Avoid opening the results panel on db deletion

Fixes https://github.com/github/vscode-codeql/issues/823

extensions/ql-vscode/CHANGELOG.md

@@ -4,6 +4,7 @@
 
 - Avoid showing an error popup when user runs a query with `@kind table` metadata. [#814](https://github.com/github/vscode-codeql/pull/814)
 - Add an option to jump from a .qlref file to the .ql file it references. [#815](https://github.com/github/vscode-codeql/pull/815)
+- Avoid opening the results panel when a database is deleted. [#831](https://github.com/github/vscode-codeql/pull/831)
 
 ## 1.4.5 - 22 March 2021
 

extensions/ql-vscode/src/interface.ts

@@ -137,9 +137,11 @@ export class InterfaceManager extends DisposableObject {
       this.databaseManager.onDidChangeDatabaseItem(({ kind }) => {
         if (kind === DatabaseEventKind.Remove) {
           this._diagnosticCollection.clear();
-          this.postMessage({
-            t: 'untoggleShowProblems'
-          });
+          if (this.isShowingPanel()) {
+            this.postMessage({
+              t: 'untoggleShowProblems'
+            });
+          }
         }
       })
     );
@@ -149,6 +151,10 @@ export class InterfaceManager extends DisposableObject {
     this.postMessage({ t: 'navigatePath', direction });
   }
 
+  private isShowingPanel() {
+    return !!this._panel;
+  }
+
   // Returns the webview panel, creating it if it doesn't already
   // exist.
   getPanel(): vscode.WebviewPanel {
@@ -168,6 +174,14 @@ export class InterfaceManager extends DisposableObject {
           ]
         }
       ));
+      // this._panel.onDidChangeViewState(
+      //   (e) => {
+      //     this.logger.log(JSON.stringify(e));
+      //   },
+      //   null,
+      //   ctx.subscriptions
+      // );
+
       this._panel.onDidDispose(
         () => {
           this._panel = undefined;