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 * Copyright (c) 2013, 2014, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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package com.sun.javafx.scene.control;

import javafx.collections.FXCollections;
import javafx.collections.ListChangeListener;
import javafx.collections.ObservableList;
import javafx.collections.transformation.SortedList;
import javafx.scene.control.TablePositionBase;

import java.util.*;

Implementation code used by the TableSelectionModel implementations. In short
this code exists to speed up some common use cases which were incredibly
slow in the old approach. The old approach essentially required a lot of
iterating through the selectedCells list. The new approach is to keep this
list for what it is good for (representing selection order primarily), and
introduce a Map to speed up the slow parts - namely looking
up whether a given row/column intersection is selected or not.
Note that a map that contains an empty bitset is used to represent that the
row is selected.
Refer to RT-33442 for more information on this issue.
/**
 * Implementation code used by the TableSelectionModel implementations. In short
 * this code exists to speed up some common use cases which were incredibly
 * slow in the old approach. The old approach essentially required a lot of
 * iterating through the selectedCells list. The new approach is to keep this
 * list for what it is good for (representing selection order primarily), and
 * introduce a Map<Integer, BitSet> to speed up the slow parts - namely looking
 * up whether a given row/column intersection is selected or not.
 *
 * Note that a map that contains an empty bitset is used to represent that the
 * row is selected.
 *
 * Refer to RT-33442 for more information on this issue.
 */
// T == TablePosition<S,?>
public abstract class SelectedCellsMap<T extends TablePositionBase> {
    private final ObservableList<T> selectedCells;
    private final ObservableList<T> sortedSelectedCells;

    private final Map<Integer, BitSet> selectedCellBitSetMap;

    public SelectedCellsMap(final ListChangeListener<T> listener) {
        selectedCells = FXCollections.<T>observableArrayList();
        sortedSelectedCells = new SortedList<>(selectedCells, (T o1, T o2) -> {
            int result = o1.getRow() - o2.getRow();
            return result == 0 ? (o1.getColumn() - o2.getColumn()) : result;
        });
        sortedSelectedCells.addListener(listener);

        selectedCellBitSetMap = new TreeMap<>((o1, o2) -> o1.compareTo(o2));
    }

    public abstract boolean isCellSelectionEnabled();

    public int size() {
        return selectedCells.size();
    }

    public T get(int i) {
        if (i < 0) {
            return null;
        }
        return sortedSelectedCells.get(i);
    }

    public void add(T tp) {
        final int row = tp.getRow();
        final int columnIndex = tp.getColumn();

        // update the bitset map
        boolean isNewBitSet = false;
        BitSet bitset;
        if (! selectedCellBitSetMap.containsKey(row)) {
            bitset = new BitSet();
            selectedCellBitSetMap.put(row, bitset);
            isNewBitSet = true;
        } else {
            bitset = selectedCellBitSetMap.get(row);
        }

        final boolean cellSelectionModeEnabled = isCellSelectionEnabled();

        if (cellSelectionModeEnabled) {
            if (columnIndex >= 0) {
                boolean isAlreadySet = bitset.get(columnIndex);

                if (!isAlreadySet) {
                    bitset.set(columnIndex);

                    // add into the list
                    selectedCells.add(tp);
                }
            } else {
                // FIXME slow path (for now)
                if (!selectedCells.contains(tp)) {
                    selectedCells.add(tp);
                }
            }
        } else {
            if (isNewBitSet) {
                if (columnIndex >= 0) {
                    bitset.set(columnIndex);
                }
                selectedCells.add(tp);
            }
        }
    }

    public void addAll(Collection<T> cells) {
        // update bitset
        for (T tp : cells) {
            final int row = tp.getRow();
            final int columnIndex = tp.getColumn();

            // update the bitset map
            BitSet bitset;
            if (! selectedCellBitSetMap.containsKey(row)) {
                bitset = new BitSet();
                selectedCellBitSetMap.put(row, bitset);
            } else {
                bitset = selectedCellBitSetMap.get(row);
            }

            if (columnIndex < 0) {
                continue;
            }

            bitset.set(columnIndex);
        }

        // add into the list
        selectedCells.addAll(cells);
    }

    public void setAll(Collection<T> cells) {
        // update bitset
        selectedCellBitSetMap.clear();
        for (T tp : cells) {
            final int row = tp.getRow();
            final int columnIndex = tp.getColumn();

            // update the bitset map
            BitSet bitset;
            if (! selectedCellBitSetMap.containsKey(row)) {
                bitset = new BitSet();
                selectedCellBitSetMap.put(row, bitset);
            } else {
                bitset = selectedCellBitSetMap.get(row);
            }

            if (columnIndex < 0) {
                continue;
            }

            bitset.set(columnIndex);
        }

        // add into the list
        selectedCells.setAll(cells);
    }

    public void remove(T tp) {
        final int row = tp.getRow();
        final int columnIndex = tp.getColumn();

        // update the bitset map
        if (selectedCellBitSetMap.containsKey(row)) {
            BitSet bitset = selectedCellBitSetMap.get(row);

            if (columnIndex >= 0) {
                bitset.clear(columnIndex);
            }

            if (bitset.isEmpty()) {
                selectedCellBitSetMap.remove(row);
            }
        }

        // update list
        selectedCells.remove(tp);
    }

    public void clear() {
        // update bitset
        selectedCellBitSetMap.clear();

        // update list
        selectedCells.clear();
    }

    public boolean isSelected(int row, int columnIndex) {
        if (columnIndex < 0) {
            return selectedCellBitSetMap.containsKey(row);
        } else {
            return selectedCellBitSetMap.containsKey(row) ? selectedCellBitSetMap.get(row).get(columnIndex) : false;
        }
    }

    public int indexOf(T tp) {
        return sortedSelectedCells.indexOf(tp);
    }

    public boolean isEmpty() {
        return selectedCells.isEmpty();
    }

    public ObservableList<T> getSelectedCells() {
        return selectedCells;
    }
}