// Slider Global vars
var aSlidemouseover                = false;
var aSlideDefaultSliderLength      = 100;
var aSlideSliderDefaultOrientation = 'horizontal';
var aSlideSliderClassName          = 'slider';
var aSlideSliderDisplayClassName   = 'slider_display';
var aSlidesliders                  = [];
var aSlidedisplays                 = [];
var aSlideslider                   = {};
var aSlidedisplay                  = {};


// aSlideAddLoadEvent
function aSlideAddLoadEvent(func)
{
		var oldonload = window.onload;
		if (typeof window.onload != 'function') {
			window.onload = func;
		}
		else {
			window.onload = function() {
				oldonload();
				func();
			};
		}
}
// aSlideGetElementsByClass: Cross-browser function that returns
// an array with all elements that have a class attribute that
// contains className
function aSlideGetElementsByClass(className)
{
	var classElements = new Array();
	var els = document.getElementsByTagName("*");
	var elsLen = els.length;
	var pattern = new RegExp("\\b" + className + "\\b");
	for (var i = 0, j = 0; i < elsLen; i++) {
		if ( pattern.test(els[i].className) ) {
			classElements[j] = els[i];
			j++;
		}
	}
	return classElements;
}
// aSlideLeft: Cross-browser version of "element.style.left"
// Returns or sets the horizontal position of an element.
function aSlideLeft(elmnt, pos)
{
	if (!(elmnt = document.getElementById(elmnt))) return 0;
	if (elmnt.style && (typeof(elmnt.style.left) == 'string')) {
		if (typeof(pos) == 'number') elmnt.style.left = pos + 'px';
		else {
			pos = parseInt(elmnt.style.left);
			if (isNaN(pos)) pos = 0;
		}
	}
	else if (elmnt.style && elmnt.style.pixelLeft) {
		if (typeof(pos) == 'number') elmnt.style.pixelLeft = pos;
		else pos = elmnt.style.pixelLeft;
	}
	return pos;
}
// aSlideTop: Cross-browser version of "element.style.top"
// Returns or sets the vertical position of an element.
function aSlideTop(elmnt, pos)
{
	if (!(elmnt = document.getElementById(elmnt))) return 0;
	if (elmnt.style && (typeof(elmnt.style.top) == 'string')) {
		if (typeof(pos) == 'number') elmnt.style.top = pos + 'px';
		else {
			pos = parseInt(elmnt.style.top);
			if (isNaN(pos)) pos = 0;
		}
	}
	else if (elmnt.style && elmnt.style.pixelTop) {
		if (typeof(pos) == 'number') elmnt.style.pixelTop = pos;
		else pos = elmnt.style.pixelTop;
	}
	return pos;
}
// moveSlider: Handles slider and display while dragging
function moveSlider(evnt)
{
	var evnt = (!evnt) ? window.event : evnt; // The mousemove event
	if (aSlidemouseover) { // Only if slider is dragged
		aSlideslider.x = aSlideslider.startOffsetX + evnt.screenX; // Horizontal mouse position relative to allowed slider positions
		aSlideslider.y = aSlideslider.startOffsetY + evnt.screenY; // Horizontal mouse position relative to allowed slider positions
		if (aSlideslider.x > aSlideslider.xMax) aSlideslider.x = aSlideslider.xMax; // Limit horizontal movement
		if (aSlideslider.x < 0) aSlideslider.x = 0; // Limit horizontal movement
		if (aSlideslider.y > aSlideslider.yMax) aSlideslider.y = aSlideslider.yMax; // Limit vertical movement
		if (aSlideslider.y < 0) aSlideslider.y = 0; // Limit vertical movement
		aSlideLeft(aSlideslider.id, aSlideslider.x);  // move slider to new horizontal position
		aSlideTop(aSlideslider.id, aSlideslider.y); // move slider to new vertical position
		var sliderVal = aSlideslider.x + aSlideslider.y; // pixel value of slider regardless of orientation
		var sliderPos = (aSlideslider.distance / aSlidedisplay.valuecount) * 
			Math.round(aSlidedisplay.valuecount * sliderVal / aSlideslider.distance);
		var v = Math.round((sliderPos * aSlideslider.scale + aSlideslider.from) * // calculate display value
			Math.pow(10, aSlidedisplay.decimals)) / Math.pow(10, aSlidedisplay.decimals);
		aSlidedisplay.value = v; // put the new value in the slider display element
		return false;
	}
	return
}
// slide: Handles the start of a slider move.
function slide(evnt)
{
	if (!evnt) evnt = window.event; // Get the mouse event causing the slider activation.
	aSlideslider = (evnt.target) ? evnt.target : evnt.srcElement; // Get the activated slider element.
	var dist = parseInt(aSlideslider.getAttribute('distance')); // The allowed slider movement in pixels.
	aSlideslider.distance = dist ? dist : aSlideDefaultSliderLength; // Deafault distance from global var.
	var ori = aSlideslider.getAttribute('orientation'); // Slider orientation: 'horizontal' or 'vertical'.
	var orientation = ((ori == 'horizontal') || (ori == 'vertical')) ? ori : aSlideSliderDefaultOrientation;
		// Default orientation from global variable.
	var displayId = aSlideslider.getAttribute('display'); // ID of associated display element.
	aSlidedisplay = document.getElementById(displayId); // Get the associated display element.
	aSlidedisplay.sliderId = aSlideslider.id; // Associate the display with the correct slider.
	var dec = parseInt(aSlidedisplay.getAttribute('decimals')); // Number of decimals to be displayed.
	aSlidedisplay.decimals = dec ? dec : 0; // Default number of decimals: 0.
	var val = parseInt(aSlidedisplay.getAttribute('valuecount'))  // Allowed number of values in the interval.
	aSlidedisplay.valuecount = val ? val : aSlideslider.distance + 1 // Default number of values: the sliding distance.
	var from = parseFloat(aSlidedisplay.getAttribute('from')) // Min/start value for the display.
	from = from ? from : 0 // Default min/start value: 0.
	var to = parseFloat(aSlidedisplay.getAttribute('to')) // Max value for the display.
	to = to ? to : aSlideslider.distance // Default number of values: the sliding distance.
	aSlideslider.scale = (to - from) / aSlideslider.distance // Slider-display scale [value-change per pixel of movement].
	if (orientation == 'vertical') { // Set limits and scale for vertical sliders.
		aSlideslider.from = to // Invert for vertical sliders. "Higher is more."
		aSlideslider.xMax = 0
		aSlideslider.yMax = aSlideslider.distance
		aSlideslider.scale = -aSlideslider.scale // Invert scale for vertical sliders. "Higher is more."
	}
	else { // Set limits for horizontal sliders.
		aSlideslider.from = from;
		aSlideslider.xMax = aSlideslider.distance;
		aSlideslider.yMax = 0;
	}
	aSlideslider.startOffsetX = aSlideLeft(aSlideslider.id) - evnt.screenX; // Slider-mouse horizontal offset at start of slide.
	aSlideslider.startOffsetY = aSlideTop(aSlideslider.id) - evnt.screenY; // Slider-mouse vertical offset at start of slide.
	aSlidemouseover = true;
	document.onmousemove = moveSlider; // Start the action if the mouse is dragged.
	document.onmouseup = sliderMouseUp; // Stop sliding.
	return false;
}
// sliderMouseUp: Handles the mouseup event after moving a slider.
// Snaps the slider position to allowed/displayed value. 
function sliderMouseUp()
{
	if (aSlidemouseover) {
		var v = (aSlidedisplay.value) ? aSlidedisplay.value : 0 // Find last display value.
		var pos = (v - aSlideslider.from)/(aSlideslider.scale) // Calculate slider position (regardless of orientation).
		if (aSlideslider.yMax == 0) {
			pos = (pos > aSlideslider.xMax) ? aSlideslider.xMax : pos;
			pos = (pos < 0) ? 0 : pos;
			aSlideLeft(aSlideslider.id, pos); // Snap horizontal slider to corresponding display position.
		}
		if (aSlideslider.xMax == 0) {
			pos = (pos > aSlideslider.yMax) ? aSlideslider.yMax : pos;
			pos = (pos < 0) ? 0 : pos;
			aSlideTop(aSlideslider.id, pos); // Snap vertical slider to corresponding display position.
		}
		if (document.removeEventListener) { // Remove event listeners from 'document' (W3C).
			document.removeEventListener('mousemove', moveSlider, false);
			document.removeEventListener('mouseup', sliderMouseUp, false);
		}
		else if (document.detachEvent) { // Remove event listeners from 'document' (IE).
			document.detachEvent('onmousemove', moveSlider);
			document.detachEvent('onmouseup', sliderMouseUp);
			document.releaseCapture();
		}
	}
	aSlidemouseover = false; // Stop the sliding.
}
function focusDisplay(evnt)
{
	if (!evnt) evnt = window.event; // Get the mouse event causing the display activation.
	var aSlidedisplay = (evnt.target) ? evnt.target : evnt.srcElement; // Get the activated display element.
	var lock = aSlidedisplay.getAttribute('typelock'); // Is the user allowed to type into the display?
	if (lock == 'on') {
		aSlidedisplay.blur();
	}
	return;
}
function aSlideInit() // Set up the sliders and the displays.
{
	aSlidesliders = aSlideGetElementsByClass(aSlideSliderClassName) // Find the horizontal sliders.
	for (var i = 0; i < aSlidesliders.length; i++) {
		aSlidesliders[i].onmousedown = slide; // Attach event listener.
	}
	aSlidedisplays = aSlideGetElementsByClass(aSlideSliderDisplayClassName) // Find the displays.
	for (var i = 0; i < aSlidedisplays.length; i++) {
		aSlidedisplays[i].value = aSlidedisplays[i].defaultValue; // Resets display on page reload.
		aSlidedisplays[i].onfocus = focusDisplay; // Attach event listener.
	}
}
aSlideAddLoadEvent(aSlideInit);