/*******************************************************************************
 * Copyright (c) 2000, 2005 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.jface.text.source;


import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;

import org.eclipse.jface.text.ITextViewer;


/**
 * This interface defines a visual component which may serve text viewers as an
 * annotation presentation area. Implementers of this interface have to define
 * the presentation modus. This can either depend on the connected viewer's view
 * port or not. If the modus is view port dependent the ruler only shows those
 * annotations that are attached to document regions that are visible in the
 * view port. If independent, the presented annotations can also be attached to
 * invisible document regions.
 *
 * This interfaces comprises three contracts:
 * <ul>
 * <li>The vertical ruler retrieves the annotations it presents from an
 *     annotation model.
 * <li>The ruler is a visual component which must be integrated in a hierarchy
 *     of SWT controls.
 * <li>The ruler provides interested clients with mapping and interaction
 *     information. This covers the mapping between coordinates of the ruler's
 *     control and line numbers based on the connected text viewer's document (see
 *     {@link org.eclipse.jface.text.source.IVerticalRulerInfo}).
 * </ul>
 * <p>
 * In order to provide backward compatibility for clients of
 * <code>IVerticalRuler</code>, extension interfaces are used as a means of
 * evolution. The following extension interfaces exist:
 * <ul>
 * <li>{@link org.eclipse.jface.text.source.IVerticalRulerExtension} since
 *     version 2.0 introducing setters for font and mouse button activity location.</li>
 * </ul></p>
 * <p>
 * Clients may implement this interface or use the default implementation
 * provided by {@link org.eclipse.jface.text.source.CompositeRuler} and
 * {@link org.eclipse.jface.text.source.VerticalRuler}.</p>
 *
 * @see org.eclipse.jface.text.source.IVerticalRulerExtension
 * @see org.eclipse.jface.text.ITextViewer
 */
public interface IVerticalRuler extends IVerticalRulerInfo {

	/**
	 * Associates an annotation model with this ruler.
	 * A value <code>null</code> is acceptable and clears the ruler.
	 *
	 * @param model the new annotation model, may be <code>null</code>
	 */
	void setModel(IAnnotationModel model);

	/**
	 * Returns the current annotation model of this ruler or <code>null</code>
	 * if the ruler has no model.
	 *
	 * @return this ruler's annotation model or <code>null</code> if there is no model
	 */
	IAnnotationModel getModel();

	/**
	 * Forces the vertical ruler to synchronize itself with its
	 * annotation model and its viewer's view port.
	 */
	void update();

	/**
	 * Creates the ruler's SWT control.
	 *
	 * @param parent the parent control of the ruler's control
	 * @param textViewer the text viewer to which this ruler belongs
	 * @return the ruler's SWT control
	 */
	Control createControl(Composite parent, ITextViewer textViewer);
}