From e006449c7f4d1d842ba4b08d6b666c64929da8ae Mon Sep 17 00:00:00 2001
From: Ed Sanders <esanders@wikimedia.org>
Date: Mon, 23 Mar 2015 02:32:00 +0000
Subject: [PATCH] Vertically center the progress bar within the visible part of
 #content

On short pages which don't extend below the fold, the progress
bar should center within the #content element.

Change-Id: I0b99e42f5bab8177d3b4ca6dd372d6403ae9b136
---
 .../targets/ve.init.mw.ViewPageTarget.init.js    | 16 +++++++---------
 1 file changed, 7 insertions(+), 9 deletions(-)

diff --git a/modules/ve-mw/init/targets/ve.init.mw.ViewPageTarget.init.js b/modules/ve-mw/init/targets/ve.init.mw.ViewPageTarget.init.js
index d594d0736b..dc0a726392 100644
--- a/modules/ve-mw/init/targets/ve.init.mw.ViewPageTarget.init.js
+++ b/modules/ve-mw/init/targets/ve.init.mw.ViewPageTarget.init.js
@@ -32,17 +32,15 @@
 				'</div>'
 			);
 		}
-		var $window = $( window ),
-			$content = $( '#content' ),
-			scrollTop = $window.scrollTop(),
+		var $content = $( '#content' ),
+			contentRect = $content[0].getBoundingClientRect(),
 			offsetTop = $content.offset().top,
-			windowHeight = $window.height();
+			windowHeight = $( window ).height(),
+			top = Math.max( contentRect.top, 0 ),
+			bottom = Math.min( contentRect.bottom, windowHeight ),
+			middle = ( top + bottom ) / 2;
 
-		if ( scrollTop > offsetTop ) {
-			init.$loading.css( 'top', ( scrollTop - offsetTop ) + ( windowHeight / 2 ) );
-		} else {
-			init.$loading.css( 'top', ( windowHeight - ( offsetTop - scrollTop ) ) / 2 );
-		}
+		init.$loading.css( 'top', middle - offsetTop );
 
 		$content.prepend( init.$loading );
 	}