Associate gutters with their elements and support showing/hiding gutters

src/gutter-container.coffee

@@ -8,6 +8,9 @@ class GutterContainer
     @textEditor = textEditor
     @emitter = new Emitter
 
+  scheduleComponentUpdate: ->
+    @textEditor.scheduleComponentUpdate()
+
   destroy: ->
     # Create a copy, because `Gutter::destroy` removes the gutter from
     # GutterContainer's @gutters.

src/gutter.coffee

@@ -70,12 +70,14 @@ class Gutter
   hide: ->
     if @visible
       @visible = false
+      @gutterContainer.scheduleComponentUpdate()
       @emitter.emit 'did-change-visible', this
 
   # Essential: Show the gutter.
   show: ->
     if not @visible
       @visible = true
+      @gutterContainer.scheduleComponentUpdate()
       @emitter.emit 'did-change-visible', this
 
   # Essential: Determine whether the gutter is visible.

src/text-editor-component.js

@@ -242,7 +242,11 @@ class TextEditorComponent {
         if (gutter.name === 'line-number') {
           return this.renderLineNumberGutter()
         } else {
-          return this.renderCustomGutter(gutter.name)
+          return $(CustomGutterComponent, {
+            key: gutter,
+            gutter: gutter,
+            height: this.getScrollHeight()
+          })
         }
       })
     } else {
@@ -323,19 +327,6 @@ class TextEditorComponent {
     }
   }
 
-  renderCustomGutter (gutterName) {
-    return $.div(
-      {
-        className: 'gutter',
-        attributes: {'gutter-name': gutterName}
-      },
-      $.div({
-        className: 'custom-decorations',
-        style: {height: this.getScrollHeight() + 'px'}
-      })
-    )
-  }
-
   renderScrollContainer () {
     const style = {
       position: 'absolute',
@@ -2106,6 +2097,35 @@ class LineNumberGutterComponent {
   }
 }
 
+class CustomGutterComponent {
+  constructor (props) {
+    this.props = props
+    etch.initialize(this)
+    this.props.gutter.element = this.element
+  }
+
+  update (props) {
+    this.props = props
+    etch.updateSync(this)
+  }
+
+  render () {
+    return $.div(
+      {
+        className: 'gutter',
+        attributes: {'gutter-name': this.props.gutter.name},
+        style: {
+          display: this.props.gutter.isVisible() ? '' : 'none'
+        }
+      },
+      $.div({
+        className: 'custom-decorations',
+        style: {height: this.props.height + 'px'}
+      })
+    )
+  }
+}
+
 class LinesTileComponent {
   constructor (props) {
     this.props = props

src/text-editor.coffee

@@ -392,6 +392,9 @@ class TextEditor extends Model
     else
       Promise.resolve()
 
+  scheduleComponentUpdate: ->
+    @component?.scheduleUpdate()
+
   serialize: ->
     tokenizedBufferState = @tokenizedBuffer.serialize()