Change an edit session's grammar on meta-l

src/app/edit-session.coffee

@@ -626,5 +626,12 @@ class EditSession
       @setCursorBufferPosition(cursorPosition) if cursorPosition
       cursorPosition = null
 
+  getGrammar: -> @languageMode.grammar
+
+  reloadGrammar: ->
+    @unfoldAll()
+    @languageMode.reloadGrammar()
+    @displayBuffer.tokenizedBuffer.resetScreenLines()
+
 _.extend(EditSession.prototype, EventEmitter)
 _.extend(EditSession.prototype, Subscriber)

src/app/editor.coffee

@@ -178,6 +178,7 @@ class Editor extends View
         'editor:checkout-head-revision': @checkoutHead
         'editor:close-other-editors': @destroyInactiveEditSessions
         'editor:close-all-editors': @destroyAllEditSessions
+        'editor:select-grammar': @selectGrammar
 
     documentation = {}
     for name, method of editorBindings
@@ -1113,3 +1114,14 @@ class Editor extends View
       @highlightedLine.addClass('cursor-line')
     else
       @highlightedLine = null
+
+  getGrammar: -> @activeEditSession.getGrammar()
+
+  selectGrammar: ->
+    GrammarView = require 'grammar-view'
+    new GrammarView(this)
+
+  reloadGrammar: ->
+    @activeEditSession.reloadGrammar()
+    @clearRenderedLines()
+    @updateDisplay()

src/app/grammar-view.coffee

@@ -0,0 +1,46 @@
+SelectList = require 'select-list'
+{$$} = require 'space-pen'
+
+module.exports =
+class GrammarView extends SelectList
+
+  @viewClass: -> "#{super} grammar-view"
+
+  filterKey: 'name'
+
+  initialize: (@editor) ->
+    @currentGrammar = @editor.getGrammar()
+    @path = @editor.getPath()
+    requireStylesheet 'grammar-view.css'
+    @command 'editor:select-grammar', =>
+      @cancel()
+      false
+    super
+
+    @populate()
+    @attach()
+
+  itemForElement: (grammar) ->
+    if grammar is @currentGrammar
+      grammarClass = 'current-grammar'
+    else
+      grammarClass = 'grammar'
+
+    $$ ->
+      @li grammar.name, class: grammarClass
+
+  populate: ->
+    @setArray(syntax.grammars)
+
+  cancelled: ->
+    @miniEditor.setText('')
+    @editor.rootView()?.focus() if @miniEditor.isFocused
+
+  confirmed: (grammar) ->
+    @cancel()
+    syntax.addGrammarForPath(@path, grammar)
+    @editor.reloadGrammar()
+
+  attach: ->
+    @editor.rootView()?.append(this)
+    @miniEditor.focus()

src/app/keymaps/editor.cson

@@ -34,3 +34,4 @@
   'meta-U': 'editor:lower-case'
   'alt-meta-w': 'editor:close-other-editors'
   'meta-P': 'editor:close-all-editors'
+  'meta-l': 'editor:select-grammar'

src/app/language-mode.coffee

@@ -16,7 +16,7 @@ class LanguageMode
 
   constructor: (@editSession) ->
     @buffer = @editSession.buffer
-    @grammar = syntax.grammarForFilePath(@buffer.getPath())
+    @reloadGrammar()
     @bracketAnchorRanges = []
 
     _.adviseBefore @editSession, 'insertText', (text) =>
@@ -47,6 +47,9 @@ class LanguageMode
         @bracketAnchorRanges.push @editSession.addAnchorRange(range)
         false
 
+  reloadGrammar: ->
+    @grammar = syntax.grammarForFilePath(@buffer.getPath())
+
   isQuote: (string) ->
     /'|"/.test(string)
 

src/app/syntax.coffee

@@ -8,6 +8,7 @@ module.exports =
 class Syntax
   constructor: ->
     @grammars = []
+    @grammarsByPath = {}
     @grammarsByFileType = {}
     @grammarsByScopeName = {}
     @globalProperties = {}
@@ -20,6 +21,12 @@ class Syntax
       @grammarsByFileType[fileType] = grammar
       @grammarsByScopeName[grammar.scopeName] = grammar
 
+  addGrammarForPath: (path, grammar) ->
+    @grammarsByPath[path] = grammar
+
+  removeGrammarForPath: (path) ->
+    delete @grammarsByPath[path]
+
   grammarForFilePath: (filePath) ->
     return @grammarsByFileType["txt"] unless filePath
 
@@ -27,7 +34,8 @@ class Syntax
     if filePath and extension.length == 0
       extension = fs.base(filePath)
 
-    @grammarsByFileType[extension] or
+    @grammarsByPath[filePath] or
+      @grammarsByFileType[extension] or
       @grammarByShebang(filePath) or
       @grammarByFileTypeSuffix(filePath) or
       @grammarsByFileType["txt"]

src/app/tokenized-buffer.coffee

@@ -21,10 +21,13 @@ class TokenizedBuffer
   constructor: (@buffer, { @languageMode, @tabLength }) ->
     @tabLength ?= 2
     @id = @constructor.idCounter++
+    @resetScreenLines()
+    @buffer.on "changed.tokenized-buffer#{@id}", (e) => @handleBufferChange(e)
+
+  resetScreenLines: ->
     @screenLines = @buildPlaceholderScreenLinesForRows(0, @buffer.getLastRow())
     @invalidRows = []
     @invalidateRow(0)
-    @buffer.on "changed.tokenized-buffer#{@id}", (e) => @handleBufferChange(e)
 
   setVisible: (@visible) ->
     @tokenizeInBackground() if @visible