mytypetransfer.java

eclipse 的程序源码

/*******************************************************************************
 * Copyright (c) 2000, 2004 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.examples.clipboard;

import java.io.*;
import org.eclipse.swt.dnd.*;

public class MyTypeTransfer extends ByteArrayTransfer {
	
	private static final String MYTYPENAME = "name_list"; //$NON-NLS-1$
	private static final int MYTYPEID = registerType(MYTYPENAME);
	private static MyTypeTransfer _instance = new MyTypeTransfer();
	
public static MyTypeTransfer getInstance () {
	return _instance;
}
public void javaToNative (Object object, TransferData transferData) {
	if (!checkMyType(object) || !isSupportedType(transferData)) {
		DND.error(DND.ERROR_INVALID_DATA);
	}
	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].firstName.getBytes();
			writeOut.writeInt(buffer.length);
			writeOut.write(buffer);
			buffer = myTypes[i].firstName.getBytes();
			writeOut.writeInt(buffer.length);
			writeOut.write(buffer);
		}
		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.firstName = new String(name);
				size = readIn.readInt();
				name = new byte[size];
				readIn.read(name);
				datum.lastName = new String(name);
				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};
}
boolean checkMyType(Object object) {
	if (object == null || !(object instanceof MyType[]) || ((MyType[])object).length == 0) return false;
	MyType[] myTypes = (MyType[])object;
	for (int i = 0; i < myTypes.length; i++) {
		if (myTypes[i] == null || 
			myTypes[i].firstName == null || 
			myTypes[i].firstName.length() == 0 ||
			myTypes[i].lastName == null ||
			myTypes[i].lastName.length() == 0) return false;
	}
	return true;
}
protected boolean validate(Object object) {
	return checkMyType(object);
}
}