bundles/org.eclipse.wst.xml.ui/src/org/eclipse/wst/xml/ui/internal/XMLFormattingStrategy.java

/*******************************************************************************
 * Copyright (c) 2007 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.xml.ui.internal;

import java.util.LinkedList;

import org.eclipse.jface.text.BadLocationException;
import org.eclipse.jface.text.IDocument;
import org.eclipse.jface.text.IRegion;
import org.eclipse.jface.text.TypedPosition;
import org.eclipse.jface.text.formatter.ContextBasedFormattingStrategy;
import org.eclipse.jface.text.formatter.FormattingContextProperties;
import org.eclipse.jface.text.formatter.IFormattingContext;
import org.eclipse.jface.text.formatter.IFormattingStrategyExtension;
import org.eclipse.text.edits.TextEdit;
import org.eclipse.wst.sse.core.StructuredModelManager;
import org.eclipse.wst.sse.core.internal.provisional.IStructuredModel;
import org.eclipse.wst.sse.core.internal.provisional.text.IStructuredDocument;
import org.eclipse.wst.sse.ui.internal.Logger;
import org.eclipse.wst.xml.core.internal.formatter.DefaultXMLPartitionFormatter;

public class XMLFormattingStrategy extends ContextBasedFormattingStrategy implements IFormattingStrategyExtension {

	/** Documents to be formatted by this strategy */
	private final LinkedList fDocuments = new LinkedList();
	/** Partitions to be formatted by this strategy */
	private final LinkedList fPartitions = new LinkedList();
	private IRegion fRegion;
	private DefaultXMLPartitionFormatter formatter = new DefaultXMLPartitionFormatter();

	/**
	 * @param formatProcessor
	 */
	public XMLFormattingStrategy() {
		super();
	}

	/*
	 * @see org.eclipse.jface.text.formatter.ContextBasedFormattingStrategy#format()
	 */
	public void format() {
		super.format();

		final IDocument document = (IDocument) fDocuments.removeFirst();
		final TypedPosition partition = (TypedPosition) fPartitions.removeFirst();

		if (document != null && partition != null && fRegion != null) {
			try {
				if (document instanceof IStructuredDocument) {
					IStructuredModel model = StructuredModelManager.getModelManager().getModelForEdit((IStructuredDocument) document);
					if (model != null) {
						try {
							TextEdit edit = formatter.format(model, fRegion.getOffset(), fRegion.getLength());
							if (edit != null) {
								try {
									model.aboutToChangeModel();
									edit.apply(document);
								}
								finally {
									model.changedModel();
								}
							}
						}
						finally {
							model.releaseFromEdit();
						}
					}
				}
			}
			catch (BadLocationException e) {
				// log for now, unless we find reason not to
				Logger.log(Logger.INFO, e.getMessage());
			}
		}
	}

	/*
	 * @see org.eclipse.jface.text.formatter.ContextBasedFormattingStrategy#formatterStarts(org.eclipse.jface.text.formatter.IFormattingContext)
	 */
	public void formatterStarts(final IFormattingContext context) {
		super.formatterStarts(context);

		fPartitions.addLast(context.getProperty(FormattingContextProperties.CONTEXT_PARTITION));
		fDocuments.addLast(context.getProperty(FormattingContextProperties.CONTEXT_MEDIUM));
		fRegion = (IRegion) context.getProperty(FormattingContextProperties.CONTEXT_REGION);
	}

	/*
	 * @see org.eclipse.jface.text.formatter.ContextBasedFormattingStrategy#formatterStops()
	 */
	public void formatterStops() {
		super.formatterStops();

		fPartitions.clear();
		fDocuments.clear();
	}
}