| /******************************************************************************* |
| * 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 Eclipse Public License v1.0 |
| * which accompanies this distribution, and is available at |
| * http://www.eclipse.org/legal/epl-v10.html |
| * |
| * Contributors: |
| * IBM Corporation - initial API and implementation |
| *******************************************************************************/ |
| package org.eclipse.jface.viewers; |
| |
| /** |
| * A label provider maps an element of the viewer's model to |
| * an optional image and optional text string used to display |
| * the element in the viewer's control. Certain label providers |
| * may allow multiple labels per element. |
| * This is an "abstract interface", defining methods common |
| * to all label providers, but does not actually define the methods |
| * to get the label(s) for an element. This interface should never |
| * be directly implemented. |
| * Most viewers will take either an <code>ILabelProvider</code> or |
| * an <code>ITableLabelProvider</code>. |
| * <p> |
| * A label provider must not be shared between viewers |
| * since a label provider generally manages SWT resources (images), |
| * which must be disposed when the viewer is disposed. |
| * To simplify life cycle management, the current label provider |
| * of a viewer is disposed when the viewer is disposed. |
| * </p> |
| * <p> |
| * Label providers can be used outside the context of viewers wherever |
| * images are needed. When label providers are used in this fashion |
| * it is the responsibility of the user to ensure <code>dispose</code> |
| * is called when the provider is no longer needed. |
| * </p> |
| * |
| * @see ILabelProvider |
| * @see ITableLabelProvider |
| */ |
| public interface IBaseLabelProvider { |
| /** |
| * Adds a listener to this label provider. |
| * Has no effect if an identical listener is already registered. |
| * <p> |
| * Label provider listeners are informed about state changes |
| * that affect the rendering of the viewer that uses this label provider. |
| * </p> |
| * |
| * @param listener a label provider listener |
| */ |
| public void addListener(ILabelProviderListener listener); |
| |
| /** |
| * Disposes of this label provider. When a label provider is |
| * attached to a viewer, the viewer will automatically call |
| * this method when the viewer is being closed. When label providers |
| * are used outside of the context of a viewer, it is the client's |
| * responsibility to ensure that this method is called when the |
| * provider is no longer needed. |
| */ |
| public void dispose(); |
| |
| /** |
| * Returns whether the label would be affected |
| * by a change to the given property of the given element. |
| * This can be used to optimize a non-structural viewer update. |
| * If the property mentioned in the update does not affect the label, |
| * then the viewer need not update the label. |
| * |
| * @param element the element |
| * @param property the property |
| * @return <code>true</code> if the label would be affected, |
| * and <code>false</code> if it would be unaffected |
| */ |
| public boolean isLabelProperty(Object element, String property); |
| |
| /** |
| * Removes a listener to this label provider. |
| * Has no affect if an identical listener is not registered. |
| * |
| * @param listener a label provider listener |
| */ |
| public void removeListener(ILabelProviderListener listener); |
| } |