merged with master

1 files changed, 8 insertions, 5 deletions

diff --git a/src/client/util/SelectionManager.ts b/src/client/util/SelectionManager.ts
index 4612f10f4..a49977c42 100644
--- a/src/client/util/SelectionManager.ts
+++ b/src/client/util/SelectionManager.ts
@@ -28,21 +28,21 @@ export namespace SelectionManager {
                 manager.SelectedDocuments.clear();
                 manager.SelectedDocuments.set(docView, true);
             }
-            Doc.UserDoc().SelectedDocs = new List(SelectionManager.SelectedDocuments().map(dv => dv.props.Document));
+            Doc.UserDoc().activeSelection = new List(SelectionManager.SelectedDocuments().map(dv => dv.props.Document));
         }
         @action
         DeselectDoc(docView: DocumentView): void {
             if (manager.SelectedDocuments.get(docView)) {
                 manager.SelectedDocuments.delete(docView);
                 docView.props.whenActiveChanged(false);
-                Doc.UserDoc().SelectedDocs = new List(SelectionManager.SelectedDocuments().map(dv => dv.props.Document));
+                Doc.UserDoc().activeSelection = new List(SelectionManager.SelectedDocuments().map(dv => dv.props.Document));
             }
         }
         @action
         DeselectAll(): void {
             Array.from(manager.SelectedDocuments.keys()).map(dv => dv.props.whenActiveChanged(false));
             manager.SelectedDocuments.clear();
-            Doc.UserDoc().SelectedDocs = new List<Doc>([]);
+            Doc.UserDoc().activeSelection = new List<Doc>([]);
         }
     }
 
@@ -55,10 +55,13 @@ export namespace SelectionManager {
         manager.SelectDoc(docView, ctrlPressed);
     }
 
+    // computed functions, such as used in IsSelected generate errors if they're called outside of a
+    // reaction context.  Specifying the context with 'outsideReaction' allows an efficiency feature
+    // to avoid unnecessary mobx invalidations when running inside a reaction.
     export function IsSelected(doc: DocumentView, outsideReaction?: boolean): boolean {
         return outsideReaction ?
-            manager.SelectedDocuments.get(doc) ? true : false :
-            computedFn(function isSelected(doc: DocumentView) {
+            manager.SelectedDocuments.get(doc) ? true : false : // get() accesses a hashtable -- setting anything in the hashtable generates a mobx invalidation for every get()
+            computedFn(function isSelected(doc: DocumentView) {  // wraapping get() in a computedFn only generates mobx() invalidations when the return value of the function for the specific get parameters has changed
                 return manager.SelectedDocuments.get(doc) ? true : false;
             })(doc);
     }