LineWrapper exposes screenLinesForRow instead of tokensForScreenRow

I *think* this is a good idea. It makes us more consistent in always passing around ScreenLine instances. We'll be able to put nice metadata on these objects, like the buffer line they correspond to etc.

spec/atom/line-wrapper-spec.coffee

@@ -16,9 +16,9 @@ describe "LineWrapper", ->
 
   describe ".tokensForScreenRow(row)", ->
     it "returns tokens for the line fragment corresponding to the given screen row", ->
-      expect(tokensText wrapper.tokensForScreenRow(3)).toEqual('    var pivot = items.shift(), current, left = [], ')
-      expect(tokensText wrapper.tokensForScreenRow(4)).toEqual('right = [];')
-      expect(tokensText wrapper.tokensForScreenRow(5)).toEqual('    while(items.length > 0) {')
+      expect(tokensText wrapper.screenLineForRow(3).tokens).toEqual('    var pivot = items.shift(), current, left = [], ')
+      expect(tokensText wrapper.screenLineForRow(4).tokens).toEqual('right = [];')
+      expect(tokensText wrapper.screenLineForRow(5).tokens).toEqual('    while(items.length > 0) {')
 
   describe ".screenLineCount()", ->
     it "returns the total number of screen lines", ->
@@ -29,9 +29,9 @@ describe "LineWrapper", ->
       describe "when the number of screen lines remains the same for the changed buffer line", ->
         it "re-wraps the existing lines and emits a change event for all its screen lines", ->
           buffer.insert([6, 28], '1234567')
-          expect(tokensText(wrapper.tokensForScreenRow(7))).toBe '      current < pivot ? left1234567.push(current) '
-          expect(tokensText(wrapper.tokensForScreenRow(8))).toBe ': right.push(current);'
-          expect(tokensText(wrapper.tokensForScreenRow(9))).toBe '    }'
+          expect(tokensText(wrapper.screenLineForRow(7).tokens)).toBe '      current < pivot ? left1234567.push(current) '
+          expect(tokensText(wrapper.screenLineForRow(8).tokens)).toBe ': right.push(current);'
+          expect(tokensText(wrapper.screenLineForRow(9).tokens)).toBe '    }'
 
           expect(changeHandler).toHaveBeenCalled()
           [event] = changeHandler.argsForCall[0]
@@ -41,10 +41,10 @@ describe "LineWrapper", ->
       describe "when the number of screen lines increases for the changed buffer line", ->
         it "re-wraps and adds an additional screen line and emits a change event for all screen lines", ->
           buffer.insert([6, 28], '1234567890')
-          expect(tokensText(wrapper.tokensForScreenRow(7))).toBe '      current < pivot ? '
-          expect(tokensText(wrapper.tokensForScreenRow(8))).toBe 'left1234567890.push(current) : '
-          expect(tokensText(wrapper.tokensForScreenRow(9))).toBe 'right.push(current);'
-          expect(tokensText(wrapper.tokensForScreenRow(10))).toBe '    }'
+          expect(tokensText(wrapper.screenLineForRow(7).tokens)).toBe '      current < pivot ? '
+          expect(tokensText(wrapper.screenLineForRow(8).tokens)).toBe 'left1234567890.push(current) : '
+          expect(tokensText(wrapper.screenLineForRow(9).tokens)).toBe 'right.push(current);'
+          expect(tokensText(wrapper.screenLineForRow(10).tokens)).toBe '    }'
 
           expect(changeHandler).toHaveBeenCalled()
           [event] = changeHandler.argsForCall[0]
@@ -54,8 +54,8 @@ describe "LineWrapper", ->
       describe "when the number of screen lines decreases for the changed buffer line", ->
         it "re-wraps and removes a screen line and emits a change event for all screen lines", ->
           buffer.change(new Range([6, 24], [6, 42]), '')
-          expect(tokensText(wrapper.tokensForScreenRow(7))).toBe '      current < pivot ?  : right.push(current);'
-          expect(tokensText(wrapper.tokensForScreenRow(8))).toBe '    }'
+          expect(tokensText(wrapper.screenLineForRow(7).tokens)).toBe '      current < pivot ?  : right.push(current);'
+          expect(tokensText(wrapper.screenLineForRow(8).tokens)).toBe '    }'
 
           expect(changeHandler).toHaveBeenCalled()
           [event] = changeHandler.argsForCall[0]
@@ -65,10 +65,10 @@ describe "LineWrapper", ->
     describe "when buffer lines are inserted", ->
       it "re-wraps existing and new screen lines and emits a change event", ->
         buffer.insert([6, 21], '1234567890 abcdefghij 1234567890\nabcdefghij')
-        expect(tokensText(wrapper.tokensForScreenRow(7))).toBe '      current < pivot1234567890 abcdefghij '
-        expect(tokensText(wrapper.tokensForScreenRow(8))).toBe '1234567890'
-        expect(tokensText(wrapper.tokensForScreenRow(9))).toBe 'abcdefghij ? left.push(current) : '
-        expect(tokensText(wrapper.tokensForScreenRow(10))).toBe 'right.push(current);'
+        expect(tokensText(wrapper.screenLineForRow(7).tokens)).toBe '      current < pivot1234567890 abcdefghij '
+        expect(tokensText(wrapper.screenLineForRow(8).tokens)).toBe '1234567890'
+        expect(tokensText(wrapper.screenLineForRow(9).tokens)).toBe 'abcdefghij ? left.push(current) : '
+        expect(tokensText(wrapper.screenLineForRow(10).tokens)).toBe 'right.push(current);'
 
         expect(changeHandler).toHaveBeenCalled()
         [event] = changeHandler.argsForCall[0]
@@ -78,10 +78,10 @@ describe "LineWrapper", ->
     describe "when buffer lines are removed", ->
       it "removes screen lines and emits a change event", ->
         buffer.change(new Range([3, 21], [7, 5]), ';')
-        expect(tokensText(wrapper.tokensForScreenRow(3))).toBe '    var pivot = items;'
-        expect(tokensText(wrapper.tokensForScreenRow(4))).toBe '    return '
-        expect(tokensText(wrapper.tokensForScreenRow(5))).toBe 'sort(left).concat(pivot).concat(sort(right));'
-        expect(tokensText(wrapper.tokensForScreenRow(6))).toBe '  };'
+        expect(tokensText(wrapper.screenLineForRow(3).tokens)).toBe '    var pivot = items;'
+        expect(tokensText(wrapper.screenLineForRow(4).tokens)).toBe '    return '
+        expect(tokensText(wrapper.screenLineForRow(5).tokens)).toBe 'sort(left).concat(pivot).concat(sort(right));'
+        expect(tokensText(wrapper.screenLineForRow(6).tokens)).toBe '  };'
 
         expect(changeHandler).toHaveBeenCalled()
         [event] = changeHandler.argsForCall[0]
@@ -91,9 +91,9 @@ describe "LineWrapper", ->
   describe ".setMaxLength(length)", ->
     it "changes the length at which lines are wrapped and emits a change event for all screen lines", ->
       wrapper.setMaxLength(40)
-      expect(tokensText wrapper.tokensForScreenRow(4)).toBe 'left = [], right = [];'
-      expect(tokensText wrapper.tokensForScreenRow(5)).toBe '    while(items.length > 0) {'
-      expect(tokensText wrapper.tokensForScreenRow(12)).toBe 'sort(left).concat(pivot).concat(sort(rig'
+      expect(tokensText wrapper.screenLineForRow(4).tokens).toBe 'left = [], right = [];'
+      expect(tokensText wrapper.screenLineForRow(5).tokens).toBe '    while(items.length > 0) {'
+      expect(tokensText wrapper.screenLineForRow(12).tokens).toBe 'sort(left).concat(pivot).concat(sort(rig'
 
       expect(changeHandler).toHaveBeenCalled()
       [event] = changeHandler.argsForCall[0]

src/atom/editor.coffee

@@ -118,7 +118,7 @@ class Editor extends View
     $(document).one 'mouseup', => @off 'mousemove', moveHandler
 
   buildLineElement: (screenRow) ->
-    tokens = @lineWrapper.tokensForScreenRow(screenRow)
+    { tokens } = @lineWrapper.screenLineForRow(screenRow)
     $$ ->
       @pre class: 'line', =>
         if tokens.length

src/atom/line-wrapper.coffee

@@ -113,11 +113,11 @@ class LineWrapper
         currentScreenRow++
       bufferRow++
 
-  tokensForScreenRow: (screenRow) ->
+  screenLineForRow: (screenRow) ->
     currentScreenRow = 0
     for wrappedLine in @wrappedLines
       for screenLine in wrappedLine.screenLines
-        return screenLine.tokens if currentScreenRow == screenRow
+        return screenLine if currentScreenRow == screenRow
         currentScreenRow++
 
   screenLineCount: ->