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

/*******************************************************************************
 * Copyright (c) 2000, 2003 IBM Corporation 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 API and implementation
 *******************************************************************************/

package org.eclipse.jface.text;
 
/**
 * Extension interface for <code>IDocument</code>.  <p>
 * 
 * It introduces the notion of sequentially rewriting a document. This is to tell a
 * document that a sequence of non-overlapping replace operation is about to be
 * performed.<p>
 * 
 * Is also introduces the concept of post notification replaces. This is, a document
 * listener who is informed about a document change can cause a derived document
 * change. As the listener is not allowed to directly modify the document, it can
 * register a replace operation that is performed directly after all document listeners
 * have been notified.
 * 
 * @since 2.0
 */
public interface IDocumentExtension {
	
	/**
	 * Interface for a post notification replace operation.
	 */
	public interface IReplace {
		
		/**
		 * Executes the replace operation on the given document.
		 * @param document the document to be changed
		 * @param owner the owner of this replace operation
		 */
		void perform(IDocument document, IDocumentListener owner);
	};
	
	/**
	 * Callback for document listeners to be used inside <code>documentChanged</code>
	 * to register a post notification replace operation on the document notifying them.
	 * 
	 * @param owner the owner of the replace operation
	 * @param replace the replace operation to be executed
	 * @exception UnsupportedOperationException if <code>registerPostNotificationReplace</code>
	 * 	is not supported by this document
	 */
	void registerPostNotificationReplace(IDocumentListener owner, IReplace replace) throws UnsupportedOperationException;
	
	/**
	 * Stops the processing of registered post notification replace operations until
	 * <code>resumePostNotificationProcessing</code> is called.
	 */
	void stopPostNotificationProcessing();
	
	/**
	 * Resumes the processing of post notification replace operations. If the queue of registered
	 * <code>IDocumentExtension.IReplace</code> objects is not empty, they are immediately processed if the 
	 * document is not inside a replace operation. If the document is inside a replace operation,
	 * they are processed directly after the replace operation has finished.
	 */
	void resumePostNotificationProcessing();
	
	/**
	 * Tells the document that it is about to be sequentially rewritten. That is a
	 * sequence of non-overlapping replace operations will be performed on it. The
	 * <code>normalize</code> flag indicates whether the rewrite is preformed from
	 * the start of the document to its end or from an arbitrary start offset.
	 * 
	 * @param normalize <code>true</code> if performed from the start to the end of the document
	 */
	void startSequentialRewrite(boolean normalize);
	
	/**
	 * Tells the document that the sequential rewrite has been finished.
	 */
	void stopSequentialRewrite();
}