2.0: Reduce offset module. Close gh-1139.

diff --git a/src/offset.js b/src/offset.js
index 04c94cadee0600f080b334de62c5059ad60f3af1..4fb37bb7cea59f7a5b36c1f8e2d0f4cda5e521d7 100644 (file)
--- a/src/offset.js
+++ b/src/offset.js
@@ -8,8 +8,8 @@ jQuery.fn.offset = function( options ) {
        }
 
        var docElem, win,
-               box = { top: 0, left: 0 },
                elem = this[ 0 ],
+               box = { top: 0, left: 0 },
                doc = elem && elem.ownerDocument;
 
        if ( !doc ) {
@@ -30,33 +30,35 @@ jQuery.fn.offset = function( options ) {
        }
        win = getWindow( doc );
        return {
-               top: box.top  + ( win.pageYOffset || docElem.scrollTop )  - ( docElem.clientTop  || 0 ),
-               left: box.left + ( win.pageXOffset || docElem.scrollLeft ) - ( docElem.clientLeft || 0 )
+               top: box.top + win.pageYOffset - docElem.clientTop,
+               left: box.left + win.pageXOffset - docElem.clientLeft
        };
 };
 
 jQuery.offset = {
 
        setOffset: function( elem, options, i ) {
-               var position = jQuery.css( elem, "position" );
+               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
+               // 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;
+               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
+               // 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;
@@ -75,6 +77,7 @@ jQuery.offset = {
 
                if ( "using" in options ) {
                        options.using.call( elem, props );
+
                } else {
                        curElem.css( props );
                }
@@ -90,13 +93,14 @@ jQuery.fn.extend({
                }
 
                var offsetParent, offset,
-                       parentOffset = { top: 0, left: 0 },
-                       elem = this[ 0 ];
+                       elem = this[ 0 ],
+                       parentOffset = { top: 0, left: 0 };
 
-               // fixed elements are offset from window (parentOffset = {top:0, left: 0}, because it is it's only offset parent
+               // 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
+                       // We assume that getBoundingClientRect is available when computed position is fixed
                        offset = elem.getBoundingClientRect();
+
                } else {
                        // Get *real* offsetParent
                        offsetParent = this.offsetParent();
@@ -108,25 +112,25 @@ jQuery.fn.extend({
                        }
 
                        // Add offsetParent borders
-                       parentOffset.top  += jQuery.css( offsetParent[ 0 ], "borderTopWidth", true );
+                       parentOffset.top += jQuery.css( offsetParent[ 0 ], "borderTopWidth", true );
                        parentOffset.left += jQuery.css( offsetParent[ 0 ], "borderLeftWidth", true );
                }
 
                // 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 - jQuery.css( elem, "marginTop", true ),
-                       left: offset.left - parentOffset.left - jQuery.css( elem, "marginLeft", true)
+                       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 || document.documentElement;
+
                        while ( offsetParent && ( !jQuery.nodeName( offsetParent, "html" ) && jQuery.css( offsetParent, "position") === "static" ) ) {
                                offsetParent = offsetParent.offsetParent;
                        }
+
                        return offsetParent || document.documentElement;
                });
        }
@@ -135,22 +139,20 @@ jQuery.fn.extend({
 
 // Create scrollLeft and scrollTop methods
 jQuery.each( {scrollLeft: "pageXOffset", scrollTop: "pageYOffset"}, function( method, prop ) {
-       var top = /Y/.test( prop );
+       var top = "pageYOffset" === 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 ];
+                               return win ? win[ prop ] : elem[ method ];
                        }
 
                        if ( win ) {
                                win.scrollTo(
-                                       !top ? val : jQuery( win ).scrollLeft(),
-                                       top ? val : jQuery( win ).scrollTop()
+                                       !top ? val : window.pageXOffset,
+                                       top ? val : window.pageYOffset
                                );
 
                        } else {
@@ -161,9 +163,5 @@ jQuery.each( {scrollLeft: "pageXOffset", scrollTop: "pageYOffset"}, function( me
 });
 
 function getWindow( elem ) {
-       return jQuery.isWindow( elem ) ?
-               elem :
-               elem.nodeType === 9 ?
-                       elem.defaultView || elem.parentWindow :
-                       false;
+       return jQuery.isWindow( elem ) ? elem : elem.nodeType === 9 && elem.defaultView;
 }