Copyright (c) 2000, 2016 IBM Corporation and others.
This program and the accompanying materials
are made available under the terms of the Eclipse Public License 2.0
which accompanies this distribution, and is available at
https://www.eclipse.org/legal/epl-2.0/
SPDX-License-Identifier: EPL-2.0
Contributors:
    IBM Corporation - initial API and implementation
/*******************************************************************************
 * Copyright (c) 2000, 2016 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.core.filebuffers.manipulation;

import org.eclipse.core.internal.filebuffers.FileBuffersPlugin;

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.SubMonitor;

import org.eclipse.core.filebuffers.IFileBufferStatusCodes;
import org.eclipse.core.filebuffers.ITextFileBuffer;

import org.eclipse.text.edits.DeleteEdit;

import org.eclipse.jface.text.BadLocationException;
import org.eclipse.jface.text.DocumentRewriteSessionType;
import org.eclipse.jface.text.IDocument;
import org.eclipse.jface.text.IRegion;

A text file buffer operation that removes all trailing whitespace.
Since:
3.1/**
 * A text file buffer operation that removes all trailing whitespace.
 *
 * @since 3.1
 */
public class RemoveTrailingWhitespaceOperation extends TextFileBufferOperation {

	
Creates a remove trailing whitespace operation.
/**
	 * Creates a remove trailing whitespace operation.
	 */
	public RemoveTrailingWhitespaceOperation() {
		super(FileBuffersMessages.RemoveTrailingWhitespaceOperation_name);
	}

	@Override
	protected MultiTextEditWithProgress computeTextEdit(ITextFileBuffer fileBuffer, IProgressMonitor progressMonitor) throws CoreException {
		IDocument document= fileBuffer.getDocument();
		int lineCount= document.getNumberOfLines();

		SubMonitor subMonitor= SubMonitor.convert(progressMonitor, FileBuffersMessages.RemoveTrailingWhitespaceOperation_task_generatingChanges, lineCount);
		try {

			MultiTextEditWithProgress multiEdit= new MultiTextEditWithProgress(FileBuffersMessages.RemoveTrailingWhitespaceOperation_task_applyingChanges);

			for (int i= 0; i < lineCount; i++) {
				IRegion region= document.getLineInformation(i);
				if (region.getLength() == 0)
					continue;

				int lineStart= region.getOffset();
				int lineExclusiveEnd= lineStart + region.getLength();
				int j= lineExclusiveEnd -1;
				while (j >= lineStart && Character.isWhitespace(document.getChar(j))) --j;
				++j;
				if (j < lineExclusiveEnd)
					multiEdit.addChild(new DeleteEdit(j, lineExclusiveEnd - j));
				subMonitor.split(1);
			}

			return multiEdit.getChildrenSize() <= 0 ? null : multiEdit;

		} catch (BadLocationException x) {
			throw new CoreException(new Status(IStatus.ERROR, FileBuffersPlugin.PLUGIN_ID, IFileBufferStatusCodes.CONTENT_CHANGE_FAILED, "", x)); //$NON-NLS-1$
		}
	}

	@Override
	protected DocumentRewriteSessionType getDocumentRewriteSessionType() {
		return DocumentRewriteSessionType.SEQUENTIAL;
	}
}