Merge pull request #1237 from atom/ks-hard-tab-cache

Fix caching of hard tabs

spec/editor-view-spec.coffee

@@ -1158,7 +1158,8 @@ describe "EditorView", ->
         line0 = editorView.renderedLines.find('.line:first')
         span0_0 = line0.children('span:eq(0)').children('span:eq(0)')
         expect(span0_0).toMatchSelector '.hard-tab'
-        expect(span0_0.text()).toBe ' '
+        expect(span0_0.text()).toBe '  '
+        expect(span0_0.text().length).toBe editor.getTabLength()
 
       it "wraps leading whitespace in a span", ->
         line1 = editorView.renderedLines.find('.line:eq(1)')
@@ -2851,3 +2852,17 @@ describe "EditorView", ->
         editorView.pixelPositionForScreenPosition([0, 5])
         editorView.pixelPositionForScreenPosition([1, 5])
         expect(editorView.measureToColumn.callCount).toBe 0
+
+  describe "when the editor contains hard tabs", ->
+    it "correctly calculates the the position left for a column", ->
+      editorView.setText('\ttest')
+      editorView.attachToDom()
+
+      expect(editorView.pixelPositionForScreenPosition([0, editor.getTabLength()]).left).toEqual 20
+      expect(editorView.pixelPositionForScreenPosition([0, editor.getTabLength() + 1]).left).toEqual 30
+
+      # Check that widths are actually being cached
+      spyOn(editorView, 'measureToColumn').andCallThrough()
+      editorView.pixelPositionForScreenPosition([0, editor.getTabLength()])
+      editorView.pixelPositionForScreenPosition([0, editor.getTabLength() + 1])
+      expect(editorView.measureToColumn.callCount).toBe 0

src/editor-view.coffee

@@ -1596,29 +1596,25 @@ class EditorView extends View
   positionLeftForLineAndColumn: (lineElement, screenRow, screenColumn) ->
     return 0 if screenColumn == 0
 
-    bufferRow = @bufferRowsForScreenRows(screenRow, screenRow)[0] ? screenRow
-    bufferColumn = @bufferPositionForScreenPosition([screenRow, screenColumn]).column
-    tokenizedLine = @editor.displayBuffer.tokenizedBuffer.tokenizedLines[bufferRow]
+    tokenizedLine = @editor.displayBuffer.lineForRow(screenRow)
 
     left = 0
     index = 0
-    startIndex = @bufferPositionForScreenPosition([screenRow, 0]).column
     for token in tokenizedLine.tokens
       for char in token.value
-        return left if index >= bufferColumn
+        return left if index >= screenColumn
 
-        if index >= startIndex
-          val = @getCharacterWidthCache(token.scopes, char)
-          if val?
-            left += val
-          else
-            return @measureToColumn(lineElement, tokenizedLine, screenColumn, startIndex)
+        val = @getCharacterWidthCache(token.scopes, char)
+        if val?
+          left += val
+        else
+          return @measureToColumn(lineElement, tokenizedLine, screenColumn)
 
         index++
     left
 
   # Private:
-  measureToColumn: (lineElement, tokenizedLine, screenColumn, lineStartBufferColumn) ->
+  measureToColumn: (lineElement, tokenizedLine, screenColumn) ->
     left = oldLeft = index = 0
     iterator = document.createNodeIterator(lineElement, NodeFilter.SHOW_TEXT, TextNodeFilter)
 
@@ -1638,7 +1634,7 @@ class EditorView extends View
         returnLeft = left if index == screenColumn
         oldLeft = left
 
-        scopes = tokenizedLine.tokenAtBufferColumn(lineStartBufferColumn + index)?.scopes
+        scopes = tokenizedLine.tokenAtBufferColumn(index)?.scopes
         cachedCharWidth = @getCharacterWidthCache(scopes, char)
 
         if cachedCharWidth?
@@ -1666,7 +1662,7 @@ class EditorView extends View
   # Private:
   getCharacterWidthCache: (scopes, char) ->
     scopes ?= NoScope
-    obj = EditorView.characterWidthCache
+    obj = @constructor.characterWidthCache
     for scope in scopes
       obj = obj[scope]
       return null unless obj?
@@ -1675,7 +1671,7 @@ class EditorView extends View
   # Private:
   setCharacterWidthCache: (scopes, char, val) ->
     scopes ?= NoScope
-    obj = EditorView.characterWidthCache
+    obj = @constructor.characterWidthCache
     for scope in scopes
       obj[scope] ?= {}
       obj = obj[scope]
@@ -1683,7 +1679,7 @@ class EditorView extends View
 
   # Private:
   clearCharacterWidthCache: ->
-    EditorView.characterWidthCache = {}
+    @constructor.characterWidthCache = {}
 
   pixelOffsetForScreenPosition: (position) ->
     {top, left} = @pixelPositionForScreenPosition(position)

src/token.coffee

@@ -135,9 +135,8 @@ class Token
       classes = 'hard-tab'
       classes += ' indent-guide' if hasIndentGuide
       classes += ' invisible-character' if invisibles.tab
-      html = @value.replace StartCharacterRegex, (match) =>
-        match = invisibles.tab ? match
-        "<span class='#{classes}'>#{@escapeString(match)}</span>"
+      value = if invisibles.tab then @value.replace(StartCharacterRegex, invisibles.tab) else @value
+      html = "<span class='#{classes}'>#{@escapeString(value)}</span>"
     else
       startIndex = 0
       endIndex = @value.length