SWT中的javax.swing.Timer等效吗？

Question

I need some means to run code on user-interface thread with delay and with ability to abort waiting. This can be done by javax.swing.Timer in Swing . Is there similar functionality in SWT ? Display#timerExec has no apparent ability to cancel future running.

Answer 1

Here is an example using Display#timerExec(int, Runnable) :

public static void main(String[] args)
{
    final Display display = new Display();
    Shell shell = new Shell(display);
    shell.setText("StackOverflow");
    shell.setLayout(new FillLayout(SWT.VERTICAL));

    final Text text = new Text(shell, SWT.BORDER);

    final Button runButton = new Button(shell, SWT.CHECK);
    runButton.setText("Stop");

    final Runnable run = new Runnable()
    {
        private int counter = 0;
        @Override
        public void run()
        {
            if(runButton.getSelection())
                return;

            text.setText(Integer.toString(counter++));

            display.timerExec(1000, this);
        }
    };

    display.timerExec(1000, run);

    runButton.addListener(SWT.Selection, new Listener()
    {
        @Override
        public void handleEvent(Event arg0)
        {
            if(!runButton.getSelection())
                display.timerExec(1000, run);
        }
    });

    shell.pack();
    shell.setSize(200, shell.getSize().y);
    shell.open();

    while (!shell.isDisposed())
    {
        if (!display.readAndDispatch())
            display.sleep();
    }
    display.dispose();
}

Answer 2

My goal was to make idle detector to smooth user interface. When user makes changes in one part of UI, then the system waits for 1000 ms and updates other parts of UI. If during the waiting, say in 800 ms, user makes changes again, then system cancels waiting for that period and start to wait for 1000 ms again.

In Swing this was solved with one-time delayed timer. Swing's Timer made good for this. And I was wondering, if the same is made in SWT?

Probably there is no direct equivalent, so I made a class with util's Timer:

public abstract class DelayedInfrequentAction implements Runnable {

    private int delay;
    private Display display;

    private Timer timer = null;

    public DelayedInfrequentAction(Display display, int delay) {
        this.display = display;
        this.delay = delay;
    }

    public synchronized void kick() {

        if( timer != null ) {
            timer.cancel();
            timer.purge();
            timer = null;
        }

        timer = new Timer(this.getClass().getSimpleName(), true);
        timer.schedule(new TimerTask() {

            @Override
            public void run() {
                display.syncExec(DelayedInfrequentAction.this);
                synchronized (DelayedInfrequentAction.this) {
                    timer = null;
                }

            }}, delay);

    }

    @Override
    abstract public void run();

}

this is not Swing's Timer equivalent, but utilizes cancelation ability of utils Timer.