Merge remote-tracking branch 'origin/master' into cj-add-react-editor-shims

Conflicts:
	src/gutter-component.coffee

src/display-buffer-marker.coffee

@@ -111,6 +111,34 @@ class DisplayBufferMarker
   setTailBufferPosition: (bufferPosition) ->
     @bufferMarker.setTailPosition(bufferPosition)
 
+  # Retrieves the screen position of the marker's start. This will always be
+  # less than or equal to the result of {DisplayBufferMarker::getEndScreenPosition}.
+  #
+  # Returns a {Point}.
+  getStartScreenPosition: ->
+    @displayBuffer.screenPositionForBufferPosition(@getStartBufferPosition(), wrapAtSoftNewlines: true)
+
+  # Retrieves the buffer position of the marker's start. This will always be
+  # less than or equal to the result of {DisplayBufferMarker::getEndBufferPosition}.
+  #
+  # Returns a {Point}.
+  getStartBufferPosition: ->
+    @bufferMarker.getStartPosition()
+
+  # Retrieves the screen position of the marker's end. This will always be
+  # greater than or equal to the result of {DisplayBufferMarker::getStartScreenPosition}.
+  #
+  # Returns a {Point}.
+  getEndScreenPosition: ->
+    @displayBuffer.screenPositionForBufferPosition(@getEndBufferPosition(), wrapAtSoftNewlines: true)
+
+  # Retrieves the buffer position of the marker's end. This will always be
+  # greater than or equal to the result of {DisplayBufferMarker::getStartBufferPosition}.
+  #
+  # Returns a {Point}.
+  getEndBufferPosition: ->
+    @bufferMarker.getEndPosition()
+
   # Sets the marker's tail to the same position as the marker's head.
   #
   # This only works if there isn't already a tail position.

src/display-buffer.coffee

@@ -43,6 +43,8 @@ class DisplayBuffer extends Model
     @charWidthsByScope = {}
     @markers = {}
     @foldsByMarkerId = {}
+    @decorations = {}
+    @decorationMarkerSubscriptions = {}
     @updateAllScreenLines()
     @createFoldForMarker(marker) for marker in @buffer.findMarkers(@getFoldMarkerAttributes())
     @subscribe @tokenizedBuffer, 'grammar-changed', (grammar) => @emit 'grammar-changed', grammar
@@ -716,6 +718,97 @@ class DisplayBuffer extends Model
   rangeForAllLines: ->
     new Range([0, 0], @clipScreenPosition([Infinity, Infinity]))
 
+  decorationsForBufferRow: (bufferRow, decorationType) ->
+    decorations = @decorations[bufferRow] ? []
+    decorations = (dec for dec in decorations when not dec.type? or dec.type is decorationType) if decorationType?
+    decorations
+
+  decorationsForBufferRowRange: (startBufferRow, endBufferRow, decorationType) ->
+    decorations = {}
+    for bufferRow in [startBufferRow..endBufferRow]
+      decorations[bufferRow] = @decorationsForBufferRow(bufferRow, decorationType)
+    decorations
+
+  addDecorationToBufferRow: (bufferRow, decoration) ->
+    @decorations[bufferRow] ?= []
+    for current in @decorations[bufferRow]
+      return if _.isEqual(current, decoration)
+    @decorations[bufferRow].push(decoration)
+    @emit 'decoration-changed', {bufferRow, decoration, action: 'add'}
+
+  removeDecorationFromBufferRow: (bufferRow, decorationPattern) ->
+    return unless decorations = @decorations[bufferRow]
+
+    removed = []
+    i = decorations.length - 1
+    while i >= 0
+      if @decorationMatchesPattern(decorations[i], decorationPattern)
+        removed.push decorations[i]
+        decorations.splice(i, 1)
+      i--
+
+    delete @decorations[bufferRow] unless @decorations[bufferRow]?
+
+    for decoration in removed
+      @emit 'decoration-changed', {bufferRow, decoration, action: 'remove'}
+
+    removed
+
+  addDecorationToBufferRowRange: (startBufferRow, endBufferRow, decoration) ->
+    for bufferRow in [startBufferRow..endBufferRow]
+      @addDecorationToBufferRow(bufferRow, decoration)
+    return
+
+  removeDecorationFromBufferRowRange: (startBufferRow, endBufferRow, decoration) ->
+    for bufferRow in [startBufferRow..endBufferRow]
+      @removeDecorationFromBufferRow(bufferRow, decoration)
+    return
+
+  decorationMatchesPattern: (decoration, decorationPattern) ->
+    return false unless decoration? and decorationPattern?
+    for key, value of decorationPattern
+      return false if decoration[key] != value
+    true
+
+  addDecorationForMarker: (marker, decoration) ->
+    startRow = marker.getStartBufferPosition().row
+    endRow = marker.getEndBufferPosition().row
+    @addDecorationToBufferRowRange(startRow, endRow, decoration)
+
+    changedSubscription = @subscribe marker, 'changed', (e) =>
+      oldStartRow = e.oldHeadBufferPosition.row
+      oldEndRow = e.oldTailBufferPosition.row
+      newStartRow = e.newHeadBufferPosition.row
+      newEndRow = e.newTailBufferPosition.row
+
+      # swap so head is always <= than tail
+      [oldEndRow, oldStartRow] = [oldStartRow, oldEndRow] if oldStartRow > oldEndRow
+      [newEndRow, newStartRow] = [newStartRow, newEndRow] if newStartRow > newEndRow
+
+      @removeDecorationFromBufferRowRange(oldStartRow, oldEndRow, decoration)
+      @addDecorationToBufferRowRange(newStartRow, newEndRow, decoration) if e.isValid
+
+    destroyedSubscription = @subscribe marker, 'destroyed', (e) =>
+      @removeDecorationForMarker(marker, decoration)
+
+    @decorationMarkerSubscriptions[marker.id] ?= []
+    @decorationMarkerSubscriptions[marker.id].push {decoration, changedSubscription, destroyedSubscription}
+
+  removeDecorationForMarker: (marker, decorationPattern) ->
+    return unless @decorationMarkerSubscriptions[marker.id]?
+
+    startRow = marker.getStartBufferPosition().row
+    endRow = marker.getEndBufferPosition().row
+    @removeDecorationFromBufferRowRange(startRow, endRow, decorationPattern)
+
+    for subscription in _.clone(@decorationMarkerSubscriptions[marker.id])
+      if @decorationMatchesPattern(subscription.decoration, decorationPattern)
+        subscription.changedSubscription.off()
+        subscription.destroyedSubscription.off()
+        @decorationMarkerSubscriptions[marker.id] = _.without(@decorationMarkerSubscriptions[marker.id], subscription)
+
+    return
+
   # Retrieves a {DisplayBufferMarker} based on its id.
   #
   # id - A {Number} representing a marker id
@@ -959,6 +1052,8 @@ class DisplayBuffer extends Model
     @emit 'marker-created', @getMarker(marker.id)
 
   createFoldForMarker: (marker) ->
+    bufferMarker = new DisplayBufferMarker({bufferMarker: marker, displayBuffer: this})
+    @addDecorationForMarker(bufferMarker, type: 'gutter', class: 'folded')
     new Fold(this, marker)
 
   foldForMarker: (marker) ->

src/editor-component.coffee

@@ -43,12 +43,14 @@ EditorComponent = React.createClass
     {editor, cursorBlinkPeriod, cursorBlinkResumeDelay} = @props
     maxLineNumberDigits = editor.getScreenLineCount().toString().length
     invisibles = if showInvisibles then @state.invisibles else {}
+    hasSelection = editor.getSelection()? and !editor.getSelection().isEmpty()
 
     if @isMounted()
       renderedRowRange = @getRenderedRowRange()
       [renderedStartRow, renderedEndRow] = renderedRowRange
       cursorScreenRanges = @getCursorScreenRanges(renderedRowRange)
       selectionScreenRanges = @getSelectionScreenRanges(renderedRowRange)
+      decorations = @getGutterDecorations(renderedRowRange)
       scrollHeight = editor.getScrollHeight()
       scrollWidth = editor.getScrollWidth()
       scrollTop = editor.getScrollTop()
@@ -67,11 +69,13 @@ EditorComponent = React.createClass
 
     className = 'editor-contents editor-colors'
     className += ' is-focused' if focused
+    className += ' has-selection' if hasSelection
 
     div className: className, style: {fontSize, lineHeight, fontFamily}, tabIndex: -1,
       GutterComponent {
         ref: 'gutter', editor, renderedRowRange, maxLineNumberDigits, scrollTop,
-        scrollHeight, lineHeightInPixels, @pendingChanges, mouseWheelScreenRow
+        scrollHeight, lineHeightInPixels, @pendingChanges, mouseWheelScreenRow,
+        decorations
       }
 
       div ref: 'scrollView', className: 'scroll-view', onMouseDown: @onMouseDown,
@@ -227,6 +231,18 @@ EditorComponent = React.createClass
 
     selectionScreenRanges
 
+  getGutterDecorations:  (renderedRowRange) ->
+    {editor} = @props
+    [renderedStartRow, renderedEndRow] = renderedRowRange
+
+    bufferRows = editor.bufferRowsForScreenRows(renderedStartRow, renderedEndRow - 1)
+
+    decorations = {}
+    for bufferRow in bufferRows
+      decorations[bufferRow] = editor.decorationsForBufferRow(bufferRow, 'gutter')
+      decorations[bufferRow].push {class: 'foldable'} if editor.isFoldableAtBufferRow(bufferRow)
+    decorations
+
   observeEditor: ->
     {editor} = @props
     @subscribe editor, 'batched-updates-started', @onBatchedUpdatesStarted
@@ -235,6 +251,7 @@ EditorComponent = React.createClass
     @subscribe editor, 'cursors-moved', @onCursorsMoved
     @subscribe editor, 'selection-removed selection-screen-range-changed', @onSelectionChanged
     @subscribe editor, 'selection-added', @onSelectionAdded
+    @subscribe editor, 'decoration-changed', @onDecorationChanged
     @subscribe editor.$scrollTop.changes, @onScrollTopChanged
     @subscribe editor.$scrollLeft.changes, @requestUpdate
     @subscribe editor.$height.changes, @requestUpdate
@@ -503,6 +520,8 @@ EditorComponent = React.createClass
     @onStoppedScrollingAfterDelay()
 
   onStoppedScrolling: ->
+    return unless @isMounted()
+
     @scrollingVertically = false
     @mouseWheelScreenRow = null
     @requestUpdate()
@@ -513,6 +532,11 @@ EditorComponent = React.createClass
     @cursorsMoved = true
     @requestUpdate()
 
+  onDecorationChanged: ->
+    @decorationChangedImmediate ?= setImmediate =>
+      @requestUpdate()
+      @decorationChangedImmediate = null
+
   selectToMousePositionUntilMouseUp: (event) ->
     {editor} = @props
     dragging = false

src/editor.coffee

@@ -214,6 +214,7 @@ class Editor extends Model
     @subscribe @displayBuffer, 'grammar-changed', => @handleGrammarChange()
     @subscribe @displayBuffer, 'tokenized', => @handleTokenization()
     @subscribe @displayBuffer, 'soft-wrap-changed', (args...) => @emit 'soft-wrap-changed', args...
+    @subscribe @displayBuffer, "decoration-changed", (e) => @emit 'decoration-changed', e
 
   getViewClass: ->
     if atom.config.get('core.useReactEditor')
@@ -1057,6 +1058,106 @@ class Editor extends Model
       selection.insertText(fn(text))
       selection.setBufferRange(range)
 
+  # Public: Get all the decorations for a buffer row.
+  #
+  # bufferRow - the {int} buffer row
+  # decorationType - the {String} decoration type to filter by eg. 'gutter'
+  #
+  # Returns an {Array} of decorations in the form `[{type: 'gutter', class: 'someclass'}, ...]`
+  # Returns an empty array when no decorations are found
+  decorationsForBufferRow: (bufferRow, decorationType) ->
+    @displayBuffer.decorationsForBufferRow(bufferRow, decorationType)
+
+  # Public: Get all the decorations for a range of buffer rows (inclusive)
+  #
+  # startBufferRow - the {int} start of the buffer row range
+  # endBufferRow - the {int} end of the buffer row range (inclusive)
+  # decorationType - the {String} decoration type to filter by eg. 'gutter'
+  #
+  # Returns an {Object} of decorations in the form `{23: [{type: 'gutter', class: 'someclass'}, ...], 24: [...]}`
+  # Returns an {Object} with keyed with all buffer rows in the range containing empty {Array}s when no decorations are found
+  decorationsForBufferRowRange: (startBufferRow, endBufferRow, decorationType) ->
+    @displayBuffer.decorationsForBufferRowRange(startBufferRow, endBufferRow, decorationType)
+
+  # Public: Adds a decoration to a buffer row. For example, use to mark a gutter
+  # line number with a class by using the form `{type: 'gutter', class: 'linter-error'}`
+  #
+  # bufferRow - the {int} buffer row
+  # decoration - the {Object} decoration type to filter by eg. `{type: 'gutter', class: 'linter-error'}`
+  #
+  # Returns nothing
+  addDecorationToBufferRow: (bufferRow, decoration) ->
+    @displayBuffer.addDecorationToBufferRow(bufferRow, decoration)
+
+  # Public: Removes a decoration from a buffer row.
+  #
+  # ```coffee
+  # editor.removeDecorationFromBufferRow(2, {type: 'gutter', class: 'linter-error'})
+  # ```
+  #
+  # All decorations matching a pattern will be removed. For example, you might
+  # have decorations with a namespace like this attached to a row:
+  #
+  # ```coffee
+  # [
+  #   {type: 'gutter', namespace: 'myns', class: 'something'},
+  #   {type: 'gutter', namespace: 'myns', class: 'something-else'}
+  # ]
+  # ```
+  #
+  # You can remove both with:
+  #
+  # ```coffee
+  # editor.removeDecorationFromBufferRow(2, {namespace: 'myns'})
+  # ```
+  #
+  # bufferRow - the {int} buffer row
+  # decorationPattern - the {Object} decoration type to filter by eg. `{type: 'gutter', class: 'linter-error'}`
+  #
+  # Returns an {Array} of the removed decorations
+  removeDecorationFromBufferRow: (bufferRow, decorationPattern) ->
+    @displayBuffer.removeDecorationFromBufferRow(bufferRow, decorationPattern)
+
+  # Public: Adds a decoration to line numbers in a buffer row range
+  #
+  # startBufferRow - the {int} start of the buffer row range
+  # endBufferRow - the {int} end of the buffer row range (inclusive)
+  # decoration - the {Object} decoration type to filter by eg. `{type: 'gutter', class: 'linter-error'}`
+  #
+  # Returns nothing
+  addDecorationToBufferRowRange: (startBufferRow, endBufferRow, decoration) ->
+    @displayBuffer.addDecorationToBufferRowRange(startBufferRow, endBufferRow, decoration)
+
+  # Public: Removes a decoration from line numbers in a buffer row range
+  #
+  # startBufferRow - the {int} start of the buffer row range
+  # endBufferRow - the {int} end of the buffer row range (inclusive)
+  # decoration - the {Object} decoration type to filter by eg. `{type: 'gutter', class: 'linter-error'}`
+  #
+  # Returns nothing
+  removeDecorationFromBufferRowRange: (startBufferRow, endBufferRow, decoration) ->
+    @displayBuffer.removeDecorationFromBufferRowRange(startBufferRow, endBufferRow, decoration)
+
+  # Public: Adds a decoration that tracks a {Marker}. When the marker moves,
+  # is invalidated, or is destroyed, the decoration will be updated to reflect the marker's state.
+  #
+  # marker - the {Marker} you want this decoration to follow
+  # decoration - the {Object} decoration type to filter by eg. `{type: 'gutter', class: 'linter-error'}`
+  #
+  # Returns nothing
+  addDecorationForMarker: (marker, decoration) ->
+    @displayBuffer.addDecorationForMarker(marker, decoration)
+
+  # Public: Removes all decorations associated with a {Marker} that match a
+  # `decorationPattern` and stop tracking the {Marker}.
+  #
+  # marker - the {Marker} to detach from
+  # decorationPattern - the {Object} decoration type to filter by eg. `{type: 'gutter', class: 'linter-error'}`
+  #
+  # Returns nothing
+  removeDecorationForMarker: (marker, decorationPattern) ->
+    @displayBuffer.removeDecorationForMarker(marker, decorationPattern)
+
   # Public: Get the {DisplayBufferMarker} for the given marker id.
   getMarker: (id) ->
     @displayBuffer.getMarker(id)
@@ -1162,6 +1263,7 @@ class Editor extends Model
   addCursor: (marker) ->
     cursor = new Cursor(editor: this, marker: marker)
     @cursors.push(cursor)
+    @addDecorationForMarker(marker, {class: 'cursor-line'})
     @emit 'cursor-added', cursor
     cursor
 

src/gutter-component.coffee

@@ -1,3 +1,4 @@
+_ = require 'underscore-plus'
 React = require 'react-atom-fork'
 {div} = require 'reactionary-atom-fork'
 {isEqual, isEqualForProperties, multiplyString, toArray} = require 'underscore-plus'
@@ -15,7 +16,7 @@ GutterComponent = React.createClass
   render: ->
     {scrollHeight, scrollTop} = @props
 
-    div className: 'gutter',
+    div className: 'gutter', onClick: @onClick,
       div className: 'line-numbers', ref: 'lineNumbers', style:
         height: scrollHeight
         WebkitTransform: "translate3d(0px, #{-scrollTop}px, 0px)"
@@ -24,6 +25,7 @@ GutterComponent = React.createClass
     @lineNumberNodesById = {}
     @lineNumberIdsByScreenRow = {}
     @screenRowsByLineNumberId = {}
+    @previousDecorations = {}
 
   componentDidMount: ->
     @appendDummyLineNumber()
@@ -36,10 +38,12 @@ GutterComponent = React.createClass
       'renderedRowRange', 'scrollTop', 'lineHeightInPixels', 'mouseWheelScreenRow'
     )
 
-    {renderedRowRange, pendingChanges} = newProps
+    {renderedRowRange, pendingChanges, decorations} = newProps
     for change in pendingChanges when Math.abs(change.screenDelta) > 0 or Math.abs(change.bufferDelta) > 0
       return true unless change.end <= renderedRowRange.start or renderedRowRange.end <= change.start
 
+    return true unless _.isEqual(@previousDecorations, decorations)
+
     false
 
   componentDidUpdate: (oldProps) ->
@@ -70,7 +74,7 @@ GutterComponent = React.createClass
     @removeLineNumberNodes(lineNumberIdsToPreserve)
 
   appendOrUpdateVisibleLineNumberNodes: ->
-    {editor, renderedRowRange, scrollTop, maxLineNumberDigits} = @props
+    {editor, renderedRowRange, scrollTop, maxLineNumberDigits, decorations} = @props
     [startRow, endRow] = renderedRowRange
 
     newLineNumberIds = null
@@ -91,12 +95,12 @@ GutterComponent = React.createClass
       visibleLineNumberIds.add(id)
 
       if @hasLineNumberNode(id)
-        @updateLineNumberNode(id, screenRow)
+        @updateLineNumberNode(id, bufferRow, screenRow, wrapCount > 0, decorations[bufferRow])
       else
         newLineNumberIds ?= []
         newLineNumbersHTML ?= ""
         newLineNumberIds.push(id)
-        newLineNumbersHTML += @buildLineNumberHTML(bufferRow, wrapCount > 0, maxLineNumberDigits, screenRow)
+        newLineNumbersHTML += @buildLineNumberHTML(bufferRow, wrapCount > 0, maxLineNumberDigits, screenRow, decorations[bufferRow])
         @screenRowsByLineNumberId[id] = screenRow
         @lineNumberIdsByScreenRow[screenRow] = id
 
@@ -110,6 +114,7 @@ GutterComponent = React.createClass
         @lineNumberNodesById[lineNumberId] = lineNumberNode
         node.appendChild(lineNumberNode)
 
+    @previousDecorations = decorations
     visibleLineNumberIds
 
   removeLineNumberNodes: (lineNumberIdsToPreserve) ->
@@ -123,7 +128,7 @@ GutterComponent = React.createClass
         delete @screenRowsByLineNumberId[lineNumberId]
         node.removeChild(lineNumberNode)
 
-  buildLineNumberHTML: (bufferRow, softWrapped, maxLineNumberDigits, screenRow) ->
+  buildLineNumberHTML: (bufferRow, softWrapped, maxLineNumberDigits, screenRow, decorations) ->
     if screenRow?
       {lineHeightInPixels} = @props
       style = "position: absolute; top: #{screenRow * lineHeightInPixels}px;"
@@ -131,7 +136,13 @@ GutterComponent = React.createClass
       style = "visibility: hidden;"
     innerHTML = @buildLineNumberInnerHTML(bufferRow, softWrapped, maxLineNumberDigits)
 
-    "<div class=\"line-number line-number-#{bufferRow}\" style=\"#{style}\" data-buffer-row=\"#{bufferRow}\" data-screen-row=\"#{screenRow}\">#{innerHTML}</div>"
+    classes = ''
+    if decorations?
+      for decoration in decorations
+        classes += decoration.class + ' ' if not softWrapped or softWrapped and decoration.softWrap
+    classes += "line-number line-number-#{bufferRow}"
+
+    "<div class=\"#{classes}\" style=\"#{style}\" data-buffer-row=\"#{bufferRow}\" data-screen-row=\"#{screenRow}\">#{innerHTML}</div>"
 
   buildLineNumberInnerHTML: (bufferRow, softWrapped, maxLineNumberDigits) ->
     if softWrapped
@@ -143,11 +154,23 @@ GutterComponent = React.createClass
     iconHTML = '<div class="icon-right"></div>'
     padding + lineNumber + iconHTML
 
-  updateLineNumberNode: (lineNumberId, screenRow) ->
+  updateLineNumberNode: (lineNumberId, bufferRow, screenRow, softWrapped, decorations) ->
+    node = @lineNumberNodesById[lineNumberId]
+    previousDecorations = @previousDecorations[bufferRow]
+
+    if previousDecorations?
+      for decoration in previousDecorations
+        node.classList.remove(decoration.class) if not contains(decorations, decoration)
+
+    if decorations?
+      for decoration in decorations
+        if not contains(previousDecorations, decoration) and (not softWrapped or softWrapped and decoration.softWrap)
+          node.classList.add(decoration.class)
+
     unless @screenRowsByLineNumberId[lineNumberId] is screenRow
       {lineHeightInPixels} = @props
-      @lineNumberNodesById[lineNumberId].style.top = screenRow * lineHeightInPixels + 'px'
-      @lineNumberNodesById[lineNumberId].dataset.screenRow = screenRow
+      node.style.top = screenRow * lineHeightInPixels + 'px'
+      node.dataset.screenRow = screenRow
       @screenRowsByLineNumberId[lineNumberId] = screenRow
       @lineNumberIdsByScreenRow[screenRow] = lineNumberId
 
@@ -156,3 +179,22 @@ GutterComponent = React.createClass
 
   lineNumberNodeForScreenRow: (screenRow) ->
     @lineNumberNodesById[@lineNumberIdsByScreenRow[screenRow]]
+
+  onClick: (event) ->
+    {editor} = @props
+    {target} = event
+    lineNumber = target.parentNode
+
+    if target.classList.contains('icon-right') and lineNumber.classList.contains('foldable')
+      bufferRow = parseInt(lineNumber.getAttribute('data-buffer-row'))
+      if lineNumber.classList.contains('folded')
+        editor.unfoldBufferRow(bufferRow)
+      else
+        editor.foldBufferRow(bufferRow)
+
+# Created because underscore uses === not _.isEqual, which we need
+contains = (array, target) ->
+  return false unless array?
+  for object in array
+    return true if _.isEqual(object, target)
+  false

src/react-editor-view.coffee

@@ -1,4 +1,5 @@
 {View, $} = require 'space-pen'
+Grim = require 'Grim'
 React = require 'react-atom-fork'
 EditorComponent = require './editor-component'
 {defaults} = require 'underscore-plus'
@@ -16,6 +17,8 @@ class ReactEditorView extends View
 
   getEditor: -> @editor
 
+  getModel: -> @editor
+
   Object.defineProperty @::, 'lineHeight', get: -> @editor.getLineHeightInPixels()
   Object.defineProperty @::, 'charWidth', get: -> @editor.getDefaultCharWidth()
   Object.defineProperty @::, 'firstRenderedScreenRow', get: -> @component.getRenderedRowRange()[0]
@@ -40,12 +43,14 @@ class ReactEditorView extends View
 
     @gutter = $(node).find('.gutter')
     @gutter.removeClassFromAllLines = (klass) =>
+      Grim.deprecate 'You no longer need to manually add and remove classes. Use `Editor::removeDecorationFromBufferRow()` and related functions'
       @gutter.find('.line-number').removeClass(klass)
 
     @gutter.getLineNumberElement = (bufferRow) =>
       @gutter.find("[data-buffer-row='#{bufferRow}']")
 
     @gutter.addClassToLine = (bufferRow, klass) =>
+      Grim.deprecate 'You no longer need to manually add and remove classes. Use `Editor::addDecorationToBufferRow()` and related functions'
       lines = @gutter.find("[data-buffer-row='#{bufferRow}']")
       lines.addClass(klass)
       lines.length > 0