/*******************************************************************************
 * Copyright (c) 2000, 2003 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials 
 * are 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
 * 
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package net.sourceforge.phpdt.internal.ui.dnd;

import net.sourceforge.phpdt.internal.ui.PHPUIMessages;
import net.sourceforge.phpeclipse.PHPeclipsePlugin;

import org.eclipse.core.runtime.IStatus;
import org.eclipse.jface.viewers.ISelection;
import org.eclipse.swt.dnd.ByteArrayTransfer;
import org.eclipse.swt.dnd.TransferData;

public class LocalSelectionTransfer extends ByteArrayTransfer {

	// First attempt to create a UUID for the type name to make sure that
	// different Eclipse applications use different "types" of
	// <code>LocalSelectionTransfer</code>
	private static final String TYPE_NAME = "local-selection-transfer-format" + (new Long(System.currentTimeMillis())).toString(); //$NON-NLS-1$;

	private static final int TYPEID = registerType(TYPE_NAME);

	private static final LocalSelectionTransfer INSTANCE = new LocalSelectionTransfer();

	private ISelection fSelection;

	private int fSelectionSetTime;

	private LocalSelectionTransfer() {
	}

	/**
	 * Returns the singleton.
	 */
	public static LocalSelectionTransfer getInstance() {
		return INSTANCE;
	}

	/**
	 * Sets the transfer data for local use.
	 */
	public void setSelection(ISelection s) {
		fSelection = s;
	}

	/**
	 * Returns the local transfer data.
	 */
	public ISelection getSelection() {
		return fSelection;
	}

	public void javaToNative(Object object, TransferData transferData) {
		// No encoding needed since this is a hardcoded string read and written
		// in the same process.
		// See nativeToJava below
		byte[] check = TYPE_NAME.getBytes();
		super.javaToNative(check, transferData);
	}

	public Object nativeToJava(TransferData transferData) {
		Object result = super.nativeToJava(transferData);
		if (isInvalidNativeType(result)) {
			PHPeclipsePlugin.log(IStatus.ERROR, PHPUIMessages
					.getString("LocalSelectionTransfer.errorMessage")); //$NON-NLS-1$
		}
		return fSelection;
	}

	private boolean isInvalidNativeType(Object result) {
		// No encoding needed since this is a hardcoded string read and written
		// in the same process.
		// See javaToNative above
		return !(result instanceof byte[])
				|| !TYPE_NAME.equals(new String((byte[]) result));
	}

	/**
	 * The type id used to identify this transfer.
	 */
	protected int[] getTypeIds() {
		return new int[] { TYPEID };
	}

	protected String[] getTypeNames() {
		return new String[] { TYPE_NAME };
	}

	public int getSelectionSetTime() {
		return fSelectionSetTime;
	}

	public void setSelectionSetTime(int time) {
		fSelectionSetTime = time;
	}

}