Enable "Close current recording" only when there's a recording (#11353)

Adds also a snapshot test where the menu is opened on an empty
start screen without dataset.

---------

Co-authored-by: Andreas Reich <[email protected]>

Author: MichaelGrupp

crates/viewer/re_viewer/src/ui/rerun_menu.rs

@@ -75,7 +75,10 @@ impl App {
 
         UICommand::SaveBlueprint.menu_button_ui(ui, &self.command_sender);
 
-        UICommand::CloseCurrentRecording.menu_button_ui(ui, &self.command_sender);
+        let has_recording = _store_context.is_some_and(|ctx| !ctx.recording.is_empty());
+        ui.add_enabled_ui(has_recording, |ui| {
+            UICommand::CloseCurrentRecording.menu_button_ui(ui, &self.command_sender);
+        });
 
         ui.add_space(SPACING);
 

crates/viewer/re_viewer/src/viewer_test_utils/mod.rs

@@ -19,6 +19,9 @@ pub fn viewer_harness() -> Harness<'static, App> {
                 build_info!(),
                 AppEnvironment::Test,
                 StartupOptions {
+                    // Don't show the welcome / example screen in tests.
+                    // See also: https://github.com/rerun-io/rerun/issues/10989
+                    hide_welcome_screen: true,
                     // Don't calculate memory limit in tests.
                     memory_limit: re_memory::MemoryLimit::UNLIMITED,
                     ..Default::default()

crates/viewer/re_viewer/tests/app_kittest.rs

@@ -41,6 +41,19 @@ async fn settings_screen() {
     harness.snapshot("settings_screen");
 }
 
+/// Opens the Rerun menu without an active recording and snapshots the app.
+/// Tests that certain recording-related entries are disabled (e.g. save or close recording).
+#[tokio::test]
+async fn menu_without_recording() {
+    let mut harness = viewer_test_utils::viewer_harness();
+    harness.get_by_label("Menu").click();
+    harness.run_ok();
+    harness.snapshot_options(
+        "menu_without_recording",
+        &SnapshotOptions::new().failed_pixel_count_threshold(2),
+    );
+}
+
 /// Tests the colormap selector UI with snapshot testing.
 /// This is defined here instead of in `re_viewer/tests` because it depends on `re_test_context`,
 /// which depends on `re_viewer_context`.