Allow setting whether a data source's end has been reached (#504)

Author: latonv

src/data-source/collection-browser-data-source-interface.ts

@@ -283,6 +283,13 @@ export interface CollectionBrowserDataSourceInterface
    */
   setFetchesSuppressed(suppressed: boolean): void;
 
+  /**
+   * Sets whether the end of the current data has been reached, indicating whether further
+   * pages should be looked up.
+   * @param reached Whether we are at the end of the data for the current query state
+   */
+  setEndOfDataReached(reached: boolean): void;
+
   /**
    * Notifies the data source that a query change has occurred, which may trigger a data
    * reset & new fetches.

src/data-source/collection-browser-data-source.ts

@@ -399,6 +399,13 @@ export class CollectionBrowserDataSource
     this.suppressFetches = suppressed;
   }
 
+  /**
+   * @inheritdoc
+   */
+  setEndOfDataReached(reached: boolean): void {
+    this.endOfDataReached = reached;
+  }
+
   /**
    * @inheritdoc
    */