ISourceReference.java

/*******************************************************************************
 * Copyright (c) 2000, 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.jdt.core;

/**
 * Common protocol for Java elements that have associated source code. This set consists of
 * {@link IClassFile}, {@link ICompilationUnit}, {@link IPackageDeclaration},
 * {@link IImportDeclaration}, {@link IImportContainer}, {@link IType}, {@link IField},
 * {@link IMethod}, {@link IInitializer}, {@link ITypeParameter}, {@link ILocalVariable}, and
 * {@link IAnnotation}.
 * <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>
 * 
 * @see IPackageFragmentRoot#attachSource(org.eclipse.core.runtime.IPath,
 *      org.eclipse.core.runtime.IPath, org.eclipse.core.runtime.IProgressMonitor)
 * @noimplement This interface is not intended to be implemented by clients.
 */
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 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>
	 * <p>
	 * If this element has no associated source code, either <code>null</code> is returned, or a
	 * source range with a -1 offset and a 0 length. {@link SourceRange#isAvailable(ISourceRange)}
	 * can be used to detect that case.
	 * </p>
	 * 
	 * @return the source range, or either <code>null</code> or [-1, 0] if this element has no
	 *         associated source code
	 * @exception JavaModelException if an exception occurs while accessing its corresponding
	 *                resource
	 * @see SourceRange#isAvailable(ISourceRange)
	 */
	ISourceRange getSourceRange() throws JavaModelException;
}