Union two Rectangles : Rectangle « 2D Graphics « Java Tutorial

1. Java Tutorial
2. 2D Graphics
3. Rectangle

// This example is from the book _Java AWT Reference_ by John Zukowski.
// Written by John Zukowski.  Copyright (c) 1997 O'Reilly & Associates.
// You may study, use, modify, and distribute this example for any purpose.
// This example is provided WITHOUT WARRANTY either expressed or
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Rectangle;

import javax.swing.JFrame;

public class union extends JFrame {
  Rectangle r = new Rectangle(50, 50, 100, 100);
  Rectangle r1 = new Rectangle(100, 100, 75, 75);

  union() {
    super("Union");
    setSize(250, 250);
  }

  public void paint(Graphics g) {
    g.setColor(Color.lightGray);
    Rectangle r2 = r.union(r1);
    g.fillRect(r2.x, r2.y, r2.width, r2.height);
    g.setColor(Color.black);
    g.drawRect(r.x, r.y, r.width, r.height);
    g.drawRect(r1.x, r1.y, r1.width, r1.height);
  }

  public static void main(String[] args) {
    JFrame f = new union();
    f.setVisible(true);
  }
}

16.41.Rectangle
	16.41.1.	java.awt.Rectangle
	16.41.2.	Draw Rectangle
	16.41.3.	drawRect (int, int, int, int) to draw a rectangle outline
	16.41.4.	drawRoundRect (int, int, int, int, int, int) to draw a rounded rectangle outline
	16.41.5.	Draw a three-dimensional rectangle outline
	16.41.6.	How do I...Fill shapes?
	16.41.7.	Fill 3D Rectangle
	16.41.8.	Draw Rectangle with Rectangle2D.Float
	16.41.9.	Draw RoundRectangle2D.Float
	16.41.10.	Ractangle with rounded corners drawn using Java 2D Graphics API
	16.41.11.	Intersection between rectangles
	16.41.12.	Grow a rectangle
	16.41.13.	Union two Rectangles
	16.41.14.	Clips the specified line to the given rectangle.
	16.41.15.	Returns a point based on (x, y) but constrained to be within the bounds of a given rectangle.
	16.41.16.	Checks, whether the given rectangle1 fully contains rectangle 2 (even if rectangle 2 has a height or width of zero!).