/*
    Written by Jonathan Snook, http://www.snook.ca/jonathan
    Add-ons by Robert Nyman, http://www.robertnyman.com
    getElementsByClassName(document, "a", "info-links")
    getElementsByClassName(document.getElementById("container"), "div", "col"); 
    getElementsByClassName(document, "*", "click-me"); 
*/


function getElementsByClassName(oElm, strTagName, strClassName){
    var arrElements = (strTagName == "*" && oElm.all)? oElm.all : oElm.getElementsByTagName(strTagName);
    var arrReturnElements = new Array();
    strClassName = strClassName.replace(/\-/g, "\\-");
    var oRegExp = new RegExp("(^|\\s)" + strClassName + "(\\s|$)");
    var oElement;
    for(var i=0; i<arrElements.length; i++){
        oElement = arrElements[i];      
        if(oRegExp.test(oElement.className)){
            arrReturnElements.push(oElement);
        }   
    }
    return (arrReturnElements)
}

//by oscar carrascosa blanco
function hacerArrastrables(){
	var losElementos = getElementsByClassName(document,"*","arrastrable");
	for (var i =0; i< losElementos.length; i++){
		makeDraggable(losElementos[i]);
		//makeDraggable(document.getElementById('capa'));
	}
}






function overlay(nombreCapa) {
	el = document.getElementById(nombreCapa);
	el.style.visibility = (el.style.visibility == "visible") ? "hidden" : "visible";
}





document.onmousemove = mouseMove;
document.onmouseup   = mouseUp;



function mouseCoords(ev){
	if(ev.pageX || ev.pageY){
		return {x:ev.pageX, y:ev.pageY};
	}
	return {
		x:ev.clientX + document.body.scrollLeft - document.body.clientLeft,
		y:ev.clientY + document.body.scrollTop  - document.body.clientTop
	};
}

var dragObject  = null;
var mouseOffset = null;

function getMouseOffset(target, ev){
	ev = ev || window.event;

	var docPos    = getPosition(target);
	var mousePos  = mouseCoords(ev);
	//alert(mousePos.x);
	return {x:mousePos.x - docPos.x, y:mousePos.y - docPos.y};
}

function getPosition(e){
	var left = 0;
	var top  = 0;

	while (e.offsetParent){
		left += e.offsetLeft;
		top  += e.offsetTop;
		e     = e.offsetParent;
	}

	left += e.offsetLeft;
	top  += e.offsetTop;

	return {x:left, y:top};
}

function mouseMove(ev){
	ev           = ev || window.event;
	var mousePos = mouseCoords(ev);

	if(dragObject){
		dragObject.style.position = 'absolute';
		dragObject.style.top      = mousePos.y - mouseOffset.y + "px";
		dragObject.style.left     = mousePos.x - mouseOffset.x + "px";

		return false;
	}
}




function mouseDown(ev){
	ev         = ev || window.event;
	var target = ev.target || ev.srcElement;

	iMouseDown = true;
	
	if(target.onmousedown || target.getAttribute('DragObj')){
		return false;
	}
}





function mouseUp(ev){


	dragObject = null;


}





function makeDraggable(item){
	if(!item) return;
	item.onmousedown = function(ev){
		dragObject  = this;
		mouseOffset = getMouseOffset(this, ev);
		return false;
	}
}