Adding keyboard shortcuts in applet

Question

How can I add keyboard shortcuts to a Java applet?

I had an assignment (I am taking Honors Computer Science) to make my name spin in a circle. I used an infinite loop, and every time I want to end, I have to go to Task Manager and end the program. Can I add a shortcut that quits the applet?

For example, if I press the space bar, it will change to another part of the program.

I looked over "How to Use Key Bindings" at Oracle's website but I could not understand it.

Answer 1

If you are using Swing (if you are creating a JApplet), then yes, Key Bindings are the way to go. What about them confuses you?

By the way, I know that this isn't directly related to your question, but if your applet is a Swing JApplet, I wouldn't use an infinite loop to do the animation, but rather I'd use a Swing Timer. If you use an infinite loop, you must take care to a) do the infinite loop in a background thread, and b) make most Swing calls from within the loop on the Swing event dispatch thread (or EDT) else you risk freezing the main Swing thread. A Swing Timer does all of this for you, and is thus much easier to use.

Answer 2

All that tutorial is saying that you need a KeyStroke , some key Object , and an Action to create a key binding.

To create your KeyStroke , take a look at the static helper methods , they should explain how to get the correct KeyStroke you need.

You can use any old Object as the key ( Object key = new Object() ).

The last thing you need is to create your Action . I would suggest extending AbstractAction since it already implements many of the methods of Action for you.

To put your key binding together do the following:

JComponent c = ...
KeyStroke keyStroke = ...
Object key = ...
Action a = ...

c.getInputMap().put(keyStroke, key);
c.getActionMap().put(key, a);