parametertype.java

著名的开源仿真软件yale

/*
 *  YALE - Yet Another Learning Environment
 *  Copyright (C) 2002, 2003
 *      Simon Fischer, Ralf Klinkenberg, Ingo Mierswa, 
 *          Katharina Morik, Oliver Ritthoff
 *      Artificial Intelligence Unit
 *      Computer Science Department
 *      University of Dortmund
 *      44221 Dortmund,  Germany
 *  email: [e-mail]
 *  web:   http://yale.cs.uni-dortmund.de/
 *
 *  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., 59 Temple Place, Suite 330, Boston, MA 02111-1307
 *  USA.
 */
package edu.udo.cs.yale.operator.parameter;

import edu.udo.cs.yale.tools.LogService;

/** A ParameterType holds information about type, range, and default value of a parameter.
 *  Lists of ParameterTypes are provided by operators.
 *
 *  @version $Id: ParameterType.java,v 2.3 2003/05/01 18:06:26 mierswa Exp $
 *  @see edu.udo.cs.yale.operator.Operator#getParameterTypes() */
public abstract class ParameterType {

    /** The key of this parameter. */
    private String key;
    /** The documentation. Used as tooltip text... */
    private String description = "No documentation for this parameter.";

    /** Creates a new ParameterType. */
    public ParameterType(String key, String description) {
	this.key = key;
	this.description = description;
    }

    /** Returns true if this parameter is optional. The default implementation returns true. */
    public boolean isOptional() { return true; }

    /** Returns the key. */
    public String getKey() {
	return key;
    }

    /** Returns a short description. */
    public String getDescription() {
	return description;
    }

    /** Sets the short description. */
    public void setDescription(String description) {
	this.description = description;
    }

    /** Returns a human readable description of the range. */
    public abstract String getRange();

    /** For single parameters the value is a String and must be converted to
     *  an Integer, Double, Boolean or String. For lists, value already is a list.
     *  If value is out of range, a corrected value must be returned. */
    public abstract Object checkValue(Object value);

    /** Returns a value that can be used if the parameter is not set. */
    public abstract Object getDefaultValue();

    /** Returns a string representation of this value. */
    public String toString(Object value) {
	if (value == null) return "";
	else return value.toString();
    }

    /** Can be called in order to report an illegal parameter value which is encountered during <tt>checkValue()</tt>. */
    public void illegalValue(Object illegal, Object corrected) {
	LogService.logMessage("Illegal value '"+illegal+"' for parameter '"+key+"' has been corrected to '"+corrected.toString()+"'.",
			      LogService.WARNING);
    }

    /** Writes an xml representation of the given key-value pair. */
    public abstract String getXML(String indent, String key, Object value);
}