import java.util.ArrayList;
import uwcse.graphics.*;
import java.awt.Color;

/**
 * In a graphics window, place at random location a square when a key
 * is pressed on the keyboard. Delete that square if it is clicked with
 * the mouse. Keep track of the squares with an ArrayList
 */

public class ArrayListExample extends GWindowEventAdapter {

    // Keep the list of squares in an ArrayList
    private ArrayList squareList;
    // The graphics window
    private GWindow window;
    // length of the side of the squares
    private int side = 20;

    /**
     * Initialize the graphics window and the list of squares
     */
    public ArrayListExample()
    {
        // Create the graphics window
        window = new GWindow("Array list example",400,400);
        window.setExitOnClose();
        // Send all of the events to this ArrayListExample
        window.addEventHandler(this);
        // Create the square list (initially empty)
        squareList = new ArrayList();
    }

    /**
     * A key has been pressed. Create a square at a random location.
     */
    public void keyPressed(GWindowEvent e)
    {
        // Center of the square
        int x = (int)(Math.random()*400);
        int y = (int)(Math.random()*400);

        // Color of the square (random)
        Color c = new Color((float)Math.random(),
                            (float)Math.random(),
                            (float)Math.random());

        // Create the square
        Rectangle r = new Rectangle(x-side/2,y-side/2,side,side,c,true);
        squareList.add(r);
        window.add(r);

        // Show it
        window.doRepaint();
    }

    /**
     * Mouse click on the window. If it is on a square, erase that square
     */
    public void mousePressed(GWindowEvent e)
    {
        // Iterate over the squares (from the last one to the first one)
        for(int i=squareList.size()-1; i>=0; i--)
        {
            // Is the click on element i of squareList?
            Rectangle r = (Rectangle)(squareList.get(i));
            int x = e.getX();
            int y = e.getY();
            if (x>=r.getX() && x<=r.getX()+r.getWidth() &&
                y>=r.getY() && y<=r.getY()+r.getHeight())
            {
                window.remove(r);
                squareList.remove(i);
                window.doRepaint();
                return;
            }
        }
    }
}