1 /******************************************************************************* 2 * Copyright (c) 2000, 2007 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.ui.forms; 12 13 /** 14 * Classes that implement this interface can be added to the managed form and 15 * take part in the form life cycle. The part is initialized with the form and 16 * will be asked to accept focus. The part can receive form input and can elect 17 * to do something according to it (for example, select an object that matches 18 * the input). 19 * <p> 20 * The form part has two 'out of sync' states in respect to the model(s) that 21 * feed the form: <b>dirty</b> and <b>stale</b>. When a part is dirty, it 22 * means that the user interacted with it and now its widgets contain state that 23 * is newer than the model. In order to sync up with the model, 'commit' needs 24 * to be called. In contrast, the model can change 'under' the form (as a result 25 * of some actions outside the form), resulting in data in the model being 26 * 'newer' than the content presented in the form. A 'stale' form part is 27 * brought in sync with the model by calling 'refresh'. The part is responsible 28 * for notifying the form when one of these states change in the part. The form 29 * reserves the right to handle this notification in the most appropriate way 30 * for the situation (for example, if the form is in a page of the multi-page 31 * editor, it may do nothing for stale parts if the page is currently not 32 * showing). 33 * <p> 34 * When the form is disposed, each registered part is disposed as well. Parts 35 * are responsible for releasing any system resources they created and for 36 * removing themselves as listeners from all event providers. 37 * 38 * @see IManagedForm 39 * @since 3.0 40 * 41 */ 42 public interface IFormPart { 43 /** 44 * Initializes the part. 45 * 46 * @param form 47 * the managed form that manages the part 48 */ 49 void initialize(IManagedForm form); 50 51 /** 52 * Disposes the part allowing it to release allocated resources. 53 */ 54 void dispose(); 55 56 /** 57 * Returns true if the part has been modified with respect to the data 58 * loaded from the model. 59 * 60 * @return true if the part has been modified with respect to the data 61 * loaded from the model 62 */ 63 boolean isDirty(); 64 65 /** 66 * If part is displaying information loaded from a model, this method 67 * instructs it to commit the new (modified) data back into the model. 68 * 69 * @param onSave 70 * indicates if commit is called during 'save' operation or for 71 * some other reason (for example, if form is contained in a 72 * wizard or a multi-page editor and the user is about to leave 73 * the page). 74 */ 75 void commit(boolean onSave); 76 77 /** 78 * Notifies the part that an object has been set as overall form's input. 79 * The part can elect to react by revealing or selecting the object, or do 80 * nothing if not applicable. 81 * 82 * @return <code>true</code> if the part has selected and revealed the 83 * input object, <code>false</code> otherwise. 84 */ 85 boolean setFormInput(Object input); 86 87 /** 88 * Instructs form part to transfer focus to the widget that should has focus 89 * in that part. The method can do nothing (if it has no widgets capable of 90 * accepting focus). 91 */ 92 void setFocus(); 93 94 /** 95 * Tests whether the form part is stale and needs refreshing. Parts can 96 * receive notification from models that will make their content stale, but 97 * may need to delay refreshing to improve performance (for example, there 98 * is no need to immediately refresh a part on a form that is current on a 99 * hidden page). 100 * <p> 101 * It is important to differentiate 'stale' and 'dirty' states. Part is 102 * 'dirty' if user interacted with its editable widgets and changed the 103 * values. In contrast, part is 'stale' when the data it presents in the 104 * widgets has been changed in the model without direct user interaction. 105 * 106 * @return <code>true</code> if the part needs refreshing, 107 * <code>false</code> otherwise. 108 */ 109 boolean isStale(); 110 111 /** 112 * Refreshes the part completely from the information freshly obtained from 113 * the model. The method will not be called if the part is not stale. 114 * Otherwise, the part is responsible for clearing the 'stale' flag after 115 * refreshing itself. 116 */ 117 void refresh(); 118 } 119