ScrollingPanel.java

/**
 * ScrollingPanel.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 (either
 * version 2 of the License or, at your option, any later version), 
 * provided that this notice and the name of the author appear in all 
 * copies. Upon request to the author, some of the packages in the 
 * JavaBayes distribution can be licensed under the GNU Lesser General
 * Public License as published by the Free Software Foundation (either
 * version 2 of the License, or (at your option) any later version).
 * 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.*;

public class ScrollingPanel extends Panel {
    Scrollbar horizontal, vertical;
    public NetworkPanel netPanel;
    
    static final int VIRTUAL_WIDTH = 10000;
    static final int VIRTUAL_HEIGHT = 10000;

    ScrollingPanel(EditorFrame editorFrame) {
        // Start the scrollbars without valid parameters since network is not there.
        horizontal = new Scrollbar(Scrollbar.HORIZONTAL, 0, VIRTUAL_WIDTH, 0, VIRTUAL_WIDTH);
        vertical = new Scrollbar(Scrollbar.VERTICAL, 0, VIRTUAL_HEIGHT, 0, VIRTUAL_HEIGHT);

        netPanel = new NetworkPanel(editorFrame, this);

        setLayout(new BorderLayout());
        add("Center", netPanel);
        add("South", horizontal);
        add("East", vertical);
    }

    /*
     * Update the scrollbars.
     */
    void setScrollbars(Dimension d) {
    	horizontal.setValues(horizontal.getValue(), d.width, 
    	                     horizontal.getMinimum(), horizontal.getMaximum());
    	vertical.setValues(vertical.getValue(), d.height, vertical.getMinimum(),
    	                   vertical.getMaximum());
    }

    /**
     * Handle the scrollbar events (set variables in the NetworkPanel).
     */
    public boolean handleEvent(Event evt) {
        if (evt.target instanceof Scrollbar) {
            if (evt.target == horizontal) {
                 netPanel.x_scroll = ((Integer)(evt.arg)).intValue();
            } else if (evt.target == vertical) {
                 netPanel.y_scroll = ((Integer)(evt.arg)).intValue();
            }
            netPanel.repaint();
        }
        return(super.handleEvent(evt));
    } 
}