| /******************************************************************************* |
| * Copyright (c) 2000, 2018 IBM Corporation and others. |
| * |
| * This program and the accompanying materials |
| * are made available under the terms of the Eclipse Public License 2.0 |
| * which accompanies this distribution, and is available at |
| * https://www.eclipse.org/legal/epl-2.0/ |
| * |
| * SPDX-License-Identifier: EPL-2.0 |
| * |
| * Contributors: |
| * IBM Corporation - initial API and implementation |
| *******************************************************************************/ |
| package org.eclipse.swt.dnd; |
| |
| import org.eclipse.swt.graphics.*; |
| import org.eclipse.swt.widgets.*; |
| |
| /** |
| * This class provides default implementations to display a source image |
| * when a drag is initiated from a <code>Table</code>. |
| * |
| * <p>Classes that wish to provide their own source image for a <code>Table</code> can |
| * extend the <code>TableDragSourceEffect</code> class, override the |
| * <code>TableDragSourceEffect.dragStart</code> method and set the field |
| * <code>DragSourceEvent.image</code> with their own image.</p> |
| * |
| * Subclasses that override any methods of this class must call the corresponding |
| * <code>super</code> method to get the default drag source effect implementation. |
| * |
| * @see DragSourceEffect |
| * @see DragSourceEvent |
| * @see <a href="http://www.eclipse.org/swt/">Sample code and further information</a> |
| * |
| * @since 3.3 |
| */ |
| public class TableDragSourceEffect extends DragSourceEffect { |
| Image dragSourceImage = null; |
| |
| /** |
| * Creates a new <code>TableDragSourceEffect</code> to handle drag effect |
| * from the specified <code>Table</code>. |
| * |
| * @param table the <code>Table</code> that the user clicks on to initiate the drag |
| */ |
| public TableDragSourceEffect(Table table) { |
| super(table); |
| } |
| |
| /** |
| * This implementation of <code>dragFinished</code> disposes the image |
| * that was created in <code>TableDragSourceEffect.dragStart</code>. |
| * |
| * Subclasses that override this method should call <code>super.dragFinished(event)</code> |
| * to dispose the image in the default implementation. |
| * |
| * @param event the information associated with the drag finished event |
| */ |
| @Override |
| public void dragFinished(DragSourceEvent event) { |
| if (dragSourceImage != null) dragSourceImage.dispose(); |
| dragSourceImage = null; |
| } |
| |
| /** |
| * This implementation of <code>dragStart</code> will create a default |
| * image that will be used during the drag. The image should be disposed |
| * when the drag is completed in the <code>TableDragSourceEffect.dragFinished</code> |
| * method. |
| * |
| * Subclasses that override this method should call <code>super.dragStart(event)</code> |
| * to use the image from the default implementation. |
| * |
| * @param event the information associated with the drag start event |
| */ |
| @Override |
| public void dragStart(DragSourceEvent event) { |
| event.image = getDragSourceImage(event); |
| } |
| |
| Image getDragSourceImage(DragSourceEvent event) { |
| if (dragSourceImage != null) dragSourceImage.dispose(); |
| dragSourceImage = TreeTableCommon.getDragSourceImage(control); |
| return dragSourceImage; |
| } |
| } |