| /******************************************************************************* |
| * Copyright (c) 2000, 2005 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.util; |
| |
| import org.eclipse.swt.dnd.DropTargetEvent; |
| import org.eclipse.swt.dnd.DropTargetListener; |
| import org.eclipse.swt.dnd.Transfer; |
| |
| /** |
| * A <code>TransferDropTargetListener</code> is a <code>DropTragetListener</code> |
| * that handles one type of SWT {@link Transfer}. |
| * The purpose of a <code>TransferDropTargetListener</code> is to: |
| * <ul> |
| * <li>Determine enablement for a drop operation. A <code>TransferDropTargetListener</code> |
| * will not be used if <code>isEnabled</code> returns false. |
| * <li>When enabled, optionally show feedback on the <code>DropTarget</code>. |
| * <li>Perform the actual drop |
| * </ul> |
| * A <code>DelegatingDropAdapter</code> allows these functions to be implemented |
| * separately for unrelated types of drags. <code>DelegatingDropAdapter</code> then |
| * combines the function of each <code>TransferDropTargetListener</code>, while |
| * allowing them to be implemented as if they were the only <code>DragSourceListener</code>. |
| * @since 3.0 |
| */ |
| public interface TransferDropTargetListener extends DropTargetListener { |
| /** |
| * Returns the <code>Transfer</code> type that this listener can |
| * accept a drop operation for. |
| * |
| * @return the <code>Transfer</code> for this listener |
| */ |
| Transfer getTransfer(); |
| |
| /** |
| * Returns <code>true</code> if this listener can handle the drop |
| * based on the given <code>DropTargetEvent</code>. |
| * <p> |
| * This method is called by the <code>DelegatingDropAdapter</code> only |
| * if the <code>DropTargetEvent</code> contains a transfer data type |
| * supported by this listener. The <code>Transfer</code> returned by the |
| * <code>#getTransfer()</code> method is used for this purpose. |
| * </p> |
| * |
| * @param event the drop target event |
| * @return <code>true</code> if the listener is enabled for the given |
| * drop target event. |
| */ |
| boolean isEnabled(DropTargetEvent event); |
| } |