/**
 * JavaScript code to detect available availability of a 
 * particular font in a browser using JavaScript and CSS. 
 * 
 * Author : Lalit Patel
 * Website: http://www.lalit.org/lab/jsoncookies
 * License: Creative Commons Attribution-ShareAlike 2.5
 *          http://creativecommons.org/licenses/by-sa/2.5/
 * Version: 0.15 
 *          changed comparision font to serif from sans-serif, 
 *          as in FF3.0 font of child element didn't fallback 
 *          to parent element if the font is missing.
 * Updated: 09 July 2009 10:52pm
 * 
 */

/**
 * Actual function that does all the work. Returns an array with all the info.
 * This test will fail for the font set as the default serif font.
 * 
 * Usage: d = new Detector();
 *        d.test('font_name');
 */
var Detector = function(){
	var h = document.getElementsByTagName("BODY")[0];
	var d = document.createElement("DIV");
	var s = document.createElement("SPAN");
	d.appendChild(s);
	d.style.fontFamily = "sans";			//font for the parent element DIV.
	s.style.fontFamily = "sans";			//serif font used as a comparator.
	s.style.fontSize   = "72px";			//we test using 72px font size, we may use any size. I guess larger the better.
	s.innerHTML        = "mmmmmmmmmmlil";		//we use m or w because these two characters take up the maximum width. And we use a L so that the same matching fonts can get separated
	h.appendChild(d);
	var defaultWidth   = s.offsetWidth;		//now we have the defaultWidth
	var defaultHeight  = s.offsetHeight;	//and the defaultHeight, we compare other fonts with these.
	h.removeChild(d);
	/* test
	 * params:
	 * font - name of the font you wish to detect
	 * return: 
	 * f[0] - Input font name.
	 * f[1] - Computed width.
	 * f[2] - Computed height.
	 * f[3] - Detected? (true/false).
	 */
	function debug(font) {
		h.appendChild(d);
		var f = [];
		f[0] = s.style.fontFamily = font;	// Name of the font
		f[1] = s.offsetWidth;				// Width
		f[2] = s.offsetHeight;				// Height
		h.removeChild(d);
		font = font.toLowerCase();
		if (font == "serif") {
			f[3] = true;	// to set arial and sans-serif true
		} else {
			f[3] = (f[1] != defaultWidth || f[2] != defaultHeight);	// Detected?
		}
		return f;
	}
	function test(font){
		f = debug(font);
		return f[3];
	}
	this.detailedTest = debug;
	this.test = test;	
}


/*!
 * isFontFaceSupported - v0.9 - 12/19/2009
 * http://paulirish.com/2009/font-face-feature-detection/
 * 
 * Copyright (c) 2009 Paul Irish
 * MIT license
 */

var isFontFaceSupported = (function(){
  
  
    var fontret,
        fontfaceCheckDelay = 100;
          
		// IE supports EOT and has had EOT support since IE 5.
		// This is a proprietary standard (ATOW) and thus this off-spec,
		// proprietary test for it is acceptable. 
    if (!(!/*@cc_on@if(@_jscript_version>=5)!@end@*/0)) fontret = true;
  
    else {
    
    // Create variables for dedicated @font-face test
      var doc = document, docElement = doc.documentElement, 
          st  = doc.createElement('style'),
          spn = doc.createElement('span'),
          wid, nwid, body = doc.body,
          callback, isCallbackCalled;

      // The following is a font, only containing the - character. Thanks Ethan Dunham.
      st.textContent = "@font-face{font-family:testfont;src:url(data:font/opentype;base64,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)}";
      doc.getElementsByTagName('head')[0].appendChild(st);
      
      
      spn.setAttribute('style','font:99px _,serif;position:absolute;visibility:hidden'); 
      
      if  (!body){
        body = docElement.appendChild(doc.createElement('fontface'));
      } 
      
      // the data-uri'd font only has the - character
      spn.innerHTML = '-------';
      spn.id        = 'fonttest';
      
      body.appendChild(spn);
      wid = spn.offsetWidth;

      spn.style.font = '99px testfont,_,serif';

      // needed for the CSSFontFaceRule false positives (ff3, chrome, op9)
      fontret = wid !== spn.offsetWidth;
      
      var delayedCheck = function(){
        if (isCallbackCalled) return;
        fontret = wid !== spn.offsetWidth;
        callback && (isCallbackCalled = true) && callback(fontret);
      }

      addEventListener('load',delayedCheck,false);
      setTimeout(delayedCheck,fontfaceCheckDelay);
    }

    function ret(){  return fontret || wid !== spn.offsetWidth; };
    
    // allow for a callback
    ret.ready = function(fn){
      (isCallbackCalled || fontret) ? fn(fontret) : (callback = fn);
    }  
          
    return ret;
})();