Revert "Revert "Don't obscure the last line of the editor with the horizontal scrollbar""

This reverts commit 1d634e471e.

spec/editor-component-spec.coffee

@@ -1,4 +1,4 @@
-{extend, flatten, toArray} = require 'underscore-plus'
+{extend, flatten, toArray, last} = require 'underscore-plus'
 ReactEditorView = require '../src/react-editor-view'
 nbsp = String.fromCharCode(160)
 
@@ -529,6 +529,25 @@ describe "EditorComponent", ->
 
       expect(editor.getScrollLeft()).toBe 100
 
+    it "does not obscure the last line with the horizontal scrollbar", ->
+      node.style.height = 4.5 * lineHeightInPixels + 'px'
+      node.style.width = 10 * charWidth + 'px'
+      component.measureHeightAndWidth()
+      editor.setScrollBottom(editor.getScrollHeight())
+      lastLineNode = last(node.querySelectorAll('.line'))
+      bottomOfLastLine = lastLineNode.getBoundingClientRect().bottom
+      topOfHorizontalScrollbar = horizontalScrollbarNode.getBoundingClientRect().top
+      expect(bottomOfLastLine).toBe topOfHorizontalScrollbar
+
+      # Render no space below the last line when there's no horizontal scrollbar
+      node.style.width = 100 * charWidth + 'px'
+      component.measureHeightAndWidth()
+      editor.setScrollBottom(editor.getScrollHeight())
+      lastLineNode = last(node.querySelectorAll('.line'))
+      bottomOfLastLine = lastLineNode.getBoundingClientRect().bottom
+      bottomOfEditor = node.getBoundingClientRect().bottom
+      expect(bottomOfLastLine).toBe bottomOfEditor
+
     describe "when a mousewheel event occurs on the editor", ->
       it "updates the horizontal or vertical scrollbar depending on which delta is greater (x or y)", ->
         node.style.height = 4.5 * lineHeightInPixels + 'px'

src/display-buffer.coffee

@@ -114,6 +114,17 @@ class DisplayBuffer extends Model
   getHeight: -> @height ? @getScrollHeight()
   setHeight: (@height) -> @height
 
+  getClientHeight: ->
+    if @horizontallyScrollable()
+      @getHeight() - @getHorizontalScrollbarHeight()
+    else
+      @getHeight()
+
+  horizontallyScrollable: ->
+    not @getSoftWrap() and @getScrollWidth() > @getWidth()
+
+  getHorizontalScrollbarHeight: -> 15
+
   getWidth: -> @width ? @getScrollWidth()
   setWidth: (newWidth) ->
     oldWidth = @width
@@ -124,13 +135,13 @@ class DisplayBuffer extends Model
   getScrollTop: -> @scrollTop
   setScrollTop: (scrollTop) ->
     if @manageScrollPosition
-      @scrollTop = Math.max(0, Math.min(@getScrollHeight() - @getHeight(), scrollTop))
+      @scrollTop = Math.max(0, Math.min(@getScrollHeight() - @getClientHeight(), scrollTop))
     else
       @scrollTop = scrollTop
 
   getScrollBottom: -> @scrollTop + @height
   setScrollBottom: (scrollBottom) ->
-    @setScrollTop(scrollBottom - @height)
+    @setScrollTop(scrollBottom - @getClientHeight())
     @getScrollBottom()
 
   getScrollLeft: -> @scrollLeft
@@ -184,7 +195,7 @@ class DisplayBuffer extends Model
     unless @getLineHeight() > 0
       throw new Error("You must assign a non-zero lineHeight before calling ::getVisibleRowRange()")
 
-    heightInLines = Math.ceil(@getHeight() / @getLineHeight()) + 1
+    heightInLines = Math.ceil(@getClientHeight() / @getLineHeight()) + 1
     startRow = Math.floor(@getScrollTop() / @getLineHeight())
     endRow = Math.min(@getLineCount(), Math.ceil(startRow + heightInLines))
     [startRow, endRow]