import java.awt.image.BufferedImage;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.util.Random;

public class CanvasPlot
{
    JLabel view;
    BufferedImage surface;
    Random random = new Random();

    public CanvasPlot()
    {
        surface = new BufferedImage(600,400,BufferedImage.TYPE_INT_RGB);
        view = new JLabel(new ImageIcon(surface));
        // Now, for each CanvasPlot object, we can use its .view member that we created above,
        // as the contents of a frame (which we create in main() below). 
        Graphics g = surface.getGraphics();
        // So now, we can draw graphics (points, lines, polygons, pixels..) using 'g', and these will 
        // show up inside 'view' above, which in turn will show up inside the frame that contains the view.
        // Loosely speaking, we say: "frame contains view contains surface provides 'g' contains graphics" :)
        g.setColor(Color.ORANGE);
        g.fillRect(0,0,600,400);
        g.setColor(Color.BLACK);
        g.drawLine(10, 20, 300, 200);
        g.dispose();

        ActionListener listener = new ActionListener() {
            public void actionPerformed(ActionEvent ae) {
                addNewElement();
            }
        };
        Timer timer = new Timer(200, listener);
        timer.start();
    }

    public void addNewElement() {
        boolean drawArc = random.nextBoolean();
        int x = random.nextInt(60);
        int y = random.nextInt(40);
        // we want (x,y) to be near the center (300,200)
        x = 30 + random.nextInt(10) - 5;
        y = 20 + random.nextInt(10) - 5;
        Graphics g = surface.getGraphics();
        if (drawArc) {
            g.setColor(Color.BLUE);
            int xx = random.nextInt(60);
            int yy = random.nextInt(40);
            drawArc(x,y,xx,yy,g);
        } else {
            drawNode(x,y,g);
        }
        g.dispose();
        view.repaint();
    }

    public static void main(String[] args)
    {
        CanvasPlot canvas = new CanvasPlot();
        JFrame frame = new JFrame();
        int vertexes = 0;
        // Change this next part later to be dynamic.
        vertexes = 10;
        int canvasSize = vertexes*vertexes;
        frame.setSize(canvasSize, canvasSize);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setContentPane(canvas.view);
        frame.pack();
        frame.setLocationByPlatform(true);
        frame.setVisible(true);
    }

    public void drawNode(int x, int y, Graphics g)
    {
            // Treat each location as a 10x10 block. If position 1,1 then go to (5,5) - If position 3,5 then go to (25, 45) eg: (x*10)-5, (y*10)-5
            int xLoc = (x*10) - 5;
            int yLoc = (y*10) - 5;
            g.setColor(Color.white);
            g.fillOval(xLoc, yLoc, 8, 8);
            g.drawOval(xLoc, yLoc, 8, 8);
    }

    public void drawArc(int x, int y, int xx, int yy, Graphics g)
    {
            int xLoc = (x*10) - 5;
            int yLoc = (y*10) - 5;
            int xxLoc = (xx*10) - 5;
            int yyLoc = (yy*10) - 5;
            g.drawLine(xLoc, yLoc, xxLoc, yyLoc);
    }
}