package Graphics;

import java.awt.*;
import java.awt.geom.Line2D;
import java.util.Random;
import javax.swing.*;

// JPanel class for drawing in
// has main to bootstrap itself in a window
public class MyPicture  extends JPanel {
    
    // automatically called when a JPanel is drawn onscreen
    public void paintComponent(Graphics g) {
    // let JPanel do its own drawing work
        super.paintComponent(g);
        
        // to simplify code, pull out height and width of the JPanel.
        final int H = getHeight();
        final int W = getWidth();
        
        // fill in background color
        setBackground(Color.WHITE);

        // set the color we are using to a new color (R, G, B)
        // change the color on the paintbrush
        g.setColor(new Color(100,150,200));
        
        // draw rectangles in the current color
        g.fillRect(20, 30, 80, 90); // filled  (80 x 90 pixels, starting at x=20, y=30)
        g.drawRect(10, 20, 100, 140); // outline

        g.setColor(Color.BLUE); // blue
        // draw ovals
        g.fillOval(400, 10, 60, 190); // filled round
        g.drawOval(280, 20, 200, 70); // outline

        g.setColor(Color.MAGENTA);
        // draw a line from (W, 0) to (0, H)
        g.drawLine(W, 0, 0, H);
        
        g.setColor(Color.PINK);
        // choose font to use
        g.setFont(new Font("Times New Roman", Font.PLAIN, 64));
        // draw text
        g.drawString("HELLO", 50, 90);
        g.drawString("WORLD!", 220, 140);

        
        
        // Graphics we were given is really a Graphics2D object, used for fancier graphics
        Graphics2D g2 = (Graphics2D) g;
        
        // magic paint that starts as RED at W/2,H/2 and shades to BLUE at W,H
        GradientPaint gradi = new GradientPaint(W/2, H/2, Color.RED, H, W, Color.BLUE);
        
        // set to use the magic paint to draw
        g2.setPaint(gradi);

        // based on number of circles, figure out how big each one is
        int howmany = 10;
        int xoffset = W / 2 / howmany;
        int yoffset = H / 2 /  howmany;
        // nested loops to draw grid of circles
        for (int i = W/2; i < W - xoffset; i = i + xoffset) {
            for (int j = H/2; j < H - yoffset; j = j + yoffset) {
                // draw filled oval at current position, filling not quite all space to next one
                g2.fillOval(i, j, xoffset - 10, yoffset - 10);
            }
        }

        // we will be drawing random lines, but want them to join up
        // so keep some endpoints
        int x1 = 0;
        int y1 = W;
        Random rand = new Random();
        
        // set the way lines will be drawn
        // in this case, width of line is 2 pixels
        g2.setStroke(new BasicStroke(2));
        
        // 100 random lines
        for (int i = 0; i < 100; i++) {
            // random color for next line
            g2.setPaint(new Color(rand.nextInt(255), rand.nextInt(255), rand.nextInt(255)));
            //new random end point
            int x2 = rand.nextInt(W/2);
            int y2 = H/2 + rand.nextInt(H/2);
            // draw a line object that uses the stroke we set (and can use double coordinates)
            g2.draw(new Line2D.Double(x1, y1, x2, y2));
            // update the end point
            x1 = x2;
            y1 = y2;
        }

    }
    
    // create a window and put the JPanel in it
	public static void main(String[] args) {
        JFrame win = new JFrame("Picture");
        win.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        win.add(new MyPicture());
        win.setSize(500,500);
        win.setVisible(true);
    }
}