From: Tim Düsterhus <duesterhus@woltlab.com>
Date: Thu, 1 Sep 2016 01:36:27 +0000 (+0200)
Subject: Avoid page jumping when scrolling is disabled
X-Git-Tag: 3.0.0_Beta_1~370^2~3
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=65176a7fa9f2a5acf193e797b871733eab45472f;p=GitHub%2FWoltLab%2FWCF.git

Avoid page jumping when scrolling is disabled
---

diff --git a/wcfsetup/install/files/js/WoltLabSuite/Core/Ui/Screen.js b/wcfsetup/install/files/js/WoltLabSuite/Core/Ui/Screen.js
index 50f3f7f361..ec9e726feb 100644
--- a/wcfsetup/install/files/js/WoltLabSuite/Core/Ui/Screen.js
+++ b/wcfsetup/install/files/js/WoltLabSuite/Core/Ui/Screen.js
@@ -11,6 +11,7 @@ define(['Core', 'Dictionary'], function(Core, Dictionary) {
 	
 	var _mql = new Dictionary();
 	var _scrollDisableCounter = 0;
+	var _scrollOffsetFrom;
 	
 	var _mqMap = Dictionary.fromObject({
 		'screen-xs': '(max-width: 544px)',                              /* smartphone */
@@ -95,6 +96,14 @@ define(['Core', 'Dictionary'], function(Core, Dictionary) {
 		 */
 		scrollDisable: function() {
 			if (_scrollDisableCounter === 0) {
+				var h = document.body.scrollTop;
+				_scrollOffsetFrom = 'body';
+				if (!h) {
+					h = document.documentElement.scrollTop;
+					_scrollOffsetFrom = 'documentElement';
+				}
+				
+				elById('pageContainer').style.setProperty('transform', 'translateY(-' + h + 'px)');
 				document.documentElement.classList.add('disableScrolling');
 			}
 			
@@ -110,6 +119,11 @@ define(['Core', 'Dictionary'], function(Core, Dictionary) {
 				
 				if (_scrollDisableCounter === 0) {
 					document.documentElement.classList.remove('disableScrolling');
+					var h = elById('pageContainer').style.getPropertyValue('transform').match(/translateY\(-(\d+)px\)/);
+					elById('pageContainer').style.removeProperty('transform');
+					if (h) {
+						document[_scrollOffsetFrom].scrollTop = ~~h[1];
+					}
 				}
 			}
 		},