import javabook.*;
import java.awt.*;

/**
 * DrawingLab3
 * Inspired by a lab from Jeff Ondich
 * @author Dave Musicant
 * @version 1.0 10/2/01
 *
 * 0. Compile it, run it, and figure out how it works.
 * 1. To slow the motion down or speed it up, change the value inside the
 *    "for" statement.
 * 2. Try to get the ball to bounce from side to side instead of up and down.
 * 3. Can you get the colors to change gradually from red to blue instead of
 *    abruptly?
 */

class DrawingLab3
{
    
    // Data values
    private int centerX;
    private int centerY;
    private int radius;
    private boolean goingUp;
    private Color currentColor;

    private DrawingBoard drawingBoard; 
    private MessageBox messageBox;
    private InputBox inputBox;

    /**
      * Constructor
      */
    public DrawingLab3()
    {
        // Create objects for the DrawingBoard and other input / output
        drawingBoard = new DrawingBoard("Time to do some drawing");
        messageBox = new MessageBox(drawingBoard);
        inputBox = new InputBox(drawingBoard);

        // Make the drawingBoard visible and bring to front
        drawingBoard.setVisible(true);
        drawingBoard.toFront();
    }

    /**
      * Method that does the actual drawing.
      */
    public void animate()
    {
        Dimension screenSize = drawingBoard.getSize();
        int screenWidth = screenSize.width;
        int screenHeight = screenSize.height;
        Color backgroundColor = new Color(255,255,255);

        // Intialize locations
        radius = 50;
        centerX = screenWidth / 2;
        centerY = radius;
        goingUp = true;
        currentColor = new Color(255,0,0);

        while (true)
        {
            // Draw the circle
            drawingBoard.setColor(currentColor);
            drawingBoard.drawCircle(centerX,centerY,radius);

            // Wait a while
            for (int i=0; i<10000; i++)
            {
            };

            // Erase the circle
            drawingBoard.setColor(backgroundColor);
            drawingBoard.drawCircle(centerX,centerY,radius);

            // Move the circle
            newCenter(screenWidth,screenHeight);
        }
    }

    public void newCenter(int width, int height)
    {
        if (goingUp)
            centerY = centerY - 1;
        else
            centerY = centerY + 1;

        if (centerY >= height - radius)
        {
            goingUp = true;
            currentColor = new Color(255,0,0);
        }
        else if (centerY <= radius)
        {
            goingUp = false;
            currentColor = new Color(0,0,255);
        }
    }
}