Merge pull request #6563 from atom/ns-fix-scroll-width-with-folds

Fix scroll width calculation when longest line is folded

src/text-editor-component.coffee

@@ -349,15 +349,15 @@ class TextEditorComponent
 
     if Math.abs(wheelDeltaX) > Math.abs(wheelDeltaY)
       # Scrolling horizontally
-      previousScrollLeft = @editor.getScrollLeft()
+      previousScrollLeft = @presenter.getScrollLeft()
       @presenter.setScrollLeft(previousScrollLeft - Math.round(wheelDeltaX * @scrollSensitivity))
-      event.preventDefault() unless previousScrollLeft is @editor.getScrollLeft()
+      event.preventDefault() unless previousScrollLeft is @presenter.getScrollLeft()
     else
       # Scrolling vertically
       @presenter.setMouseWheelScreenRow(@screenRowForNode(event.target))
-      previousScrollTop = @presenter.scrollTop
+      previousScrollTop = @presenter.getScrollTop()
       @presenter.setScrollTop(previousScrollTop - Math.round(wheelDeltaY * @scrollSensitivity))
-      event.preventDefault() unless previousScrollTop is @editor.getScrollTop()
+      event.preventDefault() unless previousScrollTop is @presenter.getScrollTop()
 
   onScrollViewScroll: =>
     if @mounted

src/text-editor-presenter.coffee

@@ -541,7 +541,8 @@ class TextEditorPresenter
 
     if @baseCharacterWidth?
       oldContentWidth = @contentWidth
-      @contentWidth = @pixelPositionForScreenPosition([@model.getLongestScreenRow(), Infinity]).left
+      clip = @model.tokenizedLineForScreenRow(@model.getLongestScreenRow())?.isSoftWrapped()
+      @contentWidth = @pixelPositionForScreenPosition([@model.getLongestScreenRow(), @model.getMaxScreenLineLength()], clip).left
       @contentWidth += 1 unless @model.isSoftWrapped() # account for cursor width
 
     if @contentHeight isnt oldContentHeight
@@ -691,6 +692,9 @@ class TextEditorPresenter
       @updateCustomGutterDecorationState()
       @updateOverlaysState()
 
+  getScrollTop: ->
+    @scrollTop
+
   didStartScrolling: ->
     if @stoppedScrollingTimeoutId?
       clearTimeout(@stoppedScrollingTimeoutId)
@@ -720,6 +724,9 @@ class TextEditorPresenter
       @updateCursorsState() unless oldScrollLeft?
       @updateOverlaysState()
 
+  getScrollLeft: ->
+    @scrollLeft
+
   setHorizontalScrollbarHeight: (horizontalScrollbarHeight) ->
     unless @measuredHorizontalScrollbarHeight is horizontalScrollbarHeight
       oldHorizontalScrollbarHeight = @measuredHorizontalScrollbarHeight