jquery/src/css/support.js

define([
	"../core",
	"../var/support"
], function( jQuery, support ) {

(function() {
	var a, reliableHiddenOffsetsVal, boxSizingVal, boxSizingReliableVal,
		pixelPositionVal,
		div = document.createElement( "div" ),
		containerStyles = "border:0;width:0;height:0;position:absolute;top:0;left:-9999px",
		divReset =
			"-webkit-box-sizing:content-box;-moz-box-sizing:content-box;box-sizing:content-box;" +
			"display:block;padding:0;margin:0;border:0";

	// Setup
	div.innerHTML = "  <link/><table></table><a href='/a'>a</a><input type='checkbox'/>";
	a = div.getElementsByTagName( "a" )[ 0 ];

	a.style.cssText = "float:left;opacity:.5";

	// Make sure that element opacity exists
	// (IE uses filter instead)
	// Use a regex to work around a WebKit issue. See #5145
	support.opacity = /^0.5/.test( a.style.opacity );

	// Verify style float existence
	// (IE uses styleFloat instead of cssFloat)
	support.cssFloat = !!a.style.cssFloat;

	div.style.backgroundClip = "content-box";
	div.cloneNode( true ).style.backgroundClip = "";
	support.clearCloneStyle = div.style.backgroundClip === "content-box";

	// Null elements to avoid leaks in IE.
	a = div = null;

	jQuery.extend(support, {
		reliableHiddenOffsets: function() {
			if ( reliableHiddenOffsetsVal != null ) {
				return reliableHiddenOffsetsVal;
			}

			var container, tds, isSupported,
				div = document.createElement( "div" ),
				body = document.getElementsByTagName( "body" )[ 0 ];

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

			// Setup
			div.setAttribute( "className", "t" );
			div.innerHTML = "  <link/><table></table><a href='/a'>a</a><input type='checkbox'/>";

			container = document.createElement( "div" );
			container.style.cssText = containerStyles;

			body.appendChild( container ).appendChild( div );

			// Support: IE8
			// 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).
			div.innerHTML = "<table><tr><td></td><td>t</td></tr></table>";
			tds = div.getElementsByTagName( "td" );
			tds[ 0 ].style.cssText = "padding:0;margin:0;border:0;display:none";
			isSupported = ( tds[ 0 ].offsetHeight === 0 );

			tds[ 0 ].style.display = "";
			tds[ 1 ].style.display = "none";

			// Support: IE8
			// Check if empty table cells still have offsetWidth/Height
			reliableHiddenOffsetsVal = isSupported && ( tds[ 0 ].offsetHeight === 0 );

			body.removeChild( container );

			// Null elements to avoid leaks in IE.
			div = body = null;

			return reliableHiddenOffsetsVal;
		},

		boxSizing: function() {
			if ( boxSizingVal == null ) {
				computeStyleTests();
			}
			return boxSizingVal;
		},

		boxSizingReliable: function() {
			if ( boxSizingReliableVal == null ) {
				computeStyleTests();
			}
			return boxSizingReliableVal;
		},

		pixelPosition: function() {
			if ( pixelPositionVal == null ) {
				computeStyleTests();
			}
			return pixelPositionVal;
		},

		reliableMarginRight: function() {
			var body, container, div, marginDiv,
				// Support: IE<9.
				// IE should pass the test but we're using getComputedStyle
				// to compute it so just return true if the method is not present.
				reliableMarginRightVal = true;

			// Use window.getComputedStyle because jsdom on node.js will break without it.
			if ( window.getComputedStyle ) {
				body = document.getElementsByTagName( "body" )[ 0 ];
				if ( !body ) {
					// Test fired too early or in an unsupported environment, exit.
					return;
				}

				container = document.createElement( "div" );
				div = document.createElement( "div" );
				container.style.cssText = containerStyles;

				body.appendChild( container ).appendChild( div );

				// Check if div with explicit width and no margin-right incorrectly
				// gets computed margin-right based on width of container. (#3333)
				// Fails in WebKit before Feb 2011 nightlies
				// WebKit Bug 13343 - getComputedStyle returns wrong value for margin-right
				marginDiv = div.appendChild( document.createElement( "div" ) );
				marginDiv.style.cssText = div.style.cssText = divReset;
				marginDiv.style.marginRight = marginDiv.style.width = "0";
				div.style.width = "1px";

				reliableMarginRightVal =
					!parseFloat( ( window.getComputedStyle( marginDiv, null ) || {} ).marginRight );

				body.removeChild( container );
			}

			return reliableMarginRightVal;
		}
	});

	function computeStyleTests() {
		var container, div,
			body = document.getElementsByTagName( "body" )[ 0 ];

		if ( !body ) {
			// Test fired too early or in an unsupported environment, exit.
			return;
		}

		container = document.createElement( "div" );
		div = document.createElement( "div" );
		container.style.cssText = containerStyles;

		body.appendChild( container ).appendChild( div );

		div.style.cssText =
			"-webkit-box-sizing:border-box;-moz-box-sizing:border-box;box-sizing:border-box;" +
				"position:absolute;display:block;padding:1px;border:1px;width:4px;" +
				"margin-top:1%;top:1%";

		// Workaround failing boxSizing test due to offsetWidth returning wrong value
		// with some non-1 values of body zoom, ticket #13543
		jQuery.swap( body, body.style.zoom != null ? { zoom: 1 } : {}, function() {
			boxSizingVal = div.offsetWidth === 4;
		});

		// Will be changed later if needed.
		boxSizingReliableVal = true;
		pixelPositionVal = false;

		// Use window.getComputedStyle because jsdom on node.js will break without it.
		if ( window.getComputedStyle ) {
			pixelPositionVal = ( window.getComputedStyle( div, null ) || {} ).top !== "1%";
			boxSizingReliableVal =
				( window.getComputedStyle( div, null ) || { width: "4px" } ).width === "4px";
		}

		body.removeChild( container );

		// Null elements to avoid leaks in IE.
		div = body = null;
	}

})();

return support;

});