Tuesday, June 8, 2010

html timer

For my presentation at Macworld in January I created a semi-time-lapse screen capture of a complete InstaDMG run to run as a demo. Since different parts of it were going to fly by at different rates I wanted to have some sort of timer to show the real clock time. Looking around for some little application or widget I did not find anything I like, and I finally gave in and made one myself.
Since I wanted this done fast, and with something I could easily control with AppleScript (sense the rest of the demo was being driven by it anyways), I decided to create a little JavaScript timer, and run it inside Safari.
        var hours = null, minutes = null, seconds = null
        var startTime = null
        var currentTimer = null
        function startTimer() {
            // setup things
            hours = document.getElementById("hours")
            minutes = document.getElementById("minutes")
            seconds = document.getElementById("seconds")
            startTime = new Date()
        function displayTimer() {
            currentTime = new Date(new Date() - startTime)
            seconds.innerHTML = currentTime.getUTCSeconds()
            minutes.innerHTML = currentTime.getUTCMinutes()
            hours.innerHTML = currentTime.getUTCHours()
            currentTimer = setTimeout('displayTimer()',500);
        function stopTimer() {
{ font-size: large }
{ width: .65in; display: inline-table; font-size: .5in; text-align: right }

    <div id="hours">0</div> hrs <div id="minutes">0</div> min <div id="seconds">0</div> sec
Then I just had to trigger it with some code like:
tell application "Safari" to do JavaScript "startTimer()" in timerDocument
Edit: figured out the problem with the hours, and the correction was to use UTC time.

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