1 /******************************************************************************* 2 * Copyright (c) 2000, 2015 IBM Corporation and others. 3 * 4 * This program and the accompanying materials 5 * are made available under the terms of the Eclipse Public License 2.0 6 * which accompanies this distribution, and is available at 7 * https://www.eclipse.org/legal/epl-2.0/ 8 * 9 * SPDX-License-Identifier: EPL-2.0 10 * 11 * Contributors: 12 * IBM Corporation - initial API and implementation 13 *******************************************************************************/ 14 package org.eclipse.ui; 15 16 /** 17 * A view is a visual component within a workbench page. It is typically used to 18 * navigate a hierarchy of information (like the workspace), open an editor, or 19 * display properties for the active editor. Modifications made in a view are 20 * saved immediately (in contrast to an editor part, which conforms to a more 21 * elaborate open-save-close lifecycle). 22 * <p> 23 * Only one instance of a particular view type may exist within a workbench 24 * page. This policy is designed to simplify part management for a user. 25 * </p> 26 * <p> 27 * This interface may be implemented directly. For convenience, a base 28 * implementation is defined in <code>ViewPart</code>. 29 * </p> 30 * <p> 31 * A view is added to the workbench in two steps: 32 * </p> 33 * <ol> 34 * <li>A view extension is contributed to the workbench registry. This extension 35 * defines the extension id and extension class.</li> 36 * <li>The view is included in the default layout for a perspective. 37 * Alternatively, the user may open the view from the Perspective menu.</li> 38 * </ol> 39 * <p> 40 * Views implement the <code>IAdaptable</code> interface; extensions are managed 41 * by the platform's adapter manager. 42 * </p> 43 * <p> 44 * As of 3.4, views may optionally adapt to {@link ISizeProvider} if they have a 45 * preferred size. The default presentation will make a best effort to allocate 46 * the preferred size to a view if it is the only part in a stack. If there is 47 * more than one part in the stack, the constraints will be disabled for that 48 * stack. The size constraints are adjusted for the size of the tab and border 49 * trim. Note that this is considered to be a hint to the presentation, and not 50 * all presentations may honor size constraints. 51 * </p> 52 * 53 * @see IWorkbenchPage#showView 54 * @see org.eclipse.ui.part.ViewPart 55 * @see ISizeProvider 56 */ 57 public interface IViewPart extends IWorkbenchPart, IPersistable { 58 /** 59 * Returns the site for this view. This method is equivalent to 60 * <code>(IViewSite) getSite()</code>. 61 * <p> 62 * The site can be <code>null</code> while the view is being initialized. After 63 * the initialization is complete, this value must be non-<code>null</code> for 64 * the remainder of the view's life cycle. 65 * </p> 66 * 67 * @return the view site; this value may be <code>null</code> if the view has 68 * not yet been initialized 69 */ getViewSite()70 IViewSite getViewSite(); 71 72 /** 73 * Initializes this view with the given view site. 74 * <p> 75 * This method is automatically called by the workbench shortly after the part 76 * is instantiated. It marks the start of the views's lifecycle. Clients must 77 * not call this method. 78 * </p> 79 * 80 * @param site the view site 81 * @exception PartInitException if this view was not initialized successfully 82 */ init(IViewSite site)83 void init(IViewSite site) throws PartInitException; 84 85 /** 86 * Initializes this view with the given view site. A memento is passed to the 87 * view which contains a snapshot of the views state from a previous session. 88 * Where possible, the view should try to recreate that state within the part 89 * controls. 90 * <p> 91 * This method is automatically called by the workbench shortly after the part 92 * is instantiated. It marks the start of the views's lifecycle. Clients must 93 * not call this method. 94 * </p> 95 * 96 * @param site the view site 97 * @param memento the IViewPart state or null if there is no previous saved 98 * state 99 * @exception PartInitException if this view was not initialized successfully 100 */ init(IViewSite site, IMemento memento)101 void init(IViewSite site, IMemento memento) throws PartInitException; 102 103 /** 104 * Saves the object state within a memento. 105 * 106 * @param memento a memento to receive the object state 107 */ 108 @Override saveState(IMemento memento)109 void saveState(IMemento memento); 110 } 111