Thread: Trying to figure out how to make a screen saver.

I know that in order to make a good screensaver, I need to ditch the title bar and the minimizing components thing.

I've tried a few things including JWindow but it's not even showing up.

What class would be good as a sort of window or GUI that wouldn't have a minimize or maximize or title bar to it and yet would still let me add a Mouse Listener to it?

I tried these things below and nothing worked.

JPanel appears to have windows too. If not, how to you get one to show up without a window? And how do you add a Mouse Listener to it?

Most screensavers will exit when you click a mouse or hit a key. (Is there a way you can make it exit if you press a key?

Like if (KEY_PRESSED == true) or something like that)

JFrame is out.

Frame is also probably out.

JSplitPane is out.

JLayeredPane seems too strange.

JApplet also a title bar, and I don't want anything that's internet run at the moment anyway.

JViewPort, whatever that is, isn't working either.

import java.awt.*;
import javax.swing.*;
import java.util.*;
import java.io.*;
 
public class Demo5 extends JWindow
{
private JButton button, button2;
private JPanel p;
public Demo5()
{
setVisible(true);
button = new JButton("Button");
button2 = new JButton("Button 2");
p = new JPanel();
p.add(button);
p.add(button2);
setFocusable(true);
add(button);
setContentPane(p);
 
 
 
 
}
 
public static void main(String[] args)
{
 
Demo5 d5 = new Demo5();
d5.setVisible(true);
JLayeredPane jlp = new JLayeredPane();
jlp.setVisible(true);
 
}
}

Frame (which is extended by JFrame) has setUndecorated method. You should also be able to add Key and Mouse Listeners.

It causes the planet to be sucked into a blackhole. You can either trust me or write some code to experiment and find out for yourself.

Ok, I have fixed that problem, though why I had to take that route is beyond me.

I told it to add a MouseListener and told it to add the MouseListener the class implemented.

However, I had thought that, like when you implement ActionListener, the class would automatically add the MouseListener that the class implements to itself without me having to bother to do it manually. Any idea why that happened?

Now I can't figure out how to get it to exit if ANY key is pressed, rather than having to list all like 200 of them.

Is it even possible to do that?

So far, it's not working.

Also, if I try to set it so that I attach an event to mouseMoved(), it will exit immediately.

That's not quite what I had hoped for.

How do I get it so that it won't exit immediately but will exit if the mouse moves?

   import java.awt.*;
   import javax.swing.*;
   import java.util.*;
   import java.io.*;
   import java.awt.event.*;
   import javax.swing.event.*;
 
 
   public class Demo5 extends JFrame implements MouseInputListener, KeyListener
   {
 
      private JPanel p;
     private int times;
 
 
      public Demo5()
      {
 
 
         setExtendedState(JFrame.MAXIMIZED_BOTH);
         setUndecorated(true);
         setVisible(true);
         p = new JPanel();
 
 
         setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
         addMouseListener(this);
         addMouseMotionListener(this);
 
         addKeyListener(this);
 
         setContentPane(p);
      }
      public  void 	mouseClicked(MouseEvent e) 
      {
         System.exit(0);
 
 
      }
 
      public void 	mouseEntered(MouseEvent e) 
      {
 
      }
 
      public  void 	mouseExited(MouseEvent e) 
      {
 
 
      }
 
      public  void 	mousePressed(MouseEvent e) 
      {
 
      }
 
      public  void 	mouseReleased(MouseEvent e) 
      {
 
      }
 
      public  void 	keyPressed(KeyEvent e) 
      {
         if (e.getModifiers() == KeyEvent.KEY_PRESSED)
            System.exit(0);
      }
 
      public  void 	keyReleased(KeyEvent e) 
      {
 
      }
 
      public  void 	keyTyped(KeyEvent e) 
      {
         if (e.getModifiers() == KeyEvent.KEY_TYPED)
            System.exit(0);
      }
 
      public void mouseDragged(MouseEvent e)
      {
         System.exit(0);
      }
 
      public void mouseMoved(MouseEvent e)
      {
 
       int y = 0;
         int y2 = 0;
 
         if (times == 0)
         {
            y = e.getYOnScreen();
            times++;
         }
 
         else 
         {
            y2 = e.getYOnScreen();
 
            if (y != y2)
               System.exit(0);
         }
 
 
      }
 
      public static void main(String[] args)
      {
 
         Demo5 d5 = new Demo5();
 
 
      }
   }

Ok, I've got it so that it now works if mouse is moved too, but still the exit for any key pressed isn't working.

Ok, could somebody please explain what I'm doing wrong? I tried a key listener to get it to exit when any key is pressed.

It should be stopping invalid keys, which always seem to have a key code of 0.

However, now it won't even print the key text.

If I remove the str = bla bla bla and the if statement, it will print again.

Why I have to add key and mouse listeners to the class manually with addKeyListener(this), etc, is beyond me.

I already have the class implementing key listener and mouse motion listener, which is an interface that implements mouse listener and some other listener, yet I still have to add them.

   import java.awt.*;
   import javax.swing.*;
   import java.util.*;
   import java.io.*;
   import java.awt.event.*;
   import javax.swing.event.*;
 
 
   public class Demo5 extends JFrame implements MouseInputListener, KeyListener
   {
 
      private ScreenSaverPanel p;
      private int times;
 
 
      private class ScreenSaverPanel extends JPanel
      {
 
         public ScreenSaverPanel()
         {
            setBackground(Color.BLACK);
         }
 
         protected void paintComponent(Graphics g)
         {
            super.paintComponent(g);
         }
 
         protected void paintBorder(Graphics g)
         {
            super.paintBorder(g);
 
         }
 
      }
      public Demo5()
      {
 
 
         setExtendedState(JFrame.MAXIMIZED_BOTH);
         setUndecorated(true);
         setVisible(true);
         p = new ScreenSaverPanel();
 
 
         setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
         addMouseListener(this);
         addMouseMotionListener(this);
 
         addKeyListener(this);
 
         setContentPane(p);
      }
      public  void 	mouseClicked(MouseEvent e) 
      {
         System.exit(0);
 
 
      }
 
      public void 	mouseEntered(MouseEvent e) 
      {
 
      }
 
      public  void 	mouseExited(MouseEvent e) 
      {
 
 
      }
 
      public  void 	mousePressed(MouseEvent e) 
      {
 
      }
 
      public  void 	mouseReleased(MouseEvent e) 
      {
 
      }
 
      public  void 	keyPressed(KeyEvent e) 
      {
 
         System.out.println("Key Code: " + e.getKeyCode());
         System.out.println("Text: " + e.getKeyText(e.getKeyCode()));
 
 
         String str = e.getKeyText(e.getKeyCode());
 
 
 
         if (str.equals(str) && e.getKeyCode() != 0)
            System.exit(0);
      }
 
      public  void 	keyReleased(KeyEvent e) 
      {
 
      }
 
      public  void 	keyTyped(KeyEvent e) 
      {
 
      }
 
      public void mouseDragged(MouseEvent e)
      {
         System.exit(0);
      }
 
      public void mouseMoved(MouseEvent e)
      {
         int y = 0;
         int y2 = 0;
         int x = 0;
         int x2 = 0;
 
         if (times == 0)
         {
            y = e.getYOnScreen();
            x = e.getXOnScreen();
            times++;
         }
 
         else 
         {
            y2 = e.getYOnScreen();
            x2 = e.getXOnScreen();
            if (y != y2 || x != x2)
               System.exit(0);
         }
 
 
 
 
      }
 
      public static void main(String[] args)
      {
 
         Demo5 d5 = new Demo5();
 
 
      }
   }

-----Edit--------
Ok, by removing the two printlines, now it will exit if I hit one of the alphabetical, not the numerical or any other, keys. But I have to hit them first. I can't hit "1b" for instance.

Ok, it'll only work for about 10 seconds after the program is started. Otherwise, no key will work.

What in the name of James Gosling do you think this is doing:

if (str.equals(str)

And why are you comparing the x and y values in the mouseMoved() function?

And if you don't care which key is pressed, why put any if statement in at all?

Also, check which component, if any, has the focus.

I don't have time to look through the multiple code dumps and edits you've done- you should keep us up to date with, you guessed it, an SSCCE. Why do you have multiple paint methods? Flickering is usually caused by incorrectly handling painting, which I know we've talked about before.

I recommend splitting up your problem into multiple parts- create a normal program that responds to ANY keypress. Create another program, completely separately, that does full-screen painting. Create an SSCCE for each, and ask specific questions.

Only when you have both working should you worry about combining them.

Ok, here's on SSCCE. It still has the key problem in it.

   import java.awt.event.*;
   import java.awt.*;
   import java.util.*;
   import java.io.*;
   import javax.swing.event.*;
   import javax.swing.*;
 
   public class KeyListenerTest extends JFrame implements KeyListener
   {
      private JPanel panel;
      public KeyListenerTest()
      {
         panel = new JPanel();
         panel.setBackground(Color.BLACK);
         addKeyListener(this);
         setDefaultCloseOperation(EXIT_ON_CLOSE);
         setContentPane(panel);
 
      }
      public  void 	keyPressed(KeyEvent e) 
      {
 
         System.out.println("A key was pressed.");
 
         System.exit(0);
      }
 
      public  void 	keyReleased(KeyEvent e) 
      {
 
      }
 
      public  void 	keyTyped(KeyEvent e) 
      {
         System.out.println("A key was typed.");
         System.exit(0);
      }
 
      public static void main(String[] args)
      {
         KeyListenerTest klt = new KeyListenerTest();
         klt.setVisible(true);
      }
 
   }

Sometimes it'll exit without a key pressed and others it won't even exit at all.

Who's James Gosling?

Thanks for making the SSCCE. Sorry, but that code seems to work just fine for me. It doesn't exit until I press a key when the JFrame is focused. And it exits every time I press a key when the JFrame is in focus. It behaves exactly how I expect it to.

Are you using some kind of weird keyboard or anything like that?

Originally Posted by javapenguin

How do you make sure the frame has focus?

I tried setFocusable().

What did you expect that to do? What does the API say that does? Does the API contain any methods that returns whether a component is focused?

Originally Posted by javapenguin

The thing is, at least it was for me, I can get it to exit if I click within like 10 seconds otherwise no.

Sometimes it exits immediately as soon as I start it.

As for how I can tell, it gives the println output for key pressed though none was and then exits.

Are you sure you're running the code you posted, and not code with a MouseListener in it? Did you recompile everything, etc? What happens if, instead of exiting, you print out the key that was pressed?

It's focusable but the key listener isn't working.

I'm using a test program. No, it has no mouse listener.

   import java.awt.event.*;
   import java.awt.*;
   import java.util.*;
   import java.io.*;
   import javax.swing.event.*;
   import javax.swing.*;
 
   public class KeyListenerTest extends JFrame implements KeyListener
   {
      private JPanel panel;
      public KeyListenerTest()
      {
         panel = new JPanel();
         setExtendedState(JFrame.MAXIMIZED_BOTH);
         panel.setBackground(Color.BLACK);
         setUndecorated(true);
         setVisible(true);
         addKeyListener(this);
      	//setFocusable(true);
         setDefaultCloseOperation(EXIT_ON_CLOSE);
         System.out.println(isFocusable());
         setContentPane(panel);
 
      }
      public  void 	keyPressed(KeyEvent e) 
      {
 
         if (isFocusable())
         {
            System.out.println("A key was pressed.");
 
            System.exit(0);
         }
 
      }
 
      public  void 	keyReleased(KeyEvent e) 
      {
 
      }
 
      public  void 	keyTyped(KeyEvent e) 
      {
         System.out.println("A key was typed.");
         System.exit(0);
      }
 
      public static void main(String[] args)
      {
         KeyListenerTest klt = new KeyListenerTest();
 
      }
 
   }

It seems it's not often going into the key listener.

A few times it goes into it without any key being pressed.

It'll print out "A key was pressed." if the key listener is called and then will exit.

Should I add a Key Listener to the JPanel instead.

Still can't figure it out.

It's not my calling setExtendedState() is it?

Sometimes the panel doesn't even change to the background I told it to.

Of course, a couple of my programs have sometimes, until refreshed or minimized then maximized, shown improper stuff that's not always there or left out components that later appear once minimized and maximized.

Not often, but it happens every once in a while.

Why isn't it calling the keyListener?

I found it's calling none of the key listener methods.

Or rather, it's not usually calling them.

Ok, I made sure with a println.

It has the key Listener, but why won't it normally use it, and why, when it does, will it exit without any keys being pressed?