jquery/src/offset.js
2009-07-17 21:08:13 +00:00

170 lines
6.8 KiB
JavaScript

if ( "getBoundingClientRect" in document.documentElement )
jQuery.fn.offset = function() {
var elem = this[0];
if ( !elem || !elem.ownerDocument ) return null;
if ( elem === elem.ownerDocument.body ) return jQuery.offset.bodyOffset( elem );
var box = elem.getBoundingClientRect(), doc = elem.ownerDocument, body = doc.body, docElem = doc.documentElement,
clientTop = docElem.clientTop || body.clientTop || 0, clientLeft = docElem.clientLeft || body.clientLeft || 0,
top = box.top + (self.pageYOffset || jQuery.support.boxModel && docElem.scrollTop || body.scrollTop ) - clientTop,
left = box.left + (self.pageXOffset || jQuery.support.boxModel && docElem.scrollLeft || body.scrollLeft) - clientLeft;
return { top: top, left: left };
};
else
jQuery.fn.offset = function() {
var elem = this[0];
if ( !elem || !elem.ownerDocument ) return null;
if ( elem === elem.ownerDocument.body ) return jQuery.offset.bodyOffset( elem );
jQuery.offset.initialize();
var offsetParent = elem.offsetParent, prevOffsetParent = elem,
doc = elem.ownerDocument, computedStyle, docElem = doc.documentElement,
body = doc.body, defaultView = doc.defaultView,
prevComputedStyle = defaultView.getComputedStyle(elem, null),
top = elem.offsetTop, left = elem.offsetLeft;
while ( (elem = elem.parentNode) && elem !== body && elem !== docElem ) {
if ( jQuery.offset.supportsFixedPosition && prevComputedStyle.position === "fixed" ) break;
computedStyle = defaultView.getComputedStyle(elem, null);
top -= elem.scrollTop, left -= elem.scrollLeft;
if ( elem === offsetParent ) {
top += elem.offsetTop, left += elem.offsetLeft;
if ( jQuery.offset.doesNotAddBorder && !(jQuery.offset.doesAddBorderForTableAndCells && /^t(able|d|h)$/i.test(elem.tagName)) )
top += parseFloat( computedStyle.borderTopWidth ) || 0,
left += parseFloat( computedStyle.borderLeftWidth ) || 0;
prevOffsetParent = offsetParent, offsetParent = elem.offsetParent;
}
if ( jQuery.offset.subtractsBorderForOverflowNotVisible && computedStyle.overflow !== "visible" )
top += parseFloat( computedStyle.borderTopWidth ) || 0,
left += parseFloat( computedStyle.borderLeftWidth ) || 0;
prevComputedStyle = computedStyle;
}
if ( prevComputedStyle.position === "relative" || prevComputedStyle.position === "static" )
top += body.offsetTop,
left += body.offsetLeft;
if ( jQuery.offset.supportsFixedPosition && prevComputedStyle.position === "fixed" )
top += Math.max( docElem.scrollTop, body.scrollTop ),
left += Math.max( docElem.scrollLeft, body.scrollLeft );
return { top: top, left: left };
};
jQuery.offset = {
initialize: function() {
var body = document.body, container = document.createElement('div'), innerDiv, checkDiv, table, td, bodyMarginTop = parseFloat( jQuery.curCSS(body, 'marginTop', true) ) || 0,
html = '<div style="position:absolute;top:0;left:0;margin:0;border:5px solid #000;padding:0;width:1px;height:1px;"><div></div></div><table style="position:absolute;top:0;left:0;margin:0;border:5px solid #000;padding:0;width:1px;height:1px;" cellpadding="0" cellspacing="0"><tr><td></td></tr></table>';
jQuery.extend( container.style, { position: 'absolute', top: 0, left: 0, margin: 0, border: 0, width: '1px', height: '1px', visibility: 'hidden' } );
container.innerHTML = html;
body.insertBefore( container, body.firstChild );
innerDiv = container.firstChild, checkDiv = innerDiv.firstChild, td = innerDiv.nextSibling.firstChild.firstChild;
this.doesNotAddBorder = (checkDiv.offsetTop !== 5);
this.doesAddBorderForTableAndCells = (td.offsetTop === 5);
checkDiv.style.position = 'fixed', checkDiv.style.top = '20px';
this.supportsFixedPosition = (checkDiv.offsetTop === 20 || checkDiv.offsetTop === 15); // safari subtracts parent border width here which is 5px
checkDiv.style.position = '', checkDiv.style.top = '';
innerDiv.style.overflow = 'hidden', innerDiv.style.position = 'relative';
this.subtractsBorderForOverflowNotVisible = (checkDiv.offsetTop === -5);
this.doesNotIncludeMarginInBodyOffset = (body.offsetTop !== bodyMarginTop);
body.removeChild( container );
jQuery.offset.initialize = function(){};
body = container = innerDiv = checkDiv = table = td = null;
},
bodyOffset: function(body) {
jQuery.offset.initialize();
var top = body.offsetTop, left = body.offsetLeft;
if ( jQuery.offset.doesNotIncludeMarginInBodyOffset )
top += parseFloat( jQuery.curCSS(body, 'marginTop', true) ) || 0,
left += parseFloat( jQuery.curCSS(body, 'marginLeft', true) ) || 0;
return { top: top, left: left };
}
};
jQuery.fn.extend({
position: function() {
if ( !this[0] ) return null;
var elem = this[0],
// Get *real* offsetParent
offsetParent = this.offsetParent(),
// Get correct offsets
offset = this.offset(),
parentOffset = /^body|html$/i.test(offsetParent[0].tagName) ? { top: 0, left: 0 } : offsetParent.offset();
// Subtract 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
offset.top -= parseFloat( jQuery.curCSS(elem, 'marginTop', true) ) || 0;
offset.left -= parseFloat( jQuery.curCSS(elem, 'marginLeft', true) ) || 0;
// Add offsetParent borders
parentOffset.top += parseFloat( jQuery.curCSS(offsetParent[0], 'borderTopWidth', true) ) || 0;
parentOffset.left += parseFloat( jQuery.curCSS(offsetParent[0], 'borderLeftWidth', true) ) || 0;
// Subtract the two offsets
return {
top: offset.top - parentOffset.top,
left: offset.left - parentOffset.left
};
},
offsetParent: function() {
var offsetParent = this[0].offsetParent || document.body;
while ( offsetParent && (!/^body|html$/i.test(offsetParent.tagName) && jQuery.css(offsetParent, 'position') === 'static') )
offsetParent = offsetParent.offsetParent;
return jQuery( offsetParent );
}
});
// Create scrollLeft and scrollTop methods
jQuery.each( ['Left', 'Top'], function(i, name) {
var method = 'scroll' + name;
jQuery.fn[ method ] = function(val) {
if ( !this[0] ) return null;
if ( val !== undefined ) {
// Set the scroll offset
return this.each(function() {
win = getWindow( this );
win ?
win.scrollTo(
!i ? val : jQuery(win).scrollLeft(),
i ? val : jQuery(win).scrollTop()
) :
this[ method ] = val;
});
} else {
var elem = this[0],
win = getWindow( elem );
// Return the scroll offset
return win && 'pageXOffset' in win ?
win[ i ? 'pageYOffset' : 'pageXOffset' ] ||
jQuery.support.boxModel && win.document.documentElement[ method ] ||
win.document.body[ method ] :
elem[ method ];
}
};
function getWindow( elem ) {
return ("scrollTo" in elem && elem.document) ? elem :
(elem.nodeName === "#document") ? elem.defaultView || elem.parentWindow :
false;
}
});