| /******************************************************************************* |
| * Copyright (c) 2000, 2006 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.swt.dnd; |
| |
| |
| /** |
| * The class <code>ByteArrayTransfer</code> provides a platform specific |
| * mechanism for converting a java <code>byte[]</code> to a platform |
| * specific representation of the byte array and vice versa. |
| * |
| * <p><code>ByteArrayTransfer</code> is never used directly but is sub-classed |
| * by transfer agents that convert between data in a java format such as a |
| * <code>String</code> and a platform specific byte array. |
| * |
| * <p>If the data you are converting <b>does not</b> map to a |
| * <code>byte[]</code>, you should sub-class <code>Transfer</code> directly |
| * and do your own mapping to a platform data type.</p> |
| * |
| * <p>The following snippet shows a subclass of ByteArrayTransfer that transfers |
| * data defined by the class <code>MyType</code>.</p> |
| * |
| * <pre><code> |
| * public class MyType { |
| * public String fileName; |
| * public long fileLength; |
| * public long lastModified; |
| * } |
| * </code></pre> |
| * |
| * <pre><code> |
| * public class MyTypeTransfer extends ByteArrayTransfer { |
| * |
| * private static final String MYTYPENAME = "my_type_name"; |
| * private static final int MYTYPEID = registerType(MYTYPENAME); |
| * private static MyTypeTransfer _instance = new MyTypeTransfer(); |
| * |
| * private MyTypeTransfer() {} |
| * |
| * public static MyTypeTransfer getInstance () { |
| * return _instance; |
| * } |
| * public void javaToNative (Object object, TransferData transferData) { |
| * if (object == null || !(object instanceof MyType[])) return; |
| * |
| * if (isSupportedType(transferData)) { |
| * MyType[] myTypes = (MyType[]) object; |
| * try { |
| * // write data to a byte array and then ask super to convert to pMedium |
| * ByteArrayOutputStream out = new ByteArrayOutputStream(); |
| * DataOutputStream writeOut = new DataOutputStream(out); |
| * for (int i = 0, length = myTypes.length; i < length; i++){ |
| * byte[] buffer = myTypes[i].fileName.getBytes(); |
| * writeOut.writeInt(buffer.length); |
| * writeOut.write(buffer); |
| * writeOut.writeLong(myTypes[i].fileLength); |
| * writeOut.writeLong(myTypes[i].lastModified); |
| * } |
| * byte[] buffer = out.toByteArray(); |
| * writeOut.close(); |
| * |
| * super.javaToNative(buffer, transferData); |
| * |
| * } catch (IOException e) { |
| * } |
| * } |
| * } |
| * public Object nativeToJava(TransferData transferData){ |
| * |
| * if (isSupportedType(transferData)) { |
| * |
| * byte[] buffer = (byte[])super.nativeToJava(transferData); |
| * if (buffer == null) return null; |
| * |
| * MyType[] myData = new MyType[0]; |
| * try { |
| * ByteArrayInputStream in = new ByteArrayInputStream(buffer); |
| * DataInputStream readIn = new DataInputStream(in); |
| * while(readIn.available() > 20) { |
| * MyType datum = new MyType(); |
| * int size = readIn.readInt(); |
| * byte[] name = new byte[size]; |
| * readIn.read(name); |
| * datum.fileName = new String(name); |
| * datum.fileLength = readIn.readLong(); |
| * datum.lastModified = readIn.readLong(); |
| * MyType[] newMyData = new MyType[myData.length + 1]; |
| * System.arraycopy(myData, 0, newMyData, 0, myData.length); |
| * newMyData[myData.length] = datum; |
| * myData = newMyData; |
| * } |
| * readIn.close(); |
| * } catch (IOException ex) { |
| * return null; |
| * } |
| * return myData; |
| * } |
| * |
| * return null; |
| * } |
| * protected String[] getTypeNames(){ |
| * return new String[]{MYTYPENAME}; |
| * } |
| * protected int[] getTypeIds(){ |
| * return new int[] {MYTYPEID}; |
| * } |
| * } |
| * </code></pre> |
| * |
| * @see Transfer |
| */ |
| public abstract class ByteArrayTransfer extends Transfer { |
| |
| public TransferData[] getSupportedTypes(){ |
| return null; |
| } |
| |
| public boolean isSupportedType(TransferData transferData){ |
| return false; |
| } |
| |
| /** |
| * This implementation of <code>javaToNative</code> converts a java |
| * <code>byte[]</code> to a platform specific representation. |
| * |
| * @param object a java <code>byte[]</code> containing the data to be converted |
| * @param transferData an empty <code>TransferData</code> object that will |
| * be filled in on return with the platform specific format of the data |
| * |
| * @see Transfer#nativeToJava |
| */ |
| protected void javaToNative (Object object, TransferData transferData) { |
| } |
| |
| /** |
| * This implementation of <code>nativeToJava</code> converts a platform specific |
| * representation of a byte array to a java <code>byte[]</code>. |
| * |
| * @param transferData the platform specific representation of the data to be converted |
| * @return a java <code>byte[]</code> containing the converted data if the conversion was |
| * successful; otherwise null |
| * |
| * @see Transfer#javaToNative |
| */ |
| protected Object nativeToJava(TransferData transferData) { |
| return null; |
| } |
| } |