Handle tab length retokenization in DisplayLayer

We still want to keep the tab length in TokenizedBuffer, because we need
it to understand if a certain buffer row is foldable or not (due to the
indent level)

src/display-buffer.coffee

@@ -122,7 +122,7 @@ class DisplayBuffer extends Model
       invisibles: invisibles
       softWrapColumn: softWrapColumn
       showIndentGuides: @config.get('editor.showIndentGuide', scope: scopeDescriptor)
-      tabLength: @config.get('editor.tabLength', scope: scopeDescriptor),
+      tabLength: @getTabLength(),
       ratioForCharacter: @ratioForCharacter.bind(this)
       isWrapBoundary: isWrapBoundary
     })
@@ -265,13 +265,20 @@ class DisplayBuffer extends Model
   #
   # Returns a {Number}.
   getTabLength: ->
-    @tokenizedBuffer.getTabLength()
+    if @tabLength?
+      @tabLength
+    else
+      @config.get('editor.tabLength', scope: @getRootScopeDescriptor())
 
   # Specifies the tab length.
   #
   # tabLength - A {Number} that defines the new tab length.
   setTabLength: (tabLength) ->
-    @tokenizedBuffer.setTabLength(tabLength)
+    return if tabLength is @tabLength
+
+    @tabLength = tabLength
+    @tokenizedBuffer.setTabLength(@tabLength)
+    @resetDisplayLayer()
 
   setIgnoreInvisibles: (ignoreInvisibles) ->
     return if ignoreInvisibles is @ignoreInvisibles

src/tokenized-buffer.coffee

@@ -117,19 +117,14 @@ class TokenizedBuffer extends Model
     @grammarUpdateDisposable = @grammar.onDidUpdate => @retokenizeLines()
     @disposables.add(@grammarUpdateDisposable)
 
-    scopeOptions = {scope: @rootScopeDescriptor}
-    @configSettings =
-      tabLength: @config.get('editor.tabLength', scopeOptions)
-      invisibles: @config.get('editor.invisibles', scopeOptions)
-      showInvisibles: @config.get('editor.showInvisibles', scopeOptions)
+    @configSettings = {tabLength: @config.get('editor.tabLength', {scope: @rootScopeDescriptor})}
 
     if @configSubscriptions?
       @configSubscriptions.dispose()
       @disposables.remove(@configSubscriptions)
     @configSubscriptions = new CompositeDisposable
-    @configSubscriptions.add @config.onDidChange 'editor.tabLength', scopeOptions, ({newValue}) =>
+    @configSubscriptions.add @config.onDidChange 'editor.tabLength', {scope: @rootScopeDescriptor}, ({newValue}) =>
       @configSettings.tabLength = newValue
-      @retokenizeLines()
     @disposables.add(@configSubscriptions)
 
     @retokenizeLines()
@@ -170,7 +165,6 @@ class TokenizedBuffer extends Model
     return if tabLength is @tabLength
 
     @tabLength = tabLength
-    @retokenizeLines()
 
   tokenizeInBackground: ->
     return if not @visible or @pendingChunk or not @isAlive()
@@ -337,18 +331,16 @@ class TokenizedBuffer extends Model
     openScopes = [@grammar.startIdForScope(@grammar.scopeName)]
     text = @buffer.lineForRow(row)
     tags = [text.length]
-    tabLength = @getTabLength()
     lineEnding = @buffer.lineEndingForRow(row)
-    new TokenizedLine({openScopes, text, tags, tabLength, lineEnding, @tokenIterator})
+    new TokenizedLine({openScopes, text, tags, lineEnding, @tokenIterator})
 
   buildTokenizedLineForRow: (row, ruleStack, openScopes) ->
     @buildTokenizedLineForRowWithText(row, @buffer.lineForRow(row), ruleStack, openScopes)
 
   buildTokenizedLineForRowWithText: (row, text, ruleStack = @stackForRow(row - 1), openScopes = @openScopesForRow(row)) ->
     lineEnding = @buffer.lineEndingForRow(row)
-    tabLength = @getTabLength()
     {tags, ruleStack} = @grammar.tokenizeLine(text, ruleStack, row is 0, false)
-    new TokenizedLine({openScopes, text, tags, ruleStack, tabLength, lineEnding, @tokenIterator})
+    new TokenizedLine({openScopes, text, tags, ruleStack, lineEnding, @tokenIterator})
 
   tokenizedLineForRow: (bufferRow) ->
     if 0 <= bufferRow < @tokenizedLines.length

src/tokenized-line.coffee

@@ -16,11 +16,7 @@ class TokenizedLine
 
     return unless properties?
 
-    {@openScopes, @text, @tags, @lineEnding, @ruleStack, @tokenIterator} = properties
-    {@startBufferColumn, @fold, @tabLength, @invisibles} = properties
-
-    @startBufferColumn ?= 0
-    @bufferDelta = @text.length
+    {@openScopes, @text, @tags, @ruleStack, @tokenIterator} = properties
 
   getTokenIterator: -> @tokenIterator.reset(this, arguments...)