Back DisplayBuffer with a telepath document

spec/app/display-buffer-spec.coffee

@@ -8,7 +8,7 @@ describe "DisplayBuffer", ->
     tabLength = 2
     atom.activatePackage('javascript-tmbundle', sync: true)
     buffer = project.bufferForPath('sample.js')
-    displayBuffer = new DisplayBuffer(buffer, { tabLength })
+    displayBuffer = new DisplayBuffer({buffer, tabLength})
     changeHandler = jasmine.createSpy 'changeHandler'
     displayBuffer.on 'changed', changeHandler
 
@@ -16,6 +16,17 @@ describe "DisplayBuffer", ->
     displayBuffer.destroy()
     buffer.release()
 
+  describe "@deserialize(state)", ->
+    it "constructs a display buffer with the same buffer, softWrapColumn, and tabLength", ->
+      displayBuffer.setTabLength(4)
+      displayBuffer.setSoftWrapColumn(64)
+      displayBuffer2 = deserialize(displayBuffer.serialize())
+      expect(displayBuffer2.id).toBe displayBuffer.id
+      expect(displayBuffer2.buffer).toBe displayBuffer.buffer
+      expect(displayBuffer2.tokenizedBuffer.buffer).toBe displayBuffer.tokenizedBuffer.buffer
+      expect(displayBuffer2.getSoftWrapColumn()).toBe displayBuffer.getSoftWrapColumn()
+      expect(displayBuffer2.getTabLength()).toBe displayBuffer.getTabLength()
+
   describe ".copy()", ->
     it "creates a new DisplayBuffer with the same initial state", ->
       marker1 = displayBuffer.markBufferRange([[1, 2], [3, 4]], id: 1)
@@ -168,7 +179,7 @@ describe "DisplayBuffer", ->
       displayBuffer.destroy()
       buffer.release()
       buffer = project.bufferForPath('two-hundred.txt')
-      displayBuffer = new DisplayBuffer(buffer, { tabLength })
+      displayBuffer = new DisplayBuffer({buffer, tabLength})
       displayBuffer.on 'changed', changeHandler
 
     describe "when folds are created and destroyed", ->
@@ -274,7 +285,7 @@ describe "DisplayBuffer", ->
 
       describe "when there is another display buffer pointing to the same buffer", ->
         it "does not create folds in the other display buffer", ->
-          otherDisplayBuffer = new DisplayBuffer(buffer, { tabLength })
+          otherDisplayBuffer = new DisplayBuffer({buffer, tabLength})
           displayBuffer.createFold(2, 4)
           expect(otherDisplayBuffer.foldsStartingAtBufferRow(2).length).toBe 0
 

src/app/display-buffer.coffee

@@ -1,6 +1,7 @@
 _ = require 'underscore'
 guid = require 'guid'
-{Point, Range} = require 'telepath'
+telepath = require 'telepath'
+{Point, Range} = telepath
 TokenizedBuffer = require 'tokenized-buffer'
 RowMap = require 'row-map'
 EventEmitter = require 'event-emitter'
@@ -11,30 +12,47 @@ Subscriber = require 'subscriber'
 
 module.exports =
 class DisplayBuffer
-  @idCounter: 1
   screenLines: null
   rowMap: null
   tokenizedBuffer: null
   markers: null
   foldsByMarkerId: null
 
-  ### Internal ###
+  @acceptsDocuments: true
+  registerDeserializer(this)
+
+  @deserialize: (state) ->
+    new DisplayBuffer(state)
+
+  constructor: (optionsOrState) ->
+    if optionsOrState instanceof telepath.Document
+      @state = optionsOrState
+      @id = @state.get('id')
+      @tokenizedBuffer = deserialize(@state.get('tokenizedBuffer'))
+      @buffer = @tokenizedBuffer.buffer
+    else
+      {@buffer, softWrapColumn} = optionsOrState
+      @id = guid.create().toString()
+      @tokenizedBuffer = new TokenizedBuffer(optionsOrState)
+      @state = telepath.create
+        deserializer: @constructor.name
+        id: @id
+        tokenizedBuffer: @tokenizedBuffer.getState()
+        softWrapColumn: softWrapColumn ? Infinity
 
-  constructor: (@buffer, options={}) ->
-    @id = guid.create().toString()
-    @tokenizedBuffer = new TokenizedBuffer(_.defaults({@buffer}, options))
-    @softWrapColumn = options.softWrapColumn ? Infinity
     @markers = {}
     @foldsByMarkerId = {}
     @updateAllScreenLines()
-
     @tokenizedBuffer.on 'grammar-changed', (grammar) => @trigger 'grammar-changed', grammar
     @tokenizedBuffer.on 'changed', @handleTokenizedBufferChange
     @subscribe @buffer, 'markers-updated', @handleMarkersUpdated
     @subscribe @buffer, 'marker-created', @handleMarkerCreated
 
+  serialize: -> @state.clone()
+  getState: -> @state
+
   copy: ->
-    newDisplayBuffer = new DisplayBuffer(@buffer, tabLength: @getTabLength())
+    newDisplayBuffer = new DisplayBuffer({@buffer, tabLength: @getTabLength()})
     for marker in @findMarkers(displayBufferId: @id)
       marker.copy(displayBufferId: newDisplayBuffer.id)
     newDisplayBuffer
@@ -62,7 +80,8 @@ class DisplayBuffer
   # Defines the limit at which the buffer begins to soft wrap text.
   #
   # softWrapColumn - A {Number} defining the soft wrap limit.
-  setSoftWrapColumn: (@softWrapColumn) ->
+  setSoftWrapColumn: (softWrapColumn) ->
+    @state.set('softWrapColumn', softWrapColumn)
     start = 0
     end = @getLastRow()
     @updateAllScreenLines()
@@ -70,6 +89,9 @@ class DisplayBuffer
     bufferDelta = 0
     @triggerChanged({ start, end, screenDelta, bufferDelta })
 
+  getSoftWrapColumn: ->
+    @state.get('softWrapColumn')
+
   # Gets the screen line for the given screen row.
   #
   # screenRow - A {Number} indicating the screen row.
@@ -379,7 +401,7 @@ class DisplayBuffer
   #
   # Returns a {Number} representing the `line` position where the wrap would take place.
   # Returns `null` if a wrap wouldn't occur.
-  findWrapColumn: (line, softWrapColumn=@softWrapColumn) ->
+  findWrapColumn: (line, softWrapColumn=@getSoftWrapColumn()) ->
     return unless line.length > softWrapColumn
 
     if /\s/.test(line[softWrapColumn])

src/app/edit-session.coffee

@@ -45,7 +45,7 @@ class EditSession
       @state = optionsOrState
       {@id, tabLength, softTabs, @softWrap} = @state.toObject()
       @setBuffer(project.bufferForId(@state.get('bufferId')))
-      @setDisplayBuffer(new DisplayBuffer(@buffer, { tabLength }))
+      @setDisplayBuffer(new DisplayBuffer({@buffer, tabLength}))
       @addSelection(marker) for marker in @findMarkers(@getSelectionMarkerAttributes())
       @setScrollTop(@state.get('scrollTop'))
       @setScrollLeft(@state.get('scrollLeft'))
@@ -59,7 +59,7 @@ class EditSession
         scrollTop: 0
         scrollLeft: 0
       @setBuffer(buffer)
-      @setDisplayBuffer(displayBuffer ? new DisplayBuffer(@buffer, { tabLength }))
+      @setDisplayBuffer(displayBuffer ? new DisplayBuffer({@buffer, tabLength}))
       @addCursorAtScreenPosition([0, 0]) unless suppressCursorCreation
 
     @languageMode = new LanguageMode(this, @buffer.getExtension())