Add onPanelWasDisposed

Author: robertbrignull

extensions/ql-vscode/src/data-extensions-editor/data-extensions-editor-view.ts

@@ -108,6 +108,10 @@ export class DataExtensionsEditorView extends AbstractWebview<
       }
     });
 
+    panel.onDidDispose(async () => {
+      await this.onPanelWasDisposed();
+    });
+
     await this.waitForPanelLoaded();
   }
 
@@ -116,6 +120,13 @@ export class DataExtensionsEditorView extends AbstractWebview<
     DataExtensionsEditorView.mostRecentlyActivePanel = panel;
   }
 
+  private async onPanelWasDisposed(): Promise<void> {
+    const panel = await this.getPanel();
+    if (panel === DataExtensionsEditorView.mostRecentlyActivePanel) {
+      DataExtensionsEditorView.mostRecentlyActivePanel = undefined;
+    }
+  }
+
   private async isTheMostRecentlyActivePanel(): Promise<boolean> {
     const panel = await this.getPanel();
     return panel === DataExtensionsEditorView.mostRecentlyActivePanel;