TableItemStringComparator.java

/*
 * Copyright (C) 2012 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.motorola.studio.android.wizards.elements.sorting;

import java.text.Collator;
import java.util.Comparator;

import org.eclipse.swt.widgets.TableItem;

/**
 * This class compares {@link TableItem}�s which have {@link String}s within
 * them.
 */
public class TableItemStringComparator implements Comparator<TableItem>
{
    /**
     * Enumerator representing the sort direction for {@link TableItemStringComparator}.
     */
    public enum SortDirection
    {
        /**
         * Ascending direction
         */
        ASCENDING(1),

        /**
         * Descending direction
         */
        DESCENDING(-1);

        int sortDirection = 1;

        SortDirection(int sortDirection)
        {
            this.sortDirection = sortDirection;
        }

        public int getSortDirectionIntValue()
        {
            return sortDirection;
        }
    }

    int columnIndex = 0;

    SortDirection sortDirection = SortDirection.ASCENDING;

    /**
     * Instantiates a {@link Comparator} for a {@link TableItem} which
     * compares {@link String}s. The index of the column to be compared
     * must be entered. Moreover, the sort direction must also be provided.
     * 
     * @param columnIndex Column index which will be compared.
     * @param sortDirection Sort direction - ascending or descending
     */
    public TableItemStringComparator(int columnIndex, SortDirection sortDirection)
    {
        // set fields
        this.columnIndex = columnIndex;
        this.sortDirection = sortDirection;
    }

    /* 
     * (non-Javadoc)
     * @see java.util.Comparator#compare(java.lang.Object, java.lang.Object)
     */
    public int compare(TableItem first, TableItem second)
    {
        // get table�s items
        TableItem firstItem = first;
        TableItem secondItem = second;
        // get their determined column textx
        String firstString = (firstItem.getText(columnIndex));
        String secondString = (secondItem.getText(columnIndex));
        // compare the strings multiplying by the "sort direction" factor, for ascending or descending purposes
        return Collator.getInstance().compare(firstString, secondString)
                * sortDirection.getSortDirectionIntValue();
    }

}