Question

MAJOR EDIT
I have restructured my question to be more appropriate and less arbitrary, but the basic message still holds.

What I want to do is make some text appear without an associated window in any of the following languages: Java, C or python. It would just be the text that I want to appear completely overlaid on whatever you happen to currently have on your desktop. It would be overlaid on all programs, etc.

Any recommendations/starting points on how to do this?

OLD POST
I’ve heard rumors that it’s possible to use assembly to make “images” appear (I don’t know what they’d actually be considered, what I heard was that my friend professor made a semi-transparent, green dollar bill sign appear and bob up and down on the lower right side of the screen)

So my question is:

Are there any assembly commands/series of commands to make things appear on your screen?
Can anyone point me in the direction to use assembly to interact with what appears on the screen?
Is it possible to have an independent symbol appear without a window associated with it? Or alternatively, is it possible to make the background window completely transparent while still keeping the image intact?
How difficult would it be to create an assembly program which makes text appear in this manner? (i.e. overlaid whatever you currently have on your screen without opening it’s own window)

NOTE if you would like to provide any examples, which would be greatly appreciated, I am currently on a mac so my computer only interprets AT&T syntax

OLD POST

Answer 1

Ultimately you DO create a window, you just set its background to transparent. Drop this code into a file called test.java and give it a shot – just tried it out on Mac OS 10.7 and it works. (The text shows up black near the top left corner of the monitor – you have to look carefully to see it.) Note that according to this post you do need Java > 1.6.

import javax.swing.*;
import java.awt.*;
public class test extends JWindow{
    public test(){
        super();
        this.setSize(500, 400);
        this.setLocation(50, 50);

        setBackground(new Color(0,0,0,0)); // this is the critical line - that fourth 0 represents alpha (or opacity)

        setAlwaysOnTop( true );  // keeps it in the foreground so you don't click away from it - note that clicks on the transparent part DO pass through to the desktop, at least on Lion

        JLabel testLabel = new JLabel("Floating text hah");
        this.add(testLabel);

    }
    public static void main(String[] args){
        System.out.println("Sup");
        test t = new test();
        t.setVisible(true);
    }
}

Hopefully this puts you on the right path.