// javascript document

/**

* png: adds ie6 support: png images for css background-image and html <img/>.

* author: drew diller

* email: drew.diller@gmail.com

* url: http://www.dillerdesign.com/experiment/png/

* version: 0.0.7a

* licensed under the mit license: http://dillerdesign.com/experiment/png/#license

*

* example usage:

* png.fix('.png_bg'); // argument is a css selector

* png.fixpng( somenode ); // argument is an htmldomelement

**/

 

/*

please read:

absolutely everything in this script is silly.  i know this.  ie's rendering of certain pixels doesn't make sense, so neither does this code!

*/

 

var png = {

 

 ns: 'png',

 imgsize: {},

 

 createvmlnamespace: function() { /* enable vml */

  if (document.namespaces && !document.namespaces[this.ns]) {

    document.namespaces.add(this.ns, 'urn:schemas-microsoft-com:vml');

  }

  if (window.attachevent) {

   window.attachevent('onbeforeunload', function() {

    png = null;

   });

  }

 },

 

 createvmlstylesheet: function() { /* style vml, enable behaviors */

  /*

   just in case lots of other developers have added

   lots of other stylesheets using document.createstylesheet

   and hit the 31-limit mark, let's not use that method!

   further reading: http://msdn.microsoft.com/en-us/library/ms531194(vs.85).aspx

  */

  var style = document.createelement('style');

  document.documentelement.firstchild.insertbefore(style, document.documentelement.firstchild.firstchild);

  var stylesheet = style.stylesheet;
  
  stylesheet.addrule(this.ns + '\\:*', '{behavior:url(#default#vml)}');

  stylesheet.addrule(this.ns + '\\:shape', 'position:absolute;');

  stylesheet.addrule('img.' + this.ns + '_sizefinder', 'behavior:none; border:none; position:absolute; z-index:-1; top:-10000px; visibility:hidden;'); /* large negative top value for avoiding vertical scrollbars for large images, suggested by james o'brien, http://www.thanatopsic.org/hendrik/ */

  this.stylesheet = stylesheet;

 },

 

 readpropertychange: function() {

  var el = event.srcelement;

  if (event.propertyname.search('background') != -1 || event.propertyname.search('border') != -1) {

   png.applyvml(el);

  }

  if (event.propertyname == 'style.display') {

   var display = (el.currentstyle.display == 'none') ? 'none' : 'block';

   for (var v in el.vml) {

    el.vml[v].shape.style.display = display;

   }

  }

  if (event.propertyname.search('filter') != -1) {

   png.vmlopacity(el);

  }

 },

 

 vmlopacity: function(el) {

  if (el.currentstyle.filter.search('lpha') != -1) {

   var trans = el.currentstyle.filter;

   trans = parseint(trans.substring(trans.lastindexof('=')+1, trans.lastindexof(')')), 10)/100;

   el.vml.color.shape.style.filter = el.currentstyle.filter; /* complete guesswork */

   el.vml.image.fill.opacity = trans; /* complete guesswork */

  }

 },

 

 handlepseudohover: function(el) {

  settimeout(function() { /* wouldn't work as intended without settimeout */

   png.applyvml(el);

  }, 1);

 },

 

 /**

 * this is the method to use in a document.

 * @param {string} selector - required - a css selector, such as '#doc .container'

 **/

 fix: function(selector) {

  var selectors = selector.split(','); /* multiple selectors supported, no need for multiple calls to this anymore */

  for (var i=0; i<selectors.length; i++) {

   this.stylesheet.addrule(selectors[i], 'behavior:expression(png.fixpng(this))'); /* seems to execute the function without adding it to the stylesheet - interesting... */

  }

 },

 

 applyvml: function(el) {

  el.runtimestyle.csstext = '';

  this.vmlfill(el);

  this.vmloffsets(el);

  this.vmlopacity(el);

  if (el.isimg) {

   this.copyimageborders(el);

  }

 },

 

 attachhandlers: function(el) {

  var self = this;

  var handlers = {resize: 'vmloffsets', move: 'vmloffsets'};

  if (el.nodename == 'a') {

   var moreforas = {mouseleave: 'handlepseudohover', mouseenter: 'handlepseudohover', focus: 'handlepseudohover', blur: 'handlepseudohover'};

   for (var a in moreforas) {

    handlers[a] = moreforas[a];

   }

  }

  for (var h in handlers) {

   el.attachevent('on' + h, function() {

    self[handlers[h]](el);

   });

  }

  el.attachevent('onpropertychange', this.readpropertychange);

 },

 

 givelayout: function(el) {

  el.style.zoom = 1;

  if (el.currentstyle.position == 'static') {

   el.style.position = 'relative';

  }

 },

 

 copyimageborders: function(el) {

  var styles = {'borderstyle':true, 'borderwidth':true, 'bordercolor':true};

  for (var s in styles) {

   el.vml.color.shape.style[s] = el.currentstyle[s];

  }

 },

 

 vmlfill: function(el) {

  if (!el.currentstyle) {

   return;

  } else {

   var elstyle = el.currentstyle;

  }

  for (var v in el.vml) {

   el.vml[v].shape.style.zindex = elstyle.zindex;

  }

  el.runtimestyle.backgroundcolor = '';

  el.runtimestyle.backgroundimage = '';

  var nocolor = (elstyle.backgroundcolor == 'transparent');

  var noimg = true;

  if (elstyle.backgroundimage != 'none' || el.isimg) {

   if (!el.isimg) {

    el.vmlbg = elstyle.backgroundimage;

    el.vmlbg = el.vmlbg.substr(5, el.vmlbg.lastindexof('")')-5);

   }

   else {

    el.vmlbg = el.src;

   }

   var lib = this;

   if (!lib.imgsize[el.vmlbg]) { /* determine size of loaded image */

    var img = document.createelement('img');

    lib.imgsize[el.vmlbg] = img;

    img.classname = lib.ns + '_sizefinder';

    img.runtimestyle.csstext = 'behavior:none; position:absolute; left:-10000px; top:-10000px; border:none;'; /* make sure to set behavior to none to prevent accidental matching of the helper elements! */

    img.attachevent('onload', function() {

     this.width = this.offsetwidth; /* weird cache-busting requirement! */

     this.height = this.offsetheight;

     lib.vmloffsets(el);

    });
 
    img.src = el.vmlbg;

    img.removeattribute('width');

    img.removeattribute('height');

    document.body.insertbefore(img, document.body.firstchild);

   }

   el.vml.image.fill.src = el.vmlbg;

   noimg = false;

  }

  el.vml.image.fill.on = !noimg;

  el.vml.image.fill.color = 'none';

  el.vml.color.shape.style.backgroundcolor = elstyle.backgroundcolor;

  el.runtimestyle.backgroundimage = 'none';

  el.runtimestyle.backgroundcolor = 'transparent';

 },

 

 /* ie can't figure out what do when the offsetleft and the clientleft add up to 1, and the vml ends up getting fuzzy... so we have to push/enlarge things by 1 pixel and then clip off the excess */

 vmloffsets: function(el) {

  var thisstyle = el.currentstyle;

  var size = {'w':el.clientwidth+1, 'h':el.clientheight+1, 'w':this.imgsize[el.vmlbg].width, 'h':this.imgsize[el.vmlbg].height, 'l':el.offsetleft, 't':el.offsettop, 'blw':el.clientleft, 'btw':el.clienttop};

  var fudge = (size.l + size.blw == 1) ? 1 : 0;

  

  /* vml shape, left, top, width, height, origin */

  var makevisible = function(vml, l, t, w, h, o) {

   vml.coordsize = w+','+h;

   vml.coordorigin = o+','+o;

   vml.path = 'm0,0l'+w+',0l'+w+','+h+'l0,'+h+' xe';

   vml.style.width = w + 'px';

   vml.style.height = h + 'px';

   vml.style.left = l + 'px';

   vml.style.top = t + 'px';

  };

  makevisible(el.vml.color.shape, (size.l + (el.isimg ? 0 : size.blw)), (size.t + (el.isimg ? 0 : size.btw)), (size.w-1), (size.h-1), 0);

  makevisible(el.vml.image.shape, (size.l + size.blw), (size.t + size.btw), (size.w), (size.h), 1);

  

  var bg = {'x':0, 'y':0};

  var figurepercentage = function(axis, position) {

   var fraction = true;

   switch(position) {

    case 'left':

    case 'top':

     bg[axis] = 0;

     break;

    case 'center':

     bg[axis] = .5;

     break;

    case 'right':

    case 'bottom':

     bg[axis] = 1;

     break;

    default:

     if (position.search('%') != -1) {

      bg[axis] = parseint(position)*.01;

     }

     else {

      fraction = false;

     }

   }

   var horz = (axis == 'x');

   bg[axis] = math.ceil(fraction ? ( (size[horz?'w': 'h'] * bg[axis]) - (size[horz?'w': 'h'] * bg[axis]) ) : parseint(position));

   if (bg[axis] == 0) {

    bg[axis]++;

   }

  };

  for (var b in bg) {

   figurepercentage(b, thisstyle['backgroundposition'+b]);

  }

  

  el.vml.image.fill.position = (bg.x/size.w) + ',' + (bg.y/size.h);

  

  var bgr = thisstyle.backgroundrepeat;

  var dc = {'t':1, 'r':size.w+fudge, 'b':size.h, 'l':1+fudge}; /* these are defaults for repeat of any kind */

  var altc = { 'x': {'b1': 'l', 'b2': 'r', 'd': 'w'}, 'y': {'b1': 't', 'b2': 'b', 'd': 'h'} };

  if (bgr != 'repeat') {

   var c = {'t':(bg.y), 'r':(bg.x+size.w), 'b':(bg.y+size.h), 'l':(bg.x)}; /* these are defaults for no-repeat - clips down to the image location */

   if (bgr.search('repeat-') != -1) { /* now let's revert to dc for repeat-x or repeat-y */

    var v = bgr.split('repeat-')[1].touppercase();

    c[altc[v].b1] = 1;

    c[altc[v].b2] = size[altc[v].d];

   }

   if (c.b > size.h) {

    c.b = size.h;

   }

   el.vml.image.shape.style.clip = 'rect('+c.t+'px '+(c.r+fudge)+'px '+c.b+'px '+(c.l+fudge)+'px)';

  }

  else {

   el.vml.image.shape.style.clip = 'rect('+dc.t+'px '+dc.r+'px '+dc.b+'px '+dc.l+'px)';

  }

 },

 

 fixpng: function(el) {

  el.style.behavior = 'none';

  if (el.nodename == 'body' || el.nodename == 'td' || el.nodename == 'tr') { /* elements not supported yet */

   return;

  }

  el.isimg = false;

  if (el.nodename == 'img') {

   if(el.src.tolowercase().search(/\.png$/) != -1) {

    el.isimg = true;

    el.style.visibility = 'hidden';

   }

   else {

    return;

   }

  }

  else if (el.currentstyle.backgroundimage.tolowercase().search('.png') == -1) {

   return;

  }

  var lib = png;

  el.vml = {color: {}, image: {}};

  var els = {shape: {}, fill: {}};

  for (var r in el.vml) {

   for (var e in els) {

    var nodestr = lib.ns + ':' + e;

    el.vml[r][e] = document.createelement(nodestr);

   }

   el.vml[r].shape.stroked = false;

   el.vml[r].shape.appendchild(el.vml[r].fill);

   el.parentnode.insertbefore(el.vml[r].shape, el);

  }

  el.vml.image.shape.fillcolor = 'none'; /* don't show blank white shapeangle when waiting for image to load. */

  el.vml.image.fill.type = 'tile'; /* ze magic!! makes image show up. */

  el.vml.color.fill.on = false; /* actually going to apply vml element's style.backgroundcolor, so hide the whiteness. */

  

  lib.attachhandlers(el);

  

  lib.givelayout(el);

  lib.givelayout(el.offsetparent);

  

  /* set up element */

  lib.applyvml(el);

 }

 

};

try {

 document.execcommand("backgroundimagecache", false, true); /* tredosoft multiple ie doesn't like this, so try{} it */

} catch(r) {}

png.createvmlnamespace();

png.createvmlstylesheet();