Offset: account for scroll when calculating position

Richard McDaniel · timmywil · commit 2d715940b9b6 · 2015-05-12T10:34:57.000-04:00
Fixes gh-1708 Close gh-1714
diff --git a/src/offset.js b/src/offset.js
@@ -131,8 +131,11 @@ jQuery.fn.extend({
 			}
 
 			// Add offsetParent borders
-			parentOffset.top += jQuery.css( offsetParent[ 0 ], "borderTopWidth", true );
-			parentOffset.left += jQuery.css( offsetParent[ 0 ], "borderLeftWidth", true );
+			// Subtract offsetParent scroll positions
+			parentOffset.top += jQuery.css( offsetParent[ 0 ], "borderTopWidth", true ) -
+				offsetParent.scrollTop();
+			parentOffset.left += jQuery.css( offsetParent[ 0 ], "borderLeftWidth", true ) -
+				offsetParent.scrollLeft();
 		}
 
 		// Subtract parent offsets and element margins
diff --git a/test/unit/offset.js b/test/unit/offset.js
@@ -407,7 +407,7 @@ testIframe("offset/table", "table", function( $ ) {
 });
 
 testIframe("offset/scroll", "scroll", function( $, win ) {
-	expect(24);
+	expect(28);
 
 	equal( $("#scroll-1").offset().top, 7, "jQuery('#scroll-1').offset().top" );
 	equal( $("#scroll-1").offset().left, 7, "jQuery('#scroll-1').offset().left" );
@@ -457,6 +457,17 @@ testIframe("offset/scroll", "scroll", function( $, win ) {
 	notEqual( $().scrollLeft(null), null, "jQuery().scrollLeft(null) testing setter on empty jquery object" );
 	strictEqual( $().scrollTop(), null, "jQuery().scrollTop(100) testing setter on empty jquery object" );
 	strictEqual( $().scrollLeft(), null, "jQuery().scrollLeft(100) testing setter on empty jquery object" );
+
+	// Tests position after parent scrolling (#15239)
+	$("#scroll-1").scrollTop(0);
+	$("#scroll-1").scrollLeft(0);
+	equal( $("#scroll-1-1").position().top, 6, "jQuery('#scroll-1-1').position().top unaffected by parent scrolling" );
+	equal( $("#scroll-1-1").position().left, 6, "jQuery('#scroll-1-1').position().left unaffected by parent scrolling" );
+
+	$("#scroll-1").scrollTop(5);
+	$("#scroll-1").scrollLeft(5);
+	equal( $("#scroll-1-1").position().top, 6, "jQuery('#scroll-1-1').position().top unaffected by parent scrolling" );
+	equal( $("#scroll-1-1").position().left, 6, "jQuery('#scroll-1-1').position().left unaffected by parent scrolling" );
 });
 
 testIframe("offset/body", "body", function( $ ) {

Original file line number	Diff line number	Diff line change
`@@ -131,8 +131,11 @@ jQuery.fn.extend({`
`131`	`131`	`}`
`132`	`132`
`133`	`133`	`// Add offsetParent borders`
`134`		`- parentOffset.top += jQuery.css( offsetParent[ 0 ], "borderTopWidth", true );`
`135`		`- parentOffset.left += jQuery.css( offsetParent[ 0 ], "borderLeftWidth", true );`
	`134`	`+ // Subtract offsetParent scroll positions`
	`135`	`+ parentOffset.top += jQuery.css( offsetParent[ 0 ], "borderTopWidth", true ) -`
	`136`	`+ offsetParent.scrollTop();`
	`137`	`+ parentOffset.left += jQuery.css( offsetParent[ 0 ], "borderLeftWidth", true ) -`
	`138`	`+ offsetParent.scrollLeft();`
`136`	`139`	`}`
`137`	`140`
`138`	`141`	`// Subtract parent offsets and element margins`