Support passing callbacks from renderer to browser.

renderer/api/lib/remote.coffee

@@ -1,6 +1,33 @@
 ipc = require 'ipc'
+IDWeakMap = require 'id_weak_map'
 v8_util = process.atomBinding 'v8_util'
 
+class CallbacksRegistry
+  constructor: ->
+    @referencesMap = {}
+    @weakMap = new IDWeakMap
+
+  get: (id) -> @weakMap.get id
+  remove: (id) -> delete @referencesMap[id]
+
+  add: (callback) ->
+    id = @weakMap.add callback
+    @referencesMap[id] = callback
+    id
+
+# Translate arguments object into a list of meta data.
+# Unlike the Meta class in browser, this function only create delegate object
+# for functions, other types of value are transfered after serialization.
+callbacksRegistry = new CallbacksRegistry
+argumentsToMetaList = (args) ->
+  metas = []
+  for arg in args
+    if typeof arg is 'function'
+      metas.push type: 'function', id: callbacksRegistry.add(arg)
+    else
+      metas.push type: 'value', value: arg
+  metas
+
 # Transform the description of value into a value or delegate object.
 metaToValue = (meta) ->
   switch meta.type
@@ -15,7 +42,7 @@ metaToValue = (meta) ->
           constructor: ->
             if @constructor == RemoteFunction
               # Constructor call.
-              obj = ipc.sendChannelSync 'ATOM_INTERNAL_CONSTRUCTOR', meta.id, Array::slice.call(arguments)
+              obj = ipc.sendChannelSync 'ATOM_INTERNAL_CONSTRUCTOR', meta.id, argumentsToMetaList(arguments)
 
               # Returning object in constructor will replace constructed object
               # with the returned object.
@@ -23,7 +50,7 @@ metaToValue = (meta) ->
               return metaToValue obj
             else
               # Function call.
-              ret = ipc.sendChannelSync 'ATOM_INTERNAL_FUNCTION_CALL', meta.id, Array::slice.call(arguments)
+              ret = ipc.sendChannelSync 'ATOM_INTERNAL_FUNCTION_CALL', meta.id, argumentsToMetaList(arguments)
               return metaToValue ret
       else
         ret = v8_util.createObjectWithName meta.name
@@ -34,7 +61,7 @@ metaToValue = (meta) ->
           if member.type is 'function'
             ret[member.name] = ->
               # Call member function.
-              ret = ipc.sendChannelSync 'ATOM_INTERNAL_MEMBER_CALL', meta.id, member.name, Array::slice.call(arguments)
+              ret = ipc.sendChannelSync 'ATOM_INTERNAL_MEMBER_CALL', meta.id, member.name, argumentsToMetaList(arguments)
               metaToValue ret
           else
             ret.__defineSetter__ member.name, (value) ->
@@ -53,6 +80,15 @@ metaToValue = (meta) ->
 
       ret
 
+# Browser calls a callback in renderer.
+ipc.on 'ATOM_INTERNAL_FUNCTION_CALL', (callbackId, args) ->
+  callback = callbacksRegistry.get callbackId
+  callback.apply global, metaToValue(args)
+
+# Browser releases a callback in renderer.
+ipc.on 'ATOM_INTERNAL_DEREFERENCE', (callbackId) ->
+  callbacksRegistry.remove callbackId
+
 # Get remote module.
 exports.require = (module) ->
   meta = ipc.sendChannelSync 'ATOM_INTERNAL_REQUIRE', module