[Selection] Begin adding context management

src/selection/ContextManager.js

@@ -0,0 +1,61 @@
+/*****************************************************************************
+ * 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(['./Path', 'zepto'], function (Path, $) {
+    function ContextManager() {
+        this.counter = 0;
+        this.paths = {};
+    }
+
+    ContextManager.prototype.nextId = function () {
+        this.counter += 1;
+        return "context-" + this.counter;
+    };
+
+    ContextManager.prototype.path = function (item, htmlElement) {
+        var $element = $(htmlElement);
+        var id = $element.attr('data-context') || this.nextId();
+
+        $element.attr('data-context', id);
+
+        if (!this.paths[id]) {
+            var $parent = $element.closest('[data-context]');
+            var parentId = $parent.attr('data-context');
+            var parentPath = this.paths[parentId];
+            this.paths[id] = new Path(item, parentPath);
+        }
+
+        return this.paths[id];
+    };
+
+    ContextManager.prototype.release = function (htmlElement) {
+        var $element = $(htmlElement);
+        var id = $element.attr('data-context');
+
+        if (id) {
+            delete this.paths[id];
+            $element.removeAttr('data-context');
+        }
+    };
+
+    return ContextManager;
+});

src/selection/SelectGesture.js

@@ -30,7 +30,7 @@ define(['zepto', './Path'], function ($, Path) {
         var $element = $(htmlElement);
         var contextManager = this.contextManager;
         var selection = this.selection;
-        var path = new Path(item, contextManager.path(htmlElement));
+        var path = contextManager.path(item, htmlElement);
 
         function select() {
             selection.add(path);
@@ -48,6 +48,10 @@ define(['zepto', './Path'], function ($, Path) {
         $element.on('click', select);
         selection.on('change', change);
         change(); // Initialize
+
+        return function () {
+            contextManager.release(htmlElement);
+        };
     };
 
     return SelectGesture;