/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * ident	"@(#)AutosizingTable.java	1.5	05/06/08 SMI"
 *
 * Copyright (c) 1999-2001 by Sun Microsystems, Inc.
 * All rights reserved.
 */
package com.sun.dhcpmgr.ui;

import javax.swing.JTable;
import javax.swing.table.*;
import javax.swing.event.TableModelEvent;
import java.awt.Component;
import java.util.Date;

import com.sun.dhcpmgr.data.IPAddress;
import com.sun.dhcpmgr.data.ValidationException;

/**
 * A subclass of Swing's JTable which automatically resizes its columns to
 * fit the data being displayed in them.
 */ 
public class AutosizingTable extends JTable {
    Date aDate = null;
    IPAddress longIP = null;
    
    /**
     * Construct the table
     */
    public AutosizingTable() {
        super();
    }

    /**
     * Construct the table with the given model.
     * @param model the TableModel to be used.
     */
    public AutosizingTable(TableModel model) {
	super(model);
    }
    
    /**
     * The table has changed; we'll resize the columns to contain the new data
     * as best they can.
     */
    public void tableChanged(TableModelEvent e) {
	/*
	 * Let JTable do its thing, which probably includes wiping out 
	 * the old columns and creating new ones
	 */
	super.tableChanged(e);
	TableModel model = getModel();
	if (model.getRowCount() == 0) {
	    // No data, so just skip all the gymnastics
	    return;
	}
	/*
	 * Set column widths by first finding largest value in each column
	 * and then sizing accordingly
	 */
	for (int i = 0; i < getColumnCount(); ++i) {
	    TableColumn col = getColumnModel().getColumn(i);

	    // Get the width of the header for this column
	    TableCellRenderer r = col.getHeaderRenderer();
	    int headerWidth = 0;
	    Component c;
	    if (r == null)
		r = getTableHeader().getDefaultRenderer();
	    if (r != null) {
		c = r.getTableCellRendererComponent(this, col.getHeaderValue(),
		    false, false, 0, 0);
		headerWidth = c.getPreferredSize().width;
	    }
	    Object maxVal = null;

	    if (model.getColumnClass(i) == String.class) {
		// Column contains strings; find the longest one
		String maxString = "";
		for (int j = 0; j < model.getRowCount(); ++j) {
		    String s = (String)model.getValueAt(j, i);
		    if (s != null) {
			if (maxString.length() < s.length()) {
			    maxString = s;
			}
		    }
		}
		maxVal = maxString;
	    } else if (model.getColumnClass(i) == IPAddress.class) {
		// Column contains IP addresses; one long one is as good as any
		if (longIP == null) {
		    try {
			longIP = new IPAddress("222.222.222.222");
		    } catch (ValidationException ex) {
			// This should never happen!
		    }
		}
		maxVal = longIP;
	    } else if (model.getColumnClass(i) == Date.class) {
		// Column contains dates; now is as good a time as any other.
		if (aDate == null) {
		    aDate = new Date();
		}
		maxVal = aDate;
	    }
	    // Now compute the width of the cell containing the longest value
	    c = getDefaultRenderer(
		model.getColumnClass(i)).getTableCellRendererComponent(
		this, maxVal, false, false, 0, i);
	    int cellWidth = c.getPreferredSize().width;

	    // Set preferred width to the greater of the header & cell widths
	    col.setPreferredWidth(Math.max(headerWidth, cellWidth));
	}
	// Now force the resizing we just did to be displayed
	sizeColumnsToFit(-1);

	// Force header to repaint itself, otherwise it won't align correctly
	getTableHeader().resizeAndRepaint();
    }
}