1 files changed, 41 insertions, 0 deletions
diff --git a/pages/ui_component_server.coffee b/pages/ui_component_server.coffee
new file mode 100644
index 00000000..240233ed
--- /dev/null
+++ b/pages/ui_component_server.coffee
@@ -0,0 +1,41 @@
+# Register the port recieved from the parent window, and stop listening for messages on the window object.
+window.addEventListener "message", (event) ->
+  return unless event.source == window.parent
+  currentFunction = arguments.callee
+
+  # Check event.data against iframeMessageSecret so we can determine that this message hasn't been spoofed.
+  chrome.storage.local.get "iframeMessageSecret", ({iframeMessageSecret: secret}) ->
+    return unless event.data == secret
+    UIComponentServer.portOpen event.ports[0]
+    window.removeEventListener "message", currentFunction # Stop listening for message events.
+
+UIComponentServer =
+  ownerPagePort: null
+  messageEventListeners: []
+
+  portOpen: (@ownerPagePort) ->
+    @ownerPagePort.onmessage = (event) => @handleMessage event
+
+  postMessage: (data) -> @ownerPagePort.postMessage data
+
+  # Execute each event listener on the current event until we get a falsy return value.
+  handleMessage: (event) ->
+    for listener in @messageEventListeners
+      retVal = listener.call this, event
+      return false unless retVal
+    true
+
+  addEventListener: (type, listener) ->
+    if type == "message"
+      @messageEventListeners.push listener
+    undefined
+
+  removeEventListener: (type, listener) ->
+    if type == "message"
+      listenerIndex = @messageEventListeners.indexOf listener
+      if listenerIndex > -1
+        @messageEventListeners = @messageEventListeners.splice listenerIndex, 1
+    undefined
+
+root = exports ? window
+root.UIComponentServer = UIComponentServer