TimerManager with random recurTime

I want a random expiration time on EACH iteration. This example will only randomize an expiration time between 5~15 seconds and use them forever.

var timer = qx.util.TimerManager.getInstance();
timer.start(function(userData, timerId)
    {
        this.debug("timer tick");
    },
    (Math.floor(Math.random()*11)*1000) + 5000,开发者_运维技巧
    this,
    null,
    0
);

I also accept an pure JS solution if any.

http://demo.qooxdoo.org/current/apiviewer/#qx.util.TimerManager

The issue is that the recurTime argument to TimerManager.start is a normal argument to a normal function, so it is evaluated only once when the function is called. It's not an expression that gets re-evaluated over and over again. That means you only get equidistant executions with TimerManager.

You probably have to code what you want by hand, e.g. using qx.event.Timer.once calculating the timeout anew with each invocation.

EDIT:

Here is a code snippet that might go in the right direction for you (this would work in the context of a qooxdoo class):

var that = this;
function doStuff(timeout) {
  // do the things here you want to do in every timeout
  // this example just logs the new calculated time offset
  that.debug(timeout);
}

function callBack() {
  // this just calls doStuff and handles a new time offset
  var timeout = (Math.floor(Math.random()*11)*1000) + 5000;
  doStuff(timeout);
  qx.event.Timer.once(callBack, that, timeout);
}

// fire off the first execution
qx.event.Timer.once(callBack, that, 5000);