org.eclipse.jdt.debug.ui/ui/org/eclipse/jdt/internal/debug/ui/actions/MoveUpAction.java

package org.eclipse.jdt.internal.debug.ui.actions;

/*
 * (c) Copyright IBM Corp. 2000, 2001.
 * All Rights Reserved.
 */

import java.util.Iterator;
import java.util.List;

import org.eclipse.jdt.internal.debug.ui.launcher.RuntimeClasspathViewer;
import org.eclipse.jface.viewers.IStructuredSelection;

/**
 * Moves selected enries in a runtime classpath viewer up one position.
 */
public class MoveUpAction extends RuntimeClasspathAction {

	public MoveUpAction(RuntimeClasspathViewer viewer) {
		super(ActionMessages.getString("MoveUpAction.Move_U&p_1"), viewer); //$NON-NLS-1$
	}
	/**
	 * Moves all selected entries up one position (if possible).
	 * 
	 * @see IAction#run()
	 */
	public void run() {
		List targets = getOrderedSelection();
		if (targets.isEmpty()) {
			return;
		}
		int top = 0;
		int index = 0;
		List list = getEntiresAsList();
		Iterator entries = targets.iterator();
		while (entries.hasNext()) {
			Object target = entries.next();
			index = list.indexOf(target);
			if (index > top) {
				top = index - 1;
				Object temp = list.get(top);
				list.set(top, target);
				list.set(index, temp);
			}
			top = index;
		} 
		setEntries(list);
	}

	/**
	 * @see SelectionListenerAction#updateSelection(IStructuredSelection)
	 */
	protected boolean updateSelection(IStructuredSelection selection) {
		return getViewer().isEnabled() && !selection.isEmpty() && !isIndexSelected(selection, 0);
	}

}