/**
 * ManyButtons2
 * 
 * this Java applet, a simple example of an array of
 * objects that added a more interesting layout manager
 * for the buttons, is an old CIS 235 applet example that
 * was redone in larger fonts for display purposes.
 *
 * RECOMMENDED SIZE: 400 x 650
 *
 * modified by: Sharon M. Tuttle
 * last modified: 2-12-01
 **/

import java.applet.Applet;
import java.awt.*;
import java.awt.event.*;

public class ManyButtons2 extends Applet implements ActionListener
{
        Label           instruction;
        Panel           line1Panel, line2Panel, below1Panel;
        Button[]        buttonSet;
        TextField       numButtonsField;
        boolean         numButtonsChosen = false;
        Label           dummy;          // placeholder until buttons added

	// added to make applet more displayable
	Font 		biggerFont;

        public void init()
        {
		biggerFont = new Font("Serif", Font.PLAIN, 30);			
	
                setLayout(new BorderLayout());
                setBackground(Color.lightGray);
                System.out.println("ManyButtons2, Version 1.1");

                // this will hold the labels and number-of-buttons
                // request
                line1Panel = new Panel();
                line1Panel.setLayout(new FlowLayout());

                line2Panel = new Panel();
                line2Panel.setLayout(new FlowLayout());

                // to get second "line" and rest, need below1Panel
                below1Panel = new Panel();
                below1Panel.setLayout(new BorderLayout());

                Label ident = new Label("CIS 235 Spring 2000");
		ident.setFont(biggerFont);
                line1Panel.add(ident);

                Label title = new Label("Array of Buttons Example");
		title.setFont(biggerFont);
                line1Panel.add(title);

                instruction = new Label("# of buttons" +
                                        " desired:");
		instruction.setFont(biggerFont);
                line2Panel.add(instruction);

                numButtonsField = new TextField(10);
                line2Panel.add(numButtonsField);
                numButtonsField.addActionListener(this);
		numButtonsField.setFont(biggerFont);
                numButtonsField.setText("");

                //--------
                // put lines 1 and 2 onto applet
                //--------

                // add line 1

                add(line1Panel, BorderLayout.NORTH);

                // add line 2 and rest

                below1Panel.add(line2Panel, BorderLayout.NORTH);

                // dummy label, to hold place for button panel later
                dummy = new Label("             ");
                below1Panel.add(dummy, BorderLayout.CENTER);

                add(below1Panel, BorderLayout.CENTER);
        }

        public void actionPerformed(ActionEvent e)
        {
                int numButtons;

                // only allowed to enter number of buttons once!
                if (numButtonsChosen == false)
                {
                        try
                        {
                           numButtons = Integer.parseInt(e.getActionCommand());

                           // is number of buttons reasonable? 
                           if ((numButtons > 0) && (numButtons <= 20))
                           {
                                numButtonsChosen = true;
                                addButtonPanel(numButtons);
                           }

                           // what if numButtons is NOT reasonable?
                           else
                           {
                                numButtonsField.setText("Try > 0, <= 20");
                           }
                        } // end try block

                        catch(NumberFormatException ex)
                        {
                                numButtonsField.setText("Try an integer");
                        }
                } 

                // if reach here --- button should have been pressed!
                else
                {
                        // print button chosen in TextField
                        numButtonsField.setText(e.getActionCommand());
                }
        }

        private void addButtonPanel(int numBtns)
        {
                Panel   buttonP;                // panel of buttons
                int     numCols = 4, numRows;   // numRows will be
                                                // computed below
                int     horizSp=3, vertSp=3;    // for buttonP
                        
                buttonSet = new Button[numBtns];

                //-------
                // change instruction label to reflect
                // new situation: button presses!
                //-------

                // this command will REMOVE a  component from
                // the applet --- won't SEE this without
                // validate(), below, however, to FORCE
                // applet re-layout.
                line2Panel.remove(instruction);
                instruction = new Label("was last button pressed");
				instruction.setFont(biggerFont);
                            
                // instruction is now being added AFTER the
                // two labels and textfield
                line2Panel.add(instruction);

                numButtonsField.setText("");

                // create a panel to hold the new buttons
                buttonP = new Panel();
                buttonP.setBackground(Color.blue);

                // how many ROWS of 4 buttons each can we
                // have with this many buttons?
                // (ceiling: nearest "whole" number >= argument)
                numRows = (int) Math.ceil( ((double)numBtns) / numCols);

// debugging code -- feel free to delete/comment out as desired
//System.out.println("numBtns: " + numBtns);
//System.out.println("numCols: " + numCols);
//System.out.println("((double)numBtns) / numCols): " + 
//                   ((double)numBtns)/numCols );
//System.out.println("numRows: " + numRows);

                buttonP.setLayout(new GridLayout(numRows, numCols, 
                                                 horizSp, vertSp));

                // make buttons sensitive to user input,
                // and add them to buttonPanel
                for(int i = 0; i < buttonSet.length; i++)
                {
                        buttonSet[i] = new Button("Button " + i);
			buttonSet[i].setFont(biggerFont);
                        buttonSet[i].addActionListener(this);
                        buttonP.add(buttonSet[i]);
                }

                // remove dummy, add buttonP in center of applet instead
                below1Panel.remove(dummy);
                below1Panel.add(buttonP, BorderLayout.CENTER);

                // force applet layout to be re-done
                validate();
        }
}