// Luke Rogers
// ID: 9320530
// ME 498/599 Computer Graphics - M.A. Ganter
//
// Please note to use this program you will need WindowListener.class in the 
// same subdirectory (folder) as this code.
//
// Draws randomly placed rectangles on the screen and fills them with a gradient
//
import java.awt.*;
import java.awt.event.*;
import java.awt.geom.*;
import WindowListener.*;
import java.awt.Component.*;

// A simple program to demonstrate simple Java graphics.
class Randomizer extends Canvas
{
   static int theFrameWidth;
   static int theFrameHeight;
   static int numRects;
   static int theMaxSize = 0;
   static Frame theFrame = new Frame();

   // This is the paint method.  It is called inside of the "show" method.
   public void paint(Graphics theGraphic)
   {
      // Cast into the graphics 2D world
      Graphics2D the2DGraphic = (Graphics2D) theGraphic;
	  
      for (int i = 1; i < numRects; i++)
      {
         // Get the current size of the frame
         Dimension theCanvasSize = theFrame.getSize();
         int theCanvasWidth = theCanvasSize.width;
         int theCanvasHeight = theCanvasSize.height;
         // Get random location and size for the object
         double rect_x = Math.random() * theCanvasWidth;
         double rect_y = Math.random()* theCanvasHeight;
         double rect_height = Math.random() * theMaxSize;
         double rect_width = Math.random() * theMaxSize;
         // Set the random rotation angle
         double rotation = Math.random();
         // Create points for gradient paint
         Point2D theFirstPoint = new Point2D.Double(rect_x,rect_y);
         Point2D theSecondPoint = new Point2D.Double(rect_x + rect_width,rect_y + rect_height);
         // generate the random color integers
         int r1 = (int)Math.rint(Math.random() * 255);
         int g1 = (int)Math.rint(Math.random() * 255);
         int b1 = (int)Math.rint(Math.random() * 255);
         int r2 = (int)Math.rint(Math.random() * 255);
         int g2 = (int)Math.rint(Math.random() * 255);
         int b2 = (int)Math.rint(Math.random() * 255);
         // set the random colors
         Color theFirstColor = new Color(r1,g1,b1);
         Color theSecondColor = new Color(r2,g2,b2);
         // make the gradient paint object
         GradientPaint theGradient = new GradientPaint(theFirstPoint,theFirstColor,theSecondPoint,theSecondColor);
         // make the rectangle
         Rectangle2D theRect = new Rectangle2D.Double(rect_x,rect_y,rect_width,rect_height);
         // set the gradient paint object on the rectangle
         the2DGraphic.setPaint(theGradient);
         the2DGraphic.fill(theRect);
         // Create an affine transformation.
         AffineTransform theTransformation = new AffineTransform();
         // set the affine transformation to rotate the rectangle
         theTransformation.rotate(rotation,rect_x,rect_y);
         // apply the transformation to the scene which also draws the object.
         the2DGraphic.setTransform(theTransformation);
      }
   }
   
   // takes input from the console which is the number of rectangles to draw
   public static void main(String[] args)
   {
      // Check for input, if none return usage
      try
      {
         String arg0 = new String(args[0]);
      }
      catch (ArrayIndexOutOfBoundsException e)
      {
         System.out.println("Usage: Randomizer <#_rectangles> {max_rect_size}");
         System.exit(0);
      }
      // make sure the first arg is is an integer
      try
      {
         numRects = Integer.parseInt(args[0]);
      }
      catch (NumberFormatException e)
      {
         System.out.println(args[0] + " is not a valid #_rectangles integer!");
         System.exit(0);
      }
      // If there is no second argument then catch the exception
      try
      {
         String arg1 = new String(args[1]);
      }
      catch (ArrayIndexOutOfBoundsException e)
      {
         System.out.println("No max_rect_size entered...");
         System.out.println("Defaulting to 100");
         // Set the Max Size to a default of 100
         theMaxSize = 100;
      }
      // make sure the second arg is is an integer
      if (theMaxSize != 100)
      {
         try
         {
            theMaxSize = Integer.parseInt(args[1]);
         }
         catch (NumberFormatException e)
         {
            System.out.println(args[1] + " is not a valid max_rect_size integer!");
            System.exit(0);
         }
      }
      // set the frame dimensions to the max screen size
      Dimension theScreenDimensions = Toolkit.getDefaultToolkit().getScreenSize();
      theFrameWidth = theScreenDimensions.width;
      theFrameHeight = theScreenDimensions.height;
      // Or set the frame dimensions using integers
      //int theFrameWidth = 1024;
      //int theFrameHeight = 768;
      // creat a listener to provide "window close" support
      WindowListener theWindow = new WindowListener();
      // create a new Randomizer object (note: it is a canvas in reality)
      Randomizer theCanvas = new Randomizer();
      // create a frame and provide a title
      //Frame theFrame = new Frame();
      // set the frame title
      theFrame.setTitle("Luke's Random Rectangle Generator");
      // add the listener to the frame
      theFrame.addWindowListener(theWindow);
      // add the canvas (Randomizer) to the frame in the center
      theFrame.add(theCanvas, BorderLayout.CENTER);
      theFrame.pack();
      // set the frame's size
      theFrame.setLocation(theScreenDimensions.width/2 - theFrameWidth/2, theScreenDimensions.height/2 - theFrameHeight/2);
      theFrame.setSize(theFrameWidth,theFrameHeight);
      // show it (note: show calls method paint amongst other things)
      theFrame.show();
   }
}