import java.awt.*;
import java.awt.event.*;

import javax.swing.*;

public class PhoneAPP extends JApplet implements ActionListener {
	Container container;
	TextArea screen;
	Button[] button;
	Panel keyPanel; 
	Panel opsPad;
	Checkbox addBox;
	Checkbox deleteBox;
	Checkbox listBox;
	
	String[] phoneBook;
	
	public static void main(String[] args) {
		JFrame jFrame = new JFrame("myPhone");

		PhoneAPP application = new PhoneAPP();
		jFrame.getContentPane().add(application);
		jFrame.setSize( 200, 270 );
		jFrame.setVisible( true );
		jFrame.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
	}
		
	public PhoneAPP(){

		phoneBook = new String[5];
		for (int i=0; i < phoneBook.length; i++){
			phoneBook[i]=null;	
		}
		
		screen = new TextArea("",5,20,TextArea.SCROLLBARS_NONE);
		
		CheckboxGroup ops = new CheckboxGroup();

		opsPad = new Panel(new GridLayout(1,3));
		addBox = new Checkbox("Add", ops, true);
		deleteBox = new Checkbox("Delete", ops, false);
		listBox = new Checkbox("List", ops, false);
	
		opsPad.add(addBox);
		opsPad.add(deleteBox);
		opsPad.add(listBox);
		
		keyPanel = new Panel(new GridLayout(5,3));
		button = new Button[15];
		
		for (int i = 0; i < 10; i++){
			button[i] = new Button(""+i);
		}
		button[10] = new Button("*");
		button[11] = new Button("#");
		button[12] = new Button("send");
		button[13] = new Button("end");
		button[14] = new Button("Dir");
		
		keyPanel.add(button[12]); keyPanel.add(button[14]); keyPanel.add(button[13]);
		
		for (int i = 1; i < 10; i++){
			keyPanel.add(button[i]);
		}
		
		keyPanel.add(button[10]); keyPanel.add(button[0]); keyPanel.add(button[11]);		
		container = getContentPane();
		container.add(screen, BorderLayout.NORTH);
		container.add(opsPad);
		container.add(keyPanel,BorderLayout.SOUTH);
		
		for (int i = 0; i < button.length; i++){
			button[i].addActionListener(this);
		}	
	}

	public void actionPerformed(ActionEvent ae) {
		char[] screenText = new char[100];
		screenText[0]=' ';
		for (int i = 1; i <  screenText.length;i++) {
			screenText[i]=(i%20==0?'\n':' ');
		}
		
		StringBuffer screenBuffer = new StringBuffer(new String(screenText));
		if (ae.getSource().equals(button[14])) { 
			if (addBox.getState())  {
					int i = 0;
					while (i < phoneBook.length && phoneBook[i] != null){ i++;}
					if (i == phoneBook.length){
						screen.setText("Directory Full");
					} else phoneBook[i]=screen.getText();

			} else if (deleteBox.getState())  {
					int i = 0;
					while (i < phoneBook.length && 
							(phoneBook[i] == null || !phoneBook[i].equals(screen.getText()) )){ i++;}					
					if (i == phoneBook.length){
						screen.setText("No matching entry");
					} else {
						screen.setText("entry " + i + " deleted");
						phoneBook[i]=null;
					} 				
			} else {
				String st = "";
				for (int i=0; i < phoneBook.length; i++){
					if (phoneBook[i] != null)
						st+=phoneBook[i]+"\n";
				}
				screen.setText(st);
			}
		} else	if (ae.getSource().equals(button[12]) 
						|| ae.getSource().equals(button[13])) {
					screen.setText("");
		} else {
			String st = (screen.getText().equals("")?screenBuffer.toString():screen.getText());
			int i;		
			for (i = 0; 
					i <  st.length() && 
					((st.charAt(i) == ' ') || (st.charAt(i) == '\n'));i++);
					
			if (i == st.length()) {
				screen.setText(screenBuffer.replace(i-1,st.length(),ae.getActionCommand()).toString());					
			} else if (i > 81) {
				screen.setText(screenBuffer.replace(i-1,st.length(),st.substring(i,st.length()).concat(ae.getActionCommand())).toString());
			} else if (i == 81){
				screenBuffer = screenBuffer.replace(i-2,80,st.substring(i,82));				
				screen.setText(screenBuffer.replace(81,st.length(),st.substring(82,st.length()).concat(ae.getActionCommand())).toString());													
			} else if (i >61){
				screenBuffer = screenBuffer.replace(i-1,80,st.substring(i,80).concat(st.substring(81,82)));
				screen.setText(screenBuffer.replace(81,st.length(),st.substring(82,st.length()).concat(ae.getActionCommand())).toString());
			} else if (i == 61){
				screenBuffer = screenBuffer.replace(i-2,60,st.substring(i,62));
				screenBuffer = screenBuffer.replace(61,80,st.substring(62,80).concat(st.substring(81,82)));
				screen.setText(screenBuffer.replace(81,st.length(),st.substring(82,st.length()).concat(ae.getActionCommand())).toString());
			} else if (i >41){
				screenBuffer = screenBuffer.replace(i-1,60,st.substring(i,60).concat(st.substring(61,62)));
				screenBuffer = screenBuffer.replace(61,80,st.substring(62,80).concat(st.substring(81,82)));
				screen.setText(screenBuffer.replace(81,st.length(),st.substring(82,st.length()).concat(ae.getActionCommand())).toString());
			} else if (i == 41){
				screenBuffer = screenBuffer.replace(i-2,40,st.substring(i,42));
				screenBuffer = screenBuffer.replace(41,60,st.substring(42,60).concat(st.substring(61,62)));
				screenBuffer = screenBuffer.replace(61,80,st.substring(62,80).concat(st.substring(81,82)));
				screen.setText(screenBuffer.replace(81,st.length(),st.substring(82,st.length()).concat(ae.getActionCommand())).toString());
			} else if (i > 21){
				screenBuffer = screenBuffer.replace(i-1,40,st.substring(i,40).concat(st.substring(41,42)));
				screenBuffer = screenBuffer.replace(41,60,st.substring(42,60).concat(st.substring(61,62)));
				screenBuffer = screenBuffer.replace(61,80,st.substring(62,80).concat(st.substring(81,82)));
				screen.setText(screenBuffer.replace(81,st.length(),st.substring(82,st.length()).concat(ae.getActionCommand())).toString());
			} 
		}
	}
}