/*******************************************************************************
 * 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;

/**
 * Extension interface for {@link org.eclipse.jface.text.ITextViewer}. Defines
 * a conceptual replacement of the original visible region concept. This interface
 * replaces {@link org.eclipse.jface.text.ITextViewerExtension3}.
 * <p>
 * Introduces the explicit concept of model and widget coordinates. For example,
 * a selection returned by the text viewer's control is a widget selection. A
 * widget selection always maps to a certain range of the viewer's document.
 * This range is considered the model selection.
 * <p>
 * All model ranges that have a corresponding widget ranges are considered
 * "exposed model ranges". The viewer can be requested to expose a given model
 * range. Thus, a visible region is a particular degeneration of exposed model
 * ranges.
 * <p>
 * This interface allows implementers to follow a sophisticated presentation
 * model in which the visible presentation is a complex projection of the
 * viewer's input document.
 * 
 * @since 3.0
 */
public interface ITextViewerExtension5 extends ITextViewerExtension3 {
	
	/**
	 * Returns the minimal region of the viewer's input document that completely
	 * comprises everything that is visible in the viewer's widget or
	 * <code>null</code> if there is no such region.
	 * 
	 * @return the minimal region of the viewer's document comprising the
	 *         contents of the viewer's widget or <code>null</code>
	 */
	IRegion getModelCoverage();
	
	/**
	 * Returns the widget line that corresponds to the given line of the
	 * viewer's input document or <code>-1</code> if there is no such line.
	 * 
	 * @param modelLine the line of the viewer's document
	 * @return the corresponding widget line or <code>-1</code>
	 */
	int modelLine2WidgetLine(int modelLine);

	/**
	 * Returns the widget offset that corresponds to the given offset in the
	 * viewer's input document or <code>-1</code> if there is no such offset
	 * 
	 * @param modelOffset the offset in the viewer's document
	 * @return the corresponding widget offset or <code>-1</code>
	 */
	int modelOffset2WidgetOffset(int modelOffset);

	/**
	 * Returns the minimal region of the viewer's widget that completely
	 * comprises the given region of the viewer's input document or
	 * <code>null</code> if there is no such region.
	 * 
	 * @param modelRange the region of the viewer's document
	 * @return the minimal region of the widget comprising
	 *         <code>modelRange</code> or <code>null</code>
	 */
	IRegion modelRange2WidgetRange(IRegion modelRange);

	/**
	 * Returns the offset of the viewer's input document that corresponds to the
	 * given widget offset or <code>-1</code> if there is no such offset
	 * 
	 * @param widgetOffset the widget offset
	 * @return the corresponding offset in the viewer's document or
	 *         <code>-1</code>
	 */
	int widgetOffset2ModelOffset(int widgetOffset);
	
	/**
	 * Returns the minimal region of the viewer's input document that completely
	 * comprises the given widget region or <code>null</code> if there is no
	 * such region.
	 * 
	 * @param widgetRange the widget region
	 * @return the minimal region of the viewer's document comprising
	 *         <code>widgetlRange</code> or <code>null</code>
	 */
	IRegion widgetRange2ModelRange(IRegion widgetRange);

	/**
	 * Returns the line of the viewer's input document that corresponds to the
	 * given widget line or <code>-1</code> if there is no such line.
	 * 
	 * @param widgetLine the widget line
	 * @return the corresponding line of the viewer's document or
	 *         <code>-1</code>
	 */
	int widgetLine2ModelLine(int widgetLine);
	
	/**
	 * Returns the widget line of the given widget offset.
	 * 
	 * @param widgetOffset the widget offset
	 * @return the widget line of the widget offset
	 */
	int widgetLineOfWidgetOffset(int widgetOffset);
	
	
	/**
	 * Returns the maximal subranges of the given model range thus that there is
	 * no offset inside a subrange for which there is no image offset.
	 * 
	 * @param modelRange the model range
	 * @return the list of subranges
	 */
	IRegion[] getCoveredModelRanges(IRegion modelRange);
	
	/**
	 * Exposes the given model range. Returns whether this call caused a change
	 * of the set of exposed model ranges.
	 * 
	 * @param modelRange the model range to be exposed
	 * @return <code>true</code> if the set of exposed model ranges changed,
	 *         <code>false</code> otherwise
	 */
	boolean exposeModelRange(IRegion modelRange);
}
