Add .right and .bottom to presenter scrollbar states

spec/text-editor-presenter-spec.coffee

@@ -111,6 +111,22 @@ describe "TextEditorPresenter", ->
           expectStateUpdate presenter, -> presenter.setHorizontalScrollbarHeight(20)
           expect(presenter.state.horizontalScrollbar.height).toBe 20
 
+      describe ".right", ->
+        it "is ::verticalScrollbarWidth if the vertical scrollbar is visible and 0 otherwise", ->
+          presenter = new TextEditorPresenter
+            model: editor
+            height: editor.getLineCount() * 10 + 50
+            contentFrameWidth: editor.getMaxScreenLineLength() * 10
+            baseCharacterWidth: 10
+            lineHeight: 10
+            horizontalScrollbarHeight: 10
+            verticalScrollbarWidth: 10
+          {state} = presenter
+
+          expect(state.horizontalScrollbar.right).toBe 0
+          presenter.setHeight((editor.getLineCount() * 10) - 1)
+          expect(state.horizontalScrollbar.right).toBe 10
+
     describe ".verticalScrollbar", ->
       describe ".visible", ->
         it "is true if the scrollHeight exceeds the computed client height", ->
@@ -145,6 +161,22 @@ describe "TextEditorPresenter", ->
           expectStateUpdate presenter, -> presenter.setVerticalScrollbarWidth(20)
           expect(presenter.state.verticalScrollbar.width).toBe 20
 
+      describe ".bottom", ->
+        it "is ::horizontalScrollbarHeight if the horizontal scrollbar is visible and 0 otherwise", ->
+          presenter = new TextEditorPresenter
+            model: editor
+            height: editor.getLineCount() * 10 - 1
+            contentFrameWidth: editor.getMaxScreenLineLength() * 10 + 50
+            baseCharacterWidth: 10
+            lineHeight: 10
+            horizontalScrollbarHeight: 10
+            verticalScrollbarWidth: 10
+          {state} = presenter
+
+          expect(state.verticalScrollbar.bottom).toBe 0
+          presenter.setContentFrameWidth(editor.getMaxScreenLineLength() * 10)
+          expect(state.verticalScrollbar.bottom).toBe 10
+
     describe ".content", ->
       describe ".scrollWidth", ->
         it "is initialized as the max of the ::contentFrameWidth and the width of the longest line", ->

src/text-editor-presenter.coffee

@@ -79,24 +79,27 @@ class TextEditorPresenter
     @state.scrollTop = @getScrollTop()
 
   updateScrollbarsState: ->
-    @state.horizontalScrollbar.height = @getHorizontalScrollbarHeight()
-    @state.verticalScrollbar.width = @getVerticalScrollbarWidth()
-
     contentWidth = @computeContentWidth()
     contentHeight = @computeContentHeight()
     clientWidthWithoutVerticalScrollbar = @getContentFrameWidth()
     clientWidthWithVerticalScrollbar = clientWidthWithoutVerticalScrollbar - @getVerticalScrollbarWidth()
     clientHeightWithoutHorizontalScrollbar = @getHeight()
     clientHeightWithHorizontalScrollbar = clientHeightWithoutHorizontalScrollbar - @getHorizontalScrollbarHeight()
-
-    @state.horizontalScrollbar.visible =
+    horizontalScrollbarVisible =
       contentWidth > clientWidthWithoutVerticalScrollbar or
         contentWidth > clientWidthWithVerticalScrollbar and contentHeight > clientHeightWithoutHorizontalScrollbar
-
-    @state.verticalScrollbar.visible =
+    verticalScrollbarVisible =
       contentHeight > clientHeightWithoutHorizontalScrollbar or
         contentHeight > clientHeightWithHorizontalScrollbar and contentWidth > clientWidthWithoutVerticalScrollbar
 
+    @state.horizontalScrollbar.visible = horizontalScrollbarVisible
+    @state.horizontalScrollbar.height = @getHorizontalScrollbarHeight()
+    @state.horizontalScrollbar.right = if verticalScrollbarVisible then @getVerticalScrollbarWidth() else 0
+
+    @state.verticalScrollbar.visible = verticalScrollbarVisible
+    @state.verticalScrollbar.width = @getVerticalScrollbarWidth()
+    @state.verticalScrollbar.bottom = if horizontalScrollbarVisible then @getHorizontalScrollbarHeight() else 0
+
     @emitter.emit 'did-update-state'
 
   updateContentState: ->