/*******************************************************************************
* Copyright (c) 2006, 2015 IBM Corporation and others.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* IBM Corporation - initial API and implementation
*******************************************************************************/
package org.eclipse.ui.internal.navigator.extensions;
import java.util.Comparator;
import org.eclipse.ui.navigator.INavigatorContentDescriptor;
import org.eclipse.ui.navigator.INavigatorContentExtension;
/**
* @since 3.2
*
*/
public class ExtensionSequenceNumberComparator implements Comparator {
/**
* The initialized singleton instance.
*/
public static final ExtensionSequenceNumberComparator INSTANCE = new ExtensionSequenceNumberComparator(true);
/**
* The initialized singleton instance.
*/
public static final ExtensionSequenceNumberComparator DESCENDING = new ExtensionSequenceNumberComparator(false);
private final int sortAscending;
/**
* Creates an instance that sorts according to the given boolean flag.
*
* @param toSortAscending
* <code>true</code> for ascending sort order or
* <code>false</code> for descending sort order.
*/
public ExtensionSequenceNumberComparator(boolean toSortAscending) {
sortAscending = toSortAscending ? 1 : -1;
}
@Override
public int compare(Object o1, Object o2) {
INavigatorContentDescriptor lvalue = null;
INavigatorContentDescriptor rvalue = null;
if (o1 instanceof INavigatorContentDescriptor) {
lvalue = (INavigatorContentDescriptor) o1;
} else if (o1 instanceof NavigatorContentExtension) {
lvalue = ((NavigatorContentExtension) o1).getDescriptor();
}
if (o2 instanceof INavigatorContentDescriptor) {
rvalue = (INavigatorContentDescriptor) o2;
} else if (o2 instanceof INavigatorContentExtension) {
rvalue = ((NavigatorContentExtension) o2).getDescriptor();
}
if (lvalue == null || rvalue == null) {
return -1 * sortAscending;
}
int c = lvalue.getSequenceNumber() - rvalue.getSequenceNumber();
if (c != 0) {
return c * sortAscending;
}
return 0;
}
}