PropertyManager.java

/**
 * PropertyManager.java
 * @author Fabio G. Cozman 
 * Copyright 1996 - 1999, Fabio G. Cozman,
 *          Carnergie Mellon University, Universidade de Sao Paulo
 * fgcozman@usp.br, http://www.cs.cmu.edu/~fgcozman/home.html
 *
 * The JavaBayes distribution 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, provided
 * that this notice and the name of the author appear in all copies.
 * If you're using the software, please notify fgcozman@usp.br so
 * that you can receive updates and patches. JavaBayes is distributed
 * "as is", 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 the JavaBayes distribution. If not, write to the Free
 * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */
 
package JavaBayesInterface;
 
import java.awt.*;
import java.util.*;

class PropertyManager {
    // The original properties.
    private Vector original_properties;
    // The vector holding a copy of the relevant properties.
    private Vector modified_properties;
    // A flag indicating whether the original properties are valid.
    private boolean are_original_properties_still_valid;
    // The index of the displayed property;
    private int displayed_property_index;
    // The text field that displays the property;
    private TextField text_field;


    /** 
     * Default constructor for PropertyManager.
     */
    PropertyManager(Vector op, TextField tf) {
        String property;
        
        // Copy the inputs into internal variables.
        original_properties = op;
        text_field = tf;
        // Make the copy of the properties.
        modified_properties = new Vector();
        if (op != null) {
            for (Enumeration e = op.elements(); e.hasMoreElements(); )
                modified_properties.addElement( e.nextElement() );
        }
        are_original_properties_still_valid = true;
        // Now display if possible.
        if (modified_properties.size() > 0) {
            property = (String)(modified_properties.firstElement());
            text_field.setText(property);
            displayed_property_index = 0;
        }
        else
            displayed_property_index = -1;
    }
    
     /*
     * Create a new property.
     */
    void new_property() {
        String property;
        
        if (displayed_property_index != -1) 
            property = (String)(modified_properties.elementAt(displayed_property_index));
        else 
            property = "";
        if ( !(property.equals(text_field.getText())) )
            update_property();

        displayed_property_index = -1;
        text_field.setText("");
    }
    
    /*
     * Go to the next property.
     */
    void next_property() {
        String property;
        
        if (displayed_property_index != -1) 
            property = 
                 (String)(modified_properties.elementAt(displayed_property_index));
        else 
            property = "";
        if ( !(property.equals(text_field.getText())) ) 
            update_property();
            
        if (modified_properties.size() > 0) {
            displayed_property_index++;
            if (displayed_property_index >= modified_properties.size())
                displayed_property_index = 0;
            property = 
                (String)(modified_properties.elementAt(displayed_property_index));
            text_field.setText(property);
        }
    }        

	/* 
	 * Modify a property when changes were detected.
	 */
	void update_property() {
	    if (displayed_property_index != -1) 
	        modified_properties.removeElementAt(displayed_property_index);
	    if (text_field.getText().equals("")) // Property was deleted.
	        displayed_property_index = -1;
        else { // Property is new or modified.
            modified_properties.addElement(text_field.getText());
            displayed_property_index =
                    modified_properties.indexOf(text_field.getText());
        }
        are_original_properties_still_valid = false;        
    }
    
    /* 
     * Modify a property when the dialog exits.
     */
    Vector update_property_on_exit() {
        String property;
        
        if (displayed_property_index != -1) 
            property = 
              (String)(modified_properties.elementAt(displayed_property_index));
        else 
            property = "";
        if ( !(property.equals(text_field.getText())) ) 
            update_property();
        if (are_original_properties_still_valid == false) 
            return(modified_properties);        
        else
            return(null);
    }
}