| /******************************************************************************* |
| * Copyright (c) 2000, 2010 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.gef.dnd; |
| |
| import org.eclipse.swt.dnd.ByteArrayTransfer; |
| import org.eclipse.swt.dnd.TransferData; |
| |
| /** |
| * Holds on to the object being transferred in a field so that |
| * DropTargetListeners can know what's being dragged before the drop occurs. The |
| * object isn't converted to bytes, so this Transfer will only work when |
| * dragging within the same instance of Eclipse. Subclasses should maintain a |
| * single instance of their Transfer and provide a static method to obtain that |
| * instance. |
| */ |
| public abstract class SimpleObjectTransfer extends ByteArrayTransfer { |
| |
| private Object object; |
| private long startTime; |
| |
| /** |
| * Returns the Object. |
| * |
| * @return The Object |
| */ |
| public Object getObject() { |
| return object; |
| } |
| |
| /** |
| * The data object is not converted to bytes. It is held onto in a field. |
| * Instead, a checksum is written out to prevent unwanted drags across |
| * mulitple running copies of Eclipse. |
| * |
| * @see org.eclipse.swt.dnd.Transfer#javaToNative(Object, TransferData) |
| */ |
| public void javaToNative(Object object, TransferData transferData) { |
| setObject(object); |
| startTime = System.currentTimeMillis(); |
| if (transferData != null) |
| super.javaToNative(String.valueOf(startTime).getBytes(), |
| transferData); |
| } |
| |
| /** |
| * The data object is not converted to bytes. It is held onto in a field. |
| * Instead, a checksum is written out to prevent unwanted drags across |
| * mulitple running. copies of Eclipse. |
| * |
| * @see org.eclipse.swt.dnd.Transfer#nativeToJava(TransferData) |
| */ |
| public Object nativeToJava(TransferData transferData) { |
| byte bytes[] = (byte[]) super.nativeToJava(transferData); |
| if (bytes == null) { |
| return null; |
| } |
| long startTime = Long.parseLong(new String(bytes)); |
| return (this.startTime == startTime) ? getObject() : null; |
| } |
| |
| /** |
| * Sets the Object. |
| * |
| * @param obj |
| * The Object |
| */ |
| public void setObject(Object obj) { |
| object = obj; |
| } |
| |
| } |