From ed7750e70e86bcff5122d663949aa741043e99cc Mon Sep 17 00:00:00 2001
From: nightwing <amirjanyan@gmail.com>
Date: Mon, 4 Feb 2013 00:01:19 +0400
Subject: [PATCH] improve MouseWheel behavior

---
 lib/ace/mouse/default_handlers.js | 26 ++++++++------------------
 lib/ace/virtual_renderer.js       |  4 ++--
 2 files changed, 10 insertions(+), 20 deletions(-)

diff --git a/lib/ace/mouse/default_handlers.js b/lib/ace/mouse/default_handlers.js
index a6ce5c61..3a7e97af 100644
--- a/lib/ace/mouse/default_handlers.js
+++ b/lib/ace/mouse/default_handlers.js
@@ -297,28 +297,18 @@ function DefaultHandlers(mouseHandler) {
     };
 
     this.onMouseWheel = function(ev) {
-        if (ev.getShiftKey() || ev.getAccelKey()){
+        if (ev.getShiftKey() || ev.getAccelKey())
             return;
-        }
+        var t = ev.domEvent.timeStamp;
+        var dt = t - (this.$lastScrollTime||0);
+        
         var editor = this.editor;
         var isScrolable = editor.renderer.isScrollableBy(ev.wheelX * ev.speed, ev.wheelY * ev.speed);
-        if (isScrolable) {
-            this.$passScrollEvent = false;
-        } else {
-            if (this.$passScrollEvent)
-                return;
-
-            if (!this.$scrollStopTimeout) {
-                var self = this;
-                this.$scrollStopTimeout = setTimeout(function() {
-                    self.$passScrollEvent = true;
-                    self.$scrollStopTimeout = null;
-                }, 200);
-            }
+        if (isScrolable || dt < 200) {
+            this.$lastScrollTime = t;
+            editor.renderer.scrollBy(ev.wheelX * ev.speed, ev.wheelY * ev.speed);
+            return ev.stop();
         }
-
-        editor.renderer.scrollBy(ev.wheelX * ev.speed, ev.wheelY * ev.speed);
-        return ev.preventDefault();
     };
 
 }).call(DefaultHandlers.prototype);
diff --git a/lib/ace/virtual_renderer.js b/lib/ace/virtual_renderer.js
index 1a9e0721..a95f999d 100644
--- a/lib/ace/virtual_renderer.js
+++ b/lib/ace/virtual_renderer.js
@@ -1122,9 +1122,9 @@ var VirtualRenderer = function(container, theme) {
     * @returns {Boolean}
     **/
     this.isScrollableBy = function(deltaX, deltaY) {
-        if (deltaY < 0 && this.session.getScrollTop() > 0)
+        if (deltaY < 0 && this.session.getScrollTop() >= 1)
            return true;
-        if (deltaY > 0 && this.session.getScrollTop() + this.$size.scrollerHeight < this.layerConfig.maxHeight)
+        if (deltaY > 0 && this.session.getScrollTop() + this.$size.scrollerHeight - this.layerConfig.maxHeight < -1)
            return true;
         // todo: handle horizontal scrolling
     };