fix birdseye reordering widget in settings

cameras are only sorted while the layout is built, so a config change that reorders them needs a fresh layout even when the active set is unchanged, which is always the case in continuous mode

frigate/output/birdseye.py

@@ -335,6 +335,7 @@ class BirdsEyeFrameManager:
 
         self.camera_layout: list[Any] = []
         self.active_cameras: set[str] = set()
+        self.layout_camera_order: list[str] = []
         self.last_output_time = 0.0
 
     def add_camera(self, cam: str) -> None:
@@ -372,6 +373,13 @@ class BirdsEyeFrameManager:
         if cam in self.cameras:
             del self.cameras[cam]
 
+    def sort_cameras(self, cameras: set[str]) -> list[str]:
+        """Sort cameras by birdseye order, falling back to name when tied."""
+        return sorted(
+            cameras,
+            key=lambda camera: (self.config.cameras[camera].birdseye.order, camera),
+        )
+
     def clear_frame(self) -> None:
         logger.debug("Clearing the birdseye frame")
         self.frame[:] = self.blank_frame
@@ -482,6 +490,7 @@ class BirdsEyeFrameManager:
             # if the layout needs to be cleared
             self.camera_layout = []
             self.active_cameras = set()
+            self.layout_camera_order = []
             self.clear_frame()
             frame_changed = True
             layout_changed = True
@@ -500,21 +509,21 @@ class BirdsEyeFrameManager:
             else:
                 reset_layout = True
 
+            sorted_active_cameras = self.sort_cameras(active_cameras)
+
+            if not reset_layout and sorted_active_cameras != self.layout_camera_order:
+                logger.debug("Birdseye camera order changed")
+                reset_layout = True
+
             if reset_layout:
                 logger.debug("Resetting Birdseye layout...")
                 self.clear_frame()
                 self.active_cameras = active_cameras
+                self.layout_camera_order = sorted_active_cameras
                 layout_changed = True  # Layout is changing due to reset
                 # this also converts added_cameras from a set to a list since we need
                 # to pop elements in order
-                active_cameras_to_add = sorted(
-                    active_cameras,
-                    # sort cameras by order and by name if the order is the same
-                    key=lambda active_camera: (
-                        self.config.cameras[active_camera].birdseye.order,
-                        active_camera,
-                    ),
-                )
+                active_cameras_to_add = sorted_active_cameras
                 if len(active_cameras) == 1:
                     # show single camera as fullscreen
                     camera = active_cameras_to_add[0]
@@ -780,6 +789,7 @@ class BirdsEyeFrameManager:
             frame_changed, layout_changed = False, False
             self.active_cameras = set()
             self.camera_layout = []
+            self.layout_camera_order = []
             print(traceback.format_exc())
 
         # if the frame was updated or the fps is too low, send frame

frigate/test/test_birdseye.py

@@ -1,8 +1,10 @@
 """Test camera user and password cleanup."""
 
+import multiprocessing as mp
 import unittest
 
-from frigate.output.birdseye import get_canvas_shape
+from frigate.config import FrigateConfig
+from frigate.output.birdseye import BirdsEyeFrameManager, get_canvas_shape
 
 
 class TestBirdseye(unittest.TestCase):
@@ -45,3 +47,70 @@ class TestBirdseye(unittest.TestCase):
         canvas_width, canvas_height = get_canvas_shape(width, height)
         assert canvas_width == width  # width will be the same
         assert canvas_height != height
+
+
+class TestBirdseyeCameraOrder(unittest.TestCase):
+    """Test that birdseye reacts to camera order changes without a restart."""
+
+    def setUp(self):
+        config = {
+            "mqtt": {"enabled": False},
+            "birdseye": {"enabled": True, "mode": "continuous"},
+            "cameras": {
+                camera: {
+                    "ffmpeg": {
+                        "inputs": [
+                            {"path": "rtsp://10.0.0.1:554/video", "roles": ["detect"]}
+                        ]
+                    },
+                    "detect": {"height": 1080, "width": 1920, "fps": 5},
+                }
+                for camera in ("back", "front", "side")
+            },
+        }
+        self.config = FrigateConfig(**config)
+        self.manager = BirdsEyeFrameManager(self.config, mp.Event())
+
+        # mark every camera as continuously active with no frame to draw, which
+        # exercises the layout without needing real yuv frames
+        for camera_data in self.manager.cameras.values():
+            camera_data["current_frame"] = None
+            camera_data["current_frame_time"] = 1.0
+            camera_data["last_active_frame"] = 1.0
+
+    def layout_order(self) -> list[str]:
+        """Return the cameras in the order the current layout renders them."""
+        return [position[0] for row in self.manager.camera_layout for position in row]
+
+    def test_layout_uses_configured_order(self):
+        """Test the layout is sorted by order, then by name when tied."""
+        self.config.cameras["side"].birdseye.order = 0
+        self.config.cameras["back"].birdseye.order = 10
+        self.config.cameras["front"].birdseye.order = 20
+
+        self.manager.update_frame()
+
+        assert self.layout_order() == ["side", "back", "front"]
+
+    def test_order_change_rebuilds_layout(self):
+        """Test a reorder relayouts even though the active cameras are unchanged."""
+        self.manager.update_frame()
+        assert self.layout_order() == ["back", "front", "side"]
+
+        # a stable active set means only an order change can reset the layout,
+        # which is what a settings reorder publishes to this process
+        self.config.cameras["side"].birdseye.order = -10
+
+        _, layout_changed = self.manager.update_frame()
+
+        assert layout_changed
+        assert self.layout_order() == ["side", "back", "front"]
+
+    def test_unchanged_order_keeps_layout(self):
+        """Test a repeat update with no order change doesn't reset the layout."""
+        self.manager.update_frame()
+
+        _, layout_changed = self.manager.update_frame()
+
+        assert not layout_changed
+        assert self.layout_order() == ["back", "front", "side"]

web/src/components/config-form/sectionExtras/BirdseyeCameraReorder.tsx

@@ -91,6 +91,7 @@ export default function BirdseyeCameraReorder({
     try {
       await axios.put("config/set", {
         requires_restart: 0,
+        update_topic: "config/cameras/*/birdseye",
         config_data: { cameras: cameraUpdates },
       });
       await updateConfig();