import javax.swing.*;
import java.awt.*; // for Graphics

public class CartesianPlane extends JApplet
{
    private int x;
    private int y;

    public void init() {
	String str;
	// Get two input values
	str = JOptionPane.showInputDialog(null, "Enter x value (-250~250)");
	//If wrong type of data entered (non-integer) or click Cancel, error occurs
	x = Integer.parseInt(str);  //Class Integer in java.lang
	
	str = JOptionPane.showInputDialog(null, "Enter y value(-250~250)");
	
	y = Integer.parseInt(str);
}


    public void paint( Graphics g ) {
		
	//JFrame plane;
	//Container contentPane;
	//Graphics g;
	int width =500;
	int height =500;
	
	/** x-axis tick marks. */
	int tickX;
	
	/** y-axis tick marks. */
	int tickY;
	
	/** Maximum x-axis value. */
	//   private int maxX;
	
	/** Maximum y-axis value. */
	//  private int maxY;
	
	/*	plane = new JFrame();
	plane.setTitle("Cartesian Plane");
	plane.setSize(600,600);
	
	plane.setLocation(100,100);
	plane.setVisible(true);
	*/
	//	int x=50, y=-100;
      	String str;
	/*
	contentPane = plane.getContentPane();
	contentPane.setBackground(Color.white);
	*/
	
	
	
	//g= contentPane.getGraphics();
	
	Graphics2D g2D = (Graphics2D) g;
	int maxX, maxY;
	
	maxX = width/2;
	maxY = height/2;
	
	int divX =10, divY=10;
	
	tickX = width/divX;
        tickY = height/divY;
	
	g2D.drawString("x 250",2*maxX-10,maxY-5);
	g2D.drawString("250 y",maxX+5,+10);
	
	
	g2D.translate(maxX,maxY);
	g2D.scale(1.0,-1.0);
	
	//	   	abstract  void scale(double sx, double sy) 
	//        Concatenates the current Graphics2D Transform with a scaling transformation Subsequent rendering is resized according to the specified scaling factors relative to the previous scaling. 
	
	g2D.drawLine(-maxX,0,maxX,0);
       	g2D.drawLine(0,maxY,0,-maxY);
	
     	// mark the x-axis
     	int count = -maxX;
      	while (count < maxX) {
	    g2D.drawLine(count,-5,count,5);
	    g2D.drawLine(-count,-5,-count,5);
	    count = count + tickX;
	}
	
      	// mark the y-axis
      	count = -maxY;
      	while (count < maxY) {
	    g2D.drawLine(-5,count, 5,count);
	    g2D.drawLine(- 5,-count, 5,-count);
	    count = count + tickY;
	}
	
      	g2D.setColor(Color.RED );
      	g2D.drawLine(0,0,x,y);
	g2D.scale(1.0,-1.0);
	//must negate y value.  scale concatenates, doesn't set
      	g2D.drawString("(" + x + "," + y + ")", x, -y); //**note -y
	g2D.scale(1.0,-1.0);

      	g2D.setColor(Color.BLUE );
      	g2D.drawLine(0,0,x,-y);
	g2D.scale(1.0,-1.0);
      	g2D.drawString("(" + x + "," + -y + ")", x, y); //**y==-Y
	g2D.scale(1.0,-1.0);

      	g2D.setColor(Color.GREEN );
      	g2D.drawLine(0,0,-x,y);
	g2D.scale(1.0,-1.0);
      	g2D.drawString("(" + -x + "," + y + ")", -x, -y);//flipped y
	g2D.scale(1.0,-1.0);

      	g2D.setColor(Color.CYAN );
      	g2D.drawLine(0,0,-x,-y);
	g2D.scale(1.0,-1.0);
      	g2D.drawString("(" + -x + "," + -y + ")", -x, y);//**flipped y
	g2D.scale(1.0,-1.0);
	
      	//g2D.drawString("(" + x + "," + y + ")", x, y);
	//	Graphics g2= contentPane.getGraphics();
	
	//      g2.drawString("(" + x+ "," + y + ")", x+250, -(y-250));
	//plane.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
    }
}