[Fixed Position] Implement remove

Implement remove button for selected elements in fixed
position view. WTD-879.

platform/commonUI/edit/src/representers/EditToolbar.js

@@ -17,9 +17,10 @@ define(
          *
          * @param structure toolbar structure, as provided by view definition
          * @param {Array} selection the current selection state
+         * @param {Function} commit callback to invoke after changes
          * @constructor
          */
-        function EditToolbar(structure, selection) {
+        function EditToolbar(structure, selection, commit) {
             var toolbarStructure = Object.create(structure || {}),
                 toolbarState,
                 properties = [];
@@ -124,11 +125,14 @@ define(
             // Invoke all functions in selections with the given name
             function invoke(method, value) {
                 if (method) {
+                    // Make the change in the selection
                     selection.forEach(function (selected) {
                         if (typeof selected[method] === 'function') {
                             selected[method](value);
                         }
                     });
+                    // ...and commit!
+                    commit();
                 }
             }
 
@@ -139,7 +143,9 @@ define(
                     converted.key = addKey(item.property);
                 }
                 if (item.method) {
-                    converted.click = function (v) { invoke(item.method, v); };
+                    converted.click = function (v) {
+                        invoke(item.method, v);
+                    };
                 }
                 return converted;
             }

platform/commonUI/edit/src/representers/EditToolbarRepresenter.js

@@ -20,6 +20,13 @@ define(
                 toolbar,
                 toolbarObject = {};
 
+            // Mark changes as ready to persist
+            function commit(message) {
+                if (scope.commit) {
+                    scope.commit(message);
+                }
+            }
+
             // Handle changes to the current selection
             function updateSelection(selection) {
                 // Make sure selection is array-like
@@ -28,7 +35,7 @@ define(
                         (selection ? [selection] : []);
 
                 // Instantiate a new toolbar...
-                toolbar = new EditToolbar(definition, selection);
+                toolbar = new EditToolbar(definition, selection, commit);
 
                 // ...and expose its structure/state
                 toolbarObject.structure = toolbar.getStructure();
@@ -37,6 +44,7 @@ define(
 
             // Update selection models to match changed toolbar state
             function updateState(state) {
+                // Update underlying state based on toolbar changes
                 state.forEach(function (value, index) {
                     toolbar.updateState(index, value);
                 });

platform/features/layout/src/FixedController.js

@@ -93,8 +93,28 @@ define(
 
             // Decorate elements in the current configuration
             function refreshElements() {
-                elementProxies = (($scope.configuration || {}).elements || [])
+                // Cache selection; we are instantiating new proxies
-                        .map(makeProxyElement);
+                // so we may want to restore this.
+                var selected = selection && selection.get(),
+                    elements = (($scope.configuration || {}).elements || []),
+                    index = -1; // Start with a 'not-found' value
+
+                // Find the selection in the new array
+                if (selected !== undefined) {
+                    index = elements.indexOf(selected.element);
+                }
+
+                // Create the new proxies...
+                elementProxies = elements.map(makeProxyElement);
+
+                // Clear old selection, and restore if appropriate
+                if (selection) {
+                    selection.deselect();
+                    if (index > -1) {
+                        selection.select(elementProxies[index]);
+                    }
+                }
+
                 // TODO: Ensure elements for all domain objects?
             }
 

platform/features/layout/src/LayoutSelection.js

@@ -75,6 +75,11 @@ define(
                 return (obj === selected) || (obj === proxy);
             }
 
+            // Getter for current selection
+            function get() {
+                return selected;
+            }
+
             // Start with the proxy selected
             selection.push(proxy);
 
@@ -95,6 +100,11 @@ define(
                  * @returns {boolean} true if selection changed
                  */
                 deselect: deselect,
+                /**
+                 * Get the currently-selected object.
+                 * @returns the currently selected object
+                 */
+                get: get,
                 /**
                  * Clear the selection, including the proxy, and dispose
                  * of this selection scope. No other calls to methods on

platform/features/layout/src/elements/ElementProxy.js

@@ -17,6 +17,7 @@ define(
          */
         function ElementProxy(element, index, elements) {
             return {
+                element: element,
                 x: new Accessor(element, 'x'),
                 y: new Accessor(element, 'y'),
                 z: new Accessor(element, 'z'),