Issue 2879 - Make "view source" command work again

lib/child/commands.js

 /*
  * This Source Code is subject to the terms of the Mozilla Public License
  * version 2.0 (the "License"). You can obtain a copy of the License at
  * http://mozilla.org/MPL/2.0/.
  */
 
 "use strict";
 
 let messageManager = require("messageManager");
 let {getNodeInfo} = require("./nodeInfo");
 let {
   state, selectElement, setAnchorElement, stopSelection
 } = require("./selection");
 let {getParentElement} = require("./utils");
 
 messageManager.addMessageListener("ElemHideHelper:Command", onCommand);
+messageManager.addMessageListener("ElemHideHelper:SerializeSelected",
+                                  serializeSelected);
 
 onShutdown.add(() =>
 {
   messageManager.removeMessageListener("ElemHideHelper:Command", onCommand);
+  messageManager.removeMessageListener("ElemHideHelper:SerializeSelected",
+                                       serializeSelected);
 });
 
 function onCommand(message)
 {
   let command = message.data;
   if (typeof exports[command] == "function")
     exports[command]();
 }
 
+function serializeNode(node)
+{
+  let result = null;
+  switch (node.nodeType)
+  {
+    case node.ELEMENT_NODE:
+      result = {
+        type: "element",
+        tagName: node.localName,
+        attributes: [],
+        children: []
+      };
+      for (let {name, value} of node.attributes)
+        result.attributes.push({name, value});
+      for (let child = node.firstChild; child; child = child.nextSibling)
+      {
+        let serialized = serializeNode(child);
+        if (serialized)
+          result.children.push(serialized);
+      }
+      break;
+    case node.TEXT_NODE:
+    case node.COMMENT_NODE:
+      result= {
+        type: node.nodeType == node.TEXT_NODE ? "text" : "comment",
+        text: node.textContent
+      };
+      break;
+  }
+  return result;
+}
+
+function serializeSelected(message)
+{
+  messageManager.sendAsyncMessage("ElemHideHelper:Response", {
+    messageId: message.data.messageId,
+    serialized: serializeNode(state.selectedElement)
+  });
+}
+
 function quit()
 {
   stopSelection();
 }
 exports.quit = quit;
 
 function select()
 {
   if (!state.selectedElement)
     return;
@@ skipping 98 matching lines @@
     counter: 0,
     element: state.selectedElement,
     origVisibility: state.selectedElement.style.visibility,
     timer: Cc["@mozilla.org/timer;1"].createInstance(Ci.nsITimer)
   };
 
   blinkState.timer.initWithCallback(doBlink, 250,
       Ci.nsITimer.TYPE_REPEATING_SLACK);
 }
 exports.blinkElement = blinkElement;