// PointDisplay.java
//
// Author: Rahul Simha
// Mar, 2008
//
// A simple display of 2D points.

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.awt.geom.*;
import java.util.*;
import java.text.*;

public class PointDisplay extends JPanel {

    ArrayList<Point2D.Double> points;   // Each point is an instance of Point2D.Double
    double minX, maxX, minY, maxY;      // Bounds.
    int numIntervals = 10;              // # tick marks.

    // To prettify.
    DecimalFormat df = new DecimalFormat();

    // GUI stuff.
    int inset=60;            // Inset of axes and bounding box.


    public PointDisplay ()
    {
        points = new ArrayList<Point2D.Double> ();
	df.setMaximumFractionDigits (4);
    }


    public void add (double x, double y)
    {
        add ( new Point2D.Double (x,y) );
    }

    public void add (Point2D.Double p)
    {
        points.add (p);
    }


    public Point2D.Double get (int i)
    {
        if ( (points == null) || (i >= points.size()) ) {
            return null;
        }
        return points.get(i);
    }


    void computeBounds ()
    {
        minX = minY = Double.MAX_VALUE;
        maxX = maxY = Double.MIN_VALUE;
        for (Point2D.Double p: points) {
            if (p.x < minX) {
                minX = p.x;
            }
            if (p.x > maxX) {
                maxX = p.x;
            }
            if (p.y < minY) {
                minY = p.y;
            }
            if (p.y > maxY) {
                maxY = p.y;
            }
        }
    }
    

    public void display ()
    {
        computeBounds ();
        // Make a frame and add this instance (as JPanel).
        JFrame frame = new JFrame ();
        frame.setSize (600, 480);
        frame.getContentPane().add (this);
        frame.addWindowListener (new WindowAdapter () {
                public void windowClosing (WindowEvent e) 
                {
                    System.exit(0);
                }
            });
        frame.setVisible (true);
    }
    

    public void paintComponent (Graphics g)
    {
        super.paintComponent (g);

        // Background.
        Dimension D = this.getSize ();
	g.setColor (Color.white);
	g.fillRect (0,0, D.width, D.height);
        Graphics2D g2 = (Graphics2D) g;
	g.setColor (Color.black);

        // Finally, draw the points.
        if ( (points == null) || (points.size() <= 1) ) {
            g.drawString ("At least two points are needed for display", 50, 100);
            return;
        }

        // Axes, bounding box.
        g.drawLine (inset,D.height-inset, D.width-inset, D.height-inset);
        g.drawLine (inset,inset, inset,D.height-inset);
        g.drawLine (D.width-inset,inset, D.width-inset,D.height-inset);
        g.drawLine (inset,inset, D.width-inset, inset);

        
        double xDelta = (maxX-minX) / numIntervals;

        // X-ticks and labels.
        for (int i=1; i<=numIntervals; i++) {
            double xTickd = i*xDelta;
            int xTick = (int) ( xTickd/(maxX-minX) * (D.width-2*inset));
            g.drawLine (inset+xTick,D.height-inset-5, inset+xTick,D.height-inset+5);
            double x = minX + i*xDelta;
            g.drawString (df.format(x), xTick+inset-5, D.height-inset+20);
        }

        // Y-ticks
        double yDelta = (maxY-minY) / numIntervals;
        for (int i=0; i<numIntervals; i++) {
            int yTick = (i+1) * (int) ((D.height-2*inset) / (double)numIntervals);
            g.drawLine (inset-5, D.height-yTick-inset, inset+5, D.height-yTick-inset);
            double y = minY + (i+1)  * yDelta;
            g.drawString (df.format(y), 1, D.height-yTick-inset);
        }

        // The points.
        g.setColor (Color.blue);
        for (Point2D.Double p: points) {
            int x = (int) ( (p.x-minX)/(maxX-minX) * (D.width-2*inset) );
            int y = (int) ((p.y-minY) / (maxY-minY) * (D.height-2.0*inset) );
            g.fillOval (inset+x-3, D.height-y-inset-3, 6, 6);
        }
    }


    public static void main (String[] argv)
    {
        // Test.
        PointDisplay pd = new PointDisplay ();
        pd.add (1, 2);
        pd.add (2, 3);
        pd.add (1.5, 2.5);
        pd.display();
    }
    
}