//
// Generic utility functions
//
// History:
// Feb 3, 2006, Incorporated into Google Mars, Noel Gorelick, gorelick@asu.edu
//


function px(size) { return size + "px"; };
function em(size) { return size + "em"; };

function makeDiv(doc, style) { 
    var div = doc.createElement('div'); 
    if (!style) {
        // default stylle for divs.  This is probably a bad thing to do
        style = { position: 'absolute', left: px(0), top: px(0)};
    }
    for (var name in style) {
        div.style[name] = style[name];
    }
    return(div);
}


function makeImage(doc, src) {
    var img = doc.createElement('img');
    img.src = src;
    return(img);
}


function getWindowHeight() {
    if (window.self && self.innerHeight) {
        return self.innerHeight
    }
    if (document.documentElement && document.documentElement.clientHeight) {
        return document.documentElement.clientHeight;
    }
    return 0;
}

function getWindowWidth() {
    if (window.self && self.innerWidth) {
        return self.innerWidth
    }
    if (document.documentElement && document.documentElement.clientWidth) {
        return document.documentElement.clientWidth;
    }
    return 0;
}

function getPosition(elem) {
    var offset = 0;
    var x = 0; y = 0;
    var w = elem.offsetWidth;
    var h = elem.offsetHeight;
    while (elem != null) {
        y += elem.offsetTop;
        x += elem.offsetLeft;
        elem = elem.offsetParent;
    }
    var out = { top: y, left: x, width: w, height: h};
    return(out);
}

// Remove  all of an DOM element's children
function removeChildren(element) {
    var t;
    var children = Array();
    while((t = element.lastChild) != null) {
        children.push(element.removeChild(t));
    }
    return(children);
}

function formatFloat(n,p) { 
    var txt = (""+n).split(".");
    return(txt.length == 1 ? n.toString() : txt[0] + "." + txt[1].substr(0,p));
}

function wrap(value, min, max) {
  while (value > max) {
    value -= (max - min);
  }
  while (value < min) {
    value += (max - min);
  }
  return value;
}

function toDeg(x) { return x*180/Math.PI; }

function getStyle(elem, name) {
    if (elem.currentStyle) 
        return(elem.currentStyle);
    else if (document.defaultView && document.defaultView.getComputedStyle)
        return(getComputedStyle(elem, name));
    else 
        return(null);
}

function htmlEscape(s) {
	s=s.replace(/&/g,'&amp;'); 
	s=s.replace(/>/g,'&gt;');
	s=s.replace(/</g,'&lt;');
	return s;
}


// /////////////////////////////////////////////////////////////////////
// These are from prototype.js
function $(id) {
    return document.getElementById(id);
}
var Class = {
  create: function() {
    return function() {
      this.initialize.apply(this, arguments);
    }
  }
}
// method for extending a class
Object.extend = function(destination, source) {
  for (property in source) {
    destination[property] = source[property];
  }
  return destination;
}