org.eclipse.jface.text/src/org/eclipse/jface/text/contentassist/IContextInformationPresenter.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.contentassist;


import org.eclipse.jface.text.ITextViewer;
import org.eclipse.jface.text.TextPresentation;


/**
 * A context information presenter determines the presentation
 * of context information depending on a given document position.
 * The interface can be implemented by clients.
 * 
 * @since 2.0
 */
public interface IContextInformationPresenter {

	/**
	 * Installs this presenter for the given context information.
	 *
	 * @param info the context information which this presenter should style
	 * @param viewer the text viewer on which the information is presented
	 * @param documentPosition the document position for which the information has been computed
	 */
	void install(IContextInformation info, ITextViewer viewer, int documentPosition);
	
	/**
	 * Updates the given presentation of the given context information 
	 * at the given document position. Returns whether update changed the
	 * presentation.
	 *
	 * @param documentPosition the current position within the document
	 * @param presentation the presentation to be updated
	 * @return <code>true</code> if the given presentation has been changed
	 */
	boolean updatePresentation(int documentPosition, TextPresentation presentation);
}