/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *

Originally from:
  http://www.arantius.com/article/lightweight+javascript+slider+control

Copyright (c) 2006 Anthony Lieuallen, http://www.arantius.com/

Permission is hereby granted, free of charge, to any person obtaining a copy of 
this software and associated documentation files (the "Software"), to deal in 
the Software without restriction, including without limitation the rights to 
use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of 
the Software, and to permit persons to whom the Software is furnished to do so, 
subject to the following conditions:

The above copyright notice and this permission notice shall be included in all 
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS 
FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR 
COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER 
IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN 
CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

New version: gslider.js (Goleango Slider)
Heavily updated by Adir Eini for www.goleango.com 
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
function gslider_addAnEvent(el, evname, func) {
    if (el.attachEvent) { // IE
        el.attachEvent("on" + evname, func);
    } else if (el.addEventListener) { // Gecko / W3C
        el.addEventListener(evname, func, true);
    } else {
        el["on" + evname] = func;
    }
}
 
function gslider_removeAnEvent(el, evname, func) {
    if (el.attachEvent) { // IE
        el.removeEvent("on" + evname, func);
    } else if (el.addEventListener) { // Gecko / W3C
        el.removeEventListener(evname, func, true);
    } else {
        el["on" + evname] = null;
    }
}
 
 function gslider_drawSliderByInputVal(slider)
 {
	slider.val = slider.input.value;
	gslider_drawSliderByVal(slider);
 }
 
function gslider_drawSliderByVal(slider)
{	
	
	var p = (slider.val-slider.min)/(slider.max-slider.min);
	var x = (slider.scroll_width-slider.double_arrow_width) * p;
	
	if (x < slider.arrow_width) x = slider.arrow_width;
	if (x > (slider.scroll_width - slider.arrow_width - slider.handle_width))
		x = slider.scroll_width - slider.arrow_width - slider.handle_width;
	
	slider.handle.style.left = x +"px";
}
/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
function gslider_setSliderByClientX(slider, clientX)
{
	var p=(clientX-slider.element.offsetLeft-slider.arrow_width)/(slider.scroll_width-slider.double_arrow_width);
	slider.val = (slider.max-slider.min)*p + slider.min;
	
	gslider_on_slider_value_change(slider);
}

function gslider_increment_one_step(slider)
{	
	slider.val += slider._unitIncrement;
	gslider_on_slider_value_change(slider);
}

function gslider_decrement_one_step(slider)
{
	slider.val -= slider._unitIncrement;
	gslider_on_slider_value_change(slider);
}

function gslider_on_slider_value_change(slider)
{
	
	var val = slider.val;
	if (!slider.is_real)
	{
		val = Math.round(val - val % slider._unitIncrement);		
	}
	else
	{
		var val100 = Math.round(val * slider._after_point_digits_power);
		var modulo = val100 % (slider._powered_unitIncrement);
		val = (val100 - modulo) / slider._after_point_digits_power;
	}	

	if (val>slider.max) val=slider.max;
	if (val<slider.min) val=slider.min;
	
	slider.val = val;
	gslider_drawSliderByVal(slider);
	set_obj_value(slider.input, val);
	if (slider.onchange != null)
		slider.onchange();
}

/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
function gslider_sliderClick(e) {
	var el=gslider_sliderFromEvent(e);
	if (!el) return;

	gslider_setSliderByClientX(el, e.clientX);
}
/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
function gslider_sliderMouseMove(e)
{
	
	if (_activeSlider == null) return;
	
	gslider_setSliderByClientX(_activeSlider, e.clientX);
	gslider_stopEvent(e);
}

function gslider_sliderMouseUp(e)
{
	_activeSlider = null;
}

/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
function gslider_sliderFromEvent(e) {

	if (!e && window.event) e=window.event;
	if (!e) return false;

	var el;
	if (e.target) el=e.target;
	if (e.srcElement) el=e.srcElement;
	
	for (var i = 0; i < gslider_array.length; i++)
	{
		if (gslider_array[i] && gslider_array[i].element == el || gslider_array[i].handle == el)
			return gslider_array[i];
	}

	return null;
}
/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
function gslider_attach_specific_slider_events(slider)
{
	gslider_drawSliderByVal(slider);
		
	set_obj_value(slider.input, slider.val);
	slider.mouse_down_func = function(e){
		
		gslider_sliderClick(e);
		var el=gslider_sliderFromEvent(e);
		if (!el) return;
		_activeSlider = el;
		gslider_stopEvent(e);
	};
	
	slider.mouse_up_func = function(e){
		
		_activeSlider = null;
		//gslider_stopEvent(e);
	};
	gslider_addAnEvent(slider.element, 'mouseup', slider.mouse_up_func);
		gslider_addAnEvent(slider.element, 'mousedown', slider.mouse_down_func);
}

function gslider_attachSliderEvents()
{
	for(var i=0; i< gslider_array.length; i++)
	{
		// set initial properties
		var slider = gslider_array[i];
		if (!slider)
			continue;
		gslider_attach_specific_slider_events(slider);			
	}
}
/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
//borrowed from prototype: http://prototype.conio.net/
function gslider_stopEvent(event) {
	if (event.preventDefault) {
		event.preventDefault();
		event.stopPropagation();
	} else {
		event.returnValue=false;
		event.cancelBubble=true;
	}
}
/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */

gslider_addAnEvent(document, 'mousemove', gslider_sliderMouseMove);
gslider_addAnEvent(document, 'mouseup', gslider_sliderMouseUp);
var _activeSlider = null;
/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */

var gslider_array = new Array();

function _assign_arrow_event_handlers(id, dir, onclick)
{	
	var obj = document.getElementById(id + "_" + dir + "_arrow");
	var onmouseoverclass = dir + '_arrow_hover';
	var onmousedownclass = dir + '_arrow_mousedown';
	var onmouseoutclass = dir + '_arrow';
	obj.className = onmouseoutclass;
	obj.onmouseover = function(){obj.className = onmouseoverclass;};
	obj.onmouseup = obj.onmouseover;
	obj.onmousedown = function(){obj.className = onmousedownclass;};
	obj.onmouseout = function(){obj.className = onmouseoutclass;};	
	obj.onclick = onclick;
}

function remove_slider(index)
{
	var slider = gslider_array[index];
	gslider_removeAnEvent(slider.element, 'mouseup', slider.mouse_up_func);
	gslider_removeAnEvent(slider.element, 'mousedown', slider.mouse_down_func);
	delete gslider_array[index];
}

function create_slider_common(id, input_obj, min, max, val, is_real, step, onchange, arrow_width)
{	
	var index = 0;
	while (gslider_array[index])
	{
		index++;
	}	
	var slider = new Object();
	slider.id = id;
	slider.min = min;
	slider.max = max;
	slider.val = val;
	
	slider.handle = document.getElementById(id + "_handle");
	slider.handle_width = slider.handle.offsetWidth;
	
	slider.onchange = onchange;
	slider.is_real = is_real;
	slider._unitIncrement = step;
	
	slider.input = input_obj;
	
	
	slider.element =  document.getElementById("slider_" + id);
	slider.scroll_width = slider.element.scrollWidth;
	if (slider.scroll_width == 0)
	{
		slider.scroll_width = parseInt(slider.element.style.width.replace(/px/, ""));
	}
	
	slider.arrow_width = arrow_width;
	slider.double_arrow_width = arrow_width * 2;
		
	if (is_real)
	{		
		slider._after_point_digits_power = 1;
		while (step * 10 != parseInt(step * 10) && slider._after_point_digits_power < 5)
		{
			slider._after_point_digits_power++;
			step = step * 10;
		}

		slider._after_point_digits_power = Math.pow(10, slider._after_point_digits_power);
		slider._powered_unitIncrement = slider._unitIncrement * slider._after_point_digits_power
	}
	
	slider.input.onkeyup = function()
	{
		if (slider.onchange)
		{
			slider.onchange();
		}
		gslider_drawSliderByInputVal(slider);
	}
	slider.input.onmouseup = slider.input.onkeyup;
	
	_assign_arrow_event_handlers(id, "left", function(){gslider_decrement_one_step(slider);});
	_assign_arrow_event_handlers(id, "right", function(){gslider_increment_one_step(slider);});
	
	slider.element.onselectstart	= function () { return false; };
	slider.handle.onselectstart	= function () { return false; };
	gslider_array[index] = slider;
	gslider_attach_specific_slider_events(slider);
	return index;
}

function create_slider_from_input_id(id, min, max, val, is_real, step, onchange, arrow_width)
{											 
	return create_slider_common(id, document.getElementById(id), min, max, val, is_real, step, onchange, arrow_width);
}

var create_slider = create_slider_from_input_id;

function create_slider_from_input_object(id, input_obj, min, max, val, is_real, step, onchange, arrow_width)
{	
	return create_slider_common(id, input_obj, min, max, val, is_real, step, onchange, arrow_width);
}