Merge pull request #1695 from atom/ns-fix-softwrap-with-scrollbars

When scrollbar is visible, account for it when soft wrapping lines

spec/editor-view-spec.coffee

@@ -1806,6 +1806,17 @@ describe "EditorView", ->
         runs ->
           expect(editor.getSoftWrapColumn()).toBeLessThan previousSoftWrapColumn
 
+      it "accounts for the width of the scrollbar if there is one", ->
+        # force the scrollbar to always be visible, regardless of OS visibility setting
+        $('#jasmine-content').prepend """
+          <style>
+            ::-webkit-scrollbar { width: 15px; }
+          </style>
+        """
+        setEditorHeightInLines(editorView, 5)
+        setEditorWidthInChars(editorView, 40)
+        expect(editor.lineForScreenRow(2).text.length).toBe 34
+
   describe "gutter rendering", ->
     beforeEach ->
       editorView.attachToDom(heightInLines: 5.5)

src/editor-view.coffee

@@ -667,11 +667,15 @@ class EditorView extends View
     @editor.setSoftWrap(not @editor.getSoftWrap())
 
   calculateWidthInChars: ->
-    Math.floor(@scrollView.width() / @charWidth)
+    Math.floor((@scrollView.width() - @getScrollbarWidth()) / @charWidth)
 
   calculateHeightInLines: ->
     Math.ceil($(window).height() / @lineHeight)
 
+  getScrollbarWidth: ->
+    scrollbarElement = @verticalScrollbar[0]
+    scrollbarElement.offsetWidth - scrollbarElement.clientWidth
+
   # Public: Enables/disables soft wrap on the editor.
   #
   # softWrap - A {Boolean} which, if `true`, enables soft wrap