forked from scottjehl/Respond
/
respond.src.js
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/
respond.src.js
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/*! matchMedia() polyfill - Test a CSS media type/query in JS. Authors & copyright (c) 2012: Scott Jehl, Paul Irish, Nicholas Zakas. Dual MIT/BSD license */
/*! NOTE: If you're already including a window.matchMedia polyfill via Modernizr or otherwise, you don't need this part */
window.matchMedia = window.matchMedia || (function( doc, undefined ) {
"use strict";
var bool,
docElem = doc.documentElement,
refNode = docElem.firstElementChild || docElem.firstChild,
// fakeBody required for <FF4 when executed in <head>
fakeBody = doc.createElement( "body" ),
div = doc.createElement( "div" );
div.id = "mq-test-1";
div.style.cssText = "position:absolute;top:-100em";
fakeBody.style.background = "none";
fakeBody.appendChild(div);
return function(q){
div.innerHTML = "­<style media=\"" + q + "\"> #mq-test-1 { width: 42px; }</style>";
docElem.insertBefore( fakeBody, refNode );
bool = div.offsetWidth === 42;
docElem.removeChild( fakeBody );
return {
matches: bool,
media: q
};
};
}( document ));
/*! Respond.js v1.1.0: min/max-width media query polyfill. (c) Scott Jehl. MIT/GPLv2 Lic. j.mp/respondjs */
(function( win ){
"use strict";
//exposed namespace
var respond = {};
win.respond = respond;
//define update even in native-mq-supporting browsers, to avoid errors
respond.update = function(){};
//expose media query support flag for external use
respond.mediaQueriesSupported = win.matchMedia && win.matchMedia( "only all" ).matches;
//if media queries are supported, exit here
if( respond.mediaQueriesSupported ){
return;
}
//define vars
var doc = win.document,
docElem = doc.documentElement,
mediastyles = [],
rules = [],
appendedEls = [],
parsedSheets = {},
resizeThrottle = 30,
head = doc.getElementsByTagName( "head" )[0] || docElem,
base = doc.getElementsByTagName( "base" )[0],
links = head.getElementsByTagName( "link" ),
requestQueue = [],
//loop stylesheets, send text content to translate
ripCSS = function(){
for( var i = 0; i < links.length; i++ ){
var sheet = links[ i ],
href = sheet.href,
media = sheet.media,
isCSS = sheet.rel && sheet.rel.toLowerCase() === "stylesheet";
//only links plz and prevent re-parsing
if( !!href && isCSS && !parsedSheets[ href ] ){
// selectivizr exposes css through the rawCssText expando
if (sheet.styleSheet && sheet.styleSheet.rawCssText) {
translate( sheet.styleSheet.rawCssText, href, media );
parsedSheets[ href ] = true;
} else {
if( (!/^([a-zA-Z:]*\/\/)/.test( href ) && !base) ||
href.replace( RegExp.$1, "" ).split( "/" )[0] === win.location.host ){
requestQueue.push( {
href: href,
media: media
} );
}
}
}
}
makeRequests();
},
//recurse through request queue, get css text
makeRequests = function(){
if( requestQueue.length ){
var thisRequest = requestQueue.shift();
ajax( thisRequest.href, function( styles ){
translate( styles, thisRequest.href, thisRequest.media );
parsedSheets[ thisRequest.href ] = true;
// by wrapping recursive function call in setTimeout
// we prevent "Stack overflow" error in IE7
win.setTimeout(function(){ makeRequests(); },0);
} );
}
},
//find media blocks in css text, convert to style blocks
translate = function( styles, href, media ){
var qs = styles.match( /@media[^\{]+\{([^\{\}]*\{[^\}\{]*\})+/gi ),
ql = qs && qs.length || 0;
//try to get CSS path
href = href.substring( 0, href.lastIndexOf( "/" ) );
var repUrls = function( css ){
return css.replace( /(url\()['"]?([^\/\)'"][^:\)'"]+)['"]?(\))/g, "$1" + href + "$2$3" );
},
useMedia = !ql && media;
//if path exists, tack on trailing slash
if( href.length ){ href += "/"; }
//if no internal queries exist, but media attr does, use that
//note: this currently lacks support for situations where a media attr is specified on a link AND
//its associated stylesheet has internal CSS media queries.
//In those cases, the media attribute will currently be ignored.
if( useMedia ){
ql = 1;
}
for( var i = 0; i < ql; i++ ){
var fullq, thisq, eachq, eql;
//media attr
if( useMedia ){
fullq = media;
rules.push( repUrls( styles ) );
}
//parse for styles
else{
fullq = qs[ i ].match( /@media *([^\{]+)\{([\S\s]+?)$/ ) && RegExp.$1;
rules.push( RegExp.$2 && repUrls( RegExp.$2 ) );
}
eachq = fullq.split( "," );
eql = eachq.length;
for( var j = 0; j < eql; j++ ){
thisq = eachq[ j ];
mediastyles.push( {
media : thisq.split( "(" )[ 0 ].match( /(only\s+)?([a-zA-Z]+)\s?/ ) && RegExp.$2 || "all",
rules : rules.length - 1,
hasquery : thisq.indexOf("(") > -1,
minw : thisq.match( /\(\s*min\-width\s*:\s*(\s*[0-9\.]+)(px|em)\s*\)/ ) && parseFloat( RegExp.$1 ) + ( RegExp.$2 || "" ),
maxw : thisq.match( /\(\s*max\-width\s*:\s*(\s*[0-9\.]+)(px|em)\s*\)/ ) && parseFloat( RegExp.$1 ) + ( RegExp.$2 || "" )
} );
}
}
applyMedia();
},
lastCall,
resizeDefer,
// returns the value of 1em in pixels
getEmValue = function() {
var ret,
div = doc.createElement('div'),
body = doc.body,
fakeUsed = false;
div.style.cssText = "position:absolute;font-size:1em;width:1em";
if( !body ){
body = fakeUsed = doc.createElement( "body" );
body.style.background = "none";
}
body.appendChild( div );
docElem.insertBefore( body, docElem.firstChild );
ret = div.offsetWidth;
if( fakeUsed ){
docElem.removeChild( body );
}
else {
body.removeChild( div );
}
//also update eminpx before returning
ret = eminpx = parseFloat(ret);
return ret;
},
//cached container for 1em value, populated the first time it's needed
eminpx,
//enable/disable styles
applyMedia = function( fromResize ){
var name = "clientWidth",
docElemProp = docElem[ name ],
currWidth = doc.compatMode === "CSS1Compat" && docElemProp || doc.body[ name ] || docElemProp,
styleBlocks = {},
lastLink = links[ links.length-1 ],
now = (new Date()).getTime();
//throttle resize calls
if( fromResize && lastCall && now - lastCall < resizeThrottle ){
win.clearTimeout( resizeDefer );
resizeDefer = win.setTimeout( applyMedia, resizeThrottle );
return;
}
else {
lastCall = now;
}
for( var i in mediastyles ){
if( mediastyles.hasOwnProperty( i ) ){
var thisstyle = mediastyles[ i ],
min = thisstyle.minw,
max = thisstyle.maxw,
minnull = min === null,
maxnull = max === null,
em = "em";
if( !!min ){
min = parseFloat( min ) * ( min.indexOf( em ) > -1 ? ( eminpx || getEmValue() ) : 1 );
}
if( !!max ){
max = parseFloat( max ) * ( max.indexOf( em ) > -1 ? ( eminpx || getEmValue() ) : 1 );
}
// if there's no media query at all (the () part), or min or max is not null, and if either is present, they're true
if( !thisstyle.hasquery || ( !minnull || !maxnull ) && ( minnull || currWidth >= min ) && ( maxnull || currWidth <= max ) ){
if( !styleBlocks[ thisstyle.media ] ){
styleBlocks[ thisstyle.media ] = [];
}
styleBlocks[ thisstyle.media ].push( rules[ thisstyle.rules ] );
}
}
}
//remove any existing respond style element(s)
for( var j in appendedEls ){
if( appendedEls.hasOwnProperty( j ) ){
if( appendedEls[ j ] && appendedEls[ j ].parentNode === head ){
head.removeChild( appendedEls[ j ] );
}
}
}
//inject active styles, grouped by media type
for( var k in styleBlocks ){
if( styleBlocks.hasOwnProperty( k ) ){
var ss = doc.createElement( "style" ),
css = styleBlocks[ k ].join( "\n" );
ss.type = "text/css";
ss.media = k;
//originally, ss was appended to a documentFragment and sheets were appended in bulk.
//this caused crashes in IE in a number of circumstances, such as when the HTML element had a bg image set, so appending beforehand seems best. Thanks to @dvelyk for the initial research on this one!
head.insertBefore( ss, lastLink.nextSibling );
if ( ss.styleSheet ){
ss.styleSheet.cssText = css;
}
else {
ss.appendChild( doc.createTextNode( css ) );
}
//push to appendedEls to track for later removal
appendedEls.push( ss );
}
}
},
//tweaked Ajax functions from Quirksmode
ajax = function( url, callback ) {
var req = xmlHttp();
if (!req){
return;
}
req.open( "GET", url, true );
req.onreadystatechange = function () {
if ( req.readyState !== 4 || req.status !== 200 && req.status !== 304 ){
return;
}
callback( req.responseText );
};
if ( req.readyState === 4 ){
return;
}
req.send( null );
},
//define ajax obj
xmlHttp = (function() {
var xmlhttpmethod = false;
try {
xmlhttpmethod = new win.XMLHttpRequest();
}
catch( e ){
xmlhttpmethod = new win.ActiveXObject( "Microsoft.XMLHTTP" );
}
return function(){
return xmlhttpmethod;
};
})();
//translate CSS
ripCSS();
//expose update for re-running respond later on
respond.update = ripCSS;
//adjust on resize
function callMedia(){
applyMedia( true );
}
if( win.addEventListener ){
win.addEventListener( "resize", callMedia, false );
}
else if( win.attachEvent ){
win.attachEvent( "onresize", callMedia );
}
})(this);