/*******************************************************************************
 * 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;

/**
 * Common protocol for Java elements that have associated source code. This set
 * consists of <code>IClassFile</code>, <code>ICompilationUnit</code>,
 * <code>IPackageDeclaration</code>, <code>IImportDeclaration</code>,
 * <code>IImportContainer</code>, <code>IType</code>, <code>IField</code>,
 * <code>IMethod</code>, and <code>IInitializer</code>.
 * </ul>
 * <p>
 * Note: For <code>IClassFile</code>, <code>IType</code> and other members
 * derived from a binary type, the implementation returns source iff the element
 * has attached source code.
 * </p>
 * <p>
 * Source reference elements may be working copies if they were created from a
 * compilation unit that is a working copy.
 * </p>
 * <p>
 * This interface is not intended to be implemented by clients.
 * </p>
 * 
 * @see IPackageFragmentRoot#attachSource
 */
public interface ISourceReference {
	/**
	 * Returns whether this element exists in the model.
	 * 
	 * @return <code>true</code> if this element exists in the Java model
	 * @since 2.0
	 */
	boolean exists();

	/**
	 * Returns the source code associated with this element. This extracts the
	 * substring from the source buffer containing this source element. This
	 * corresponds to the source range that would be returned by
	 * <code>getSourceRange</code>.
	 * <p>
	 * For class files, this returns the source of the entire compilation unit
	 * associated with the class file (if there is one).
	 * </p>
	 * 
	 * @return the source code, or <code>null</code> if this element has no
	 *         associated source code
	 * @exception JavaModelException
	 *                if this element does not exist or if an exception occurs
	 *                while accessing its corresponding resource
	 */
	String getSource() throws JavaModelException;

	/**
	 * Returns the source range associated with this element.
	 * <p>
	 * For class files, this returns the range of the entire compilation unit
	 * associated with the class file (if there is one).
	 * </p>
	 * 
	 * @return the source range, or <code>null</code> if this element has no
	 *         associated source code
	 * @exception JavaModelException
	 *                if this element does not exist or if an exception occurs
	 *                while accessing its corresponding resource
	 */
	ISourceRange getSourceRange() throws JavaModelException;
}
