/* 
* Spinbutton plugin for jQuery
* http://www.softwareunity.com/jquery/JQuerySpinBtn/
*
* Adds bells and whistles to any ordinary textbox to
* make it look and feel like a SpinButton Control.
*
* Copyright (c) 2006-2009 Software Unity Ltd
* Dual licensed under the MIT and GPL licenses.
* http://www.softwareunity.com/jquery/MIT-LICENSE.txt
* http://www.softwareunity.com/jquery/GPL-LICENSE.txt
*
* Originally written by George Adamson, Software Unity (george.jquery@softwareunity.com) August 2006.
* - Added min/max options
* - Added step size option
* - Added bigStep (page up/down) option
*
* Modifications made by Mark Gibson, (mgibson@designlinks.net) September 2006:
* - Converted to jQuery plugin
* - Allow limited or unlimited min/max values
* - Allow custom class names, and add class to input element
* - Removed global vars
* - Reset (to original or through config) when invalid value entered
* - Repeat whilst holding mouse button down (with initial pause, like keyboard repeat)
* - Support mouse wheel in Firefox
* - Fix double click in IE
* - Refactored some code and renamed some vars
*
* Tested in IE6, Opera9, Firefox 1.5
* v1.0  11 Aug 2006 - George Adamson	- First release
* v1.1     Aug 2006 - George Adamson	- Minor enhancements
* v1.2  27 Sep 2006 - Mark Gibson		- Major enhancements
* v1.3a 28 Sep 2006 - George Adamson	- Minor enhancements
 
Sample usage:
 
// Create group of settings to initialise spinbutton(s). (Optional)
var myOptions = {
min: 0,						// Set lower limit.
max: 100,					// Set upper limit.
step: 1,					// Set increment size.
spinClass: mySpinBtnClass,	// CSS class to style the spinbutton. (Class also specifies url of the up/down button image.)
upClass: mySpinUpClass,		// CSS class for style when mouse over up button.
downClass: mySpinDnClass	// CSS class for style when mouse over down button.
}
 
$(document).ready(function(){

// Initialise INPUT element(s) as SpinButtons: (passing options if desired)
$("#myInputElement").SpinButton(myOptions);

});
 
*/
$.fn.SpinButton = function (cfg) {
    return this.each(function () {

        // Apply specified options or defaults:
        // (Ought to refactor this some day to use $.extend() instead)
        this.spinCfg = {
            //min: cfg && cfg.min ? Number(cfg.min) : null,
            //max: cfg && cfg.max ? Number(cfg.max) : null,
            min: cfg && !isNaN(parseFloat(cfg.min)) ? Number(cfg.min) : null, // Fixes bug with min:0
            max: cfg && !isNaN(parseFloat(cfg.max)) ? Number(cfg.max) : null,
            step: cfg && cfg.step ? Number(cfg.step) : 1,
            page: cfg && cfg.page ? Number(cfg.page) : 10,
            upClass: cfg && cfg.upClass ? cfg.upClass : 'up',
            downClass: cfg && cfg.downClass ? cfg.downClass : 'down',
            reset: cfg && cfg.reset ? cfg.reset : this.value,
            delay: cfg && cfg.delay ? Number(cfg.delay) : 500,
            interval: cfg && cfg.interval ? Number(cfg.interval) : 100,
            _btn_width: 20,
            _btn_height: 12,
            _direction: null,
            _delay: null,
            _repeat: null
        };

        this.adjustValue = function (i) {
            var v = (isNaN(this.value) ? this.spinCfg.reset : Number(this.value)) + Number(i);
            if (this.spinCfg.min !== null) v = Math.max(v, this.spinCfg.min);
            if (this.spinCfg.max !== null) v = Math.min(v, this.spinCfg.max);
            this.value = v;
        };

        $(this)
		.addClass(cfg && cfg.spinClass ? cfg.spinClass : 'spin-button')

		.mousemove(function (e) {
		    // Determine which button mouse is over, or not (spin direction):
		    var x = e.pageX || e.x;
		    var y = e.pageY || e.y;
		    var el = e.target || e.srcElement;
		    var direction =
				(x > coord(el, 'offsetLeft') + el.offsetWidth - this.spinCfg._btn_width)
				? ((y < coord(el, 'offsetTop') + this.spinCfg._btn_height) ? 1 : -1) : 0;

		    if (direction !== this.spinCfg._direction) {
		        // Style up/down buttons:
		        switch (direction) {
		            case 1: // Up arrow:
		                $(this).removeClass(this.spinCfg.downClass).addClass(this.spinCfg.upClass);
		                break;
		            case -1: // Down arrow:
		                $(this).removeClass(this.spinCfg.upClass).addClass(this.spinCfg.downClass);
		                break;
		            default: // Mouse is elsewhere in the textbox
		                $(this).removeClass(this.spinCfg.upClass).removeClass(this.spinCfg.downClass);
		        }

		        // Set spin direction:
		        this.spinCfg._direction = direction;
		    }
		})

		.mouseout(function () {
		    // Reset up/down buttons to their normal appearance when mouse moves away:
		    $(this).removeClass(this.spinCfg.upClass).removeClass(this.spinCfg.downClass);
		    this.spinCfg._direction = null;
		})

		.mousedown(function (e) {
		    if (this.spinCfg._direction != 0) {
		        // Respond to click on one of the buttons:
		        var self = this;
		        var adjust = function () {
		            self.adjustValue(self.spinCfg._direction * self.spinCfg.step);
		        };

		        adjust();

		        // Initial delay before repeating adjustment
		        self.spinCfg._delay = window.setTimeout(function () {
		            adjust();
		            // Repeat adjust at regular intervals
		            self.spinCfg._repeat = window.setInterval(adjust, self.spinCfg.interval);
		        }, self.spinCfg.delay);
		    }
		})

		.mouseup(function (e) {
		    // Cancel repeating adjustment
		    window.clearInterval(this.spinCfg._repeat);
		    window.clearTimeout(this.spinCfg._delay);
		})

		.dblclick(function (e) {
		    if ($.browser.msie)
		        this.adjustValue(this.spinCfg._direction * this.spinCfg.step);
		})

		.keydown(function (e) {
		    // Respond to up/down arrow keys.
		    switch (e.keyCode) {
		        case 38: this.adjustValue(this.spinCfg.step); break; // Up
		        case 40: this.adjustValue(-this.spinCfg.step); break; // Down
		        case 33: this.adjustValue(this.spinCfg.page); break; // PageUp
		        case 34: this.adjustValue(-this.spinCfg.page); break; // PageDown
		    }
		})

		.bind("mousewheel", function (e) {
		    // Respond to mouse wheel in IE. (It returns up/dn motion in multiples of 120)
		    if (e.wheelDelta >= 120)
		        this.adjustValue(this.spinCfg.step);
		    else if (e.wheelDelta <= -120)
		        this.adjustValue(-this.spinCfg.step);

		    e.preventDefault();
		})

		.change(function (e) {
		    this.adjustValue(0);
		});

        if (this.addEventListener) {
            // Respond to mouse wheel in Firefox
            this.addEventListener('DOMMouseScroll', function (e) {
                if (e.detail > 0)
                    this.adjustValue(-this.spinCfg.step);
                else if (e.detail < 0)
                    this.adjustValue(this.spinCfg.step);

                e.preventDefault();
            }, false);
        }
    });

    function coord(el, prop) {
        var c = el[prop], b = document.body;

        while ((el = el.offsetParent) && (el != b)) {
            if (!$.browser.msie || (el.currentStyle.position != 'relative'))
                c += el[prop];
        }

        return c;
    }
};