Add Editor::lineTextForScreenRow()

Closes #3055

spec/editor-spec.coffee

@@ -2773,6 +2773,11 @@ describe "Editor", ->
         expect(cursor1.getBufferPosition()).toEqual [0,0]
         expect(cursor3.getBufferPosition()).toEqual [1,2]
 
+  describe 'reading text', ->
+    it '.lineTextForScreenRow(row)', ->
+      editor.foldBufferRow(4)
+      expect(editor.lineTextForScreenRow(5)).toEqual '    return sort(left).concat(pivot).concat(sort(right));'
+
   describe ".deleteLine()", ->
     it "deletes the first line when the cursor is there", ->
       editor.getLastCursor().moveToTop()

src/editor.coffee

@@ -418,6 +418,12 @@ class Editor extends Model
     deprecate 'Use Editor::lineTextForBufferRow(bufferRow) instead'
     @lineTextForBufferRow(bufferRow)
 
+  # Public: Returns a {String} representing the contents of the line at the
+  # given screen row.
+  #
+  # * `screenRow` A {Number} representing a zero-indexed screen row.
+  lineTextForScreenRow: (screenRow) -> @displayBuffer.tokenizedLineForScreenRow(screenRow).text
+
   # Gets the screen line for the given screen row.
   #
   # * `screenRow` - A {Number} indicating the screen row.