bundles/org.eclipse.e4.ui.workbench/src/org/eclipse/e4/workbench/ui/internal/ActiveChildLookupFunction.java

/*******************************************************************************
 * Copyright (c) 2009 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.e4.workbench.ui.internal;

import org.eclipse.e4.core.services.context.IEclipseContext;
import org.eclipse.e4.core.services.context.spi.ContextFunction;
import org.eclipse.e4.core.services.context.spi.IContextConstants;

/**
 *
 */
public class ActiveChildLookupFunction extends ContextFunction {

	private String localVar;
	private String var;

	public ActiveChildLookupFunction(String var, String localVar) {
		this.var = var;
		this.localVar = localVar;
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.e4.core.services.context.spi.ContextFunction#compute(org.
	 * eclipse.e4.core.services.context.IEclipseContext, java.lang.Object[])
	 */
	@Override
	public Object compute(IEclipseContext context, Object[] arguments) {
		IEclipseContext childContext = (IEclipseContext) context
				.getLocal(IContextConstants.ACTIVE_CHILD);
		if (childContext != null) {
			return childContext.get(var);
		}
		return context.get(localVar);
	}

}