From 3a27e7b0ea527dfe8bfbb84e8899e50016205910 Mon Sep 17 00:00:00 2001
From: barisusakli <barisusakli@gmail.com>
Date: Tue, 29 Mar 2016 12:39:41 +0300
Subject: [PATCH] closes #4405

---
 public/src/client/topic.js      |  8 ++++----
 public/src/modules/navigator.js | 18 +++++++++++++++---
 2 files changed, 19 insertions(+), 7 deletions(-)

diff --git a/public/src/client/topic.js b/public/src/client/topic.js
index cd0464e9aa..9d52262676 100644
--- a/public/src/client/topic.js
+++ b/public/src/client/topic.js
@@ -222,10 +222,10 @@ define('forum/topic', [
 
 	function updateTopicTitle() {
 		var span = components.get('navbar/title').find('span');
-		if ($(window).scrollTop() > 50) {
-			span.html(ajaxify.data.title).show();
-		} else {
-			span.html('').hide();
+		if ($(window).scrollTop() > 50 && span.hasClass('hidden')) {
+			span.html(ajaxify.data.title).removeClass('hidden');
+		} else if ($(window).scrollTop() <= 50 && !span.hasClass('hidden')) {
+			span.html('').addClass('hidden');
 		}
 		if ($(window).scrollTop() > 300) {
 			app.removeAlert('bookmark');
diff --git a/public/src/modules/navigator.js b/public/src/modules/navigator.js
index 7127f1f15c..89bfc737ee 100644
--- a/public/src/modules/navigator.js
+++ b/public/src/modules/navigator.js
@@ -103,7 +103,10 @@ define('navigator', ['forum/pagination', 'components'], function(pagination, com
 			index = parseInt(els.first().attr('data-index'), 10) + 1;
 		}
 
-		var middleOfViewport = $(window).scrollTop() + $(window).height() / 2;
+		var scrollTop = $(window).scrollTop();
+		var windowHeight = $(window).height();
+		var documentHeight = $(document).height();
+		var middleOfViewport = scrollTop + windowHeight / 2;
 		var previousDistance = Number.MAX_VALUE;
 		els.each(function() {
 			var distanceToMiddle = Math.abs(middleOfViewport - $(this).offset().top);
@@ -118,10 +121,19 @@ define('navigator', ['forum/pagination', 'components'], function(pagination, com
 			}
 		});
 
+
+		// check if we are at the top
+		if (scrollTop === 0 && parseInt(els.first().attr('data-index'), 10) === 0) {
+			index = 1;
+		// check if we are near the bottom
+		} else if (scrollTop + windowHeight > documentHeight - 100 && parseInt(els.last().attr('data-index'), 10) === count - 1) {
+			index = count;
+		}
+
 		// If a threshold is undefined, try to determine one based on new index
 		if (threshold === undefined) {
-			var anchorEl = components.get('post/anchor', index - 1),
-				anchorRect = anchorEl.get(0).getBoundingClientRect();
+			var anchorEl = components.get('post/anchor', index - 1);
+			var anchorRect = anchorEl.get(0).getBoundingClientRect();
 
 			threshold = anchorRect.top;
 		}