[java-gnome-hackers] Timer API problem

[Tom B. <Tom...@Su...>]

I'd like to modify the org.gnu.glib.Timer API before more people start
using it.  The problem is that it uses the Runnable interface which
defines a void method, while GLib's timeout facility uses a function
that returns a boolean.  This boolean return makes it very easy to
define a one-shot timer, and for a timeout function to stop itself
cleanly -- just return false instead of true.  With a Runnable
interface, one has to jump through hoops to achieve the same result.

Since you can't overload a method's return value and since timers are
traditionally thought to fire rather than run anyway, I'd like to define
the following to replace Timer's use of Runnable:

package org.gnu.glib;

public interface Fireable {
    /**
     * This method executes when "fired" by a subsystem, such as by 
     * a timer.
     *
     * @return true if the timer should continue executing, or false
     *  if this is the last invocation of this method.
     */
    boolean fire();
}

One option is to make Fireable an inner interface of Timer.  Timer's
constructor would change to:

    public Timer(int interval, Fireable target) {}

and Timer._run() can then be deleted.

Any objections?  One nice side-benefit is that an invokeLater method
becomes trivial to implement by using a one-shot timer.

Tom