/*******************************************************************************
 * Copyright (c) 2000, 2003 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials 
 * are made available under the terms of the Common Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/cpl-v10.html
 * 
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/

package net.sourceforge.phpdt.core;

import org.eclipse.core.runtime.IPath;
import org.eclipse.core.runtime.IProgressMonitor;

/**
 * Abstract base implementation of all classpath variable initializers.
 * Classpath variable initializers are used in conjunction with the
 * "net.sourceforge.phpdt.core.classpathVariableInitializer" extension point.
 * <p>
 * Clients should subclass this class to implement a specific classpath variable
 * initializer. The subclass must have a public 0-argument constructor and a
 * concrete implementation of <code>initialize</code>.
 * 
 * @see IClasspathEntry
 * @since 2.0
 */
public abstract class ClasspathVariableInitializer {

	/**
	 * Creates a new classpath variable initializer.
	 */
	public ClasspathVariableInitializer() {
	}

	/**
	 * Binds a value to the workspace classpath variable with the given name, or
	 * fails silently if this cannot be done.
	 * <p>
	 * A variable initializer is automatically activated whenever a variable
	 * value is needed and none has been recorded so far. The implementation of
	 * the initializer can set the corresponding variable using
	 * <code>JavaCore#setClasspathVariable</code>.
	 * 
	 * @param variable
	 *            the name of the workspace classpath variable that requires a
	 *            binding
	 * 
	 * @see JavaCore#getClasspathVariable(String)
	 * @see JavaCore#setClasspathVariable(String, IPath, IProgressMonitor)
	 * @see JavaCore#setClasspathVariables(String[], IPath[], IProgressMonitor)
	 */
	public abstract void initialize(String variable);
}