core/plugins/org.eclipse.dltk.core.manipulation/src/org/eclipse/dltk/internal/corext/refactoring/changes/UndoSourceModuleChange.java

/*******************************************************************************
 * Copyright (c) 2000, 2017 IBM Corporation and others.
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v. 2.0 which is available at
 * http://www.eclipse.org/legal/epl-2.0.
 * 
 * SPDX-License-Identifier: EPL-2.0
 *
 *******************************************************************************/
package org.eclipse.dltk.internal.corext.refactoring.changes;

import org.eclipse.core.resources.IFile;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.Status;
import org.eclipse.core.runtime.SubProgressMonitor;
import org.eclipse.dltk.core.ISourceModule;
import org.eclipse.dltk.internal.core.manipulation.Messages;
import org.eclipse.dltk.internal.core.manipulation.ScriptManipulationPlugin;
import org.eclipse.dltk.internal.corext.refactoring.RefactoringCoreMessages;
import org.eclipse.ltk.core.refactoring.Change;
import org.eclipse.ltk.core.refactoring.ContentStamp;
import org.eclipse.ltk.core.refactoring.UndoTextFileChange;
import org.eclipse.text.edits.UndoEdit;

public class UndoSourceModuleChange extends UndoTextFileChange {

	private ISourceModule fCUnit;

	public UndoSourceModuleChange(String name, ISourceModule unit, UndoEdit undo, ContentStamp stampToRestore,
			int saveMode) throws CoreException {
		super(name, getFile(unit), undo, stampToRestore, saveMode);
		fCUnit = unit;
	}

	private static IFile getFile(ISourceModule cunit) throws CoreException {
		IFile file = (IFile) cunit.getResource();
		if (file == null)
			throw new CoreException(new Status(IStatus.ERROR, ScriptManipulationPlugin.getPluginId(), IStatus.ERROR,
					Messages.format(RefactoringCoreMessages.UndoSourceModuleChange_no_resource, cunit.getElementName()),
					null));
		return file;
	}

	@Override
	public Object getModifiedElement() {
		return fCUnit;
	}

	@Override
	protected Change createUndoChange(UndoEdit edit, ContentStamp stampToRestore) throws CoreException {
		return new UndoSourceModuleChange(getName(), fCUnit, edit, stampToRestore, getSaveMode());
	}

	@Override
	public Change perform(IProgressMonitor pm) throws CoreException {
		pm.beginTask("", 2); //$NON-NLS-1$
		fCUnit.becomeWorkingCopy(null, new SubProgressMonitor(pm, 1));
		try {
			return super.perform(new SubProgressMonitor(pm, 1));
		} finally {
			fCUnit.discardWorkingCopy();
		}
	}
}