| /****************************************************************************** |
| * Copyright (c) 2002, 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.gmf.runtime.common.ui.services.dnd.core; |
| |
| import org.eclipse.jface.viewers.ISelection; |
| import org.eclipse.swt.dnd.ByteArrayTransfer; |
| import org.eclipse.swt.dnd.TransferData; |
| |
| /** |
| * This class can be used to transfer a <code>ISelection</code> between two |
| * parts in a workbench in a drag and drop operation. This class does not |
| * marshall the data. |
| * |
| * @author Vishy Ramaswamy |
| */ |
| public final class SelectionTransfer |
| extends ByteArrayTransfer { |
| |
| /** |
| * Create a UUID for the type name to make sure that each instance of an |
| * Eclipse application uses a different "type" of |
| * <code>SelectionTransfer</code> |
| */ |
| private static final String TYPE_NAME = "Element Selection Format" + (new Long(System.currentTimeMillis())).toString(); //$NON-NLS-1$ |
| |
| /** |
| * Attribute for the type id |
| */ |
| private static final int TYPE_ID = registerType(TYPE_NAME); |
| |
| /** |
| * Create the singleton. |
| */ |
| private static SelectionTransfer instance = new SelectionTransfer(); |
| |
| /** |
| * Return the singleton. |
| * |
| * @return the singleton instance of the SelectionTransfer class |
| */ |
| public static SelectionTransfer getInstance() { |
| return instance; |
| } |
| |
| /** |
| * Create a <code>SelectionTransfer</code>. |
| */ |
| private SelectionTransfer() { |
| super(); |
| } |
| |
| /** |
| * Attribute that holds on to the selection. |
| */ |
| private ISelection selection = null; |
| |
| /** |
| * Converts the <code>TYPE_NAME</code> into a <code>byte[]</code> |
| * |
| * @see org.eclipse.swt.dnd.Transfer#javaToNative(java.lang.Object, |
| * org.eclipse.swt.dnd.TransferData) |
| */ |
| public void javaToNative(Object object, TransferData transferData) { |
| byte[] check = TYPE_NAME.getBytes(); |
| super.javaToNative(check, transferData); |
| } |
| |
| /** |
| * Retrieves the <code>byte[]</code> associated with |
| * <code>TYPE_NAME</code>. Verifies it is the same as the |
| * <code>TYPE_NAME</code> and then returns the <code>selection</code>. |
| * |
| * @return <code>Object</code> |
| * @see org.eclipse.swt.dnd.Transfer#nativeToJava(org.eclipse.swt.dnd.TransferData) |
| */ |
| public Object nativeToJava(TransferData transferData) { |
| Object result = super.nativeToJava(transferData); |
| if (isInvalidNativeType(result)) { |
| return null; |
| } |
| |
| return getSelection(); |
| } |
| |
| /** |
| * Check if the tranfer type is valid |
| * |
| * @param result |
| * with the transfer type to check |
| * @return true if the type is valid, false if it isn't |
| */ |
| private boolean isInvalidNativeType(Object result) { |
| return !(result instanceof byte[]) |
| || !TYPE_NAME.equals(new String((byte[]) result)); |
| } |
| |
| /** |
| * Returns the type ids supported by this agent |
| * |
| * @return <code>int[]</code> |
| * @see org.eclipse.swt.dnd.Transfer#getTypeIds() |
| */ |
| protected int[] getTypeIds() { |
| return new int[] {TYPE_ID}; |
| } |
| |
| /** |
| * Returns the type names supported by this agent |
| * |
| * @return <code>String[]</code> |
| * @see org.eclipse.swt.dnd.Transfer#getTypeNames() |
| */ |
| protected String[] getTypeNames() { |
| return new String[] {TYPE_NAME}; |
| } |
| |
| /** |
| * Returns the selection. |
| * |
| * @return <code>selection</code> |
| */ |
| public ISelection getSelection() { |
| return selection; |
| } |
| |
| /** |
| * Sets the selection. |
| * |
| * @param aSelection |
| * The selection to set |
| */ |
| public void setSelection(ISelection aSelection) { |
| this.selection = aSelection; |
| } |
| } |