org.gluster.storage.management.console.utils.TableViewerComparator.java Source code

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Here is the source code for org.gluster.storage.management.console.utils.TableViewerComparator.java

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/*******************************************************************************
 * Copyright (c) 2006-2011 Gluster, Inc. <http://www.gluster.com>
 * This file is part of Gluster Management Console.
 *
 * Gluster Management Console is free software; you can redistribute
 * it and/or modify it under the terms of the GNU General Public
 * License as published by the Free Software Foundation; either
 * version 3 of the License, or (at your option) any later version.
 *
 * Gluster Management Console 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 for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see
 * <http://www.gnu.org/licenses/>.
 *******************************************************************************/
package org.gluster.storage.management.console.utils;

import org.eclipse.jface.viewers.Viewer;
import org.eclipse.jface.viewers.ViewerComparator;
import org.eclipse.swt.SWT;

/**
 * Comparator for sorting contents of a table viewer
 */
public class TableViewerComparator extends ViewerComparator {
    private int column = -1;
    private static final int ASCENDING = 0;
    private static final int DESCENDING = 1;
    private static final int NONE = -1;
    private int direction = DESCENDING;

    public TableViewerComparator() {
        this(NONE);
    }

    public TableViewerComparator(int direction) {
        this.direction = direction;
    }

    public int getDirection() {
        return direction == DESCENDING ? SWT.DOWN : (direction == ASCENDING ? SWT.UP : SWT.NONE);
    }

    public void setColumn(int column) {
        if (column == this.column) {
            // Same column as last sort; toggle the direction
            direction = 1 - direction;
        } else {
            // first column selection or new column; do an ascending sort
            direction = ASCENDING;
            this.column = column;
        }
    }

    @Override
    public int compare(Viewer viewer, Object e1, Object e2) {
        if (direction == NONE) {
            // no sorting
            return 0;
        }

        int result = super.compare(viewer, e1, e2);
        // If descending order, flip the direction
        if (direction == DESCENDING) {
            result = -result;
        }

        return result;
    }
}