Problems changing a JFrame to an Applet

[John Bose]

Hi all. I have written a graphics Swing program where after pressing a start button, a game begins where you are given molecules and quizzed about them. As a JFrame, the program works fine. Here the abridged working code:

import javax.swing.*;
import javax.swing.event.*;
import java.awt.*;
import java.awt.event.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JFrame;
import javax.swing.Timer;
import javax.sound.midi.*;
import java.applet.*;
import java.net.URL;
import java.awt.event.MouseMotionListener;
import java.awt.event.MouseEvent;

public class Shapes
{
	// initialize variables

	int xMousePosition;
	int yMousePosition;

	JFrame frame;

public void init()
{
	//Execute a job on the event-dispatching thread:
	//creating this applet's GUI.
	try
	{
		javax.swing.SwingUtilities.invokeAndWait(new Runnable()
		{
			public void run()
			{
				createGUI();
			}
		});
	}
	catch (Exception e)
	{
		System.err.println("createGUI didn't successfully complete");
	}
}

private void createGUI()
{
	frame = new JFrame();
	frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
	frame.setSize(800,640);

	MyDrawPanel gamefield = new MyDrawPanel();
	gamefield.setBackground(Color.white);

	JButton startButton = new JButton("Start Game");
	startButton.addActionListener(new StartListener());

	frame.getContentPane().add(BorderLayout.SOUTH, startButton);
	frame.getContentPane().add(BorderLayout.CENTER, gamefield);

	MouseDetector mousedetector = new MouseDetector();
	gamefield.addMouseListener(mousedetector);
	gamefield.addMouseMotionListener(mousedetector);

	Timer t = new Timer(delay, new Ticker());
    	t.start();

	frame.setVisible(true);
}

public void reset()
{
	// this method works fine
}

class MyDrawPanel extends JPanel
{
	public void paintComponent (Graphics g)
	{
		// draw stuff--this works fine
	}
}

class StartListener implements ActionListener
{
	public void actionPerformed(ActionEvent event)
	{
		// do stuff to start game
	}
}

class Ticker implements ActionListener
{
	public void actionPerformed(ActionEvent event)
	{
		//do stuff

		frame.repaint();
	}
}

class MouseDetector extends MouseInputAdapter
{
	public void mousePressed(MouseEvent e)
	{
		xMousePosition = e.getX();
		yMousePosition = e.getY();

		if (gameInProgress)
		{
			// do stuff
		}					
	}
}
     
}

Now I am trying to put the program on the web and make an applet. As of now, I have written the following code and up loaded the program on my website. However, when I go to the site, the program does not show up. I get a white screen, even when I set the background to black. I know the problem is not the html code, because I got another simpler program to work as an applet, but for some reason this is not working. I do get the "Java" into before it goes blank, and I do not get an error message on the page when an applet normally does not work. I have the feeling I'm close, but what is wrong? Thank you for any help you can give. Here is the non-working applet:

import javax.swing.*;
import javax.swing.AbstractAction;
import javax.swing.Action;
import javax.swing.KeyStroke;
import javax.swing.event.*;
import java.awt.*;
import java.awt.event.*;
import java.applet.Applet;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JFrame;
import javax.swing.Timer;
import javax.sound.midi.*;
import java.applet.*;
import java.net.URL;
import java.awt.event.MouseMotionListener;
import java.awt.event.MouseEvent;


public class TestApplet extends Applet
	implements MouseListener, MouseMotionListener
{

	// initialize variables

	JFrame frame;

	Action startGame;


public void init()
{
	//Execute a job on the event-dispatching thread:
	//creating this applet's GUI.
	try
	{
		javax.swing.SwingUtilities.invokeAndWait(new Runnable()
		{
			public void run()
			{
				createGUI();
			}
		});
	}
	catch (Exception e)
	{
		System.err.println("createGUI didn't successfully complete");
	}
}

private void createGUI() {
	frame = new JFrame();
	
	MyDrawPanel gamefield = new MyDrawPanel();
	gamefield.setBackground(Color.black);

	startGame = new StartGameAction();
	gamefield.getInputMap().put( KeyStroke.getKeyStroke( "ENTER" ), "doStartGame");
	gamefield.getActionMap().put( "doStartGame", startGame);
	frame.getRootPane().getInputMap(JComponent.WHEN_ANCESTOR_OF_FOCUSED_COMPONENT).put( KeyStroke.getKeyStroke( "ENTER" ), "doStartGame");
	frame.getRootPane().getActionMap().put( "doStartGame", startGame);

	frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

	frame.getContentPane().add(gamefield);
	frame.setSize(800,640);

	addMouseListener(this);
	addMouseMotionListener(this);

	Timer t = new Timer(delay, new Ticker());
    	t.start();

	frame.setVisible(true);
}



public void reset()
{
	// same method as before that works
}
 
class MyDrawPanel extends JPanel
{
	public void paintComponent(Graphics g)
	{
 		// draw stuff--same as before
	}
}

public void mouseEntered(MouseEvent mouseevent)
{
}

public void mouseExited(MouseEvent mouseevent)
{
}

public void mousePressed(MouseEvent mouseevent)
{
}

public void mouseReleased(MouseEvent mouseevent)
{
}

public void mouseMoved(MouseEvent mouseevent)
{
}

public void mouseDragged(MouseEvent mouseevent)
{
}

public void mouseClicked(MouseEvent mouseevent)
{
	xMousePosition = mouseevent.getX();
	yMousePosition = mouseevent.getY();

	// do stuff--same as before with the mouse
}

class Ticker implements ActionListener
{
	public void actionPerformed(ActionEvent event)
	{
		// do stuff-same as before
		frame.repaint();
	}
}

class StartGameAction extends AbstractAction
{
	public void actionPerformed( ActionEvent tf )
	{
		//this starts with the molecules
	}
}

class StartListener implements ActionListener
{
	public void actionPerformed(ActionEvent event)
	{
		//this starts with the molecules
	}
}


}

[Ulf Dittmer]

Are there any messages in the Java Console? That's where errors would show up.

Post the applet tag, and also the structure of the files and directories in the file system.

[Michael Dunn]

a JFrame is a container to display your program as a stand-alone app.
an applet is a container to display your program in a browser ('extends Applet' is the container)
so, basically, you've added nothing to the applet container

read all the posts on this forums first page, you should find plenty of sample code to study

as most of your components are Swing, extend JApplet
do not use invokeAndWait()
never use mouseClicked() - pressed or released are much better

[Maki Jav]

Yes, he did not put anything into the Applet. What will it display?


Maki Jav

[John Bose]

Something came up and I won't be able to work on it for a few days. I'll let people know what happens.