From ddf5d1ab4567d5c2eb2526d85efb921dfe7b5a3c Mon Sep 17 00:00:00 2001
From: DanyaPostfactum <danya.postfactum@gmail.com>
Date: Thu, 12 Sep 2013 02:48:46 +1000
Subject: [PATCH] Improve autoscroll behavior for text dragging

---
 lib/ace/css/editor.css            |  1 +
 lib/ace/mouse/dragdrop_handler.js | 11 ++++++-----
 2 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/lib/ace/css/editor.css b/lib/ace/css/editor.css
index 1244c1b0..89141ec2 100644
--- a/lib/ace/css/editor.css
+++ b/lib/ace/css/editor.css
@@ -16,6 +16,7 @@
     top: 0;
     bottom: 0;
     background-color: inherit;
+    z-index: 8;
 }
 
 .ace_content {
diff --git a/lib/ace/mouse/dragdrop_handler.js b/lib/ace/mouse/dragdrop_handler.js
index fcd13840..8d760e6e 100644
--- a/lib/ace/mouse/dragdrop_handler.js
+++ b/lib/ace/mouse/dragdrop_handler.js
@@ -193,16 +193,15 @@ function DragdropHandler(mouseHandler) {
         };
         var nearestXOffset = Math.min(offsets.x.left, offsets.x.right);
         var nearestYOffset = Math.min(offsets.y.top, offsets.y.bottom);
-        var scrollX = 0;
-        var scrollY = 0;
+        var scrollCursor = {row: dragCursor.row, column: dragCursor.column};
         if (nearestXOffset / characterWidth <= 2) {
-            scrollX = characterWidth * (offsets.x.left < offsets.x.right ? -1 : +1);
+            scrollCursor.column += (offsets.x.left < offsets.x.right ? -3 : +2);
         }
         if (nearestYOffset / lineHeight <= 1) {
-            scrollY = lineHeight * (offsets.y.top < offsets.y.bottom ? -1 : +1);
+            scrollCursor.row += (offsets.y.top < offsets.y.bottom ? -1 : +1);
         }
         editor.moveCursorToPosition(dragCursor);
-        editor.renderer.scrollBy(scrollX, scrollY);
+        editor.renderer.scrollCursorIntoView(scrollCursor);
     }
 
     function addDragMarker() {
@@ -220,7 +219,9 @@ function DragdropHandler(mouseHandler) {
         clearInterval(timerId);
         editor.session.removeMarker(dragSelectionMarker);
         dragSelectionMarker = null;
+        editor.$blockScrolling += 1;
         editor.selection.fromOrientedRange(range);
+        editor.$blockScrolling -= 1;
         range = null;
         counter = 0;
         event.removeListener(document, "mousemove", onMouseMove);