/*
 * Copyright (C) 2002-2004 Andrea Mazzolini
 * andreamazzolini@users.sourceforge.net
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */
package net.sourceforge.sqlexplorer.plugin.views;

import org.eclipse.swt.dnd.ByteArrayTransfer;
import org.eclipse.swt.dnd.TransferData;


public class TableNodeTransfer extends ByteArrayTransfer  {
	public String toString(){
		return "TableNodeTransfer";
	}
	private static final String TYPE_NAME= "TableNodeTransfer-format" + (new Long(System.currentTimeMillis())).toString(); //$NON-NLS-1$;
	private static final int TYPEID= registerType(TYPE_NAME);
	
	private static final TableNodeTransfer INSTANCE= new TableNodeTransfer();
	
	private Object selection;
	
	/**
	 * Only the singleton instance of this class may be used. 
	 */
	private TableNodeTransfer() {
	}
	/**
	 * Returns the singleton.
	 */
	public static TableNodeTransfer getInstance() {
		return INSTANCE;
	}
	/**
	 * Returns the local transfer data.
	 * 
	 * @return the local transfer data
	 */
	public Object getSelection() {
		return selection;
	}
	/**
	 * Tests whether native drop data matches this transfer type.
	 * 
	 * @param result result of converting the native drop data to Java
	 * @return true if the native drop data does not match this transfer type.
	 * 	false otherwise.
	 */
	private boolean isInvalidNativeType(Object result) {
		return !(result instanceof byte[]) || !TYPE_NAME.equals(new String((byte[])result));
	}
	/**
	 * Returns the type id used to identify this transfer.
	 * 
	 * @return the type id used to identify this transfer.
	 */
	protected int[] getTypeIds() {
		return new int[] {TYPEID};
	}
	/**
	 * Returns the type name used to identify this transfer.
	 * 
	 * @return the type name used to identify this transfer.
	 */
	protected String[] getTypeNames(){
		return new String[] {TYPE_NAME};
	}	
	/**
	 * Overrides org.eclipse.swt.dnd.ByteArrayTransfer#javaToNative(Object,
	 * TransferData).
	 * Only encode the transfer type name since the selection is read and
	 * written in the same process.
	 * 
	 * @see org.eclipse.swt.dnd.ByteArrayTransfer#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);
	}
	/**
	 * Overrides org.eclipse.swt.dnd.ByteArrayTransfer#nativeToJava(TransferData).
	 * Test if the native drop data matches this transfer type.
	 * 
	 * @see org.eclipse.swt.dnd.ByteArrayTransfer#nativeToJava(TransferData)
	 */
	public Object nativeToJava(TransferData transferData) {
		Object result= super.nativeToJava(transferData);
		if (isInvalidNativeType(result)) {
			//System.out.println("isInvalidNativeType");
			return null;
			/*ILog log = ViewsPlugin.getDefault().getLog();
			log.log(
				new Status(
					IStatus.ERROR, 
					ViewsPlugin.PLUGIN_ID, 
					IStatus.ERROR, 
					ResourceNavigatorMessages.getString("LocalSelectionTransfer.errorMessage"), null));	//$NON-NLS-1$*/
		}
		return selection;
	}
	/**
	 * Sets the transfer data for local use.
	 * 
	 * @param s the transfer data
	 */	
	public void setSelection(Object s) {
		selection = s;
	}

}