// purpose: demonstrate rendering of randomly colored boxes

import java.util.*;
import javax.swing.*;
import java.awt.*;
import java.awt.image.*;

public class RandomBoxes {

    // RGB value base
    public static final int RGB_BASE = 256;

    // ******  desired dimensions and background
    public static final int PICTURE_WIDTH  = 500;
    public static final int PICTURE_HEIGHT = 600;
    public static final Color BACKGROUND_COLOR = Color.BLACK;

    public static final int MAX_BOX_WIDTH  = 100;
    public static final int MAX_BOX_HEIGHT = 200;

    public static final int NUMBER_ITERATIONS = 500000;

    // ****** convenience constant
    public static final int RGB = BufferedImage.TYPE_INT_RGB;

    // method main(): program starting point
    public static void main( String[] args ) throws Exception {
        // ******  set up window
        JFrame window = new JFrame( "Wowie-zowie" );

        window.setAlwaysOnTop( true );
        window.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );

        // ****** set up a surface for painting the image
        BufferedImage surface = new BufferedImage(
                            PICTURE_WIDTH, PICTURE_HEIGHT, RGB );

        // ****** get the window to put the surface on its content pane
        ImageIcon icon = new ImageIcon( surface );
        JLabel pane = new JLabel( icon );
        window.setContentPane( pane );

        // ****** size and display the window
        window.pack();
        window.setVisible( true );

        // ******  get a renderer to manipulate the surface's display
        Graphics g = surface.getGraphics();
        pane.setBackground( Color.BLACK );

        // ****** paint the entire surface the background color
        g.setColor( BACKGROUND_COLOR );
        g.fillRect( 0, 0, PICTURE_WIDTH, PICTURE_HEIGHT );

        // ****** set up counter to keep track of the number of boxes
        int counter = 0;

        // ****** ready to produce the drawing
        while ( counter < NUMBER_ITERATIONS ) {
            // ****** pause for observation purposes
            Pause.untilReady();
    
            // ****** get random number generator
            Random dice = new Random();

            // get random description of a box
            int red   = dice.nextInt( RGB_BASE );
            int green = dice.nextInt( RGB_BASE );
            int blue  = dice.nextInt( RGB_BASE );
    
            int x = dice.nextInt( PICTURE_WIDTH );
            int y = dice.nextInt( PICTURE_HEIGHT );
    
            int w = dice.nextInt( MAX_BOX_WIDTH );
            int h = dice.nextInt( MAX_BOX_HEIGHT );
    
            Color c = new Color( red, green, blue );
    
            // ****** send renderer two messages; i.e., drawing commands
            g.setColor( c );
            g.fillRect( x, y, w, h  );

            // ****** move counter along
            counter = counter + 1;

            // ****** pause to appreciate current box
            Pause.moment();

            // ****** explicitly repaint the window pane
            pane.repaint();
        }

        Capturer.takeSnapshot( pane );
    }
}