WIP: Use rake to start compiling resources (like require.coffee)

src/app/anchor.coffee

@@ -0,0 +1,81 @@
+Point = require 'point'
+EventEmitter = require 'event-emitter'
+_ = require 'underscore'
+
+module.exports =
+class Anchor
+  buffer: null
+  editSession: null # optional
+  bufferPosition: null
+  screenPosition: null
+  ignoreEqual: false
+  strong: false
+
+  constructor: (@buffer, options = {}) ->
+    { @editSession, @ignoreEqual, @strong } = options
+
+  handleBufferChange: (e) ->
+    { oldRange, newRange } = e
+    position = @getBufferPosition()
+
+    if oldRange.containsPoint(position, exclusive: true)
+      if @strong
+        @setBufferPosition(oldRange.start)
+      else
+        @destroy()
+      return
+
+    if @ignoreEqual
+      return if position.isLessThanOrEqual(oldRange.end)
+    else
+      return if position.isLessThan(oldRange.end)
+
+    newRow = newRange.end.row
+    newColumn = newRange.end.column
+    if position.row == oldRange.end.row
+      newColumn += position.column - oldRange.end.column
+    else
+      newColumn = position.column
+      newRow += position.row - oldRange.end.row
+
+    @setBufferPosition([newRow, newColumn], bufferChange: true)
+
+  getBufferPosition: ->
+    @bufferPosition
+
+  setBufferPosition: (position, options={}) ->
+    @bufferPosition = Point.fromObject(position)
+    clip = options.clip ? true
+    @bufferPosition = @buffer.clipPosition(@bufferPosition) if clip
+    @refreshScreenPosition(options)
+
+  getScreenPosition: ->
+    @screenPosition
+
+  setScreenPosition: (position, options={}) ->
+    previousScreenPosition = @screenPosition
+    @screenPosition = Point.fromObject(position)
+    clip = options.clip ? true
+    assignBufferPosition = options.assignBufferPosition ? true
+
+    @screenPosition = @editSession.clipScreenPosition(@screenPosition, options) if clip
+    @bufferPosition = @editSession.bufferPositionForScreenPosition(@screenPosition, options) if assignBufferPosition
+
+    Object.freeze @screenPosition
+    Object.freeze @bufferPosition
+
+    unless @screenPosition.isEqual(previousScreenPosition)
+      @trigger 'change-screen-position', @screenPosition, bufferChange: options.bufferChange
+
+  refreshScreenPosition: (options={}) ->
+    return unless @editSession
+    screenPosition = @editSession.screenPositionForBufferPosition(@bufferPosition, options)
+    @setScreenPosition(screenPosition, bufferChange: options.bufferChange, clip: false, assignBufferPosition: false)
+
+  destroy: ->
+    @buffer.removeAnchor(this)
+    @editSession?.removeAnchor(this)
+    @trigger 'destroy'
+    @off()
+
+_.extend(Anchor.prototype, EventEmitter)