Support guide column callback function

This allows a config function to be registered
in the atom.coffee file to support different wrap
guide columns depending on the type of file being
viewed.

spec/app/root-view-spec.coffee

@@ -406,7 +406,7 @@ describe "RootView", ->
     describe ".activateExtension(extension)", ->
       it "calls activate on the extension", ->
         rootView.activateExtension(extension)
-        expect(extension.activate).toHaveBeenCalledWith(rootView, undefined)
+        expect(extension.activate).toHaveBeenCalledWith(rootView, undefined, undefined)
 
       it "calls activate on the extension with its previous state", ->
         rootView.activateExtension(extension)
@@ -414,9 +414,14 @@ describe "RootView", ->
 
         newRootView = RootView.deserialize(rootView.serialize())
         newRootView.activateExtension(extension)
-        expect(extension.activate).toHaveBeenCalledWith(newRootView, "it worked")
+        expect(extension.activate).toHaveBeenCalledWith(newRootView, "it worked", undefined)
         newRootView.remove()
 
+      it "calls activate on the extension with the config data", ->
+        config = {}
+        rootView.activateExtension(extension, config)
+        expect(extension.activate).toHaveBeenCalledWith(rootView, undefined, config)
+
       it "throws an exception if the extension has no 'name' property", ->
         expect(-> rootView.activateExtension({ activate: -> })).toThrow()
 

spec/extensions/wrap-guide-spec.coffee

@@ -24,7 +24,7 @@ describe "WrapGuide", ->
 
   describe "@updateGuide", ->
     it "positions the guide at the configured column", ->
-      width = editor.charWidth * wrapGuide.column
+      width = editor.charWidth * wrapGuide.getGuideColumn()
       expect(width).toBeGreaterThan(0)
       expect(wrapGuide.position().left).toBe(width)
 
@@ -34,3 +34,27 @@ describe "WrapGuide", ->
       expect(initial).toBeGreaterThan(0)
       rootView.trigger('increase-font-size')
       expect(wrapGuide.position().left).toBeGreaterThan(initial)
+
+  describe "overriding getGuideColumn", ->
+    it "invokes the callback with the editor path", ->
+      editorPath = null
+      wrapGuide.getGuideColumn = (path) ->
+        editorPath = path
+        80
+      wrapGuide.updateGuide(editor)
+      expect(editorPath).toBe(require.resolve('fixtures/sample.js'))
+
+    it "uses the function from the config data", ->
+      rootView.find('.wrap-guide').remove()
+      config =
+        getGuideColumn: ->
+          1
+      requireExtension('wrap-guide', config)
+      wrapGuide = rootView.find('.wrap-guide').view()
+      expect(wrapGuide.getGuideColumn).toBe(config.getGuideColumn)
+
+    it "hides the guide when the column is less than 1", ->
+      wrapGuide.getGuideColumn = (path) ->
+        -1
+      wrapGuide.updateGuide(editor)
+      expect(wrapGuide).toBeHidden()

src/app/root-view.coffee

@@ -97,10 +97,10 @@ class RootView extends View
       when 'PaneColumn' then PaneColumn.deserialize(viewState, this)
       when 'Editor' then Editor.deserialize(viewState, this)
 
-  activateExtension: (extension) ->
+  activateExtension: (extension, config) ->
     throw new Error("Trying to activate an extension with no name") unless extension.name?
     @extensions[extension.name] = extension
-    extension.activate(this, @extensionStates[extension.name])
+    extension.activate(this, @extensionStates[extension.name], config)
 
   deactivateExtension: (extension) ->
     extension.deactivate?()

src/app/window.coffee

@@ -61,9 +61,9 @@ windowAdditions =
     unless $("head style[id='#{id}']").length
       $('head').append "<style id='#{id}'>#{text}</style>"
 
-  requireExtension: (name) ->
+  requireExtension: (name, config) ->
     extensionPath = require.resolve name
-    extension = rootView.activateExtension require(extensionPath)
+    extension = rootView.activateExtension(require(extensionPath), config)
 
     extensionKeymapPath = fs.join(fs.directory(extensionPath), "keymap.coffee")
     require extensionKeymapPath if fs.exists(extensionKeymapPath)

src/extensions/wrap-guide/wrap-guide.coffee

@@ -2,28 +2,38 @@
 
 module.exports =
 class WrapGuide extends View
-  @activate: (rootView) ->
+  @activate: (rootView, state, config) ->
     requireStylesheet 'wrap-guide.css'
 
     for editor in rootView.getEditors()
-      @appendToEditorPane(rootView, editor) if rootView.parents('html').length
+      if rootView.parents('html').length
+        @appendToEditorPane(rootView, editor, config)
 
     rootView.on 'editor-open', (e, editor) =>
-      @appendToEditorPane(rootView, editor)
+      @appendToEditorPane(rootView, editor, config)
 
-  @appendToEditorPane: (rootView, editor) ->
+  @appendToEditorPane: (rootView, editor, config) ->
     if lines = editor.pane()?.find('.lines')
-      lines.append(new WrapGuide(rootView, editor))
+      lines.append(new WrapGuide(rootView, editor, config))
 
   @content: ->
     @div class: 'wrap-guide'
 
-  column: 80
+  getGuideColumn: null
+
+  initialize: (@rootView, @editor, config = {}) =>
+    if typeof config.getGuideColumn is 'function'
+      @getGuideColumn = config.getGuideColumn
+    else
+      @getGuideColumn = -> 80
 
-  initialize: (@rootView, @editor) =>
     @updateGuide(@editor)
     @editor.on 'editor-path-change', => @updateGuide(@editor)
     @rootView.on 'font-size-change', => @updateGuide(@editor)
 
   updateGuide: (editor) ->
-    @css('left', "#{editor.charWidth * @column}px")
+    column = @getGuideColumn(editor.getPath())
+    if column > 0
+      @css('left', "#{editor.charWidth * column}px").show()
+    else
+      @hide()