/*

 * Copyright (c) 2007-2010 Nokia Corporation and/or its subsidiary(-ies). 

 * All rights reserved.

 * This component and the accompanying materials are made available

 * under the terms of "Eclipse Public License v1.0"

 * which accompanies this distribution, and is available

 * at the URL "http://www.eclipse.org/legal/epl-v10.html".

 *

 * Initial Contributors:

 * Nokia Corporation - initial contribution.

 *

 * Contributors:

 *

 * Description:

 *

 * Table column sorter

 *

 */

package com.nokia.trace.eventview;

import org.eclipse.jface.viewers.TableViewer;

import org.eclipse.jface.viewers.Viewer;

import org.eclipse.jface.viewers.ViewerComparator;

import org.eclipse.swt.SWT;

import org.eclipse.swt.events.SelectionAdapter;

import org.eclipse.swt.events.SelectionEvent;

import org.eclipse.swt.widgets.TableColumn;

/**

 * Table column sorter class

 * 

 */

public abstract class TableColumnSorter extends ViewerComparator {

	/**

	 * Ascending sorting

	 */

	public static final int ASC = 1;

	/**

	 * No sorting

	 */

	public static final int NONE = 0;

	/**

	 * Descending sorting

	 */

	public static final int DESC = -1;

	/**

	 * Current direction

	 */

	private int direction = 0;

	/**

	 * Column for this sorter

	 */

	private TableColumn column;

	/**

	 * Table viewer for this column

	 */

	private TableViewer viewer;

	/**

	 * Constructor

	 * 

	 * @param viewer

	 *            table viewer

	 * @param column

	 *            column

	 */

	public TableColumnSorter(final TableViewer viewer, TableColumn column) {

		this.column = column;

		this.viewer = viewer;

		this.column.addSelectionListener(new SelectionAdapter() {

			@Override

			public void widgetSelected(SelectionEvent e) {

				if (viewer.getComparator() != null) {

					if (viewer.getComparator() == TableColumnSorter.this) {

						int tdirection = TableColumnSorter.this.direction;

						if (tdirection == ASC) {

							setSorter(TableColumnSorter.this, DESC);

						} else if (tdirection == DESC) {

							setSorter(TableColumnSorter.this, NONE);

						}

					} else {

						setSorter(TableColumnSorter.this, ASC);

					}

				} else {

					setSorter(TableColumnSorter.this, ASC);

				}

			}

		});

	}

	/**

	 * Sets sorter

	 * 

	 * @param sorter

	 *            the sorter

	 * @param direction

	 *            direction

	 */

	public void setSorter(TableColumnSorter sorter, int direction) {

		if (direction == NONE) {

			column.getParent().setSortColumn(null);

			column.getParent().setSortDirection(SWT.NONE);

			viewer.setComparator(null);

		} else {

			column.getParent().setSortColumn(column);

			sorter.direction = direction;

			if (direction == ASC) {

				column.getParent().setSortDirection(SWT.DOWN);

			} else {

				column.getParent().setSortDirection(SWT.UP);

			}

			if (viewer.getComparator() == sorter) {

				viewer.refresh();

			} else {

				viewer.setComparator(sorter);

			}

		}

	}

	/*

	 * (non-Javadoc)

	 * 

	 * @see

	 * org.eclipse.jface.viewers.ViewerComparator#compare(org.eclipse.jface.

	 * viewers.Viewer, java.lang.Object, java.lang.Object)

	 */

	@Override

	public int compare(Viewer viewer, Object o1, Object o2) {

		return direction * doCompare(viewer, o1, o2);

	}

	/**

	 * Compare method

	 * 

	 * @param TableViewer

	 *            table viewer

	 * @param o1

	 *            object 1

	 * @param o2

	 *            object 2

	 * @return less than 0 if o1 is smaller than o2, 0 if equal, more than 0 if

	 *         o1 is bigger than o2

	 */

	protected abstract int doCompare(Viewer TableViewer, Object o1, Object o2);

}