1 files changed, 24 insertions, 0 deletions
diff --git a/src/client/util/SelectionManager.ts b/src/client/util/SelectionManager.ts
index 9a968aeda..6fb758eac 100644
--- a/src/client/util/SelectionManager.ts
+++ b/src/client/util/SelectionManager.ts
@@ -12,9 +12,14 @@ export namespace SelectionManager {
 
         @observable IsDragging: boolean = false;
         SelectedDocuments: ObservableMap<DocumentView, boolean> = new ObservableMap();
+
+        @observable public lastSelection: DocumentView | undefined;
+
         @action
         SelectDoc(docView: DocumentView, ctrlPressed: boolean): void {
 
+            this.lastSelection = docView;
+
             // if doc is not in SelectedDocuments, add it
             if (!manager.SelectedDocuments.get(docView)) {
                 if (!ctrlPressed) {
@@ -33,6 +38,15 @@ export namespace SelectionManager {
         }
         @action
         DeselectDoc(docView: DocumentView): void {
+
+            if (this.lastSelection === docView) {
+                const list = Array.from(manager.SelectedDocuments.keys());
+                if (list.length > 0) {
+                    this.lastSelection = list[list.length - 1];
+                } else {
+                    this.lastSelection = undefined;
+                }
+            }
             if (manager.SelectedDocuments.get(docView)) {
                 manager.SelectedDocuments.delete(docView);
                 docView.props.whenActiveChanged(false);
@@ -41,10 +55,16 @@ export namespace SelectionManager {
         }
         @action
         DeselectAll(): void {
+            this.lastSelection = undefined;
             Array.from(manager.SelectedDocuments.keys()).map(dv => dv.props.whenActiveChanged(false));
             manager.SelectedDocuments.clear();
             Doc.UserDoc().activeSelection = new List<Doc>([]);
         }
+
+        @action
+        getLast(): DocumentView | undefined {
+            return this.lastSelection;
+        }
     }
 
     const manager = new Manager();
@@ -56,6 +76,10 @@ export namespace SelectionManager {
         manager.SelectDoc(docView, ctrlPressed);
     }
 
+    export function LastSelection(): DocumentView | undefined {
+        return manager.getLast();
+    }
+
     // 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.