import javax.swing.*;
import java.awt.*;

public class Frame 
{  
    public static void main(String[] args) 
    {
	SwingApp app = new SwingApp(300, 200);	    // set app window size
	app.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
    }
}

class SwingApp extends JFrame
{
    private final DrawPanel panel;		    // class variable
    
    public SwingApp(int width, int height)	    // class constructor
    {
	super();				    // call to super class constructor
	Container pane = super.getContentPane();    // create layout, set colors
	panel = new DrawPanel();		    // add GUI components
	panel.setBackground(Color.yellow);
	pane.add(panel);
	
	Toolkit toolkit = Toolkit.getDefaultToolkit();	// optionally position JFrame
	Dimension screenSize = toolkit.getScreenSize(); // in the middle of the screen 
	super.setLocation((screenSize.width - width)/2, (screenSize.height - height)/2);	
	super.setTitle("Swing app");		    // set desired window title
	super.setSize(width, height);		    // set desired window size
	super.setVisible(true);	
	// add here more code for GUI components
    }
}

class DrawPanel extends JPanel			    // main window panel
{
    private final String s;			    // string to draw
    private final int border;			    // border width around the string
    
    public DrawPanel()				    // class constructor
    {
	s = "Welcome to CSCI201";
	border = 5;
    }
    
    @Override
    public void paintComponent(Graphics g)
    {
	super.paintComponent(g);		    // must be the 1st line
	// add here more code for drawing on panel 
	g.setFont(new Font("Serif", Font.BOLD, 20));
	int leading = g.getFontMetrics().getLeading();
	int ascent  = g.getFontMetrics().getAscent();

	int fontHeight  = g.getFontMetrics().getHeight();
	int stringWidth = g.getFontMetrics().stringWidth(s);

      // (x,y) is the position of the blue box top left corner
	int x = (getWidth() - stringWidth - 2*border) / 2;
	int y = (getHeight() - fontHeight - 2*border) / 2;
	g.setColor(Color.blue);
	g.fillRect(x, y, stringWidth + 2*border, fontHeight + 2*border);

      // drawing the string in white atop the box
	g.setColor(Color.white);
	g.drawString(s, x + border, y + ascent + leading + border); 	
    }
}