content: /*******************************************************************************
   * 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.wst.jsdt.internal.corext.refactoring.changes;
  
  import org.eclipse.core.resources.IFile;
  import org.eclipse.core.runtime.Assert;
  import org.eclipse.core.runtime.CoreException;
  import org.eclipse.core.runtime.IProgressMonitor;
  import org.eclipse.core.runtime.SubProgressMonitor;
  import org.eclipse.jface.text.IDocument;
  import org.eclipse.ltk.core.refactoring.Change;
  import org.eclipse.ltk.core.refactoring.ChangeDescriptor;
  import org.eclipse.ltk.core.refactoring.ContentStamp;
  import org.eclipse.ltk.core.refactoring.TextFileChange;
  import org.eclipse.text.edits.UndoEdit;
  import org.eclipse.wst.jsdt.core.IJavaScriptUnit;
  import org.eclipse.wst.jsdt.internal.corext.util.JavaModelUtil;
  import org.eclipse.wst.jsdt.internal.ui.JavaScriptPlugin;
  
  public class CompilationUnitChange extends TextFileChange {
  
  	private final IJavaScriptUnit fCUnit;
  	
  	/** The (optional) refactoring descriptor */
  	private ChangeDescriptor fDescriptor;
  	
  	/**
  	 * Creates a new <code>CompilationUnitChange</code>.
  	 * 
  	 * @param name the change's name mainly used to render the change in the UI
  	 * @param cunit the compilation unit this text change works on
  	 */
  	public CompilationUnitChange(String name, IJavaScriptUnit cunit) {
  		super(name, getFile(cunit));
  		Assert.isNotNull(cunit);
  		fCUnit= cunit;
  		setTextType("js"); //$NON-NLS-1$
  	}
  	
  	private static IFile getFile(IJavaScriptUnit cunit) {
  		return (IFile) cunit.getResource();
  	}
  	
  	/* non java-doc
  	 * Method declared in IChange.
  	 */
  	public Object getModifiedElement(){
  		return fCUnit;
  	}
  	
  	/**
  	 * Returns the compilation unit this change works on.
  	 * 
  	 * @return the compilation unit this change works on
  	 */
  	public IJavaScriptUnit getCompilationUnit() {
  		return fCUnit;
  	}
  	
  	/**
  	 * {@inheritDoc}
  	 */
  	protected IDocument acquireDocument(IProgressMonitor pm) throws CoreException {
  		pm.beginTask("", 2); //$NON-NLS-1$
  		fCUnit.becomeWorkingCopy(new SubProgressMonitor(pm, 1));
  		return super.acquireDocument(new SubProgressMonitor(pm, 1));
  	}
  	
  	/**
  	 * {@inheritDoc}
  	 */
  	protected void releaseDocument(IDocument document, IProgressMonitor pm) throws CoreException {
  		boolean isModified= isDocumentModified();
  		super.releaseDocument(document, pm);
  		try {
  			fCUnit.discardWorkingCopy();
  		} finally {
  			if (isModified && !isDocumentAcquired()) {
  				if (fCUnit.isWorkingCopy())
  					JavaModelUtil.reconcile(fCUnit);
  				else
  					fCUnit.makeConsistent(pm);
  			}
  		}
  	}
  	
  	/**
  	 * {@inheritDoc}
  	 */
  	protected Change createUndoChange(UndoEdit edit, ContentStamp stampToRestore) {
  		try {
  			return new UndoCompilationUnitChange(getName(), fCUnit, edit, stampToRestore, getSaveMode());
  		} catch (CoreException e) {
  			JavaScriptPlugin.log(e);
  			return null;
  		}
  	}
  	
  	/**
  	 * {@inheritDoc}
  	 */
  	public Object getAdapter(Class adapter) {
  		if (IJavaScriptUnit.class.equals(adapter))
  			return fCUnit;
  		return super.getAdapter(adapter);
  	}
  	
  	/**
  	 * Sets the refactoring descriptor for this change
  	 * 
  	 * @param descriptor the descriptor to set
  	 */
  	public void setDescriptor(ChangeDescriptor descriptor) {
  		fDescriptor= descriptor;
  	}
  	
  	/**
  	 * {@inheritDoc}
  	 */
  	public ChangeDescriptor getDescriptor() {
  		return fDescriptor;
  	}
  }
  
  