/*
 *------------------------------------------------------------------------------
 *  Copyright (C) 2014-2015 University of Dundee. All rights reserved.
 *
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *  This program 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 General Public License for more details.
 *  
 *  You should have received a copy of the GNU General Public License along
 *  with this program; if not, write to the Free Software Foundation, Inc.,
 *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 *------------------------------------------------------------------------------
 */

package org.openmicroscopy.shoola.util.ui.table;

import java.awt.Cursor;
import java.awt.datatransfer.DataFlavor;
import java.awt.datatransfer.Transferable;
import java.awt.dnd.DragSource;

import javax.activation.ActivationDataFlavor;
import javax.activation.DataHandler;
import javax.swing.JComponent;
import javax.swing.JTable;
import javax.swing.TransferHandler;

/**
 * TransferHandler for reordering rows in a JTable
 * 
 * Based on a stackoverflow post by Aaron Davidson:
 * http://stackoverflow.com/questions
 * /638807/how-do-i-drag-and-drop-a-row-in-a-jtable
 * 
 * @author Dominik Lindner      <a
 *         href="mailto:d.lindner@dundee.ac.uk">d.lindner@dundee.ac.uk</a>
 */
public class TableRowTransferHandler extends TransferHandler {

	private static final long serialVersionUID = -2692838348100758280L;

	/** DataFlavor for handling int values */
	private final DataFlavor localObjectFlavor = new ActivationDataFlavor(
			(new int[0]).getClass(), "Integer Row Indices");

	/** Reference to the table */
	private JTable table = null;

	/**
	 * Creates a new instance
	 * @param table Reference to the table
	 */
	public TableRowTransferHandler(JTable table) {
		this.table = table;
	}

	@Override
	protected Transferable createTransferable(JComponent c) {
		return new DataHandler(table.getSelectedRows(),
				localObjectFlavor.getMimeType());
	}

	@Override
	public boolean canImport(TransferHandler.TransferSupport info) {
		boolean b = info.getComponent() == table && info.isDrop()
				&& info.isDataFlavorSupported(localObjectFlavor);
		table.setCursor(b ? DragSource.DefaultMoveDrop
				: DragSource.DefaultMoveNoDrop);
		return b;
	}

	@Override
	public int getSourceActions(JComponent c) {
		return TransferHandler.COPY_OR_MOVE;
	}

	@Override
	public boolean importData(TransferHandler.TransferSupport info) {
	    if (!info.isDrop())
	        return false;
		JTable target = (JTable) info.getComponent();
		JTable.DropLocation dl = (JTable.DropLocation) info.getDropLocation();
		int index = dl.getRow();
		int max = table.getModel().getRowCount();
		if (index < 0 || index > max)
			index = max;
		target.setCursor(Cursor.getPredefinedCursor(Cursor.DEFAULT_CURSOR));
		try {
			int[] rowFrom = (int[]) info.getTransferable().getTransferData(
					localObjectFlavor);
				int newIndex = ((Reorderable) table.getModel()).reorder(rowFrom, index);
				target.getSelectionModel().addSelectionInterval(newIndex, newIndex+rowFrom.length-1);
				return true;
		} catch (Exception e) {
		}
		return false;
	}

	@Override
	protected void exportDone(JComponent c, Transferable t, int act) {
		if (act == TransferHandler.MOVE || act == TransferHandler.NONE) {
			table.setCursor(Cursor.getPredefinedCursor(Cursor.DEFAULT_CURSOR));
		}
	}

}