在Java中每隔X秒更改焦点按钮

Question

I'm looking for the best way to do the following. If someone could point me in the right direction I'd be greatfull.

I have 5 buttons,

Button 1
Button 2
Button 3
Button 4
Button 5

What I'd like to happen is every 5 seconds the focus of the button move one down. So the app starts and Button 1 has focus. Then 5 seconds later button 2 takes focus and so on so on until Button 5 and then back to Button 1. When I say focus I mean that if the space bar was pressed the button would be pressed. Any assistance would be appreciated. Thanks

Answer 1

You could use a java swing timer for this task. Take a look at the example in oracle docs

http://docs.oracle.com/javase/tutorial/uiswing/misc/timer.html

Answer 2

You can create thread that sleeps for 5 senconds, then awakes and sets focus to the next button. Store your buttons in array.

final int n = 5;
final int TIMEOUT = 5000;
Button[] buttons = new Button[n];
// fill the array

new Thread() {
    for (i = 0;  ;  i < n ? i++ : i = 0) {
        buttons.requestFocusInWindow();
        try {
            Thread.sleep(TIMEOUT);
        } catch(InterruptedException e) {}
    }
}.start();

You can also use java.util.Timer

Answer 3

You can use the KeyboardFocusManager for this as well. Sample code below using Timer object from java.util. The code below changes focus every 500 ms.

    final KeyboardFocusManager manager = KeyboardFocusManager.getCurrentKeyboardFocusManager();

    Timer timer = new Timer();
    timer.scheduleAtFixedRate(new TimerTask() {

        public void run() {
            manager.focusNextComponent();
        }

    }, 0, 500);

Hope this helps.