jquery/src/support.js

197 lines
6.3 KiB
JavaScript

(function( jQuery ) {
(function() {
jQuery.support = {};
var root = document.documentElement,
script = document.createElement("script"),
div = document.createElement("div"),
id = "script" + jQuery.now();
div.style.display = "none";
div.innerHTML = " <link/><table></table><a href='/a' style='color:red;float:left;opacity:.55;'>a</a><input type='checkbox'/>";
var all = div.getElementsByTagName("*"),
a = div.getElementsByTagName("a")[0],
select = document.createElement("select"),
opt = select.appendChild( document.createElement("option") );
// Can't get basic test support
if ( !all || !all.length || !a ) {
return;
}
jQuery.support = {
// IE strips leading whitespace when .innerHTML is used
leadingWhitespace: div.firstChild.nodeType === 3,
// Make sure that tbody elements aren't automatically inserted
// IE will insert them into empty tables
tbody: !div.getElementsByTagName("tbody").length,
// Make sure that link elements get serialized correctly by innerHTML
// This requires a wrapper element in IE
htmlSerialize: !!div.getElementsByTagName("link").length,
// Get the style information from getAttribute
// (IE uses .cssText insted)
style: /red/.test( a.getAttribute("style") ),
// Make sure that URLs aren't manipulated
// (IE normalizes it by default)
hrefNormalized: a.getAttribute("href") === "/a",
// Make sure that element opacity exists
// (IE uses filter instead)
// Use a regex to work around a WebKit issue. See #5145
opacity: /^0.55$/.test( a.style.opacity ),
// Verify style float existence
// (IE uses styleFloat instead of cssFloat)
cssFloat: !!a.style.cssFloat,
// Make sure that if no value is specified for a checkbox
// that it defaults to "on".
// (WebKit defaults to "" instead)
checkOn: div.getElementsByTagName("input")[0].value === "on",
// Make sure that a selected-by-default option has a working selected property.
// (WebKit defaults to false instead of true, IE too, if it's in an optgroup)
optSelected: opt.selected,
// Will be defined later
deleteExpando: true,
optDisabled: false,
checkClone: false,
scriptEval: false,
noCloneEvent: true,
boxModel: null,
inlineBlockNeedsLayout: false,
shrinkWrapBlocks: false,
reliableHiddenOffsets: true
};
// Make sure that the options inside disabled selects aren't marked as disabled
// (WebKit marks them as diabled)
select.disabled = true;
jQuery.support.optDisabled = !opt.disabled;
script.type = "text/javascript";
try {
script.appendChild( document.createTextNode( "window." + id + "=1;" ) );
} catch(e) {}
root.insertBefore( script, root.firstChild );
// Make sure that the execution of code works by injecting a script
// tag with appendChild/createTextNode
// (IE doesn't support this, fails, and uses .text instead)
if ( window[ id ] ) {
jQuery.support.scriptEval = true;
delete window[ id ];
}
// Test to see if it's possible to delete an expando from an element
// Fails in Internet Explorer
try {
delete script.test;
} catch(e) {
jQuery.support.deleteExpando = false;
}
root.removeChild( script );
if ( div.attachEvent && div.fireEvent ) {
div.attachEvent("onclick", function click() {
// Cloning a node shouldn't copy over any
// bound event handlers (IE does this)
jQuery.support.noCloneEvent = false;
div.detachEvent("onclick", click);
});
div.cloneNode(true).fireEvent("onclick");
}
div = document.createElement("div");
div.innerHTML = "<input type='radio' name='radiotest' checked='checked'/>";
var fragment = document.createDocumentFragment();
fragment.appendChild( div.firstChild );
// WebKit doesn't clone checked state correctly in fragments
jQuery.support.checkClone = fragment.cloneNode(true).cloneNode(true).lastChild.checked;
// Figure out if the W3C box model works as expected
// document.body must exist before we can do this
jQuery(function() {
var div = document.createElement("div");
div.style.width = div.style.paddingLeft = "1px";
document.body.appendChild( div );
jQuery.boxModel = jQuery.support.boxModel = div.offsetWidth === 2;
if ( "zoom" in div.style ) {
// Check if natively block-level elements act like inline-block
// elements when setting their display to 'inline' and giving
// them layout
// (IE < 8 does this)
div.style.display = "inline";
div.style.zoom = 1;
jQuery.support.inlineBlockNeedsLayout = div.offsetWidth === 2;
// Check if elements with layout shrink-wrap their children
// (IE 6 does this)
div.style.display = "";
div.innerHTML = "<div style='width:4px;'></div>";
jQuery.support.shrinkWrapBlocks = div.offsetWidth !== 2;
}
div.innerHTML = "<table><tr><td style='padding:0;border:0;display:none'></td><td>t</td></tr></table>";
var tds = div.getElementsByTagName("td");
// Check if table cells still have offsetWidth/Height when they are set
// to display:none and there are still other visible table cells in a
// table row; if so, offsetWidth/Height are not reliable for use when
// determining if an element has been hidden directly using
// display:none (it is still safe to use offsets if a parent element is
// hidden; don safety goggles and see bug #4512 for more information).
// (only IE 8 fails this test)
jQuery.support.reliableHiddenOffsets = tds[0].offsetHeight === 0;
tds[0].style.display = "";
tds[1].style.display = "none";
// Check if empty table cells still have offsetWidth/Height
// (IE < 8 fail this test)
jQuery.support.reliableHiddenOffsets = jQuery.support.reliableHiddenOffsets && tds[0].offsetHeight === 0;
div.innerHTML = "";
document.body.removeChild( div ).style.display = "none";
div = tds = null;
});
// Technique from Juriy Zaytsev
// http://thinkweb2.com/projects/prototype/detecting-event-support-without-browser-sniffing/
var eventSupported = function( eventName ) {
var el = document.createElement("div");
eventName = "on" + eventName;
var isSupported = (eventName in el);
if ( !isSupported ) {
el.setAttribute(eventName, "return;");
isSupported = typeof el[eventName] === "function";
}
el = null;
return isSupported;
};
jQuery.support.submitBubbles = eventSupported("submit");
jQuery.support.changeBubbles = eventSupported("change");
// release memory in IE
root = script = div = all = a = null;
})();
})( jQuery );