/*
 * JBoss, Home of Professional Open Source.
 *
 * See the LEGAL.txt file distributed with this work for information regarding copyright ownership and licensing.
 *
 * See the AUTHORS.txt file distributed with this work for a full listing of individual contributors.
 */
package org.teiid.designer.ui.wizards;

import java.text.Collator;
import org.eclipse.jface.viewers.ContentViewer;
import org.eclipse.jface.viewers.IBaseLabelProvider;
import org.eclipse.jface.viewers.ILabelProvider;
import org.eclipse.jface.viewers.ITableLabelProvider;
import org.eclipse.jface.viewers.Viewer;
import org.eclipse.jface.viewers.ViewerSorter;

/**
 * @since 8.0
 */
public class SingleColumnTableViewerSorter extends ViewerSorter {

	public SingleColumnTableViewerSorter() {
		super();
	}

	public SingleColumnTableViewerSorter(Collator collator) {
		super(collator);
	}

	/**
	 * Returns a negative, zero, or positive number depending on whether the
	 * first element is less than, equal to, or greater than the second element.
	 * <p>
	 * The default implementation of this method is based on comparing the
	 * elements' categories as computed by the <code>category</code> framework
	 * method. Elements within the same category are further subjected to a case
	 * insensitive compare of their label strings, either as computed by the
	 * content viewer's label provider, or their <code>toString</code> values
	 * in other cases. Subclasses may override.
	 * </p>
	 *
	 * @param viewer
	 *            the viewer
	 * @param e1
	 *            the first element
	 * @param e2
	 *            the second element
	 * @return a negative number if the first element is less than the second
	 *         element; the value <code>0</code> if the first element is equal
	 *         to the second element; and a positive number if the first element
	 *         is greater than the second element
	 */
	@Override
    public int compare(Viewer viewer, Object e1, Object e2) {

		int cat1 = category(e1);
		int cat2 = category(e2);

		if (cat1 != cat2)
			return cat1 - cat2;

		// cat1 == cat2

		String name1;
		String name2;

		if (viewer == null || !(viewer instanceof ContentViewer)) {
			name1 = e1.toString();
			name2 = e2.toString();
		} else {
			IBaseLabelProvider prov = ((ContentViewer) viewer)
					.getLabelProvider();
			if (prov instanceof ILabelProvider) {
				ILabelProvider lprov = (ILabelProvider) prov;
				name1 = lprov.getText(e1);
				name2 = lprov.getText(e2);
			} else if (prov instanceof ITableLabelProvider) {
				ITableLabelProvider lprov = (ITableLabelProvider) prov;
				name1 = lprov.getColumnText(e1, 0);
				name2 = lprov.getColumnText(e2, 0);
			} else {
				name1 = e1.toString();
				name2 = e2.toString();
			}
		}
		if (name1 == null)
			name1 = "";//$NON-NLS-1$
		if (name2 == null)
			name2 = "";//$NON-NLS-1$
		return getComparator().compare(name1, name2);
	}

}