1 package org.argeo.cms.ui.eclipse.forms; 2 3 /** 4 * Classes that implement this interface can be added to the managed form and 5 * take part in the form life cycle. The part is initialized with the form and 6 * will be asked to accept focus. The part can receive form input and can elect 7 * to do something according to it (for example, select an object that matches 8 * the input). 9 * <p> 10 * The form part has two 'out of sync' states in respect to the model(s) that 11 * feed the form: <b>dirty</b> and <b>stale</b>. When a part is dirty, it 12 * means that the user interacted with it and now its widgets contain state that 13 * is newer than the model. In order to sync up with the model, 'commit' needs 14 * to be called. In contrast, the model can change 'under' the form (as a result 15 * of some actions outside the form), resulting in data in the model being 16 * 'newer' than the content presented in the form. A 'stale' form part is 17 * brought in sync with the model by calling 'refresh'. The part is responsible 18 * for notifying the form when one of these states change in the part. The form 19 * reserves the right to handle this notification in the most appropriate way 20 * for the situation (for example, if the form is in a page of the multi-page 21 * editor, it may do nothing for stale parts if the page is currently not 22 * showing). 23 * <p> 24 * When the form is disposed, each registered part is disposed as well. Parts 25 * are responsible for releasing any system resources they created and for 26 * removing themselves as listeners from all event providers. 27 * 28 * @see IManagedForm 29 * @since 1.0 30 * 31 */ 32 public interface IFormPart { 33 /** 34 * Initializes the part. 35 * 36 * @param form 37 * the managed form that manages the part 38 */ 39 void initialize(IManagedForm form); 40 41 /** 42 * Disposes the part allowing it to release allocated resources. 43 */ 44 void dispose(); 45 46 /** 47 * Returns true if the part has been modified with respect to the data 48 * loaded from the model. 49 * 50 * @return true if the part has been modified with respect to the data 51 * loaded from the model 52 */ 53 boolean isDirty(); 54 55 /** 56 * If part is displaying information loaded from a model, this method 57 * instructs it to commit the new (modified) data back into the model. 58 * 59 * @param onSave 60 * indicates if commit is called during 'save' operation or for 61 * some other reason (for example, if form is contained in a 62 * wizard or a multi-page editor and the user is about to leave 63 * the page). 64 */ 65 void commit(boolean onSave); 66 67 /** 68 * Notifies the part that an object has been set as overall form's input. 69 * The part can elect to react by revealing or selecting the object, or do 70 * nothing if not applicable. 71 * 72 * @return <code>true</code> if the part has selected and revealed the 73 * input object, <code>false</code> otherwise. 74 */ 75 boolean setFormInput(Object input); 76 77 /** 78 * Instructs form part to transfer focus to the widget that should has focus 79 * in that part. The method can do nothing (if it has no widgets capable of 80 * accepting focus). 81 */ 82 void setFocus(); 83 84 /** 85 * Tests whether the form part is stale and needs refreshing. Parts can 86 * receive notification from models that will make their content stale, but 87 * may need to delay refreshing to improve performance (for example, there 88 * is no need to immediately refresh a part on a form that is current on a 89 * hidden page). 90 * <p> 91 * It is important to differentiate 'stale' and 'dirty' states. Part is 92 * 'dirty' if user interacted with its editable widgets and changed the 93 * values. In contrast, part is 'stale' when the data it presents in the 94 * widgets has been changed in the model without direct user interaction. 95 * 96 * @return <code>true</code> if the part needs refreshing, 97 * <code>false</code> otherwise. 98 */ 99 boolean isStale(); 100 101 /** 102 * Refreshes the part completely from the information freshly obtained from 103 * the model. The method will not be called if the part is not stale. 104 * Otherwise, the part is responsible for clearing the 'stale' flag after 105 * refreshing itself. 106 */ 107 void refresh(); 108 }