[Limits] Display limit state in legend of plot

WTD-1223.

platform/features/plot/src/PlotController.js

@@ -29,10 +29,11 @@ define(
         "./elements/PlotUpdater",
         "./elements/PlotPalette",
         "./elements/PlotAxis",
+        "./elements/PlotLimitTracker",
         "./modes/PlotModeOptions",
         "./SubPlotFactory"
     ],
-    function (PlotUpdater, PlotPalette, PlotAxis, PlotModeOptions, SubPlotFactory) {
+    function (PlotUpdater, PlotPalette, PlotAxis, PlotLimitTracker, PlotModeOptions, SubPlotFactory) {
         "use strict";
 
         var AXIS_DEFAULTS = [
@@ -56,6 +57,7 @@ define(
                 modeOptions = new PlotModeOptions([], subPlotFactory),
                 subplots = [],
                 cachedObjects = [],
+                limitTracker,
                 updater,
                 handle,
                 domainOffset;
@@ -102,6 +104,10 @@ define(
                     ($scope.axes[0].active || {}).key,
                     ($scope.axes[1].active || {}).key
                 );
+                limitTracker = new PlotLimitTracker(
+                    handle,
+                    ($scope.axes[1].active || {}).key
+                );
             }
 
             // Handle new telemetry data in this plot
@@ -113,6 +119,9 @@ define(
                     updater.update();
                     modeOptions.getModeHandler().plotTelemetry(updater);
                 }
+                if (limitTracker) {
+                    limitTracker.update();
+                }
                 update();
             }
 
@@ -226,6 +235,15 @@ define(
                 getSubPlots: function () {
                     return modeOptions.getModeHandler().getSubPlots();
                 },
+                /**
+                 * Get the CSS class to apply to the legend for this domain
+                 * object; this will reflect limit state.
+                 * @returns {string} the CSS class
+                 */
+                getLegendClass: function (telemetryObject) {
+                    return limitTracker &&
+                        limitTracker.getLegendClass(telemetryObject);
+                },
                 /**
                  * Explicitly update all plots.
                  */

platform/features/plot/src/elements/PlotLimitTracker.js

@@ -0,0 +1,69 @@
+/*****************************************************************************
+ * Open MCT Web, Copyright (c) 2014-2015, United States Government
+ * as represented by the Administrator of the National Aeronautics and Space
+ * Administration. All rights reserved.
+ *
+ * Open MCT Web 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 Web 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.
+ *****************************************************************************/
+/*global define,Float32Array*/
+
+/**
+ * Prepares data to be rendered in a GL Plot. Handles
+ * the conversion from data API to displayable buffers.
+ */
+define(
+    [],
+    function () {
+        'use strict';
+
+        var MAX_POINTS = 86400,
+            INITIAL_SIZE = 675; // 1/128 of MAX_POINTS
+
+        /**
+         * @constructor
+         * @param {TelemetryHandle} handle the handle to telemetry access
+         * @param {string} range the key to use when looking up range values
+         */
+        function PlotLimitTracker(handle, range) {
+            var legendClasses = {};
+
+            function updateLimit(telemetryObject) {
+                var limit = telemetryObject.getCapability('limit'),
+                    value = handle.getRangeValue(telemetryObject, range);
+
+                if (limit && (value !== undefined)) {
+                    legendClasses[telemetryObject.getId()] =
+                        (limit.evaluate(value, range) || {}).cssClass;
+                }
+            }
+
+            return {
+                update: function () {
+                    legendClasses = {};
+                    handle.getTelemetryObjects().forEach(updateLimit);
+                },
+                getLegendClass: function (domainObject) {
+                    var id = domainObject && domainObject.getId();
+                    return id && legendClasses[id];
+                }
+            };
+        }
+
+        return PlotLimitTracker;
+
+    }
+);