offset.js
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define([
"./core",
"./var/strundefined",
"./core/access",
"./css/var/rnumnonpx",
"./css/curCSS",
"./css/addGetHookIf",
"./css/support",
"./core/init",
"./css",
"./selector" // contains
], function( jQuery, strundefined, access, rnumnonpx, curCSS, addGetHookIf, support ) {
var docElem = window.document.documentElement;
/**
* Gets a window from an element
*/
function getWindow( elem ) {
return jQuery.isWindow( elem ) ? elem : elem.nodeType === 9 && elem.defaultView;
}
jQuery.offset = {
setOffset: function( elem, options, i ) {
var curPosition, curLeft, curCSSTop, curTop, curOffset, curCSSLeft, calculatePosition,
position = jQuery.css( elem, "position" ),
curElem = jQuery( elem ),
props = {};
// Set position first, in-case top/left are set even on static elem
if ( position === "static" ) {
elem.style.position = "relative";
}
curOffset = curElem.offset();
curCSSTop = jQuery.css( elem, "top" );
curCSSLeft = jQuery.css( elem, "left" );
calculatePosition = ( position === "absolute" || position === "fixed" ) &&
( curCSSTop + curCSSLeft ).indexOf("auto") > -1;
// Need to be able to calculate position if either
// top or left is auto and position is either absolute or fixed
if ( calculatePosition ) {
curPosition = curElem.position();
curTop = curPosition.top;
curLeft = curPosition.left;
} else {
curTop = parseFloat( curCSSTop ) || 0;
curLeft = parseFloat( curCSSLeft ) || 0;
}
if ( jQuery.isFunction( options ) ) {
options = options.call( elem, i, curOffset );
}
if ( options.top != null ) {
props.top = ( options.top - curOffset.top ) + curTop;
}
if ( options.left != null ) {
props.left = ( options.left - curOffset.left ) + curLeft;
}
if ( "using" in options ) {
options.using.call( elem, props );
} else {
curElem.css( props );
}
}
};
jQuery.fn.extend({
offset: function( options ) {
if ( arguments.length ) {
return options === undefined ?
this :
this.each(function( i ) {
jQuery.offset.setOffset( this, options, i );
});
}
var docElem, win,
elem = this[ 0 ],
box = { top: 0, left: 0 },
doc = elem && elem.ownerDocument;
if ( !doc ) {
return;
}
docElem = doc.documentElement;
// Make sure it's not a disconnected DOM node
if ( !jQuery.contains( docElem, elem ) ) {
return box;
}
// Support: BlackBerry 5, iOS 3 (original iPhone)
// If we don't have gBCR, just use 0,0 rather than error
if ( typeof elem.getBoundingClientRect !== strundefined ) {
box = elem.getBoundingClientRect();
}
win = getWindow( doc );
return {
top: box.top + win.pageYOffset - docElem.clientTop,
left: box.left + win.pageXOffset - docElem.clientLeft
};
},
position: function() {
if ( !this[ 0 ] ) {
return;
}
var offsetParent, offset,
elem = this[ 0 ],
parentOffset = { top: 0, left: 0 };
// Fixed elements are offset from window (parentOffset = {top:0, left: 0}, because it is its only offset parent
if ( jQuery.css( elem, "position" ) === "fixed" ) {
// Assume getBoundingClientRect is there when computed position is fixed
offset = elem.getBoundingClientRect();
} else {
// Get *real* offsetParent
offsetParent = this.offsetParent();
// Get correct offsets
offset = this.offset();
if ( !jQuery.nodeName( offsetParent[ 0 ], "html" ) ) {
parentOffset = offsetParent.offset();
}
// Add offsetParent borders
parentOffset.top += jQuery.css( offsetParent[ 0 ], "borderTopWidth", true );
parentOffset.left += jQuery.css( offsetParent[ 0 ], "borderLeftWidth", true );
}
// Subtract parent offsets and element margins
return {
top: offset.top - parentOffset.top - jQuery.css( elem, "marginTop", true ),
left: offset.left - parentOffset.left - jQuery.css( elem, "marginLeft", true )
};
},
offsetParent: function() {
return this.map(function() {
var offsetParent = this.offsetParent || docElem;
while ( offsetParent && ( !jQuery.nodeName( offsetParent, "html" ) && jQuery.css( offsetParent, "position" ) === "static" ) ) {
offsetParent = offsetParent.offsetParent;
}
return offsetParent || docElem;
});
}
});
// Create scrollLeft and scrollTop methods
jQuery.each( { scrollLeft: "pageXOffset", scrollTop: "pageYOffset" }, function( method, prop ) {
var top = "pageYOffset" === prop;
jQuery.fn[ method ] = function( val ) {
return access( this, function( elem, method, val ) {
var win = getWindow( elem );
if ( val === undefined ) {
return win ? win[ prop ] : elem[ method ];
}
if ( win ) {
win.scrollTo(
!top ? val : window.pageXOffset,
top ? val : window.pageYOffset
);
} else {
elem[ method ] = val;
}
}, method, val, arguments.length, null );
};
});
// Support: Safari<7+, Chrome<37+
// Add the top/left cssHooks using jQuery.fn.position
// Webkit bug: https://bugs.webkit.org/show_bug.cgi?id=29084
// Blink bug: https://code.google.com/p/chromium/issues/detail?id=229280
// getComputedStyle returns percent when specified for top/left/bottom/right;
// rather than make the css module depend on the offset module, just check for it here
jQuery.each( [ "top", "left" ], function( i, prop ) {
jQuery.cssHooks[ prop ] = addGetHookIf( support.pixelPosition,
function( elem, computed ) {
if ( computed ) {
computed = curCSS( elem, prop );
// If curCSS returns percentage, fallback to offset
return rnumnonpx.test( computed ) ?
jQuery( elem ).position()[ prop ] + "px" :
computed;
}
}
);
});
return jQuery;
});