| package org.eclipse.swt.dnd; |
| |
| /* |
| * Copyright (c) 2000, 2002 IBM Corp. All rights reserved. |
| * This file is made available under the terms of the Common Public License v1.0 |
| * which accompanies this distribution, and is available at |
| * http://www.eclipse.org/legal/cpl-v10.html |
| */ |
| |
| import org.eclipse.swt.internal.gtk.OS; |
| |
| /** |
| * 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. See |
| * <code>Transfer</code> for additional information. |
| * |
| * <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 sublcass 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> |
| * |
| * <code><pre> |
| * 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}; |
| * } |
| * } |
| */ |
| public abstract class ByteArrayTransfer extends Transfer { |
| |
| public TransferData[] getSupportedTypes(){ |
| int[] types = getTypeIds(); |
| TransferData[] data = new TransferData[types.length]; |
| for (int i = 0; i < types.length; i++) { |
| data[i] = new TransferData(); |
| data[i].type = types[i]; |
| } |
| return data; |
| } |
| |
| public boolean isSupportedType(TransferData transferData){ |
| if ( transferData == null ) return false; |
| int[] types = getTypeIds(); |
| for (int i = 0; i < types.length; i++) { |
| if (transferData.type == types[i]) return true; |
| } |
| return false; |
| } |
| |
| /** |
| * This implementation of <code>javaToNative</code> converts a java |
| * <code>byte[]</code> to a platform specific representation. For additional |
| * information see <code>Transfer#javaToNative</code>. |
| * |
| * @see Transfer#javaToNative |
| * |
| * @param object a java <code>byte[]</code> containing the data to be converted |
| * @param transferData an empty <code>TransferData</code> object; this |
| * object will be filled in on return with the platform specific format of the data |
| */ |
| protected void javaToNative (Object object, TransferData transferData){ |
| if ((object == null) || !(object instanceof byte[]) || !(isSupportedType(transferData))) { |
| transferData.result = 0; |
| return; |
| } |
| byte[] buffer = (byte[])object; |
| transferData.pValue = OS.g_malloc(buffer.length); |
| OS.memmove(transferData.pValue, buffer, buffer.length); |
| transferData.length = buffer.length; |
| transferData.format = 8; |
| transferData.result = 1; |
| } |
| |
| /** |
| * This implementation of <code>nativeToJava</code> converts a platform specific |
| * representation of a byte array to a java <code>byte[]</code>. |
| * For additional information see <code>Transfer#nativeToJava</code>. |
| * |
| * @see Transfer#nativeToJava |
| * |
| * @param transferData the platform specific representation of the data to be |
| * been converted |
| * @return a java <code>byte[]</code> containing the converted data if the |
| * conversion was successful; otherwise null |
| */ |
| protected Object nativeToJava(TransferData transferData){ |
| if ( !isSupportedType(transferData) || transferData.pValue == 0 ) return null; |
| int size = transferData.format * transferData.length / 8; |
| byte[] buffer = new byte[size]; |
| OS.memmove(buffer, transferData.pValue, size); |
| return buffer; |
| } |
| |
| } |