jquery/src/offset.js

192 lines
5.2 KiB
JavaScript

var rroot = /^(?:body|html)$/i;
jQuery.fn.offset = function( options ) {
if ( arguments.length ) {
return options === undefined ?
this :
this.each(function( i ) {
jQuery.offset.setOffset( this, options, i );
});
}
var docElem, body, win, clientTop, clientLeft, scrollTop, scrollLeft,
box = { top: 0, left: 0 },
elem = this[ 0 ],
doc = elem && elem.ownerDocument;
if ( !doc ) {
return;
}
if ( (body = doc.body) === elem ) {
return jQuery.offset.bodyOffset( elem );
}
docElem = doc.documentElement;
// Make sure it's not a disconnected DOM node
if ( !jQuery.contains( docElem, elem ) ) {
return box;
}
// If we don't have gBCR, just use 0,0 rather than error
// BlackBerry 5, iOS 3 (original iPhone)
if ( typeof elem.getBoundingClientRect !== "undefined" ) {
box = elem.getBoundingClientRect();
}
win = getWindow( doc );
clientTop = docElem.clientTop || body.clientTop || 0;
clientLeft = docElem.clientLeft || body.clientLeft || 0;
scrollTop = win.pageYOffset || docElem.scrollTop;
scrollLeft = win.pageXOffset || docElem.scrollLeft;
return {
top: box.top + scrollTop - clientTop,
left: box.left + scrollLeft - clientLeft
};
};
jQuery.offset = {
bodyOffset: function( body ) {
var top = body.offsetTop,
left = body.offsetLeft;
if ( jQuery.support.doesNotIncludeMarginInBodyOffset ) {
top += parseFloat( jQuery.css(body, "marginTop") ) || 0;
left += parseFloat( jQuery.css(body, "marginLeft") ) || 0;
}
return { top: top, left: left };
},
setOffset: function( elem, options, i ) {
var position = jQuery.css( elem, "position" );
// set position first, in-case top/left are set even on static elem
if ( position === "static" ) {
elem.style.position = "relative";
}
var curElem = jQuery( elem ),
curOffset = curElem.offset(),
curCSSTop = jQuery.css( elem, "top" ),
curCSSLeft = jQuery.css( elem, "left" ),
calculatePosition = ( position === "absolute" || position === "fixed" ) && jQuery.inArray("auto", [curCSSTop, curCSSLeft]) > -1,
props = {}, curPosition = {}, curTop, curLeft;
// 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({
position: function() {
if ( !this[ 0 ] ) {
return;
}
var offsetParent, offset,
parentOffset = { top: 0, left: 0 },
elem = this[ 0 ];
// fixed elements are offset from window (parentOffset = {top:0, left: 0}, because it is it's only offset parent
if ( jQuery.css( elem, "position" ) === "fixed" ) {
// we assume that getBoundingClientRect is available when computed position is fixed
offset = elem.getBoundingClientRect();
} else {
// Get *real* offsetParent
offsetParent = this.offsetParent();
// Get correct offsets
offset = this.offset();
if ( !rroot.test( offsetParent[ 0 ].nodeName ) ) {
parentOffset = offsetParent.offset();
}
// Add offsetParent borders
parentOffset.top += parseFloat( jQuery.css( offsetParent[ 0 ], "borderTopWidth" ) ) || 0;
parentOffset.left += parseFloat( jQuery.css( offsetParent[ 0 ], "borderLeftWidth" ) ) || 0;
}
// Subtract parent offsets and element margins
// note: when an element has margin: auto the offsetLeft and marginLeft
// are the same in Safari causing offset.left to incorrectly be 0
return {
top: offset.top - parentOffset.top - ( parseFloat( jQuery.css( elem, "marginTop" ) ) || 0 ),
left: offset.left - parentOffset.left - ( parseFloat( jQuery.css( elem, "marginLeft" ) ) || 0 )
};
},
offsetParent: function() {
return this.map(function() {
var offsetParent = this.offsetParent || document.body;
while ( offsetParent && (!rroot.test(offsetParent.nodeName) && jQuery.css(offsetParent, "position") === "static") ) {
offsetParent = offsetParent.offsetParent;
}
return offsetParent || document.body;
});
}
});
// Create scrollLeft and scrollTop methods
jQuery.each( {scrollLeft: "pageXOffset", scrollTop: "pageYOffset"}, function( method, prop ) {
var top = /Y/.test( prop );
jQuery.fn[ method ] = function( val ) {
return jQuery.access( this, function( elem, method, val ) {
var win = getWindow( elem );
if ( val === undefined ) {
return win ? (prop in win) ? win[ prop ] :
win.document.documentElement[ method ] :
elem[ method ];
}
if ( win ) {
win.scrollTo(
!top ? val : jQuery( win ).scrollLeft(),
top ? val : jQuery( win ).scrollTop()
);
} else {
elem[ method ] = val;
}
}, method, val, arguments.length, null );
};
});
function getWindow( elem ) {
return jQuery.isWindow( elem ) ?
elem :
elem.nodeType === 9 ?
elem.defaultView || elem.parentWindow :
false;
}