offset.js
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define( [
"./core",
"./core/access",
"./var/document",
"./var/documentElement",
"./var/isFunction",
"./css/var/rnumnonpx",
"./css/curCSS",
"./css/addGetHookIf",
"./css/support",
"./var/isWindow",
"./core/init",
"./css",
"./selector" // contains
], function( jQuery, access, document, documentElement, isFunction, rnumnonpx,
curCSS, addGetHookIf, support, isWindow ) {
"use strict";
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 ( isFunction( options ) ) {
// Use jQuery.extend here to allow modification of coordinates argument (gh-1848)
options = options.call( elem, i, jQuery.extend( {}, 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() relates an element's border box to the document origin
offset: function( options ) {
// Preserve chaining for setter
if ( arguments.length ) {
return options === undefined ?
this :
this.each( function( i ) {
jQuery.offset.setOffset( this, options, i );
} );
}
var rect, win,
elem = this[ 0 ];
if ( !elem ) {
return;
}
// Return zeros for disconnected and hidden (display: none) elements (gh-2310)
// Support: IE <=11 only
// Running getBoundingClientRect on a
// disconnected node in IE throws an error
if ( !elem.getClientRects().length ) {
return { top: 0, left: 0 };
}
// Get document-relative position by adding viewport scroll to viewport-relative gBCR
rect = elem.getBoundingClientRect();
win = elem.ownerDocument.defaultView;
return {
top: rect.top + win.pageYOffset,
left: rect.left + win.pageXOffset
};
},
// position() relates an element's margin box to its offset parent's padding box
// This corresponds to the behavior of CSS absolute positioning
position: function() {
if ( !this[ 0 ] ) {
return;
}
var offsetParent, offset, doc,
elem = this[ 0 ],
parentOffset = { top: 0, left: 0 };
// position:fixed elements are offset from the viewport, which itself always has zero offset
if ( jQuery.css( elem, "position" ) === "fixed" ) {
// Assume position:fixed implies availability of getBoundingClientRect
offset = elem.getBoundingClientRect();
} else {
offset = this.offset();
// Account for the *real* offset parent, which can be the document or its root element
// when a statically positioned element is identified
doc = elem.ownerDocument;
offsetParent = elem.offsetParent || doc.documentElement;
while ( offsetParent &&
( offsetParent === doc.body || offsetParent === doc.documentElement ) &&
jQuery.css( offsetParent, "position" ) === "static" ) {
offsetParent = offsetParent.parentNode;
}
if ( offsetParent && offsetParent !== elem && offsetParent.nodeType === 1 ) {
// Incorporate borders into its offset, since they are outside its content origin
parentOffset = jQuery( offsetParent ).offset();
parentOffset.top += jQuery.css( offsetParent, "borderTopWidth", true );
parentOffset.left += jQuery.css( offsetParent, "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 )
};
},
// This method will return documentElement in the following cases:
// 1) For the element inside the iframe without offsetParent, this method will return
// documentElement of the parent window
// 2) For the hidden or detached element
// 3) For body or html element, i.e. in case of the html node - it will return itself
//
// but those exceptions were never presented as a real life use-cases
// and might be considered as more preferable results.
//
// This logic, however, is not guaranteed and can change at any point in the future
offsetParent: function() {
return this.map( function() {
var offsetParent = this.offsetParent;
while ( offsetParent && jQuery.css( offsetParent, "position" ) === "static" ) {
offsetParent = offsetParent.offsetParent;
}
return offsetParent || documentElement;
} );
}
} );
// 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 ) {
// Coalesce documents and windows
var win;
if ( isWindow( elem ) ) {
win = elem;
} else if ( elem.nodeType === 9 ) {
win = elem.defaultView;
}
if ( val === undefined ) {
return win ? win[ prop ] : elem[ method ];
}
if ( win ) {
win.scrollTo(
!top ? val : win.pageXOffset,
top ? val : win.pageYOffset
);
} else {
elem[ method ] = val;
}
}, method, val, arguments.length );
};
} );
// Support: Safari <=7 - 9.1, Chrome <=37 - 49
// Add the top/left cssHooks using jQuery.fn.position
// Webkit bug: https://bugs.webkit.org/show_bug.cgi?id=29084
// Blink bug: https://bugs.chromium.org/p/chromium/issues/detail?id=589347
// 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;
} );