Allow autoHeight to be set from the editor

spec/text-editor-spec.coffee

@@ -5804,6 +5804,31 @@ describe "TextEditor", ->
       atom.config.set('editor.scrollPastEnd', true)
       expect(scrollPastEndSpy).not.toHaveBeenCalled()
 
+  describe "auto height", ->
+    it "returns true by default but can be customized", ->
+      expect(editor.getAutoHeight()).toBe(true)
+
+      editor.setAutoHeight(false)
+      expect(editor.getAutoHeight()).toBe(false)
+
+      editor.setAutoHeight(true)
+      expect(editor.getAutoHeight()).toBe(true)
+
+    it "emits a onDidChangeAutoHeight event when it changes", ->
+      autoHeightSpy = jasmine.createSpy('onDidChangeAutoHeight')
+      editor.onDidChangeAutoHeight(autoHeightSpy)
+
+      editor.setAutoHeight(true)
+      expect(autoHeightSpy).toHaveBeenCalled()
+
+      autoHeightSpy.reset()
+      editor.setAutoHeight(false)
+      expect(autoHeightSpy).toHaveBeenCalled()
+
+      autoHeightSpy.reset()
+      editor.setAutoHeight(false)
+      expect(autoHeightSpy).not.toHaveBeenCalled()
+
   describe '.get/setPlaceholderText()', ->
     it 'can be created with placeholderText', ->
       newEditor = atom.workspace.buildTextEditor(

src/text-editor-element.coffee

@@ -17,7 +17,6 @@ class TextEditorElement extends HTMLElement
   focusOnAttach: false
   hasTiledRendering: true
   logicalDisplayBuffer: true
-  autoHeight: true
 
   createdCallback: ->
     # Use globals when the following instance variables aren't set.
@@ -39,8 +38,7 @@ class TextEditorElement extends HTMLElement
     @setAttribute('tabindex', -1)
 
   initializeContent: (attributes) ->
-    unless @autoHeight
-      @style.height = "100%"
+    @resetAutoHeight()
 
     if @config.get('editor.useShadowDOM')
       @useShadowDOM = true
@@ -90,7 +88,7 @@ class TextEditorElement extends HTMLElement
     @subscriptions.add @component.onDidChangeScrollLeft =>
       @emitter.emit("did-change-scroll-left", arguments...)
 
-  initialize: (model, {@views, @config, @themes, @workspace, @assert, @styles, @grammars}, @autoHeight = true) ->
+  initialize: (model, {@views, @config, @themes, @workspace, @assert, @styles, @grammars}) ->
     throw new Error("Must pass a views parameter when initializing TextEditorElements") unless @views?
     throw new Error("Must pass a config parameter when initializing TextEditorElements") unless @config?
     throw new Error("Must pass a themes parameter when initializing TextEditorElements") unless @themes?
@@ -117,6 +115,7 @@ class TextEditorElement extends HTMLElement
     @model.onDidChangeEncoding => @addEncodingAttribute()
     @model.onDidDestroy => @unmountComponent()
     @model.onDidChangeMini (mini) => if mini then @addMiniAttribute() else @removeMiniAttribute()
+    @model.onDidChangeAutoHeight(@resetAutoHeight.bind(this))
     @model
 
   getModel: ->
@@ -193,6 +192,10 @@ class TextEditorElement extends HTMLElement
   removeMiniAttribute: ->
     @removeAttribute("mini")
 
+  resetAutoHeight: ->
+    unless @getModel().getAutoHeight()
+      @style.height = "100%"
+
   addEncodingAttribute: ->
     @dataset.encoding = @model.getEncoding()
 

src/text-editor.coffee

@@ -141,7 +141,6 @@ class TextEditor extends Model
     @cursors = []
     @cursorsByMarkerId = new Map
     @selections = []
-    @autoHeight ?= true
     @hasTerminatedPendingState = false
 
     @showInvisibles ?= true
@@ -3395,7 +3394,7 @@ class TextEditor extends Model
 
   # Get the Element for the editor.
   getElement: ->
-    @editorElement ?= new TextEditorElement().initialize(this, atom, @autoHeight)
+    @editorElement ?= new TextEditorElement().initialize(this, atom)
 
   # Essential: Retrieves the greyed out placeholder of a mini editor.
   #
@@ -3470,6 +3469,17 @@ class TextEditor extends Model
     Grim.deprecate("This is now a view method. Call TextEditorElement::getHeight instead.")
     @height
 
+  getAutoHeight: ->
+    @autoHeight ? true
+
+  setAutoHeight: (autoHeight) ->
+    if autoHeight isnt @autoHeight
+      @autoHeight = autoHeight
+      @emitter.emit('did-change-auto-height')
+
+  onDidChangeAutoHeight: (callback) ->
+    @emitter.on('did-change-auto-height', callback)
+
   setWidth: (width, reentrant=false) ->
     if reentrant
       oldWidth = @width