Update comments

Author: janodvarko

MessageManager/lib/myPanel.js

@@ -23,6 +23,8 @@ const MyPanel = Class(
   icon: "./icon-16.png",
   url: "./myPanel.html",
 
+  // Initialization
+
   /**
    * Executed by the framework when an instance of this panel is created.
    * There is one instance of this panel per {@Toolbox}. The panel is
@@ -43,6 +45,9 @@ const MyPanel = Class(
   * ready (document state == interactive).
   */
   onReady: function() {
+    // This is the way how to get access to the inner <iframe> element.
+    // The frame is using type="content" and so, the access to the inner
+    // document must be done through a message manager.
     this.panelFrame = viewFor(this);
 
     // Get frame's message manager. Read more about message managers on MDN:
@@ -51,7 +56,7 @@ const MyPanel = Class(
     messageManager.addMessageListener("message/from/content",
       this.onMessage);
 
-    // Load frame script with content API for receiving
+    // Load helper frame script with content API for receiving
     // and sending messages.
     let url = self.data.url("frame-script.js");
     messageManager.loadFrameScript(url, false);
@@ -62,12 +67,20 @@ const MyPanel = Class(
 
   // Chrome <-> Content Communication
 
+  /**
+   * Handle messages coming from the content scope (see 'frame-script.js'
+   * that is responsible for sending them).
+   */
   onMessage: function(message) {
     const { type, data } = message.data;
 
     console.log("Message from content: " + data);
   },
 
+  /**
+   * Send message to the content scope (see 'frame-script.js'
+   * that is responsible for handling them).
+   */
   postContentMessage: function(type, data) {
     let { messageManager } = this.panelFrame.frameLoader;
     messageManager.sendAsyncMessage("message/from/chrome", {
@@ -77,6 +90,7 @@ const MyPanel = Class(
   },
 });
 
+// Register panel
 const myTool = new Tool({
   name: "MyTool",
   panels: {