1 files changed, 120 insertions, 0 deletions
diff --git a/js/xpconnect/loader/ComponentUtils.jsm b/js/xpconnect/loader/ComponentUtils.jsm
new file mode 100644
index 0000000000..664d13a7db
--- /dev/null
+++ b/js/xpconnect/loader/ComponentUtils.jsm
@@ -0,0 +1,120 @@
+/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*-
+ * vim: sw=2 ts=2 sts=2 et filetype=javascript
+ * 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/. */
+
+/**
+ * Deprecated utilities for JavaScript components loaded by the JS component
+ * loader.
+ *
+ * Import into a JS component using
+ * 'Components.utils.import("resource://gre/modules/ComponentUtils.jsm");'
+ *
+ * Exposing a JS 'class' as a component using these utility methods consists
+ * of several steps:
+ * 0. Import ComponentUtils, as described above.
+ * 1. Declare the 'class' (or multiple classes) implementing the component(s):
+ *  function MyComponent() {
+ *    // constructor
+ *  }
+ *  MyComponent.prototype = {
+ *    // properties required for XPCOM registration:
+ *    classID:          Components.ID("{xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx}"),
+ *
+ *    // [optional] custom factory (an object implementing nsIFactory). If not
+ *    // provided, the default factory is used, which returns
+ *    // |(new MyComponent()).QueryInterface(iid)| in its createInstance().
+ *    _xpcom_factory: { ... },
+ *
+ *    // QueryInterface implementation, e.g. using the generateQI helper
+ *    QueryInterface: ChromeUtils.generateQI(
+ *      [Components.interfaces.nsIObserver,
+ *       Components.interfaces.nsIMyInterface,
+ *       "nsIFoo",
+ *       "nsIBar" ]),
+ *
+ *    // The following properties were used prior to Mozilla 2, but are no
+ *    // longer supported. They may still be included for compatibility with
+ *    // prior versions of ComponentUtils. In Mozilla 2, this information is
+ *    // included in the .manifest file which registers this JS component.
+ *    classDescription: "unique text description",
+ *    contractID:       "@example.com/xxx;1",
+ *
+ *    // ...component implementation...
+ *  };
+ *
+ * 2. Create an array of component constructors (like the one
+ * created in step 1):
+ *  var components = [MyComponent];
+ *
+ * 3. Define the NSGetFactory entry point:
+ *  this.NSGetFactory = ComponentUtils.generateNSGetFactory(components);
+ */
+
+var EXPORTED_SYMBOLS = ["ComponentUtils"];
+
+const nsIFactoryQI = ChromeUtils.generateQI(["nsIFactory"]);
+
+var ComponentUtils = {
+  /**
+   * Generate a NSGetFactory function given an array of components.
+   */
+  generateNSGetFactory: function XPCU_generateNSGetFactory(componentsArray) {
+    let classes = {};
+    for (let i = 0; i < componentsArray.length; i++) {
+        let component = componentsArray[i];
+        if (!(component.prototype.classID instanceof Components.ID))
+          throw Error("In generateNSGetFactory, classID missing or incorrect for component " + component);
+
+        classes[component.prototype.classID] = this._getFactory(component);
+    }
+    return function NSGetFactory(cid) {
+      let cidstring = cid.toString();
+      if (cidstring in classes)
+        return classes[cidstring];
+      throw Cr.NS_ERROR_FACTORY_NOT_REGISTERED;
+    }
+  },
+
+  /**
+   * Returns an nsIFactory for |component|.
+   */
+  _getFactory: function XPCOMUtils__getFactory(component) {
+    var factory = component.prototype._xpcom_factory;
+    if (!factory) {
+      factory = {
+        createInstance: function(outer, iid) {
+          if (outer)
+            throw Cr.NS_ERROR_NO_AGGREGATION;
+          return (new component()).QueryInterface(iid);
+        },
+        QueryInterface: nsIFactoryQI
+      }
+    }
+    return factory;
+  },
+
+  /**
+   * generates a singleton nsIFactory implementation that can be used as
+   * the _xpcom_factory of the component.
+   * @param aServiceConstructor
+   *        Constructor function of the component.
+   */
+  generateSingletonFactory:
+  function XPCOMUtils_generateSingletonFactory(aServiceConstructor) {
+    return {
+      _instance: null,
+      createInstance: function XPCU_SF_createInstance(aOuter, aIID) {
+        if (aOuter !== null) {
+          throw Cr.NS_ERROR_NO_AGGREGATION;
+        }
+        if (this._instance === null) {
+          this._instance = new aServiceConstructor();
+        }
+        return this._instance.QueryInterface(aIID);
+      },
+      QueryInterface: nsIFactoryQI
+    };
+  },
+};