DeleteFileChange.java

/*******************************************************************************
 * Copyright (c) 2000, 2006 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.rubypeople.rdt.internal.corext.refactoring.nls.changes;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;

import org.eclipse.core.resources.IFile;
import org.eclipse.core.resources.ResourcesPlugin;
import org.eclipse.core.runtime.Assert;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IPath;
import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.ltk.core.refactoring.Change;
import org.eclipse.ltk.core.refactoring.RefactoringStatus;
import org.rubypeople.rdt.core.IRubyModelStatusConstants;
import org.rubypeople.rdt.core.RubyModelException;
import org.rubypeople.rdt.internal.corext.refactoring.base.RDTChange;
import org.rubypeople.rdt.internal.corext.util.IOCloser;
import org.rubypeople.rdt.refactoring.core.Messages;

public class DeleteFileChange extends RDTChange {

	private IPath fPath;

	private String fSource;

	public DeleteFileChange(IFile file) {
		Assert.isNotNull(file, "file"); //$NON-NLS-1$
		fPath = file.getFullPath().removeFirstSegments(
				ResourcesPlugin.getWorkspace().getRoot().getFullPath()
						.segmentCount());
	}

	public RefactoringStatus isValid(IProgressMonitor pm) throws CoreException {
		return isValid(pm, READ_ONLY | DIRTY);
	}

	public Change perform(IProgressMonitor pm) throws CoreException {
		try {
			pm.beginTask(Messages.deleteFile_deleting_resource, 1);
			IFile file = ResourcesPlugin.getWorkspace().getRoot()
					.getFile(fPath);
			Assert.isNotNull(file);
			Assert.isTrue(file.exists());
			Assert.isTrue(!file.isReadOnly());
			fSource = getSource(file);
			CreateFileChange undo = createUndoChange(file, fPath, file
					.getModificationStamp(), fSource);
			file.delete(true, true, pm);
			return undo;
		} finally {
			pm.done();
		}
	}

	private String getSource(IFile file) throws CoreException {
		String encoding = null;
		try {
			encoding = file.getCharset();
		} catch (CoreException ex) {
			// fall through. Take default encoding.
		}

		StringBuffer sb = new StringBuffer();
		BufferedReader br = null;
		InputStream in = null;
		try {
			in = file.getContents();
			if (encoding != null)
				br = new BufferedReader(new InputStreamReader(in, encoding));
			else
				br = new BufferedReader(new InputStreamReader(in));
			int read = 0;
			while ((read = br.read()) != -1)
				sb.append((char) read);
		} catch (IOException e) {
			throw new RubyModelException(e,
					IRubyModelStatusConstants.IO_EXCEPTION);
		} finally {
			try {
				IOCloser.rethrows(br, in);
			} catch (IOException e) {
				throw new RubyModelException(e,
						IRubyModelStatusConstants.IO_EXCEPTION);
			}
		}
		return sb.toString();
	}

	private static CreateFileChange createUndoChange(IFile file, IPath path,
			long stampToRestore, String source) {
		String encoding;
		try {
			encoding = file.getCharset(false);
		} catch (CoreException e) {
			encoding = null;
		}
		return new CreateFileChange(path, source, encoding, stampToRestore);
	}

	public String getName() {
		return Messages.deleteFile_Delete_File;
	}

	public Object getModifiedElement() {
		return ResourcesPlugin.getWorkspace().getRoot().getFile(fPath);
	}
}