added timing

python_app/gui/main.py

@@ -2,10 +2,13 @@
 
 from __future__ import annotations
 
+import os
 from pathlib import Path
+import signal
 import sys
 
 import pyqtgraph as pg
+from PyQt6.QtCore import QTimer
 from PyQt6.QtWidgets import QApplication
 
 # Ensure imports are resolved when started as a script.
@@ -17,6 +20,38 @@ from python_app.gui.app_window import AppWindow
 from python_app.gui.theme import apply_light_theme
 
 
+def _is_headless() -> bool:
+    """Return whether the launcher requested a non-interactive deployment."""
+    return os.environ.get("RADAR_SYSTEM_HEADLESS", "").strip().lower() in {
+        "1",
+        "true",
+        "yes",
+        "on",
+    }
+
+
+def _install_unix_signal_handlers(app: QApplication, window: AppWindow) -> None:
+    """Route SIGINT and SIGTERM through the Qt event loop into a clean shutdown.
+
+    `window.close()` runs `closeEvent`, which aborts any active capture and
+    shuts down managed C++ processes; only then does the Qt loop exit. A
+    short repeating timer keeps the Python interpreter pinned in the event
+    loop just long enough to deliver pending signals.
+    """
+
+    def _request_shutdown(*_args: object) -> None:
+        window.close()
+        app.quit()
+
+    for sig in (signal.SIGINT, signal.SIGTERM):
+        signal.signal(sig, _request_shutdown)
+
+    keepalive_timer = QTimer(app)
+    keepalive_timer.setInterval(200)
+    keepalive_timer.timeout.connect(lambda: None)
+    keepalive_timer.start()
+
+
 def main() -> int:
     """Run Qt event loop and show main radar control window."""
     app = QApplication(sys.argv)
@@ -24,7 +59,10 @@ def main() -> int:
     # PyQtGraph foreground controls axis lines, tick text, labels, and titles.
     pg.setConfigOptions(antialias=True, background="#ffffff", foreground="#ffffff")
     window = AppWindow(PROJECT_ROOT)
-    window.showMaximized()
+    if _is_headless():
+        _install_unix_signal_handlers(app, window)
+    else:
+        window.showMaximized()
     return app.exec()