source: timingandestimationplugin/branches/trac0.11/timingandestimationplugin/htdocs/StopwatchDisplay.js

/**
 * Copyright (C) 2010, Tay Ray Chuan
 */

/*
 * add buttons to control the stopwatch
 *
 * Button 'flow' has states: start -> stop <-> continue
 * Button 'reset' has state: reset
 */
jQuery(function($) {
    StopwatchDisplay = function() {
        /* the stopwatch (looks like 00:00:00) */
        var field_hour = $('<span>00</span>');
        var field_min = $('<span>00</span>');
        var field_sec = $('<span>00</span>');

        var display = $('<div></div>')
            .append(field_hour)
            .append(':')
            .append(field_min)
            .append(':')
            .append(field_sec);

        field_hour = field_hour[0].firstChild;
        field_min = field_min[0].firstChild;
        field_sec = field_sec[0].firstChild;

        var interval_id;
        var start_time = null;
            var end_time;
            var total_time=0 ;
            var now = function(){ return Math.floor((new Date()).getTime() / 1000);};
        var interval_func = function() {
                        var interval = (now() - start_time)+total_time;
                        var h = 0, m = 0, s = 0;
                        s = interval % 60;
                        m = Math.floor(interval/60) % 60;
                        h = Math.floor(interval/3600);
                        field_sec.nodeValue = s < 10 ? '0'+s : s;
                        field_min.nodeValue = m < 10 ? '0'+m : m;
                        field_hour.nodeValue = h < 10 ? '0'+h : h;
        };

        return {
            display: display,

            pause_stopwatch: function() {
                clearInterval(interval_id);
                interval_id = null;
                    total_time += now() - start_time;
                    start_time = null;
            },
            continue_stopwatch: function() {
                /*
                 * We really want to do an add (of the seconds on the display)
                 * - which is what we get when start_time is subtracted later.
                 */
                    start_time = now();
                interval_id = setInterval(interval_func, 100);
            },
            reset_stopwatch: function() {
                field_hour.nodeValue = '00';
                field_min.nodeValue = '00';
                field_sec.nodeValue = '00';
                                start_time=null;
                                total_time=0;
            },
            get_hours: function() {
                                var total = total_time;
                    if (start_time) total += (now() - start_time);
                                return Math.round( ( total / 3600 ) * 100) / 100;
            }
        };
    }();
});