1 /******************************************************************************* 2 * Copyright (c) 2000, 2005 IBM Corporation and others. 3 * All rights reserved. This program and the accompanying materials 4 * are made available under the terms of the Eclipse Public License v1.0 5 * which accompanies this distribution, and is available at 6 * http://www.eclipse.org/legal/epl-v10.html 7 * 8 * Contributors: 9 * IBM Corporation - initial API and implementation 10 *******************************************************************************/ 11 package org.eclipse.jface.text; 12 13 14 15 /** 16 * Computes the information to be shown in a hover popup which appears on top of 17 * the text viewer's text widget when a hover event occurs. If the text hover 18 * does not provide information no hover popup is shown. Any implementer of this 19 * interface must be capable of operating in a non-UI thread. 20 * <p> 21 * 22 * In order to provide backward compatibility for clients of 23 * <code>ITextHover</code>, extension interfaces are used as a means of 24 * evolution. The following extension interfaces exist: 25 * <ul> 26 * <li>{@link org.eclipse.jface.text.ITextHoverExtension} since version 3.0 27 * allowing a text hover to provide a creator for the hover control. This allows 28 * for sophisticated hovers in a way that information computed by the hover can 29 * be displayed in the best possible form.</li> 30 * </ul></p> 31 * <p> 32 * Clients may implement this interface.</p> 33 * 34 * @see org.eclipse.jface.text.ITextHoverExtension 35 * @see org.eclipse.jface.text.ITextViewer 36 */ 37 public interface ITextHover { 38 39 /** 40 * Returns the information which should be presented when a hover popup is shown 41 * for the specified hover region. The hover region has the same semantics 42 * as the region returned by <code>getHoverRegion</code>. If the returned 43 * information is <code>null</code> or empty no hover popup will be shown. 44 * 45 * @param textViewer the viewer on which the hover popup should be shown 46 * @param hoverRegion the text range in the viewer which is used to determine 47 * the hover display information 48 * @return the hover popup display information 49 */ 50 String getHoverInfo(ITextViewer textViewer, IRegion hoverRegion); 51 52 /** 53 * Returns the text region which should serve as the source of information 54 * to compute the hover popup display information. The popup has been requested 55 * for the given offset.<p> 56 * For example, if hover information can be provided on a per method basis in a 57 * source viewer, the offset should be used to find the enclosing method and the 58 * source range of the method should be returned. 59 * 60 * @param textViewer the viewer on which the hover popup should be shown 61 * @param offset the offset for which the hover request has been issued 62 * @return the hover region used to compute the hover display information 63 */ 64 IRegion getHoverRegion(ITextViewer textViewer, int offset); 65 } 66