package net.sourceforge.squirrel_sql.client.mainframe.action;
/*
 * Copyright (C) 2003 Colin Bell
 * colbell@users.sourceforge.net
 *
 * This library 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
 */
import net.sourceforge.squirrel_sql.fw.util.ICommand;

import net.sourceforge.squirrel_sql.client.IApplication;
import net.sourceforge.squirrel_sql.client.preferences.SquirrelPreferences;

/**
 * This <CODE>ICommand</CODE> allows the user to show/hide drivers in the
 * Drivers List that cannot be loaded.
 *
 * @author	<A HREF="mailto:colbell@users.sourceforge.net">Colin Bell</A>
 */
public class ShowLoadedDriversOnlyCommand implements ICommand
{
	/** Application API. */
	private final IApplication _app;

	/**
	 * If <TT>null</TT> then flip showing/hiding the drivers
	 * else if <TT>Boolean.TRUE</TT> then show the drivers
	 * else hide them.
	 */
	private Boolean _show;

	/**
	 * Ctor. When created using this the command will flip 
	 * whether loaded drivers are shown or hidden.
	 * 
	 * @param	app		Application API.
	 * 
	 * @throws	IllegalArgumentException
	 * 			Thrown if null IApplication passed.
	 */
	public ShowLoadedDriversOnlyCommand(IApplication app)
	{
		this(app, null);
	}

	/**
	 * Ctor specifying whether whether loaded drivers 
	 * should be shown or hidden.
	 * 
	 * @param	app		Application API.
	 * @param	show	If <TT>true</TT> show the drivers.
	 * 
	 * @throws	IllegalArgumentException
	 * 			Thrown if null IApplication passed.
	 */
	public ShowLoadedDriversOnlyCommand(IApplication app, boolean show)
	{
		this(app, Boolean.valueOf(show));
	}

	/**
	 * Ctor specifying whether whether loaded drivers 
	 * should be shown or hidden.
	 * 
	 * @param	app		Application API.
	 * @param	show	If <TT>null</TT> then flip showing
	 * 					the drivers, <TT>Boolean.TRUE</TT> show the drivers
	 * 					else hide the drivers.
	 * 
	 * @throws	IllegalArgumentException
	 * 			Thrown if null IApplication passed.
	 */
	private ShowLoadedDriversOnlyCommand(IApplication app, Boolean show)
	{
		super();
		if (app == null)
		{
			throw new IllegalArgumentException("IApplication == null");
		}
		_app = app;
		_show = show;
	}

	/**
	 * Execute this command.
    */
	public void execute()
	{
		SquirrelPreferences prefs = _app.getSquirrelPreferences();
		if (_show == null)
		{
			prefs.setShowLoadedDriversOnly(!prefs.getShowLoadedDriversOnly());
		}
		else
		{
			prefs.setShowLoadedDriversOnly(_show.booleanValue());
		}
	}
}