From 797be76c95377cb37fe47b73e7261895370857e7 Mon Sep 17 00:00:00 2001
From: Tor Hveem <tor@hveem.no>
Date: Mon, 9 Dec 2013 11:10:11 +0100
Subject: [PATCH 1/3] try to improve scrolling experience

---
 js/websockets.js | 15 +++++----------
 1 file changed, 5 insertions(+), 10 deletions(-)

diff --git a/js/websockets.js b/js/websockets.js
index 1dea75b..901edad 100644
--- a/js/websockets.js
+++ b/js/websockets.js
@@ -580,16 +580,11 @@ weechat.controller('WeechatCtrl', ['$rootScope', '$scope', '$store', '$timeout',
     $rootScope.scrollToBottom = function() {
         // FIXME doesn't work if the settimeout runs without a short delay
         var scroll = function() {
-            var readmarker = document.getElementById('readmarker');
-            if(readmarker) {
-                readmarker.scrollIntoView();
-            }else{
-                var bl = document.getElementById('bufferlines');
-                var sTop = bl.scrollTop;
-                var sVal = bl.scrollHeight - bl.clientHeight;
-                if(sTop < sVal) {
-                    bl.scrollTop = sVal;
-                }
+            var bl = document.getElementById('bufferlines');
+            var sTop = bl.scrollTop;
+            var sVal = bl.scrollHeight - bl.clientHeight;
+            if(sTop < sVal) {
+                bl.scrollTop = sVal;
             }
         };
         // Here be scrolling dragons

From fe0c070a6c496b7e039b238b3422fd2e2b4f1a15 Mon Sep 17 00:00:00 2001
From: Lorenz H-S <lorenz-dev@lgh-alumni.de>
Date: Mon, 23 Dec 2013 22:34:21 +0100
Subject: [PATCH 2/3] Only scroll when at the bottom of the buffer

I think this behaviour is a lot more natural. Because it no longer "scrolls to bottom", I also renamed it.
---
 js/websockets.js | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/js/websockets.js b/js/websockets.js
index 901edad..c0476af 100644
--- a/js/websockets.js
+++ b/js/websockets.js
@@ -35,7 +35,7 @@ weechat.factory('handlers', ['$rootScope', 'models', 'plugins', function($rootSc
             }
 
             if (buffer.active) {
-                $rootScope.scrollToBottom();
+                $rootScope.scrollWithBuffer();
             }
 
             if (!initial && !buffer.active) {
@@ -480,7 +480,7 @@ weechat.controller('WeechatCtrl', ['$rootScope', '$scope', '$store', '$timeout',
     }
 
     $rootScope.$on('activeBufferChanged', function() {
-        $rootScope.scrollToBottom();
+        $rootScope.scrollWithBuffer();
 
         var ab = models.getActiveBuffer();
         $rootScope.pageTitle = ab.shortName + ' | ' + ab.title;
@@ -577,13 +577,13 @@ weechat.controller('WeechatCtrl', ['$rootScope', '$scope', '$store', '$timeout',
         }
     };
 
-    $rootScope.scrollToBottom = function() {
+    $rootScope.scrollWithBuffer = function() {
         // FIXME doesn't work if the settimeout runs without a short delay
         var scroll = function() {
             var bl = document.getElementById('bufferlines');
             var sTop = bl.scrollTop;
             var sVal = bl.scrollHeight - bl.clientHeight;
-            if(sTop < sVal) {
+            if(sTop == sVal) {
                 bl.scrollTop = sVal;
             }
         };

From f38c4b020e1a48e86542d003a319a5d0f84f5c32 Mon Sep 17 00:00:00 2001
From: Lorenz H-S <lorenz-dev@lgh-alumni.de>
Date: Sat, 28 Dec 2013 16:50:31 +0100
Subject: [PATCH 3/3] Fix scrolling behaviour for good (?)

---
 js/websockets.js | 24 +++++++++++++++++-------
 1 file changed, 17 insertions(+), 7 deletions(-)

diff --git a/js/websockets.js b/js/websockets.js
index c0476af..17daf3c 100644
--- a/js/websockets.js
+++ b/js/websockets.js
@@ -480,7 +480,7 @@ weechat.controller('WeechatCtrl', ['$rootScope', '$scope', '$store', '$timeout',
     }
 
     $rootScope.$on('activeBufferChanged', function() {
-        $rootScope.scrollWithBuffer();
+        $rootScope.scrollWithBuffer(true);
 
         var ab = models.getActiveBuffer();
         $rootScope.pageTitle = ab.shortName + ' | ' + ab.title;
@@ -577,14 +577,24 @@ weechat.controller('WeechatCtrl', ['$rootScope', '$scope', '$store', '$timeout',
         }
     };
 
-    $rootScope.scrollWithBuffer = function() {
-        // FIXME doesn't work if the settimeout runs without a short delay
+    $rootScope.scrollWithBuffer = function(nonIncremental) {
+        // First, get scrolling status *before* modification
+        // This is required to determine where we were in the buffer pre-change
+        var bl = document.getElementById('bufferlines');
+        var sVal = bl.scrollHeight - bl.clientHeight;
+
         var scroll = function() {
-            var bl = document.getElementById('bufferlines');
             var sTop = bl.scrollTop;
-            var sVal = bl.scrollHeight - bl.clientHeight;
-            if(sTop == sVal) {
-                bl.scrollTop = sVal;
+            // Determine if we want to scroll at all
+            if (nonIncremental && sTop < sVal || sTop == sVal) {
+                var readmarker = document.getElementById('readmarker');
+                if(nonIncremental && readmarker) {
+                    // Switching channels, scroll to read marker
+                    readmarker.scrollIntoView();
+                } else {
+                    // New message, scroll with buffer (i.e. to bottom)
+                    bl.scrollTop = bl.scrollHeight - bl.clientHeight;
+                }
             }
         };
         // Here be scrolling dragons