empty viewport, prevent duplicate series meta from add, protect broadcast events when no data has changed

platform/core/src/services/DicomMetadataStore/DicomMetadataStore.js

@@ -72,11 +72,16 @@ const BaseImplementation = {
       study = _model.studies[_model.studies.length - 1];
     }
 
-    study.addSeries(instances);
-    this._broadcastEvent(EVENTS.INSTANCES_ADDED, {
-      StudyInstanceUID,
-      SeriesInstanceUID,
-    });
+    // TODO: Worth identifying why this is being called many times with series
+    // that are already "added"?
+    const didAddSeries = study.addSeries(instances);
+
+    if (didAddSeries) {
+      this._broadcastEvent(EVENTS.INSTANCES_ADDED, {
+        StudyInstanceUID,
+        SeriesInstanceUID,
+      });
+    }
   },
   addStudy(study) {
     const { StudyInstanceUID } = study;

platform/core/src/services/DicomMetadataStore/createStudyMetadata.js

@@ -4,9 +4,24 @@ function createStudyMetadata(StudyInstanceUID) {
   return {
     StudyInstanceUID,
     series: [],
+    /**
+     *
+     * @param {object[]} instances
+     * @param {string} instances[].SeriesInstanceUID
+     * @returns {bool} true if series were added; false if series already exist
+     */
     addSeries: function(instances) {
-      const series = createSeriesMetadata(instances);
-      this.series.push(series);
+      const { SeriesInstanceUID } = instances[0];
+      const seriesExists = this.series.some(
+        s => s.SeriesInstanceUID === SeriesInstanceUID
+      );
+
+      if (!seriesExists) {
+        const series = createSeriesMetadata(instances);
+        this.series.push(series);
+      }
+
+      return !seriesExists;
     },
   };
 }

platform/core/src/services/DisplaySetService/DisplaySetService.js

@@ -6,6 +6,7 @@ const displaySetCache = [];
 export default class DisplaySetService {
   constructor() {
     this.displaySets = {};
+    this.activeDisplaySets = [];
     this.listeners = {};
     this.EVENTS = EVENTS;
 
@@ -77,9 +78,10 @@ export default class DisplaySetService {
       displaySetsAdded = displaySets;
     }
 
+    // TODO: This is tricky. How do we know we're not resetting to the same/existing DSs?
+    // TODO: This is likely run anytime we touch DicomMetadataStore. How do we prevent uneccessary broadcasts?
     if (displaySetsAdded && displaySetsAdded.length) {
       this._broadcastEvent(EVENTS.DISPLAY_SETS_ADDED, displaySetsAdded);
-
       this._broadcastEvent(EVENTS.DISPLAY_SETS_CHANGED, this.activeDisplaySets);
     }
   };

platform/core/src/services/_shared/pubSubServiceInterface.js

@@ -13,7 +13,7 @@ export default {
 };
 
 /**
- * Subscribe to measurement updates.
+ * Subscribe to updates.
  *
  * @param {string} eventName The name of the event
  * @param {Function} callback Events callback
@@ -24,7 +24,7 @@ function subscribe(eventName, callback) {
     const listenerId = guid();
     const subscription = { id: listenerId, callback };
 
-    console.info(`displaySetService: Subscribing to '${eventName}'.`);
+    console.info(`Subscribing to '${eventName}'.`);
     if (Array.isArray(this.listeners[eventName])) {
       this.listeners[eventName].push(subscription);
     } else {
@@ -60,7 +60,7 @@ function _unsubscribe(eventName, listenerId) {
 }
 
 /**
- * Check if a given displaySetService event is valid.
+ * Check if a given event is valid.
  *
  * @param {string} eventName The name of the event
  * @return {boolean} Event name validation
@@ -70,7 +70,7 @@ function _isValidEvent(eventName) {
 }
 
 /**
- * Broadcasts displaySetService changes.
+ * Broadcasts changes.
  *
  * @param {string} eventName - The event name
  * @param {func} callbackProps - Properties to pass callback