/*******************************************************************************
 * Copyright (c) 2000, 2004 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.source;


import java.util.Iterator;

import org.eclipse.jface.text.IDocument;
import org.eclipse.jface.text.Position;


/**
 * This interface defines the model for managing annotations attached to a document.
 * The model maintains a set of annotations for a given document and notifies registered annotation 
 * model listeners about annotation model changes. It also provides methods
 * for querying the current position of an annotation managed
 * by this model.
 * <p>
 * In order to provide backward compatibility for clients of <code>IAnnotationModel</code>, extension
 * interfaces are used to provide a means of evolution. The following extension interfaces
 * exist:
 * <ul>
 * <li> {@link org.eclipse.jface.text.source.IAnnotationModelExtension} since version 3.0 introducing the concept
 *      of model piggybacking annotation models, modification time stamps, and enhanced manipulation methods.
 * </li>
 * </ul>
 * </p>
 * 
 * Clients may implement this interface or use the default implementation provided
 * by <code>AnnotationModel</code>.
 *
 * @see org.eclipse.jface.text.source.IAnnotationModelExtension
 * @see org.eclipse.jface.text.source.Annotation
 * @see org.eclipse.jface.text.source.IAnnotationModelListener
 */
public interface IAnnotationModel {
	
	/**
	 * Registers the annotation model listener with this annotation model.
	 * After registration listener is informed about each change of this model.
	 * If the listener is already registered nothing happens.
	 *
	 * @param listener the listener to be registered, may not be <code>null</code>
	 */
	void addAnnotationModelListener(IAnnotationModelListener listener);
	
	/**
	 * Removes the listener from the model's list of annotation model listeners.
	 * If the listener is not registered with the model nothing happens.
	 *
	 * @param listener the listener to be removed, may not be <code>null</code>
	 */
	void removeAnnotationModelListener(IAnnotationModelListener listener);
	
	/**
	 * Connects the annotation model to a document. The annotations managed 
	 * by this model must subsequently update according to the changes applied 
	 * to the document. Once an annotation model is connected to a document,
	 * all further <code>connect</code> calls must mention the document the 
	 * model is already connected to. An annotation model primarily uses 
	 * <code>connect</code> and <code>disconnect</code> for reference counting 
	 * the document. Reference counting frees the clients from keeping tracker
	 * whether a model has already been connected to a document.
	 *
	 * @param document the document the model gets connected to,
	 *		may not be <code>null</code>
	 *
	 * @see #disconnect(IDocument)
	 */
	void connect(IDocument document);
	 
	/**
	 * Disconnects this model from a document. After that, document changes no longer matter.
	 * An annotation model may only be disconnected from a document to which it has been
	 * connected before. If the model reference counts the connections to a document,
	 * the connection to the document may only be terminated if the reference count does
	 * down to 0.
	 *
	 * @param document the document the model gets disconnected from,
	 *		may not be <code>null</code>
	 *
	 * @see #connect(IDocument) for further specification details
	 */
	void disconnect(IDocument document);
	
	/**
	 * Adds a annotation to this annotation model. The annotation is associated with
	 * with the given position which describes the range covered by the annotation. 
	 * All registered annotation model listeners are informed about the change.
	 * If the model is connected to a document, the position is automatically
	 * updated on document changes. If the annotation is already managed by
	 * this annotation model or is not a valid position in the connected nothing happens.
	 *
	 * @param annotation the annotation to add, may not be <code>null</code>
	 * @param position the position describing the range covered by this annotation,
	 *		may not be <code>null</code>	 
	 */
	void addAnnotation(Annotation annotation, Position position);
	
	/**
	 * Removes the given annotation from the model. I.e. the annotation is no 
	 * longer managed by this model. The position associated with the annotation
	 * is no longer updated on document changes. If the annotation is not
	 * managed by this model, nothing happens.
	 *
	 * @param annotation the annotation to be removed from this model,
	 *		may not be <code>null</code>
	 */
	void removeAnnotation(Annotation annotation);
			
	/**
	 * Returns all annotations managed by this model.
	 *
	 * @return all annotations managed by this model
	 */
	Iterator getAnnotationIterator();
		
	/**
	 * Returns the position associated with the given annotation.
	 *
	 * @param annotation the annotation whose position should be returned
	 * @return the position of the given annotation or <code>null</code> if no
	 *		associated annotation exists
	 */
	Position getPosition(Annotation annotation);
}	 

