(i); 86 } 87 88 void ListSelectionModel::SetSelectionFromAnchorTo(int index) { 89 if (anchor_ == kUnselectedIndex) { 90 SetSelectedIndex(index); 91 } else { 92 int delta = std::abs(index - anchor_); 93 SelectedIndices new_selection(delta + 1, 0); 94 for (int i = 0, min = std::min(index, anchor_); i <= delta; ++i) 95 new_selection[i] = i + min; 96 selected_indices_.swap(new_selection); 97 active_ = index; 98 } 99 } 100 101 void ListSelectionModel::AddSelectionFromAnchorTo(int index) { 102 if (anchor_ == kUnselectedIndex) { 103 SetSelectedIndex(index); 104 } else { 105 for (int i = std::min(index, anchor_), end = std::max(index, anchor_); 106 i <= end; ++i) { 107 if (!IsSelected(i)) 108 selected_indices_.push_back(i); 109 } 110 std::sort(selected_indices_.begin(), selected_indices_.end()); 111 active_ = index; 112 } 113 } 114 115 void ListSelectionModel::Move(int from, int to) { 116 DCHECK_NE(to, from); 117 bool was_anchor = from == anchor_; 118 bool was_active = from == active_; 119 bool was_selected = IsSelected(from); 120 if (to < from) { 121 IncrementFrom(to); 122 DecrementFrom(from + 1); 123 } else { 124 DecrementFrom(from); 125 IncrementFrom(to); 126 } 127 if (was_active) 128 active_ = to; 129 if (was_anchor) 130 anchor_ = to; 131 if (was_selected) 132 AddIndexToSelection(to); 133 } 134 135 void ListSelectionModel::Clear() { 136 anchor_ = active_ = kUnselectedIndex; 137 SelectedIndices empty_selection; 138 selected_indices_.swap(empty_selection); 139 } 140 141 void ListSelectionModel::Copy(const ListSelectionModel& source) { 142 selected_indices_ = source.selected_indices_; 143 active_ = source.active_; 144 anchor_ = source.anchor_; 145 } 146 147 bool ListSelectionModel::Equals(const ListSelectionModel& rhs) const { 148 return active_ == rhs.active() && 149 anchor_ == rhs.anchor() && 150 selected_indices() == rhs.selected_indices(); 151 } 152 153 } // namespace ui 154