org.eclipse.text/src/org/eclipse/jface/text/DocumentPartitioningChangedEvent.java

/**********************************************************************
Copyright (c) 2000, 2003 IBM Corp. and others.
All rights reserved. This program and the accompanying materials
are made available under the terms of the Common Public License v1.0
which accompanies this distribution, and is available at
http://www.eclipse.org/legal/cpl-v10.html

Contributors:
	IBM Corporation - Initial implementation
**********************************************************************/
package org.eclipse.jface.text;

import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;

/**
 * Event describing the change of document partitionings.
 * 
 * @see org.eclipse.jface.text.IDocumentExtension3
 * @since 3.0
 */
public class DocumentPartitioningChangedEvent {
	
	/** The document whose partitionings changed */
	private final IDocument fDocument;
	/** The map of partitionings to changed regions. */
	private final Map fMap= new HashMap();

	
	/**
	 * Creates a new document partitioning changed event for the given document.
	 * 
	 * @param document the changed document
	 */
	public DocumentPartitioningChangedEvent(IDocument document) {
		fDocument= document;
	}
	
	/**
	 * Returns the changed document.
	 * 
	 * @return the changed document
	 */
	public IDocument getDocument() {
		return fDocument;
	}

	/**
	 * Returns the changed region of the given partitioning or <code>null</code>
	 * if the given partitioning did not change.
	 * 
	 * @param partitioning the partitioning
	 * @return the changed regionn of the given partitioning or <code>null</code>
	 */
	public IRegion getChangedRegion(String partitioning) {
		return (IRegion) fMap.get(partitioning);
	}

	
	/**
	 * Returns the set of changed partitionings.
	 * 
	 * @return the set of changed partitionings
	 */
	public String[] getChangedPartitionings() {
		String[] partitionings= new String[fMap.size()];
		fMap.keySet().toArray(partitionings);
		return partitionings;
	}

	/**
	 * Sets the specified range as changed region for the given partitioning.
	 * 
	 * @param partitioning the partitioning
	 * @param offset the region offset
	 * @param length the region length
	 */
	public void setPartitionChange(String partitioning, int offset, int length) {
		Assert.isNotNull(partitioning);
		fMap.put(partitioning, new Region(offset, length));
	}

	/**
	 * Returns <code>true</code> if the set of changed partitionings is empty. <code>false</code>
	 * otherwise.
	 * 
	 * @return <code>true</code> if the set of changed partitionings is empty.
	 */
	public boolean isEmpty() {
		return fMap.isEmpty();
	}
	
	/**
	 * Returns the coverage of this event. This is the minimal region that contains all
	 * changed regions of all changed partitionings.
	 * 
	 * @return the coverage of this event
	 */
	public IRegion getCoverage() {
		if (fMap.isEmpty())
			return new Region(0, 0);
			
		int offset= -1;
		int endOffset= -1;
		Iterator e= fMap.values().iterator();
		while (e.hasNext()) {
			IRegion r= (IRegion) e.next();
			
			if (offset < 0 || r.getOffset() < offset)
				offset= r.getOffset();
				
			int end= r.getOffset() + r.getLength();
			if (end > endOffset)
				endOffset= end;
		}
		
		return new Region(offset, endOffset - offset);
	}
}