1 files changed, 97 insertions, 0 deletions
diff --git a/devtools/client/jsonview/converter-observer.js b/devtools/client/jsonview/converter-observer.js
new file mode 100644
index 000000000..9b149c565
--- /dev/null
+++ b/devtools/client/jsonview/converter-observer.js
@@ -0,0 +1,97 @@
+/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
+/* vim: set ft=javascript ts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+const Cu = Components.utils;
+
+const {XPCOMUtils} = Cu.import("resource://gre/modules/XPCOMUtils.jsm", {});
+const {Services} = Cu.import("resource://gre/modules/Services.jsm", {});
+
+// Load devtools module lazily.
+XPCOMUtils.defineLazyGetter(this, "devtools", function () {
+  const {devtools} = Cu.import("resource://devtools/shared/Loader.jsm", {});
+  return devtools;
+});
+
+// Load JsonView services lazily.
+XPCOMUtils.defineLazyGetter(this, "JsonViewService", function () {
+  const {JsonViewService} = devtools.require("devtools/client/jsonview/converter-child");
+  return JsonViewService;
+});
+
+XPCOMUtils.defineLazyGetter(this, "JsonViewSniffer", function () {
+  const {JsonViewSniffer} = devtools.require("devtools/client/jsonview/converter-sniffer");
+  return JsonViewSniffer;
+});
+
+// Constants
+const JSON_VIEW_PREF = "devtools.jsonview.enabled";
+
+/**
+ * Listen for 'devtools.jsonview.enabled' preference changes and
+ * register/unregister the JSON View XPCOM services as appropriate.
+ */
+function ConverterObserver() {
+}
+
+ConverterObserver.prototype = {
+  initialize: function () {
+    // Only the DevEdition has this feature available by default.
+    // Users need to manually flip 'devtools.jsonview.enabled' preference
+    // to have it available in other distributions.
+    if (this.isEnabled()) {
+      this.register();
+    }
+
+    Services.prefs.addObserver(JSON_VIEW_PREF, this, false);
+    Services.obs.addObserver(this, "xpcom-shutdown", false);
+  },
+
+  observe: function (subject, topic, data) {
+    switch (topic) {
+      case "xpcom-shutdown":
+        this.onShutdown();
+        break;
+      case "nsPref:changed":
+        this.onPrefChanged();
+        break;
+    }
+  },
+
+  onShutdown: function () {
+    Services.prefs.removeObserver(JSON_VIEW_PREF, observer);
+    Services.obs.removeObserver(observer, "xpcom-shutdown");
+  },
+
+  onPrefChanged: function () {
+    if (this.isEnabled()) {
+      this.register();
+    } else {
+      this.unregister();
+    }
+  },
+
+  register: function () {
+    JsonViewSniffer.register();
+    JsonViewService.register();
+  },
+
+  unregister: function () {
+    JsonViewSniffer.unregister();
+    JsonViewService.unregister();
+  },
+
+  isEnabled: function () {
+    return Services.prefs.getBoolPref(JSON_VIEW_PREF);
+  },
+};
+
+// Listen to JSON View 'enable' pref and perform dynamic
+// registration or unregistration of the main application
+// component.
+var observer = new ConverterObserver();
+observer.initialize();