[Sub-object] Basic Path/Selection implementation

src/selection/Path.js

@@ -0,0 +1,57 @@
+/*****************************************************************************
+ * Open MCT, Copyright (c) 2014-2016, United States Government
+ * as represented by the Administrator of the National Aeronautics and Space
+ * Administration. All rights reserved.
+ *
+ * Open MCT is licensed under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * http://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * Open MCT includes source code licensed under additional open source
+ * licenses. See the Open Source Licenses file (LICENSES.md) included with
+ * this source code distribution or the Licensing information page available
+ * at runtime from the About dialog for additional information.
+ *****************************************************************************/
+
+define([], function () {
+    var NULL_PATH;
+
+    function Path(item, path) {
+        this.item = item;
+        this.parent = path || NULL_PATH;
+    }
+
+    Path.prototype.matches = function (path) {
+        return (this.item === path.head()) && this.parent.matches(path.path());
+    };
+
+    Path.prototype.head = function () {
+        return this.item;
+    };
+
+    Path.prototype.depth = function () {
+        return 1 + this.parent.depth();
+    };
+
+    Path.prototype.tail = function () {
+        return this.parent;
+    };
+
+    NULL_PATH = new Path(undefined, undefined);
+    NULL_PATH.parent = NULL_PATH;
+    NULL_PATH.depth = function () {
+        return 0;
+    };
+    NULL_PATH.matches = function (path) {
+        return path.depth() === 0;
+    };
+
+    return Path;
+});