1 files changed, 54 insertions, 0 deletions
diff --git a/addon-sdk/source/lib/sdk/deprecated/events/assembler.js b/addon-sdk/source/lib/sdk/deprecated/events/assembler.js
new file mode 100644
index 000000000..bb297c24f
--- /dev/null
+++ b/addon-sdk/source/lib/sdk/deprecated/events/assembler.js
@@ -0,0 +1,54 @@
+/* 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 { Class } = require("../../core/heritage");
+const { removeListener, on } = require("../../dom/events");
+
+/**
+ * Event targets
+ * can be added / removed by calling `observe / ignore` methods. Composer should
+ * provide array of event types it wishes to handle as property
+ * `supportedEventsTypes` and function for handling all those events as
+ * `handleEvent` property.
+ */
+exports.DOMEventAssembler = Class({
+  /**
+   * Function that is supposed to handle all the supported events (that are
+   * present in the `supportedEventsTypes`) from all the observed
+   * `eventTargets`.
+   * @param {Event} event
+   *    Event being dispatched.
+   */
+  handleEvent() {
+    throw new TypeError("Instance of DOMEventAssembler must implement `handleEvent` method");
+  },
+  /**
+   * Array of supported event names.
+   * @type {String[]}
+   */
+  get supportedEventsTypes() {
+    throw new TypeError("Instance of DOMEventAssembler must implement `handleEvent` field");
+  },
+  /**
+   * Adds `eventTarget` to the list of observed `eventTarget`s. Listeners for
+   * supported events will be registered on the given `eventTarget`.
+   * @param {EventTarget} eventTarget
+   */
+  observe: function observe(eventTarget) {
+    this.supportedEventsTypes.forEach(function(eventType) {
+      on(eventTarget, eventType, this);
+    }, this);
+  },
+  /**
+   * Removes `eventTarget` from the list of observed `eventTarget`s. Listeners
+   * for all supported events will be unregistered from the given `eventTarget`.
+   * @param {EventTarget} eventTarget
+   */
+  ignore: function ignore(eventTarget) {
+    this.supportedEventsTypes.forEach(function(eventType) {
+      removeListener(eventTarget, eventType, this);
+    }, this);
+  }
+});