🐎 Cache gutterVisible state in React component

This avoids a config read on every render.

spec/text-editor-component-spec.coffee

@@ -561,12 +561,12 @@ describe "TextEditorComponent", ->
       expect(component.refs.gutter?).toBe false
 
       atom.config.set("editor.showLineNumbers", false)
-      nextAnimationFrame()
+      expect(nextAnimationFrame).toBe noAnimationFrame
 
       expect(component.refs.gutter?).toBe false
 
       editor.setGutterVisible(true)
-      nextAnimationFrame()
+      expect(nextAnimationFrame).toBe noAnimationFrame
 
       expect(component.refs.gutter?).toBe false
 
@@ -2517,7 +2517,8 @@ describe "TextEditorComponent", ->
 
   describe "when the 'mini' property is true", ->
     beforeEach ->
-      component.setProps(mini: true)
+      editor.setMini(true)
+      nextAnimationFrame()
 
     it "does not render the gutter", ->
       expect(componentNode.querySelector('.gutter')).toBeNull()

src/lines-component.coffee

@@ -23,12 +23,12 @@ LinesComponent = React.createClass
     if performedInitialMeasurement
       {editor, overlayDecorations, highlightDecorations, scrollHeight, scrollWidth, placeholderText, backgroundColor} = @props
       {lineHeightInPixels, defaultCharWidth, scrollViewHeight, scopedCharacterWidthsChangeCount} = @props
-      {scrollTop, scrollLeft, cursorPixelRects, mini} = @props
+      {scrollTop, scrollLeft, cursorPixelRects} = @props
       style =
         height: Math.max(scrollHeight, scrollViewHeight)
         width: scrollWidth
         WebkitTransform: @getTransform()
-        backgroundColor: if mini then null else backgroundColor
+        backgroundColor: if editor.isMini() then null else backgroundColor
 
     div {className: 'lines', style},
       div className: 'placeholder-text', placeholderText if placeholderText?
@@ -162,7 +162,7 @@ LinesComponent = React.createClass
     @lineNodesByLineId.hasOwnProperty(lineId)
 
   buildLineHTML: (line, screenRow) ->
-    {mini, showIndentGuide, lineHeightInPixels, lineDecorations, lineWidth} = @props
+    {showIndentGuide, lineHeightInPixels, lineDecorations, lineWidth} = @props
     {tokens, text, lineEnding, fold, isSoftWrapped, indentLevel} = line
 
     classes = ''
@@ -208,7 +208,7 @@ LinesComponent = React.createClass
       @buildEndOfLineHTML(line) or ' '
 
   buildLineInnerHTML: (line) ->
-    {mini, showIndentGuide} = @props
+    {editor, showIndentGuide} = @props
     {tokens, text} = line
     innerHTML = ""
 
@@ -217,7 +217,7 @@ LinesComponent = React.createClass
     lineIsWhitespaceOnly = firstTrailingWhitespacePosition is 0
     for token in tokens
       innerHTML += @updateScopeStack(scopeStack, token.scopes)
-      hasIndentGuide = not mini and showIndentGuide and (token.hasLeadingWhitespace() or (token.hasTrailingWhitespace() and lineIsWhitespaceOnly))
+      hasIndentGuide = not editor.isMini() and showIndentGuide and (token.hasLeadingWhitespace() or (token.hasTrailingWhitespace() and lineIsWhitespaceOnly))
       innerHTML += token.getValueAsHtml({hasIndentGuide})
 
     innerHTML += @popScope(scopeStack) while scopeStack.length > 0

src/text-editor-component.coffee

@@ -48,7 +48,7 @@ TextEditorComponent = React.createClass
 
   render: ->
     {focused, showIndentGuide, showLineNumbers, visible} = @state
-    {editor, mini, cursorBlinkPeriod, cursorBlinkResumeDelay, hostElement, useShadowDOM} = @props
+    {editor, cursorBlinkPeriod, cursorBlinkResumeDelay, hostElement, useShadowDOM} = @props
     maxLineNumberDigits = editor.getLineCount().toString().length
     hasSelection = editor.getLastSelection()? and !editor.getLastSelection().isEmpty()
     style = {}
@@ -96,7 +96,7 @@ TextEditorComponent = React.createClass
     className += ' has-selection' if hasSelection
 
     div {className, style},
-      if @shouldRenderGutter()
+      if @gutterVisible
         GutterComponent {
           ref: 'gutter', onMouseDown: @onGutterMouseDown, lineDecorations,
           defaultCharWidth, editor, renderedRowRange, maxLineNumberDigits, scrollViewHeight,
@@ -118,7 +118,7 @@ TextEditorComponent = React.createClass
           @scrollingVertically, scrollHeight, scrollWidth, mouseWheelScreenRow,
           visible, scrollViewHeight, @scopedCharacterWidthsChangeCount, lineWidth, @useHardwareAcceleration,
           placeholderText, @performedInitialMeasurement, @backgroundColor, cursorPixelRects,
-          cursorBlinkPeriod, cursorBlinkResumeDelay, mini, useShadowDOM
+          cursorBlinkPeriod, cursorBlinkResumeDelay, useShadowDOM
         }
 
         ScrollbarComponent
@@ -159,9 +159,6 @@ TextEditorComponent = React.createClass
     {editor} = @props
     Math.max(1, Math.ceil(editor.getHeight() / editor.getLineHeightInPixels()))
 
-  shouldRenderGutter: ->
-    not @props.mini and @props.editor.isGutterVisible() and atom.config.get('editor.showLineNumbers')
-
   getInitialState: -> {}
 
   getDefaultProps: ->
@@ -190,7 +187,7 @@ TextEditorComponent = React.createClass
 
     @domPollingIntervalId = setInterval(@pollDOM, @domPollingInterval)
     @updateParentViewFocusedClassIfNeeded({})
-    @updateParentViewMiniClassIfNeeded({})
+    @updateParentViewMiniClass()
     @checkForVisibilityChange()
 
   componentWillUnmount: ->
@@ -202,9 +199,6 @@ TextEditorComponent = React.createClass
     clearInterval(@domPollingIntervalId)
     @domPollingIntervalId = null
 
-  componentWillReceiveProps: (newProps) ->
-    @props.editor.setMini(newProps.mini)
-
   componentDidUpdate: (prevProps, prevState) ->
     cursorMoved = @cursorMoved
     selectionChanged = @selectionChanged
@@ -214,7 +208,7 @@ TextEditorComponent = React.createClass
 
     if @props.editor.isAlive()
       @updateParentViewFocusedClassIfNeeded(prevState)
-      @updateParentViewMiniClassIfNeeded(prevState)
+      @updateParentViewMiniClass()
       @props.hostElement.__spacePenView.trigger 'cursor:moved' if cursorMoved
       @props.hostElement.__spacePenView.trigger 'selection:changed' if selectionChanged
       @props.hostElement.__spacePenView.trigger 'editor:display-updated'
@@ -308,8 +302,8 @@ TextEditorComponent = React.createClass
     cursorPixelRects
 
   getLineDecorations: (decorationsByMarkerId) ->
-    {editor, mini} = @props
-    return {} if mini
+    {editor} = @props
+    return {} if editor.isMini()
 
     decorationsByScreenRow = {}
     for markerId, decorations of decorationsByMarkerId
@@ -377,6 +371,8 @@ TextEditorComponent = React.createClass
   observeEditor: ->
     {editor} = @props
     @subscribe editor.onDidChange(@onScreenLinesChanged)
+    @subscribe editor.onDidChangeGutterVisible(@updateGutterVisible)
+    @subscribe editor.onDidChangeMini(@setMini)
     @subscribe editor.observeGrammar(@onGrammarChanged)
     @subscribe editor.observeCursors(@onCursorAdded)
     @subscribe editor.observeSelections(@onSelectionAdded)
@@ -463,8 +459,7 @@ TextEditorComponent = React.createClass
     scopeDescriptor = editor.getRootScopeDescriptor()
 
     subscriptions.add atom.config.observe 'editor.showIndentGuide', scope: scopeDescriptor, @setShowIndentGuide
-    subscriptions.add atom.config.onDidChange 'editor.showLineNumbers', scope: scopeDescriptor, @requestUpdate
-    subscriptions.add editor.onDidChangeGutterVisible @requestUpdate
+    subscriptions.add atom.config.observe 'editor.showLineNumbers', scope: scopeDescriptor, @updateGutterVisible
     subscriptions.add atom.config.observe 'editor.scrollSensitivity', scope: scopeDescriptor, @setScrollSensitivity
 
   focused: ->
@@ -882,7 +877,7 @@ TextEditorComponent = React.createClass
       @backgroundColor = backgroundColor
       @requestUpdate() unless suppressUpdate
 
-    if @shouldRenderGutter()
+    if @refs.gutter?
       gutterBackgroundColor = getComputedStyle(@refs.gutter.getDOMNode()).backgroundColor
       if gutterBackgroundColor isnt @gutterBackgroundColor
         @gutterBackgroundColor = gutterBackgroundColor
@@ -1002,6 +997,16 @@ TextEditorComponent = React.createClass
   setShowIndentGuide: (showIndentGuide) ->
     @setState({showIndentGuide})
 
+  setMini: ->
+    @updateGutterVisible()
+    @requestUpdate()
+
+  updateGutterVisible: ->
+    gutterVisible = not @props.editor.isMini() and @props.editor.isGutterVisible() and atom.config.get('editor.showLineNumbers')
+    if gutterVisible isnt @gutterVisible
+      @gutterVisible = gutterVisible
+      @requestUpdate()
+
   # Deprecated
   setInvisibles: (invisibles={}) ->
     grim.deprecate "Use config.set('editor.invisibles', invisibles) instead"
@@ -1045,10 +1050,9 @@ TextEditorComponent = React.createClass
       @props.hostElement.classList.toggle('is-focused', @state.focused)
       @props.rootElement.classList.toggle('is-focused', @state.focused)
 
-  updateParentViewMiniClassIfNeeded: (prevProps) ->
-    if prevProps.mini isnt @props.mini
-      @props.hostElement.classList.toggle('mini', @props.mini)
-      @props.rootElement.classList.toggle('mini', @props.mini)
+  updateParentViewMiniClass: ->
+    @props.hostElement.classList.toggle('mini', @props.editor.isMini())
+    @props.rootElement.classList.toggle('mini', @props.editor.isMini())
 
   runScrollBenchmark: ->
     unless process.env.NODE_ENV is 'production'

src/text-editor-element.coffee

@@ -109,7 +109,6 @@ class TextEditorElement extends HTMLElement
       rootElement: @rootElement
       stylesElement: @stylesElement
       editor: @model
-      mini: @model.mini
       lineOverdrawMargin: @lineOverdrawMargin
       useShadowDOM: @useShadowDOM
     )

src/text-editor.coffee

@@ -533,9 +533,14 @@ class TextEditor extends Model
     if mini isnt @mini
       @mini = mini
       @updateInvisibles()
+      @emitter.emit 'did-change-mini', @mini
+    @mini
 
   isMini: -> @mini
 
+  onDidChangeMini: (callback) ->
+    @emitter.on 'did-change-mini', callback
+
   setGutterVisible: (gutterVisible) ->
     unless gutterVisible is @gutterVisible
       @gutterVisible = gutterVisible