jquery/src/offset.js

92 lines
3.0 KiB
JavaScript

// The Offset Method
// Originally By Brandon Aaron, part of the Dimension Plugin
// http://jquery.com/plugins/project/dimensions
jQuery.fn.offset = function() {
var left = 0, top = 0, elem = this[0], results;
if ( elem ) with ( jQuery.browser ) {
var absolute = jQuery.css(elem, "position") == "absolute",
parent = elem.parentNode,
offsetParent = elem.offsetParent,
doc = elem.ownerDocument,
safari2 = safari && !absolute && parseInt(version) < 522;
// Use getBoundingClientRect if available
if ( elem.getBoundingClientRect ) {
box = elem.getBoundingClientRect();
// Add the document scroll offsets
add(
box.left + Math.max(doc.documentElement.scrollLeft, doc.body.scrollLeft),
box.top + Math.max(doc.documentElement.scrollTop, doc.body.scrollTop)
);
// IE adds the HTML element's border, by default it is medium which is 2px
// IE 6 and IE 7 quirks mode the border width is overwritable by the following css html { border: 0; }
// IE 7 standards mode, the border is always 2px
if ( msie ) {
var border = jQuery("html").css("borderWidth");
border = (border == "medium" || jQuery.boxModel && parseInt(version) >= 7) && 2 || border;
add( -border, -border );
}
// Otherwise loop through the offsetParents and parentNodes
} else {
// Initial element offsets
add( elem.offsetLeft, elem.offsetTop );
// Get parent offsets
while ( offsetParent ) {
// Add offsetParent offsets
add( offsetParent.offsetLeft, offsetParent.offsetTop );
// Mozilla and Safari > 2 does not include the border on offset parents
// However Mozilla adds the border for table cells
if ( mozilla && /^t[d|h]$/i.test(parent.tagName) || !safari2 )
border( offsetParent );
// Safari <= 2 doubles body offsets with an absolutely positioned element or parent
if ( safari2 && !absolute && jQuery.css(offsetParent, "position") == "absolute" )
absolute = true;
// Get next offsetParent
offsetParent = offsetParent.offsetParent;
}
// Get parent scroll offsets
while ( parent.tagName && /^body|html$/i.test(parent.tagName) ) {
// Work around opera inline/table scrollLeft/Top bug
if ( /^inline|table-row.*$/i.test(jQuery.css(parent, "display")) )
// Subtract parent scroll offsets
add( -parent.scrollLeft, -parent.scrollTop );
// Mozilla does not add the border for a parent that has overflow != visible
if ( mozilla && jQuery.css(parent, "overflow") != "visible" )
border( parent );
// Get next parent
parent = parent.parentNode;
}
// Safari doubles body offsets with an absolutely positioned element or parent
if ( safari && absolute )
add( -doc.body.offsetLeft, -doc.body.offsetTop );
}
// Return an object with top and left properties
results = { top: top, left: left };
}
return results;
function border(elem) {
add( jQuery.css(elem, "borderLeftWidth"), jQuery.css(elem, "borderTopWidth") );
}
function add(l, t) {
left += parseInt(l) || 0;
top += parseInt(t) || 0;
}
};