jquery/src/support.js

(function( jQuery ) {

jQuery.support = (function() {

	var support,
		all,
		a,
		select,
		opt,
		input,
		fragment,
		tds,
		events,
		eventName,
		i,
		isSupported,
		div = document.createElement( "div" ),
		documentElement = document.documentElement;

	// Preliminary tests
	div.setAttribute("className", "t");
	div.innerHTML = "   <link/><table></table><a href='/a' style='top:1px;float:left;opacity:.55;'>a</a><input type='checkbox'/>";

	all = div.getElementsByTagName( "*" );
	a = div.getElementsByTagName( "a" )[ 0 ];

	// Can't get basic test support
	if ( !all || !all.length || !a ) {
		return {};
	}

	// First batch of supports tests
	select = document.createElement( "select" );
	opt = select.appendChild( document.createElement("option") );
	input = div.getElementsByTagName( "input" )[ 0 ];

	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 instead)
		style: /top/.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: ( input.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,

		// Test setAttribute on camelCase class. If it works, we need attrFixes when doing get/setAttribute (ie6/7)
		getSetAttribute: div.className !== "t",

		// Tests for enctype support on a form(#6743)
		enctype: !!document.createElement("form").enctype,

		// Makes sure cloning an html5 element does not cause problems
		// Where outerHTML is undefined, this still works
		html5Clone: document.createElement("nav").cloneNode( true ).outerHTML !== "<:nav></:nav>",

		// Will be defined later
		submitBubbles: true,
		changeBubbles: true,
		focusinBubbles: false,
		deleteExpando: true,
		noCloneEvent: true,
		inlineBlockNeedsLayout: false,
		shrinkWrapBlocks: false,
		reliableMarginRight: true,
		pixelMargin: true
	};

	//jQuery.boxModel DEPRECATED in 1.3, use jQuery.support.boxModel instead
	jQuery.boxModel = support.boxModel = document.compatMode === "CSS1Compat";

	// Make sure checked status is properly cloned
	input.checked = true;
	support.noCloneChecked = input.cloneNode( true ).checked;

	// Make sure that the options inside disabled selects aren't marked as disabled
	// (WebKit marks them as disabled)
	select.disabled = true;
	support.optDisabled = !opt.disabled;

	// Test to see if it's possible to delete an expando from an element
	// Fails in Internet Explorer
	try {
		delete div.test;
	} catch( e ) {
		support.deleteExpando = false;
	}

	if ( !div.addEventListener && div.attachEvent && div.fireEvent ) {
		div.attachEvent( "onclick", function() {
			// Cloning a node shouldn't copy over any
			// bound event handlers (IE does this)
			support.noCloneEvent = false;
		});
		div.cloneNode( true ).fireEvent( "onclick" );
	}

	// Check if a radio maintains its value
	// after being appended to the DOM
	input = document.createElement("input");
	input.value = "t";
	input.setAttribute("type", "radio");
	support.radioValue = input.value === "t";

	input.setAttribute("checked", "checked");
	div.appendChild( input );
	fragment = document.createDocumentFragment();
	fragment.appendChild( div.lastChild );

	// WebKit doesn't clone checked state correctly in fragments
	support.checkClone = fragment.cloneNode( true ).cloneNode( true ).lastChild.checked;

	// Check if a disconnected checkbox will retain its checked
	// value of true after appended to the DOM (IE6/7)
	support.appendChecked = input.checked;

	fragment.removeChild( input );
	fragment.appendChild( div );

	// Technique from Juriy Zaytsev
	// http://perfectionkills.com/detecting-event-support-without-browser-sniffing/
	// We only care about the case where non-standard event systems
	// are used, namely in IE. Short-circuiting here helps us to
	// avoid an eval call (in setAttribute) which can cause CSP
	// to go haywire. See: https://developer.mozilla.org/en/Security/CSP
	if ( div.attachEvent ) {
		for ( i in {
			submit: 1,
			change: 1,
			focusin: 1
		}) {
			eventName = "on" + i;
			isSupported = ( eventName in div );
			if ( !isSupported ) {
				div.setAttribute( eventName, "return;" );
				isSupported = ( typeof div[ eventName ] === "function" );
			}
			support[ i + "Bubbles" ] = isSupported;
		}
	}

	fragment.removeChild( div );

	// Null elements to avoid leaks in IE
	fragment = select = opt = div = input = null;

	// Run tests that need a body at doc ready
	jQuery(function() {
		var container, outer, inner, table, td, offsetSupport,
			marginDiv, conMarginTop, style, html, positionTopLeftWidthHeight,
			paddingMarginBorderVisibility, paddingMarginBorder,
			body = document.getElementsByTagName("body")[0];

		if ( !body ) {
			// Return for frameset docs that don't have a body
			return;
		}

		conMarginTop = 1;
		paddingMarginBorder = "padding:0;margin:0;border:";
		positionTopLeftWidthHeight = "position:absolute;top:0;left:0;width:1px;height:1px;";
		paddingMarginBorderVisibility = paddingMarginBorder + "0;visibility:hidden;";
		style = "style='" + positionTopLeftWidthHeight + paddingMarginBorder + "5px solid #000;";
		html = "<div " + style + "display:block;'><div style='" + paddingMarginBorder + "0;display:block;overflow:hidden;'></div></div>" +
			"<table " + style + "' cellpadding='0' cellspacing='0'>" +
			"<tr><td></td></tr></table>";

		container = document.createElement("div");
		container.style.cssText = paddingMarginBorderVisibility + "width:0;height:0;position:static;top:0;margin-top:" + conMarginTop + "px";
		body.insertBefore( container, body.firstChild );

		// Construct the test element
		div = document.createElement("div");
		container.appendChild( div );

		// 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)
		div.innerHTML = "<table><tr><td style='" + paddingMarginBorder + "0;display:none'></td><td>t</td></tr></table>";
		tds = div.getElementsByTagName( "td" );
		isSupported = ( 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)
		support.reliableHiddenOffsets = isSupported && ( tds[ 0 ].offsetHeight === 0 );

		// Check if div with explicit width and no margin-right incorrectly
		// gets computed margin-right based on width of container. For more
		// info see bug #3333
		// Fails in WebKit before Feb 2011 nightlies
		// WebKit Bug 13343 - getComputedStyle returns wrong value for margin-right
		if ( window.getComputedStyle ) {
			div.innerHTML = "";
			marginDiv = document.createElement( "div" );
			marginDiv.style.width = "0";
			marginDiv.style.marginRight = "0";
			div.style.width = "2px";
			div.appendChild( marginDiv );
			support.reliableMarginRight =
				( parseInt( ( window.getComputedStyle( marginDiv, null ) || { marginRight: 0 } ).marginRight, 10 ) || 0 ) === 0;
		}

		// Figure out if the W3C box model works as expected
		div.innerHTML = "";
		div.style.width = div.style.paddingLeft = "1px";
		jQuery.boxModel = support.boxModel = div.offsetWidth === 2;

		if ( typeof div.style.zoom !== "undefined" ) {
			// 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.innerHTML = "";
			div.style.width = div.style.padding = "1px";
			div.style.border = 0;
			div.style.overflow = "hidden";
			div.style.display = "inline";
			div.style.zoom = 1;
			support.inlineBlockNeedsLayout = ( div.offsetWidth === 3 );

			// Check if elements with layout shrink-wrap their children
			// (IE 6 does this)
			div.style.display = "block";
			div.style.overflow = "visible";
			div.innerHTML = "<div style='width:5px;'></div>";
			support.shrinkWrapBlocks = ( div.offsetWidth !== 3 );
		}

		div.style.cssText = positionTopLeftWidthHeight + paddingMarginBorderVisibility;
		div.innerHTML = html;

		outer = div.firstChild;
		inner = outer.firstChild;
		td = outer.nextSibling.firstChild.firstChild;

		offsetSupport = {
			doesNotAddBorder: ( inner.offsetTop !== 5 ),
			doesAddBorderForTableAndCells: ( td.offsetTop === 5 )
		};

		inner.style.position = "fixed";
		inner.style.top = "20px";

		// safari subtracts parent border width here which is 5px
		offsetSupport.fixedPosition = ( inner.offsetTop === 20 || inner.offsetTop === 15 );
		inner.style.position = inner.style.top = "";

		outer.style.overflow = "hidden";
		outer.style.position = "relative";

		offsetSupport.subtractsBorderForOverflowNotVisible = ( inner.offsetTop === -5 );
		offsetSupport.doesNotIncludeMarginInBodyOffset = ( body.offsetTop !== conMarginTop );

		if ( window.getComputedStyle ) {
			div.style.marginTop = "1%";
			support.pixelMargin = ( window.getComputedStyle( div, null ) || { marginTop: 0 } ).marginTop !== "1%";
		}

		if ( typeof container.style.zoom !== "undefined" ) {
			container.style.zoom = 1;
		}

		body.removeChild( container );
		marginDiv = div = container = null;

		jQuery.extend( support, offsetSupport );
	});

	return support;
})();

})( jQuery );