--- a/extension/modules/content-injector.js	Thu Aug 06 14:53:41 2009 -0700
+++ b/extension/modules/content-injector.js	Thu Aug 06 15:50:24 2009 -0700
@@ -4,8 +4,45 @@
 const Ci = Components.interfaces;
 const Cu = Components.utils;
 
+const REQUEST_BOX_NAME = "powerbox_superpower_request";
+const REQUEST_BOX_TEXT = "This web page wants superpowers.";
+const REQUEST_BOX_BUTTON_TEXT = "Huh?";
+
 Components.utils.import("resource://gre/modules/XPCOMUtils.jsm");
 
+function getParentChromeWindow(window) {
+  var mainWindow = window.QueryInterface(Ci.nsIInterfaceRequestor)
+                   .getInterface(Ci.nsIWebNavigation)
+                   .QueryInterface(Ci.nsIDocShellTreeItem)
+                   .rootTreeItem
+                   .QueryInterface(Ci.nsIInterfaceRequestor)
+                   .getInterface(Ci.nsIDOMWindow);
+  return mainWindow.wrappedJSObject;
+}
+
+function showRequestNotificationBox(window, caps, callback) {
+  var tabbrowser = getParentChromeWindow(window).getBrowser();
+  var browser = tabbrowser.getBrowserForDocument(window.document);
+
+  if (browser) {
+    var nBox = tabbrowser.getNotificationBox(browser);
+
+    var oldNotification = nBox.getNotificationWithValue(REQUEST_BOX_NAME);
+    if (oldNotification)
+      nBox.removeNotification(oldNotification);
+
+    nBox.appendNotification(REQUEST_BOX_TEXT,
+                            REQUEST_BOX_NAME,
+                            null,
+                            nBox.PRIORITY_INFO_MEDIUM,
+                            [{accessKey: null,
+                              // TODO: Implement a real callback.
+                              callback: function() {},
+                              label: REQUEST_BOX_BUTTON_TEXT,
+                              popup: null}]);
+  }
+}
+
 function buildRequestor(window) {
   return function request(caps, callback) {
     if (!(typeof(caps) == "object" ||
@@ -19,7 +56,7 @@
       caps = new XPCSafeJSObjectWrapper(caps);
     callback = new XPCSafeJSObjectWrapper(callback);
 
-    // TODO: Present UI to user and inject requested capabilities.
+    showRequestNotificationBox(window, caps, callback);
   };
 }