org.eclipse.jface.text/src/org/eclipse/jface/text/presentation/IPresentationReconciler.java

/*******************************************************************************
 * Copyright (c) 2000, 2005 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.jface.text.presentation;


import org.eclipse.jface.text.ITextViewer;


/**
 * An <code>IPresentationReconciler</code> defines and maintains the representation of a text
 * viewer's document in the presence of changes applied to the document. An
 * <code>IPresentationReconciler</code> is a <code>ITextViewer</code> add-on.
 * <p>
 * The presentation reconciler keeps track of changes applied to the text viewer. It sends each
 * change to presentation damagers which are registered for the content types of the regions in
 * which the change occurred. The presentation reconciler passes the computed damage to presentation
 * repairer which construct text presentations. When applied to the presentation reconciler's text
 * viewer, those text presentations bring the document's presentation in sync with the document's
 * content and thus repair the damage. A presentation damager is expected to return damage which is
 * a valid input for a presentation repairer registered for the same content type as the damager.
 * </p>
 * <p>
 * A presentation reconciler should always be configured with a pair of damager/repairer strategies.
 * I.e. for each damager there should be a corresponding repairer.
 * </p>
 * <p>
 * The interface may be implemented by clients. Clients may use <code>PresentationReconciler</code>
 * as the standard implementation of this interface.
 * </p>
 * <p>
 * In order to provided backward compatibility for clients of <code>IPresentationReconciler</code>,
 * extension interfaces are used to provide a means of evolution. The following extension interface
 * exists:
 * </p>
 * <ul>
 * <li>{@link org.eclipse.jface.text.presentation.IPresentationReconcilerExtension} since version
 * 3.0 adding support for documents with multiple partitionings.</li>
 * </ul>
 *
 *
 * @see org.eclipse.jface.text.presentation.IPresentationReconcilerExtension
 * @see org.eclipse.jface.text.ITextViewer
 * @see org.eclipse.jface.text.presentation.IPresentationDamager
 * @see org.eclipse.jface.text.presentation.IPresentationRepairer
 * @see org.eclipse.jface.text.TextPresentation
 */
public interface IPresentationReconciler {

	/**
	 * Installs this presentation reconciler on the given text viewer. After
	 * this method has been finished, the reconciler is operational. I.e., it
	 * works without requesting further client actions until
	 * <code>uninstall</code> is called.
	 * <p>
	 * The <code>install</code> and <code>uninstall</code> methods must be
	 * called in sequence; i.e. repeatedly calling <code>install</code>
	 * without calling <code>uninstall</code> may throw an exception.
	 * </p>
	 *
	 * @param viewer the viewer on which this presentation reconciler is
	 *        installed
	 */
	void install(ITextViewer viewer);

	/**
	 * Removes the reconciler from the text viewer it has previously been
	 * installed on.
	 */
	void uninstall();

	/**
	 * Returns the presentation damager registered with this presentation reconciler
	 * for the specified content type.
	 *
	 * @param contentType the content type for which to determine the damager
	 * @return the presentation damager registered for the given content type, or
	 *		<code>null</code> if there is no damager
	 */
	IPresentationDamager getDamager(String contentType);

	/**
	 * Returns the presentation repairer registered with this presentation reconciler
	 * for the specified content type.
	 *
	 * @param contentType the content type for which to determine the repairer
	 * @return the presentation repairer registered for the given content type, or
	 *		<code>null</code> if there is no repairer
	 */
	IPresentationRepairer getRepairer(String contentType);
}