import java.awt.*;
import java.awt.event.*;
import java.util.*;

class adUserInfoExt extends adUserInfo {

    public boolean ignore = false;

    public adUserInfoExt(String user_id, String user_name) {
	super(user_id, user_name);
    }

}
class adChatterListLayout implements LayoutManager {
    public void addLayoutComponent(String name, Component comp) {}

    public void removeLayoutComponent(Component comp) {}

    public Dimension preferredLayoutSize(Container parent) {
	synchronized (parent.getTreeLock()) {

	    Component[] c = parent.getComponents();

	    if (c == null)
		return new Dimension();

	    Dimension d = null;
	    // Only have one component.
	    for (int i = 0; i < c.length; i++) {
		d = c[i].getSize();

	    }

	    return d;
      
	}
    }

    public Dimension minimumLayoutSize(Container parent) {
	return preferredLayoutSize(parent);
    }

    public void layoutContainer(Container parent) {}

}

class adChatterScrollPane extends ScrollPane {
    private Image offscr_image = null;

    private adChatterList chatter_list = null;
    public adChatterScrollPane() {
	chatter_list = new adChatterList(null);
	chatter_list.setBounds(0, 0, 100, 390);
	add(chatter_list);

    }

    public void addChatter(String name) {
	chatter_list.addChatter(new adUserInfoExt("1", name));
	chatter_list.repaint();
	chatter_list.invalidate();
    }

    public void paint(Graphics g) {
	if (offscr_image == null) 
	    offscr_image = createImage(getSize().width, getSize().height);

	Graphics offscr_graphics = offscr_image.getGraphics();
	offscr_graphics.clearRect(0, 0, getSize().width, getSize().height);
	System.out.println(this + "paint()");
	super.paint(offscr_graphics);
	
	g.drawImage(offscr_image, 0, 0, this);

    }

    public void update(Graphics g) {
	paint(g);
    }

}
public class adChatterList extends Container 
    implements MouseListener, AdjustmentListener {
    /**
     * Icon dimension
     */
    private final static int ICON_WIDTH  = 32;
    private final static int ICON_HEIGHT = 32;

    private final static int GAP_H = 2; // Space in pixels between icon and text
    private final static int GAP_V = 2; // Gap between two name labels

    private final static int INSET_X = 2;
    private final static int INSET_Y = 2;

    private final static int SCROLLBAR_WIDTH = 20;
    private int select_index = -1;

    Image icon = null;

    private Image ignore_icon = null;
    private Vector user_list = null;
    private Image offscr_image = null;
    private Dimension d = null;

    private int width = 0;
    private int height = 0;

    private Scrollbar v_scrollbar = null;
    private Scrollbar h_scrollbar = null;
    private int num_of_displays = -1;
    private int start_idx = 0;

    public adChatterList(Image icon) {
	user_list = new Vector();
	this.icon = icon;
	//icon = getToolkit().getImage("fish2.gif");
	//ignore_icon = getToolkit().getImage("ignore.gif");
	addMouseListener(this);

	v_scrollbar = new Scrollbar(Scrollbar.VERTICAL);
	h_scrollbar = new Scrollbar(Scrollbar.HORIZONTAL);

	v_scrollbar.setVisible(false);
	v_scrollbar.addAdjustmentListener(this);
	setLayout(null);

	add(v_scrollbar);

    }

    public adUserInfo getSelectedItem() {
	if (select_index < 0 || select_index > user_list.size())
	    return null;

	return (adUserInfo) user_list.elementAt(select_index);
    }

    private void initialize() {
	d = getSize();
	
	v_scrollbar.setBounds(d.width - SCROLLBAR_WIDTH, 0, SCROLLBAR_WIDTH, d.height);

	num_of_displays = d.height / (ICON_HEIGHT + 2 * INSET_Y + GAP_V);
	v_scrollbar.setVisibleAmount(num_of_displays);

	System.out.println("Num of display=" + num_of_displays);
    }
    public void addChatter(adUserInfo user_info) {

	if (d == null)
	    initialize();

	user_list.addElement(user_info);

	if (user_list.size() > num_of_displays) {
	    v_scrollbar.setVisible(true);
	    v_scrollbar.setMaximum(user_list.size());
	} else
	    v_scrollbar.setVisible(false);


	repaint();
    }

    public void removeChatter(adUserInfo user_info) {
	// Need to optimized this method.
	
	// first look through the whole list for the same user id.
	for (int i = 0; i < user_list.size(); i++) {
	    adUserInfo obj = (adUserInfo) user_list.elementAt(i);
	    if (obj.user_id.equals(user_info.user_id)) {
		user_list.removeElement(obj);
		return;
	    }
	}
	    
	return;
    }

    public void paint(Graphics g) {

	if (d == null)
	    initialize();

	g.setColor(getBackground());
	g.fillRect(0, 0, getSize().width, getSize().height);
	/**
	 * Draw border around the component
	 */
	g.setColor(Color.gray);
	g.draw3DRect(0, 0, d.width - 1, d.height - 1, false);
	g.draw3DRect(1, 1, d.width - 2, d.height - 2, false);

	/**
	 * End drawing border
	 */

	int x = 2;
	int y = 2;

	
	for (int i = start_idx; (i < user_list.size()) && (i < start_idx + num_of_displays); i++) {
	    if (select_index == i) {
		g.setColor(Color.blue);
		g.fillRect(x, y, d.width, ICON_HEIGHT + 2 * INSET_Y);
		g.setColor(Color.white);
	    } else {
		g.setColor(Color.lightGray);
		g.fillRect(x, y, d.width, ICON_HEIGHT + 2 * INSET_Y);
		g.setColor(Color.black);
	    }
	    adUserInfoExt user_info = (adUserInfoExt) user_list.elementAt(i);
	    g.drawImage(icon, x + INSET_X, y + INSET_Y, ICON_WIDTH, ICON_HEIGHT, this);
	    if (user_info.ignore) {
		g.setColor(Color.red);
		g.drawLine(x + INSET_X, y + INSET_Y, x + INSET_X + ICON_WIDTH, y + INSET_Y + ICON_HEIGHT);
		g.drawLine(x + INSET_X + ICON_WIDTH, y + INSET_Y, x + INSET_X, y + INSET_Y + ICON_HEIGHT);
	    }
	    //g.drawImage(ignore_icon, x + INSET_X, y + INSET_Y, ICON_WIDTH, ICON_HEIGHT, this);
	    g.drawString(user_info.user_name, x + INSET_X + ICON_WIDTH + GAP_H, y + 20);
	    y += (ICON_HEIGHT + 2 * INSET_Y + GAP_V);
	}
	super.paint(g);

    }
    public Dimension getPreferredSize() {
	return getSize();
    }
    
    public void update(Graphics g) {
	System.out.println(this + "update()");
	paint(g);
    }
    public void mouseClicked(MouseEvent e) {

    }

    public void mouseEntered(MouseEvent e) {
    }

    public void mouseExited(MouseEvent e) {
    }

    public void mousePressed(MouseEvent e) {
      Point pt = e.getPoint();
      select_index = pt.y / (ICON_HEIGHT + 2 * INSET_Y + GAP_V);
      repaint();
    }

    public void mouseReleased(MouseEvent e) {
    }

    public void adjustmentValueChanged(AdjustmentEvent e) {
	start_idx = e.getValue();
	repaint();
    }
    public static void main(String args[]) {
	Frame f = new Frame();

	//final adChatterScrollPane sp = new adChatterScrollPane();
	final adChatterList sp = new adChatterList(null);
	sp.setBounds(15, 50, 200, 390);
	Button add = new Button("add");
	add.setBounds(320, 60, 50, 30);
	add.addActionListener(new ActionListener() {
		private int count = 0;
		public void actionPerformed(ActionEvent e) {
		    sp.addChatter(new adUserInfo("1", "David" + (count++)));
		}
	    });

	f.setLayout(null);
	f.add(sp);
	f.add(add);
	f.setSize(570, 400);

	f.addWindowListener(new WindowAdapter() {
		public void windowClosing(WindowEvent e) {
		    System.exit(0);
		}
	    });

	f.show();
	
    }
}