Fix scroll bars not appearing on certain settings

Setting the bounds origins directly caused the scroll bar to not show up due to scroller management being hidden in `scroll(to: )`. This commit fixes that by canceling the animation after the call instead.

Author: nangtrongvuon

Sources/XiEditor/EditViewController.swift

@@ -325,6 +325,9 @@ class EditViewController: NSViewController, EditViewDataSource, FindDelegate, Sc
         if first..<last != visibleLines {
             document.sendWillScroll(first: first, last: last)
             visibleLines = first..<last
+
+            // Cancels the scroll animation to prevent jerky scrolling.
+            scrollView.contentView.setBoundsOrigin(newOrigin)
         }
         editView.needsDisplay = true
     }

Sources/XiEditor/XiClipView.swift

@@ -21,13 +21,8 @@ protocol ScrollInterested: class {
 class XiClipView: NSClipView {
     weak var delegate: ScrollInterested?
 
-    // Smooth scrolling (like the MacBook trackpad or Apple Magic Mouse) sends scroll events that are chunked, continuous and cumulative, 
-    // and thus the scroll view's clipView's bounds is set properly (in small increments) for each of these small chunks of scrolling. 
-    // Scrolling with notched mice scrolls in discrete units, takes into account acceleration but does not redraw the view when the view is continuously redrawn (like in xi-mac) during scrolling. 
-    // This is because the bounds origin is only set after the scrolling has stopped completely.
-    // We bypass this by simply setting the bound origin immediately. 
     override func scroll(to newOrigin: NSPoint) {
         delegate?.willScroll(to: newOrigin)
-        super.setBoundsOrigin(newOrigin)
+        super.scroll(to: newOrigin)
     }
 }