/**
 * ArrayListDriver.java
 * 
 * Demonstrates a few of the methods for working with an ArrayList.
 * 
 * @author Tom Cormen
 */

import java.util.ArrayList;
import java.util.Random;

public class ArrayListDriver {
  private static final int MAX_X = 200, MAX_Y = 150;  // max coordinate values
  private static final double MAX_RADIUS = 100.0;     // size of largest circle
  
  public static void main(String[] args) {
    ArrayList<GeomShape> shapes = new ArrayList<GeomShape>();  // a polymorphic ArrayList
    Random generator = new Random();  // random number generator
    
    final int INIT_LIST_SIZE = 8;
    // Randomly add some shapes to the ArrayList.
    for (int i = 0; i < INIT_LIST_SIZE; i++) {
      shapes.add(getRandomShape(generator));
    }
    
    // See what we've got.
    System.out.println("After adding " + INIT_LIST_SIZE + " shapes:");
    for (int i = 0; i < shapes.size(); i++)
      System.out.println(shapes.get(i));
    
    // Insert a shape into the middle of the ArrayList.
    GeomShape latecomer = getRandomShape(generator);
    shapes.add(3, latecomer);
    
    // See what we've got now.
    System.out.println("\nAfter adding:");
    for (int i = 0; i < shapes.size(); i++)
      System.out.println(shapes.get(i));
    
    // And delete a shape from the middle of the ArrayList.
    shapes.remove(5);
    
    // See what we've got now.
    System.out.println("\nAfter removing:");
    for (int i = 0; i < shapes.size(); i++)
      System.out.println(shapes.get(i));
    
    // Find where we put the latecomer.
    System.out.println("\nThe latecomer is at index " + shapes.indexOf(latecomer));
  }
  
  /**
   * Create a randomly generated shape object.
   * 
   * @param generator
   * @return an object that implements the GeomShape interface
   */
  public static GeomShape getRandomShape(Random generator) {
    // Randomly pick a Circle or Rectangle to create.
    if (generator.nextInt(2) == 0)
      // Chose Circle.  Randomly choose a center and radius.
      return new Circle(generator.nextInt(MAX_X), generator.nextInt(MAX_Y),
          generator.nextDouble() * MAX_RADIUS);
    else {
      // Chose Rectangle.  Randomly choose its corners.
      int x1 = generator.nextInt(MAX_X);
      int x2 = generator.nextInt(MAX_X);
      int y1 = generator.nextInt(MAX_Y);
      int y2 = generator.nextInt(MAX_Y);
      return new Rectangle(Math.min(x1, x2), Math.min(y1, y2),
          Math.abs(x1 - x2), Math.abs(y1 - y2));
    }
  }
}