From ece0005d734e98e29cca4ff1feb41b62fcdee313 Mon Sep 17 00:00:00 2001
From: Cyril Achard <cyril.achard@epfl.ch>
Date: Thu, 28 May 2026 14:13:16 +0200
Subject: [PATCH 01/20] Add GenTL hardware trigger support

Add generic hardware-trigger support for GenTL cameras and expose trigger settings in CameraSettings.

- Introduce CameraTriggerSettings model (config.py) with role/input/output/timeout/strict and helpers to coerce and serialize.
- Allow CameraSettings to read/write backend-specific trigger options.
- GenTLCameraBackend: import and use trigger settings, apply trigger timeout override, persist actual trigger config, and mark hardware_trigger capability as BEST_EFFORT.
- Implement trigger configuration paths: off, external/follower (input), and master (output). Add helper methods (_set_enum_node, _node, _node_symbolics, _trigger_attr, _trigger_to_dict) to safely interact with GenICam nodes.
- Improve lifecycle handling: configure trigger after other settings, restore a safe non-triggering state on stop, and provide waits_for_hardware_trigger property and clearer timeout messages when waiting for hardware triggers.
- Add DEFAULT_CAPABILITIES entry for hardware_trigger in base defaults.

These changes enable safer and configurable hardware-trigger operation for GenTL backends and improve error reporting and shutdown behavior.
---
 dlclivegui/cameras/backends/gentl_backend.py | 180 ++++++++++++++++++-
 dlclivegui/cameras/base.py                   |   1 +
 dlclivegui/config.py                         |  96 ++++++++++
 3 files changed, 270 insertions(+), 7 deletions(-)

diff --git a/dlclivegui/cameras/backends/gentl_backend.py b/dlclivegui/cameras/backends/gentl_backend.py
index b55abdf..18c17d2 100644
--- a/dlclivegui/cameras/backends/gentl_backend.py
+++ b/dlclivegui/cameras/backends/gentl_backend.py
@@ -7,11 +7,12 @@
 import threading
 import time
 from pathlib import Path
-from typing import ClassVar
+from typing import Any, ClassVar
 
 import cv2
 import numpy as np
 
+from ...config import CameraTriggerSettings
 from ..base import CameraBackend, SupportLevel, register_backend
 from ..factory import DetectedCamera
 from .utils import gentl_discovery as cti_finder
@@ -105,6 +106,16 @@ def __init__(self, settings):
             self._gain = self._positive_float(ns.get("gain", props.get("gain")))
 
         self._timeout: float = float(ns.get("timeout", props.get("timeout", 2.0)))
+        try:
+            self._trigger = CameraTriggerSettings.from_any(ns.get("trigger", props.get("trigger")))
+        except Exception as exc:
+            LOG.warning("Invalid GenTL trigger config; falling back to trigger role=off: %s", exc)
+            self._trigger = CameraTriggerSettings()
+
+        trigger_timeout = self._positive_float(self._trigger_attr(self._trigger, "timeout", None))
+        if trigger_timeout is not None:
+            self._timeout = float(trigger_timeout)
+
         self._requested_resolution: tuple[int, int] | None = self._get_requested_resolution_or_none()
 
         self._actual_width: int | None = None
@@ -154,6 +165,7 @@ def static_capabilities(cls) -> dict[str, SupportLevel]:
             "set_gain": SupportLevel.SUPPORTED,
             "device_discovery": SupportLevel.SUPPORTED,
             "stable_identity": SupportLevel.SUPPORTED,
+            "hardware_trigger": SupportLevel.BEST_EFFORT,
         }
 
     # ------------------------------------------------------------------
@@ -420,11 +432,12 @@ def open(self) -> None:
                     self._device_label = self._resolve_device_label(node_map)
 
                     self._configure_pixel_format(node_map)
-                    self._configure_trigger(node_map)
                     self._configure_resolution(node_map)
                     self._configure_exposure(node_map)
                     self._configure_gain(node_map)
                     self._configure_frame_rate(node_map)
+                    self._configure_trigger(node_map)  # keep low in the list
+                    self._ensure_settings_ns()["trigger_actual"] = self._trigger_to_dict(self._trigger)
                     self._read_telemetry(node_map)
                     self._persist_device_metadata(selected_info, selected_serial)
 
@@ -449,6 +462,11 @@ def open(self) -> None:
                     f"Failed to open GenTL camera.\n\nLoaded CTIs: {loaded}\nFailed CTIs: {failed}\nReason: {exc}"
                 ) from exc
 
+    @property
+    def waits_for_hardware_trigger(self) -> bool:
+        role = str(self._trigger_attr(getattr(self, "_trigger", None), "role", "off") or "off").lower()
+        return role in {"external", "follower"}
+
     def read(self) -> tuple[np.ndarray, float]:
         if self._acquirer is None:
             raise RuntimeError("GenTL image acquirer not initialised")
@@ -470,6 +488,9 @@ def read(self) -> tuple[np.ndarray, float]:
                 except ValueError:
                     frame = array.copy()
         except HarvesterTimeoutError as exc:
+            role = str(self._trigger_attr(getattr(self, "_trigger", None), "role", "off") or "off").lower()
+            if role in {"external", "follower"}:
+                raise TimeoutError(str(exc) + " (GenTL timeout; waiting for hardware trigger?)") from exc
             raise TimeoutError(str(exc) + " (GenTL timeout)") from exc
 
         frame = self._convert_frame(frame)
@@ -502,6 +523,12 @@ def close(self) -> None:
             except Exception:
                 pass
 
+            try:
+                node_map = self._acquirer.remote_device.node_map
+                self._call_with_optional_lock(self._restore_trigger_idle, node_map)
+            except Exception:
+                pass
+
             try:
                 destroy = getattr(self._acquirer, "destroy", None)
                 if destroy is not None:
@@ -949,6 +976,62 @@ def _create_acquirer(self, serial: str | None, index: int):
     # ------------------------------------------------------------------
     # Camera configuration helpers
     # ------------------------------------------------------------------
+    @staticmethod
+    def _node(node_map, name: str):
+        try:
+            return getattr(node_map, name)
+        except Exception:
+            return None
+
+    @staticmethod
+    def _node_symbolics(node) -> list[str]:
+        try:
+            return list(getattr(node, "symbolics", []) or [])
+        except Exception:
+            return []
+
+    def _set_enum_node(self, node_map, name: str, value: str, *, strict: bool = False) -> bool:
+        node = self._node(node_map, name)
+        if node is None:
+            if strict:
+                raise RuntimeError(f"GenICam node '{name}' is not available")
+            LOG.debug("GenICam node '%s' is not available; skipping", name)
+            return False
+
+        symbolics = self._node_symbolics(node)
+        if symbolics and value not in symbolics:
+            if strict:
+                raise RuntimeError(f"GenICam node '{name}' does not support '{value}'. Available: {symbolics}")
+            LOG.warning("GenICam node '%s' does not support '%s'. Available: %s", name, value, symbolics)
+            return False
+
+        try:
+            node.value = value
+            return True
+        except Exception as exc:
+            if strict:
+                raise RuntimeError(f"Failed to set GenICam node '{name}' to '{value}': {exc}") from exc
+            LOG.warning("Failed to set GenICam node '%s' to '%s': %s", name, value, exc)
+            return False
+
+    @staticmethod
+    def _trigger_attr(trigger, name: str, default=None):
+        if isinstance(trigger, dict):
+            return trigger.get(name, default)
+        return getattr(trigger, name, default)
+
+    @staticmethod
+    def _trigger_to_dict(trigger) -> dict[str, Any]:
+        if trigger is None:
+            return {}
+        if isinstance(trigger, dict):
+            return dict(trigger)
+        if hasattr(trigger, "model_dump"):
+            try:
+                return trigger.model_dump(exclude_none=True)
+            except Exception:
+                pass
+        return {}
 
     def _configure_pixel_format(self, node_map) -> None:
         try:
@@ -1004,12 +1087,95 @@ def _configure_pixel_format(self, node_map) -> None:
             LOG.warning("Failed to configure pixel format '%s': %s", self._pixel_format, e)
 
     def _configure_trigger(self, node_map) -> None:
+        cfg = self._trigger
+        role = str(self._trigger_attr(cfg, "role", "off") or "off").strip().lower()
+        strict = bool(self._trigger_attr(cfg, "strict", False))
+
+        if role in {"off", "disabled"}:
+            self._configure_trigger_off(node_map, strict=strict)
+            return
+
+        if role in {"external", "follower"}:
+            self._configure_trigger_input(node_map, cfg, strict=strict)
+            return
+
+        if role == "master":
+            self._configure_trigger_master(node_map, cfg, strict=strict)
+            return
+
+        if strict:
+            raise RuntimeError(f"Unsupported GenTL trigger role: {role!r}")
+
+        LOG.warning("Unsupported GenTL trigger role '%s'; disabling trigger.", role)
+        self._configure_trigger_off(node_map, strict=False)
+
+    def _configure_trigger_off(self, node_map, *, strict: bool = False) -> None:
+        self._set_enum_node(node_map, "TriggerMode", "Off", strict=strict)
+
+    def _configure_trigger_input(self, node_map, cfg, *, strict: bool = False) -> None:
+        selector = str(self._trigger_attr(cfg, "selector", "FrameStart") or "FrameStart")
+        source = str(self._trigger_attr(cfg, "source", "Line0") or "Line0")
+        activation = str(self._trigger_attr(cfg, "activation", "RisingEdge") or "RisingEdge")
+
+        # Disable trigger while changing trigger-related nodes.
+        self._set_enum_node(node_map, "TriggerMode", "Off", strict=False)
+
+        self._set_enum_node(node_map, "TriggerSelector", selector, strict=strict)
+        self._set_enum_node(node_map, "TriggerSource", source, strict=strict)
+        self._set_enum_node(node_map, "TriggerActivation", activation, strict=strict)
+
+        self._set_enum_node(node_map, "AcquisitionMode", "Continuous", strict=False)
+
+        if not self._set_enum_node(node_map, "TriggerMode", "On", strict=strict):
+            if strict:
+                raise RuntimeError("Could not enable GenTL TriggerMode=On")
+
+        LOG.info(
+            "GenTL trigger input configured: role=%s selector=%s source=%s activation=%s",
+            self._trigger_attr(cfg, "role", "external"),
+            selector,
+            source,
+            activation,
+        )
+
+    def _configure_trigger_master(self, node_map, cfg, *, strict: bool = False) -> None:
+        output_line = str(self._trigger_attr(cfg, "output_line", "Line2") or "Line2")
+        output_source = str(self._trigger_attr(cfg, "output_source", "ExposureActive") or "ExposureActive")
+
+        # Master camera runs freerun and exposes an output signal.
+        self._configure_trigger_off(node_map, strict=False)
+
+        self._set_enum_node(node_map, "LineSelector", output_line, strict=strict)
+        self._set_enum_node(node_map, "LineMode", "Output", strict=strict)
+        self._set_enum_node(node_map, "LineSource", output_source, strict=strict)
+
+        LOG.info(
+            "GenTL trigger master configured: output_line=%s output_source=%s",
+            output_line,
+            output_source,
+        )
+
+    def _restore_trigger_idle(self, node_map) -> None:
+        """Best-effort restore to a safe non-triggering state after acquisition stops.
+
+        Important:
+        - This should be called after acquirer.stop(), not while acquisition is active.
+        - It is intentionally non-strict because shutdown should not fail if a node
+        is missing or read-only.
+        """
+        role = str(self._trigger_attr(getattr(self, "_trigger", None), "role", "off") or "off").lower()
+
         try:
-            trigger_mode = getattr(node_map, "TriggerMode", None)
-            if trigger_mode is not None and "Off" in getattr(trigger_mode, "symbolics", []):
-                trigger_mode.value = "Off"
-        except Exception as e:
-            LOG.warning("Failed to disable trigger mode: %s", e)
+            if role in {"external", "follower"}:
+                self._set_enum_node(node_map, "TriggerMode", "Off", strict=False)
+
+            elif role == "master":
+                # Stop driving output if the camera exposes these nodes.
+                self._set_enum_node(node_map, "LineSource", "Off", strict=False)
+                self._set_enum_node(node_map, "LineMode", "Input", strict=False)
+
+        except Exception:
+            LOG.debug("Best-effort GenTL trigger restore failed", exc_info=True)
 
     def _configure_resolution(self, node_map) -> None:
         if self._requested_resolution is None:
diff --git a/dlclivegui/cameras/base.py b/dlclivegui/cameras/base.py
index bc91ce9..fefedd1 100644
--- a/dlclivegui/cameras/base.py
+++ b/dlclivegui/cameras/base.py
@@ -70,6 +70,7 @@ class SupportLevel(str, Enum):
     "set_gain": SupportLevel.UNSUPPORTED,
     "device_discovery": SupportLevel.UNSUPPORTED,
     "stable_identity": SupportLevel.UNSUPPORTED,
+    "hardware_trigger": SupportLevel.UNSUPPORTED,
 }
 
 
diff --git a/dlclivegui/config.py b/dlclivegui/config.py
index 6d9e1de..154eabf 100644
--- a/dlclivegui/config.py
+++ b/dlclivegui/config.py
@@ -12,6 +12,8 @@
 TileLayout = Literal["auto", "2x2", "1x4", "4x1"]
 Precision = Literal["FP32", "FP16"]
 ModelType = Literal["pytorch", "tensorflow"]
+TriggerRole = Literal["off", "external", "master", "follower"]
+TriggerActivation = Literal["RisingEdge", "FallingEdge", "AnyEdge", "LevelHigh", "LevelLow"]
 
 
 class CameraSettings(BaseModel):
@@ -168,6 +170,100 @@ def check_diff(old: CameraSettings, new: CameraSettings) -> dict:
                 pass
         return out
 
+    def backend_options(self, backend: str | None = None) -> dict[str, Any]:
+        key = backend or self.backend
+        props = self.properties if isinstance(self.properties, dict) else {}
+        ns = props.get(str(key).lower(), {})
+        return ns if isinstance(ns, dict) else {}
+
+    def get_trigger_settings(self, backend: str | None = None) -> CameraTriggerSettings:
+        ns = self.backend_options(backend)
+        return CameraTriggerSettings.from_any(ns.get("trigger"))
+
+    def set_trigger_settings(self, trigger: CameraTriggerSettings, backend: str | None = None) -> None:
+        key = backend or self.backend
+        if not isinstance(self.properties, dict):
+            self.properties = {}
+        ns = self.properties.setdefault(str(key).lower(), {})
+        if not isinstance(ns, dict):
+            ns = {}
+            self.properties[str(key).lower()] = ns
+        ns["trigger"] = trigger.to_properties()
+
+
+class CameraTriggerSettings(BaseModel):
+    """
+    Generic hardware-trigger settings.
+
+    Backend-specific code may ignore fields that are unsupported by a given
+    camera/SDK. For GenTL, these map to common GenICam nodes such as:
+    TriggerMode, TriggerSelector, TriggerSource, TriggerActivation,
+    LineSelector, LineMode, and LineSource.
+    """
+
+    role: TriggerRole = "off"
+
+    # Input trigger config: external/follower
+    selector: str = "FrameStart"
+    source: str = "Line0"
+    activation: TriggerActivation | str = "RisingEdge"
+
+    # Output config: master
+    output_line: str = "Line2"
+    output_source: str = "ExposureActive"
+
+    # Runtime behavior
+    timeout: float | None = None
+    strict: bool = False
+
+    @field_validator("role", mode="before")
+    @classmethod
+    def _coerce_role(cls, v):
+        if v is None:
+            return "off"
+
+        s = str(v).strip().lower()
+        aliases = {
+            "": "off",
+            "none": "off",
+            "false": "off",
+            "disabled": "off",
+            "disable": "off",
+            "off": "off",
+            "true": "external",
+            "on": "external",
+            "trigger": "external",
+            "triggered": "external",
+            "external": "external",
+            "follower": "follower",
+            "slave": "follower",
+            "master": "master",
+            "main": "master",
+        }
+        return aliases.get(s, s)
+
+    @field_validator("timeout", mode="before")
+    @classmethod
+    def _coerce_timeout(cls, v):
+        if v in (None, ""):
+            return None
+        try:
+            fv = float(v)
+        except Exception:
+            return None
+        return fv if fv > 0 else None
+
+    @classmethod
+    def from_any(cls, value) -> CameraTriggerSettings:
+        if isinstance(value, cls):
+            return value
+        if isinstance(value, dict):
+            return cls(**value)
+        return cls()
+
+    def to_properties(self) -> dict[str, Any]:
+        return self.model_dump(exclude_none=True)
+
 
 class MultiCameraSettings(BaseModel):
     cameras: list[CameraSettings] = Field(default_factory=list)

From de99825ab04fbf96dbf7376c4920afae65c75918 Mon Sep 17 00:00:00 2001
From: Cyril Achard <cyril.achard@epfl.ch>
Date: Thu, 28 May 2026 14:13:44 +0200
Subject: [PATCH 02/20] Handle camera trigger defaults & trigger-aware startup

Populate gentl trigger defaults on save and allow saving configs with empty DLCLive model path. Add _with_camera_defaults_for_save to ensure CameraTriggerSettings are present for gentl cameras and thread through allow_empty_model_path in _dlc_settings_from_ui/_current_config so configs can be saved without a model while preserving existing DLC fields.

Improve multi-camera runtime robustness: treat TimeoutError from hardware-trigger backends as an expected 'no trigger' event (don't count as a camera failure) and add _trigger_role_from_settings/_camera_start_priority helpers. Start active cameras sorted by trigger role so trigger-waiting (external/follower) devices are armed before masters. Also extend DLCLive configuration error handling to include RuntimeError.
---
 dlclivegui/gui/main_window.py                 | 47 ++++++++++++--
 .../services/multi_camera_controller.py       | 64 +++++++++++++++++++
 2 files changed, 104 insertions(+), 7 deletions(-)

diff --git a/dlclivegui/gui/main_window.py b/dlclivegui/gui/main_window.py
index 0e3beb0..8a66e6a 100644
--- a/dlclivegui/gui/main_window.py
+++ b/dlclivegui/gui/main_window.py
@@ -56,6 +56,7 @@
     ApplicationSettings,
     BoundingBoxSettings,
     CameraSettings,
+    CameraTriggerSettings,
     DLCProcessorSettings,
     MultiCameraSettings,
     RecordingSettings,
@@ -854,15 +855,36 @@ def _apply_config(self, config: ApplicationSettings) -> None:
         # Update recording path preview
         self._update_recording_path_preview()
 
-    def _current_config(self) -> ApplicationSettings:
+    def _with_camera_defaults_for_save(self, settings: MultiCameraSettings) -> MultiCameraSettings:
+        out = settings.model_copy(deep=True)
+
+        for cam in out.cameras:
+            backend = (cam.backend or "").lower()
+            if backend != "gentl":
+                continue
+
+            if not isinstance(cam.properties, dict):
+                cam.properties = {}
+
+            ns = cam.properties.setdefault("gentl", {})
+            if not isinstance(ns, dict):
+                ns = {}
+                cam.properties["gentl"] = ns
+
+            ns.setdefault("trigger", CameraTriggerSettings().model_dump(exclude_none=True))
+
+        return out
+
+    def _current_config(self, *, allow_empty_model_path=False) -> ApplicationSettings:
         # Get the first camera from multi-camera config for backward compatibility
+        multi_camera = self._with_camera_defaults_for_save(self._config.multi_camera)
         active_cameras = self._config.multi_camera.get_active_cameras()
         camera = active_cameras[0] if active_cameras else CameraSettings()
 
         return ApplicationSettings(
             camera=camera,
-            multi_camera=self._config.multi_camera,
-            dlc=self._dlc_settings_from_ui(),
+            multi_camera=multi_camera,
+            dlc=self._dlc_settings_from_ui(allow_empty_model_path=allow_empty_model_path),
             recording=self._recording_settings_from_ui(),
             bbox=self._bbox_settings_from_ui(),
             visualization=self._visualization_settings_from_ui(),
@@ -874,13 +896,24 @@ def _parse_json(self, value: str) -> dict:
             return {}
         return json.loads(text)
 
-    def _dlc_settings_from_ui(self) -> DLCProcessorSettings:
+    def _dlc_settings_from_ui(self, *, allow_empty_model_path=False) -> DLCProcessorSettings:
         model_path = self.model_path_edit.text().strip()
         if Path(model_path).exists() and Path(model_path).suffix == ".pb":
             # IMPORTANT NOTE: DLClive expects a directory for TensorFlow models,
             # so if user selects a .pb file, we should pass the parent directory to DLCLive
             model_path = str(Path(model_path).parent)
-        if model_path == "":
+        if not model_path:
+            if allow_empty_model_path:
+                return DLCProcessorSettings(
+                    model_path="",
+                    model_directory=self._config.dlc.model_directory,  # Preserve from config
+                    device=self._config.dlc.device,  # Preserve from config
+                    dynamic=self._config.dlc.dynamic,  # Preserve from config
+                    resize=self._config.dlc.resize,  # Preserve from config
+                    precision=self._config.dlc.precision,  # Preserve from config
+                    model_type=None,
+                    # additional_options=self._parse_json(self.additional_options_edit.toPlainText()),
+                )
             raise ValueError("Model path cannot be empty. Please enter a valid path to a DLCLive model file.")
         try:
             model_bknd = DLCLiveProcessor.get_model_backend(model_path)
@@ -965,7 +998,7 @@ def _action_save_config_as(self) -> None:
 
     def _save_config_to_path(self, path: Path) -> None:
         try:
-            config = self._current_config()
+            config = self._current_config(allow_empty_model_path=True)
             config.save(path)
             self._settings_store.set_last_config_path(str(path))
             self._settings_store.save_full_config_snapshot(config)
@@ -1611,7 +1644,7 @@ def _stop_preview(self) -> None:
     def _configure_dlc(self) -> bool:
         try:
             settings = self._dlc_settings_from_ui()
-        except (ValueError, json.JSONDecodeError) as exc:
+        except (ValueError, RuntimeError, json.JSONDecodeError) as exc:
             self._show_error(f"Invalid DLCLive settings: {exc}")
             return False
         if not settings.model_path:
diff --git a/dlclivegui/services/multi_camera_controller.py b/dlclivegui/services/multi_camera_controller.py
index ad1a863..778a86e 100644
--- a/dlclivegui/services/multi_camera_controller.py
+++ b/dlclivegui/services/multi_camera_controller.py
@@ -99,6 +99,29 @@ def run(self) -> None:
                 consecutive_errors = 0
                 self.frame_captured.emit(self._camera_id, frame, timestamp)
 
+            except TimeoutError as exc:
+                if self._stop_event.is_set():
+                    break
+
+                # In hardware-trigger mode, a timeout usually means:
+                # "no trigger pulse arrived during this poll interval".
+                # This is expected and should not count as a camera failure.
+                if bool(getattr(self._backend, "waits_for_hardware_trigger", False)):
+                    LOGGER.debug(
+                        "[Worker %s] waiting for hardware trigger: %s",
+                        self._camera_id,
+                        exc,
+                    )
+                    consecutive_errors = 0
+                    continue
+
+                consecutive_errors += 1
+                if consecutive_errors >= self._max_consecutive_errors:
+                    self.error_occurred.emit(self._camera_id, f"Camera read timeout: {exc}")
+                    break
+                time.sleep(self._retry_delay)
+                continue
+
             except Exception as exc:
                 consecutive_errors += 1
                 if self._stop_event.is_set():
@@ -142,6 +165,46 @@ def get_camera_id(settings: CameraSettings) -> str:
     return f"{backend}:index:{int(settings.index)}"
 
 
+def _trigger_role_from_settings(settings: CameraSettings) -> str:
+    backend = (settings.backend or "").lower()
+    props = settings.properties if isinstance(settings.properties, dict) else {}
+    ns = props.get(backend, {}) if isinstance(props.get(backend), dict) else {}
+
+    trigger = ns.get("trigger", {})
+    if not isinstance(trigger, dict):
+        return "off"
+
+    role = str(trigger.get("role", "off") or "off").strip().lower()
+
+    # Match CameraTriggerSettings aliases enough for controller ordering.
+    if role in {"true", "on", "trigger", "triggered"}:
+        return "external"
+    if role in {"slave"}:
+        return "follower"
+    if role in {"main"}:
+        return "master"
+    if role in {"false", "none", "disabled", "disable", ""}:
+        return "off"
+
+    return role
+
+
+def _camera_start_priority(settings: CameraSettings) -> int:
+    """Start trigger-waiting cameras before trigger-generating cameras.
+
+    Priority:
+      0: external/follower cameras, which should be armed first
+      1: normal/free-run cameras
+      2: master cameras, which may generate trigger pulses
+    """
+    role = _trigger_role_from_settings(settings)
+    if role in {"external", "follower"}:
+        return 0
+    if role == "master":
+        return 2
+    return 1
+
+
 class MultiCameraController(QObject):
     """Controller for managing multiple cameras simultaneously."""
 
@@ -184,6 +247,7 @@ def start(self, camera_settings: list[CameraSettings]) -> None:
             return
 
         active_settings = [s for s in camera_settings if s.enabled][: self.MAX_CAMERAS]
+        active_settings = sorted(active_settings, key=_camera_start_priority)
         if not active_settings:
             LOGGER.warning("No active cameras to start")
             return

From a27a1f26e40ee7f6ca0e267ddc2164031ef78fe6 Mon Sep 17 00:00:00 2001
From: Cyril Achard <cyril.achard@epfl.ch>
Date: Thu, 28 May 2026 14:13:55 +0200
Subject: [PATCH 03/20] Improve signal handling and graceful shutdown

Enhance Qt app signal handling to support SIGTERM and SIGBREAK, and make Ctrl+C shutdown more robust. Adds a quitting flag and a two-stage interrupt: first interrupt triggers window close and schedules app.quit, second interrupt forces immediate exit (os._exit(130)). Parents the keepalive QTimer to the QApplication, sets a 100ms interval, and safely stops any previous timer to avoid duplicates. Adds logging and exception handling around window close and timer cleanup, and uses QTimer.singleShot to ensure Qt leaves its event loop even if closeEvent cleanup is asynchronous.
---
 dlclivegui/main.py | 60 +++++++++++++++++++++++++++++++++++++---------
 1 file changed, 49 insertions(+), 11 deletions(-)

diff --git a/dlclivegui/main.py b/dlclivegui/main.py
index eace8bd..9e38a08 100644
--- a/dlclivegui/main.py
+++ b/dlclivegui/main.py
@@ -27,32 +27,70 @@
 
 def _maybe_allow_keyboard_interrupt(app: QApplication) -> None:
     """
-    Gracefully handle Ctrl+C (SIGINT) by closing the main window and quitting Qt.
+    Gracefully handle Ctrl+C/SIGTERM by closing the main window and quitting Qt.
+
+    Notes:
+    - The small timer keeps Python signal handling responsive while Qt owns the event loop.
+    - First Ctrl+C tries graceful cleanup via closeEvent().
+    - Second Ctrl+C exits immediately with code 130.
     """
+    quitting = {"requested": False}
 
     def _request_quit() -> None:
+        if quitting["requested"]:
+            return
+
+        quitting["requested"] = True
         logging.info("Keyboard interrupt received, closing application...")
+
         win = getattr(app, "_main_window", None)
+
         if win is not None:
-            # Trigger your existing closeEvent cleanup (camera stop, threads, timers, etc.)
-            win.close()
-        else:
-            app.quit()
+            try:
+                # Trigger existing closeEvent cleanup:
+                # camera stop, controller shutdown, timers, DLC shutdown, etc.
+                win.close()
+            except Exception:
+                logging.exception("Error while closing main window after Ctrl+C")
+
+        # Explicitly ask Qt to leave app.exec().
+        # Do this even after win.close(), because closeEvent cleanup can be async
+        # and relying only on quitOnLastWindowClosed can be fragile.
+        QTimer.singleShot(0, app.quit)
+
+    def _force_exit() -> None:
+        logging.warning("Second interrupt received, forcing process exit.")
+        os._exit(130)
 
     def _sigint_handler(_signum, _frame) -> None:
+        if quitting["requested"]:
+            _force_exit()
         QTimer.singleShot(0, _request_quit)
 
     signal.signal(signal.SIGINT, _sigint_handler)
 
-    # Keepalive timer to allow Python to handle signals while Qt is running.
-    sig_timer = QTimer()
-    sig_timer.setInterval(100)  # 50–200ms typical; keep low overhead
+    # Ctrl+Break on Windows.
+    if hasattr(signal, "SIGBREAK"):
+        signal.signal(signal.SIGBREAK, _sigint_handler)
+
+    # Useful when process is terminated from shells/process managers.
+    if hasattr(signal, "SIGTERM"):
+        signal.signal(signal.SIGTERM, _sigint_handler)
+
+    # Parent the timer to app so Qt owns its lifetime.
+    sig_timer = QTimer(app)
+    sig_timer.setInterval(100)
     sig_timer.timeout.connect(lambda: None)
     sig_timer.start()
 
-    if hasattr(app, "_sig_timer"):
-        app._sig_timer.stop()  # Stop any existing timer to avoid duplicates
-    app._sig_timer = sig_timer  # Store on app to keep it alive and allow cleanup on exit
+    old_timer = getattr(app, "_sig_timer", None)
+    if old_timer is not None:
+        try:
+            old_timer.stop()
+        except Exception:
+            pass
+
+    app._sig_timer = sig_timer
 
 
 def configure_logging(debug: bool = False) -> None:

From 4e6dac0ff7801de836690ad7ab0f236d4f6c9a67 Mon Sep 17 00:00:00 2001
From: Cyril Achard <cyril.achard@epfl.ch>
Date: Thu, 28 May 2026 14:14:12 +0200
Subject: [PATCH 04/20] Add GenTL trigger tests and fake node map

Add a comprehensive test suite for GenTL hardware trigger handling (tests/cameras/backends/test_gentl_trigger.py). Tests cover trigger roles (off/external/follower/master), selector/source/activation settings, strict vs non-strict behavior for invalid sources, master output configuration, alias mapping, timeout handling and error messaging, and persistence of trigger_actual for debugging. Update the test conftest fake node map (tests/cameras/backends/conftest.py) to include Trigger* and Line* nodes (AcquisitionMode, TriggerSelector, TriggerMode, TriggerSource, TriggerActivation, LineSelector, LineMode, LineSource) so the tests can exercise trigger and GPIO-related configuration.
---
 tests/cameras/backends/conftest.py           |  12 +
 tests/cameras/backends/test_gentl_trigger.py | 333 +++++++++++++++++++
 2 files changed, 345 insertions(+)
 create mode 100644 tests/cameras/backends/test_gentl_trigger.py

diff --git a/tests/cameras/backends/conftest.py b/tests/cameras/backends/conftest.py
index 9459c35..f21bf48 100644
--- a/tests/cameras/backends/conftest.py
+++ b/tests/cameras/backends/conftest.py
@@ -599,6 +599,18 @@ def __init__(
         self.GainAuto = _FakeNode("Off")
         self.Gain = _FakeNode(float(gain))
 
+        # Trigger input nodes
+        self.AcquisitionMode = _FakeNode("Continuous", symbolics=["Continuous", "SingleFrame"])
+        self.TriggerSelector = _FakeNode("FrameStart", symbolics=["FrameStart"])
+        self.TriggerMode = _FakeNode("Off", symbolics=["Off", "On"])
+        self.TriggerSource = _FakeNode("Line0", symbolics=["Line0", "Line1", "Software"])
+        self.TriggerActivation = _FakeNode("RisingEdge", symbolics=["RisingEdge", "FallingEdge"])
+
+        # GPIO output nodes for master/follower setups
+        self.LineSelector = _FakeNode("Line0", symbolics=["Line0", "Line1", "Line2"])
+        self.LineMode = _FakeNode("Input", symbolics=["Input", "Output"])
+        self.LineSource = _FakeNode("Off", symbolics=["Off", "ExposureActive", "AcquisitionActive"])
+
 
 class _FakeRemoteDevice:
     def __init__(self, node_map: _FakeNodeMap):
diff --git a/tests/cameras/backends/test_gentl_trigger.py b/tests/cameras/backends/test_gentl_trigger.py
new file mode 100644
index 0000000..f0d5f45
--- /dev/null
+++ b/tests/cameras/backends/test_gentl_trigger.py
@@ -0,0 +1,333 @@
+# tests/cameras/backends/test_gentl_trigger.py
+from __future__ import annotations
+
+import pytest
+
+# ---------------------------------------------------------------------
+# GenTL hardware trigger configuration
+# ---------------------------------------------------------------------
+
+
+def _gentl_trigger_settings(gentl_settings_factory, trigger: dict, **kwargs):
+    """Build CameraSettings with a GenTL trigger block."""
+    return gentl_settings_factory(properties={"gentl": {"trigger": trigger}}, **kwargs)
+
+
+def test_gentl_capabilities_advertise_hardware_trigger_best_effort(patch_gentl_sdk):
+    gb = patch_gentl_sdk
+
+    caps = gb.GenTLCameraBackend.static_capabilities()
+
+    assert caps.get("hardware_trigger") == gb.SupportLevel.BEST_EFFORT
+
+
+def test_trigger_default_off_configures_trigger_mode_off(patch_gentl_sdk, gentl_settings_factory):
+    gb = patch_gentl_sdk
+
+    settings = gentl_settings_factory()
+    be = gb.GenTLCameraBackend(settings)
+
+    be.open()
+    nm = be._acquirer.remote_device.node_map
+
+    assert nm.TriggerMode.value == "Off"
+
+    ns = settings.properties.get("gentl", {})
+    assert ns.get("trigger_actual", {}).get("role") == "off"
+
+    be.close()
+
+
+def test_trigger_explicit_off_configures_trigger_mode_off(patch_gentl_sdk, gentl_settings_factory):
+    gb = patch_gentl_sdk
+
+    settings = _gentl_trigger_settings(gentl_settings_factory, {"role": "off"})
+    be = gb.GenTLCameraBackend(settings)
+
+    be.open()
+    nm = be._acquirer.remote_device.node_map
+
+    assert nm.TriggerMode.value == "Off"
+    assert settings.properties["gentl"]["trigger_actual"]["role"] == "off"
+
+    be.close()
+
+
+def test_trigger_external_configures_input_line_and_timeout(patch_gentl_sdk, gentl_settings_factory):
+    gb = patch_gentl_sdk
+
+    settings = _gentl_trigger_settings(
+        gentl_settings_factory,
+        {
+            "role": "external",
+            "selector": "FrameStart",
+            "source": "Line0",
+            "activation": "RisingEdge",
+            "timeout": 10.0,
+        },
+    )
+    be = gb.GenTLCameraBackend(settings)
+
+    be.open()
+    nm = be._acquirer.remote_device.node_map
+
+    assert nm.TriggerSelector.value == "FrameStart"
+    assert nm.TriggerSource.value == "Line0"
+    assert nm.TriggerActivation.value == "RisingEdge"
+    assert nm.TriggerMode.value == "On"
+    assert be._timeout == pytest.approx(10.0)
+
+    ns = settings.properties["gentl"]
+    assert ns["trigger_actual"]["role"] == "external"
+    assert ns["trigger_actual"]["source"] == "Line0"
+
+    be.close()
+
+
+def test_trigger_follower_configures_input_line(patch_gentl_sdk, gentl_settings_factory):
+    gb = patch_gentl_sdk
+
+    settings = _gentl_trigger_settings(
+        gentl_settings_factory,
+        {
+            "role": "follower",
+            "selector": "FrameStart",
+            "source": "Line1",
+            "activation": "FallingEdge",
+        },
+    )
+    be = gb.GenTLCameraBackend(settings)
+
+    be.open()
+    nm = be._acquirer.remote_device.node_map
+
+    assert nm.TriggerSelector.value == "FrameStart"
+    assert nm.TriggerSource.value == "Line1"
+    assert nm.TriggerActivation.value == "FallingEdge"
+    assert nm.TriggerMode.value == "On"
+
+    ns = settings.properties["gentl"]
+    assert ns["trigger_actual"]["role"] == "follower"
+
+    be.close()
+
+
+def test_trigger_master_configures_output_line_and_keeps_trigger_off(patch_gentl_sdk, gentl_settings_factory):
+    gb = patch_gentl_sdk
+
+    settings = _gentl_trigger_settings(
+        gentl_settings_factory,
+        {
+            "role": "master",
+            "output_line": "Line2",
+            "output_source": "ExposureActive",
+        },
+    )
+    be = gb.GenTLCameraBackend(settings)
+
+    be.open()
+    nm = be._acquirer.remote_device.node_map
+
+    assert nm.TriggerMode.value == "Off"
+    assert nm.LineSelector.value == "Line2"
+    assert nm.LineMode.value == "Output"
+    assert nm.LineSource.value == "ExposureActive"
+
+    ns = settings.properties["gentl"]
+    assert ns["trigger_actual"]["role"] == "master"
+    assert ns["trigger_actual"]["output_line"] == "Line2"
+
+    be.close()
+
+
+def test_trigger_invalid_source_non_strict_does_not_crash(patch_gentl_sdk, gentl_settings_factory):
+    gb = patch_gentl_sdk
+
+    settings = _gentl_trigger_settings(
+        gentl_settings_factory,
+        {
+            "role": "external",
+            "source": "LineDoesNotExist",
+            "strict": False,
+        },
+    )
+    be = gb.GenTLCameraBackend(settings)
+
+    be.open()
+    nm = be._acquirer.remote_device.node_map
+
+    # Source was unsupported, so the fake node should retain its default.
+    assert nm.TriggerSource.value == "Line0"
+    # Non-strict mode should still allow opening; TriggerMode may be enabled
+    # because TriggerSource failure is best-effort in this mode.
+    assert be._acquirer is not None
+
+    be.close()
+
+
+def test_trigger_invalid_source_strict_raises_and_cleans_up(patch_gentl_sdk, gentl_settings_factory):
+    gb = patch_gentl_sdk
+
+    settings = _gentl_trigger_settings(
+        gentl_settings_factory,
+        {
+            "role": "external",
+            "source": "LineDoesNotExist",
+            "strict": True,
+        },
+    )
+    be = gb.GenTLCameraBackend(settings)
+
+    with pytest.raises(RuntimeError):
+        be.open()
+
+    assert be._harvester is None
+    assert be._shared_entry is None
+    assert be._acquirer is None
+
+
+def test_trigger_invalid_master_output_source_non_strict_does_not_crash(patch_gentl_sdk, gentl_settings_factory):
+    gb = patch_gentl_sdk
+
+    settings = _gentl_trigger_settings(
+        gentl_settings_factory,
+        {
+            "role": "master",
+            "output_line": "Line2",
+            "output_source": "NotARealLineSource",
+            "strict": False,
+        },
+    )
+    be = gb.GenTLCameraBackend(settings)
+
+    be.open()
+    nm = be._acquirer.remote_device.node_map
+
+    assert nm.TriggerMode.value == "Off"
+    assert nm.LineSelector.value == "Line2"
+    assert nm.LineMode.value == "Output"
+    # Unsupported source should not be applied in non-strict mode.
+    assert nm.LineSource.value == "Off"
+
+    be.close()
+
+
+def test_trigger_invalid_master_output_source_strict_raises_and_cleans_up(patch_gentl_sdk, gentl_settings_factory):
+    gb = patch_gentl_sdk
+
+    settings = _gentl_trigger_settings(
+        gentl_settings_factory,
+        {
+            "role": "master",
+            "output_line": "Line2",
+            "output_source": "NotARealLineSource",
+            "strict": True,
+        },
+    )
+    be = gb.GenTLCameraBackend(settings)
+
+    with pytest.raises(RuntimeError):
+        be.open()
+
+    assert be._harvester is None
+    assert be._shared_entry is None
+    assert be._acquirer is None
+
+
+def test_trigger_alias_on_maps_to_external(patch_gentl_sdk, gentl_settings_factory):
+    gb = patch_gentl_sdk
+
+    settings = _gentl_trigger_settings(
+        gentl_settings_factory,
+        {
+            "role": "on",
+            "source": "Line1",
+        },
+    )
+    be = gb.GenTLCameraBackend(settings)
+
+    be.open()
+    nm = be._acquirer.remote_device.node_map
+
+    assert nm.TriggerMode.value == "On"
+    assert nm.TriggerSource.value == "Line1"
+    assert settings.properties["gentl"]["trigger_actual"]["role"] == "external"
+
+    be.close()
+
+
+def test_trigger_timeout_overrides_default_fetch_timeout(patch_gentl_sdk, gentl_settings_factory):
+    gb = patch_gentl_sdk
+
+    settings = _gentl_trigger_settings(
+        gentl_settings_factory,
+        {
+            "role": "external",
+            "timeout": 7.5,
+        },
+    )
+    be = gb.GenTLCameraBackend(settings)
+
+    be.open()
+    assert be._timeout == pytest.approx(7.5)
+
+    # Fake acquisition is started, so read should pass and record the timeout.
+    frame, _ = be.read()
+    assert frame is not None
+    assert be._acquirer.fetch_calls[-1] == pytest.approx(7.5)
+
+    be.close()
+
+
+def test_trigger_timeout_error_mentions_hardware_trigger_when_waiting(patch_gentl_sdk, gentl_settings_factory):
+    gb = patch_gentl_sdk
+
+    settings = _gentl_trigger_settings(
+        gentl_settings_factory,
+        {
+            "role": "external",
+            "timeout": 3.0,
+        },
+        # fast_start keeps acquisition stopped; fake fetch then raises timeout.
+        # This lets us assert the backend timeout message without hardware.
+    )
+    settings.properties["gentl"]["fast_start"] = True
+    be = gb.GenTLCameraBackend(settings)
+
+    be.open()
+
+    with pytest.raises(TimeoutError) as ei:
+        be.read()
+
+    msg = str(ei.value).lower()
+    assert "gentl timeout" in msg
+    assert "hardware trigger" in msg or "trigger" in msg
+
+    be.close()
+
+
+def test_trigger_actual_is_persisted_for_debugging(patch_gentl_sdk, gentl_settings_factory):
+    gb = patch_gentl_sdk
+
+    settings = _gentl_trigger_settings(
+        gentl_settings_factory,
+        {
+            "role": "follower",
+            "source": "Line1",
+            "activation": "FallingEdge",
+            "timeout": 9.0,
+            "strict": False,
+        },
+    )
+    be = gb.GenTLCameraBackend(settings)
+
+    be.open()
+
+    actual = settings.properties["gentl"].get("trigger_actual")
+    assert isinstance(actual, dict)
+    assert actual["role"] == "follower"
+    assert actual["source"] == "Line1"
+    assert actual["activation"] == "FallingEdge"
+    assert actual["timeout"] == pytest.approx(9.0)
+
+    be.close()

From 3e40d948349b1c1550ac8fc1cfce69ce534e05a5 Mon Sep 17 00:00:00 2001
From: Cyril Achard <cyril.achard@epfl.ch>
Date: Thu, 28 May 2026 15:01:03 +0200
Subject: [PATCH 05/20] Respect user camera order for display/tiling

Use the user-configured camera order for display/tiling and ensure tiling geometry matches displayed frames. Changes:

- GUI: populate the inference camera dropdown from active cameras in the configured order and only add entries for cameras that are actually running.
- MultiCameraController: store the user display order, derive startup order by sorting for trigger safety (followers/external first, master last), emit frames/timestamps in display order (with any unexpected IDs appended deterministically), clear display order on stop, and handle no-active-cameras early.
- Utils: compute_tiling_geometry now uses the frames' display order (insertion order) rather than sorted keys so tile dimensions and overlays align with the tiled frame; updated docstrings to reflect this.

These changes ensure consistent tiling, overlay transforms, and UI behavior that follow the user's configured ordering.
---
 dlclivegui/gui/main_window.py                 |  6 ++-
 .../services/multi_camera_controller.py       | 38 ++++++++++++++++---
 dlclivegui/utils/display.py                   | 10 ++---
 3 files changed, 42 insertions(+), 12 deletions(-)

diff --git a/dlclivegui/gui/main_window.py b/dlclivegui/gui/main_window.py
index 8a66e6a..def6094 100644
--- a/dlclivegui/gui/main_window.py
+++ b/dlclivegui/gui/main_window.py
@@ -1298,8 +1298,10 @@ def _refresh_dlc_camera_list_running(self) -> None:
         """Populate the inference camera dropdown from currently running cameras."""
         self.dlc_camera_combo.blockSignals(True)
         self.dlc_camera_combo.clear()
-        for cam_id in sorted(self._running_cams_ids):
-            self.dlc_camera_combo.addItem(self._label_for_cam_id(cam_id), cam_id)
+        for cam in self._config.multi_camera.get_active_cameras():
+            cam_id = get_camera_id(cam)
+            if cam_id in self._running_cams_ids:
+                self.dlc_camera_combo.addItem(self._label_for_cam_id(cam_id), cam_id)
 
         # Keep current selection if still present, else select first running
         if self._inference_camera_id in self._running_cams_ids:
diff --git a/dlclivegui/services/multi_camera_controller.py b/dlclivegui/services/multi_camera_controller.py
index 778a86e..17af14e 100644
--- a/dlclivegui/services/multi_camera_controller.py
+++ b/dlclivegui/services/multi_camera_controller.py
@@ -229,6 +229,7 @@ def __init__(self):
         self._frame_lock = Lock()
         self._running = False
         self._started_cameras: set = set()
+        self._camera_display_order: list[str] = []
         self._failed_cameras: dict[str, str] = {}  # camera_id -> error message
         self._expected_cameras: int = 0  # Number of cameras we're trying to start
 
@@ -246,8 +247,17 @@ def start(self, camera_settings: list[CameraSettings]) -> None:
             LOGGER.warning("Multi-camera controller already running")
             return
 
-        active_settings = [s for s in camera_settings if s.enabled][: self.MAX_CAMERAS]
-        active_settings = sorted(active_settings, key=_camera_start_priority)
+        active_settings_user_order = [s for s in camera_settings if s.enabled][: self.MAX_CAMERAS]
+        if not active_settings_user_order:
+            LOGGER.warning("No active cameras to start")
+            return
+
+        # Display/tile order follows the user-configured camera order.
+        self._camera_display_order = [get_camera_id(s) for s in active_settings_user_order]
+
+        # Startup order may differ for trigger safety:
+        # followers/external first, master last.
+        active_settings = sorted(active_settings_user_order, key=_camera_start_priority)
         if not active_settings:
             LOGGER.warning("No active cameras to start")
             return
@@ -339,6 +349,7 @@ def stop(self, wait: bool = True) -> None:
         self._settings.clear()
         self._started_cameras.clear()
         self._failed_cameras.clear()
+        self._camera_display_order.clear()
         self._expected_cameras = 0
         self.all_stopped.emit()
 
@@ -361,10 +372,27 @@ def _on_frame_captured(self, camera_id: str, frame: np.ndarray, timestamp: float
 
             # Emit frame data without tiling (tiling done in GUI for performance)
             if self._frames:
+                ordered_frames: dict[str, np.ndarray] = {}
+                ordered_timestamps: dict[str, float] = {}
+
+                for cam_id in self._camera_display_order:
+                    if cam_id in self._frames:
+                        ordered_frames[cam_id] = self._frames[cam_id]
+                    if cam_id in self._timestamps:
+                        ordered_timestamps[cam_id] = self._timestamps[cam_id]
+
+                # Any unexpected/legacy IDs, appended deterministically.
+                for cam_id in self._frames:
+                    if cam_id not in ordered_frames:
+                        ordered_frames[cam_id] = self._frames[cam_id]
+                for cam_id in self._timestamps:
+                    if cam_id not in ordered_timestamps:
+                        ordered_timestamps[cam_id] = self._timestamps[cam_id]
+
                 frame_data = MultiFrameData(
-                    frames=dict(self._frames),
-                    timestamps=dict(self._timestamps),
-                    source_camera_id=camera_id,  # Track which camera triggered this
+                    frames=ordered_frames,
+                    timestamps=ordered_timestamps,
+                    source_camera_id=camera_id,
                     tiled_frame=None,
                 )
                 self.frame_ready.emit(frame_data)
diff --git a/dlclivegui/utils/display.py b/dlclivegui/utils/display.py
index 0eac657..01b0be0 100644
--- a/dlclivegui/utils/display.py
+++ b/dlclivegui/utils/display.py
@@ -38,10 +38,10 @@ def compute_tiling_geometry(
     """Compute consistent tiling geometry for both tiling and overlay transforms.
 
     Returns:
-        (sorted_cam_ids, rows, cols, tile_w, tile_h)
+        (cam_ids, rows, cols, tile_w, tile_h)
 
     Notes:
-    - We intentionally base tile aspect on the first frame in sorted_cam_ids,
+    - We intentionally base tile aspect on the first frame in cam_ids,
       because create_tiled_frame uses the same ordering. This guarantees that
       compute_tile_info() and create_tiled_frame() agree on tile_w/tile_h.
     - If frames have different aspect ratios, they will be resized (possibly distorted)
@@ -50,7 +50,7 @@ def compute_tiling_geometry(
     if not frames:
         return ([], 1, 1, 640, 480)
 
-    cam_ids = sorted(frames.keys())
+    cam_ids = list(frames.keys())
     frames_list = [frames[cid] for cid in cam_ids]
     num_frames = len(frames_list)
 
@@ -63,7 +63,7 @@ def compute_tiling_geometry(
 
     max_w, max_h = max_canvas
 
-    # Reference aspect is based on the first frame in sorted order (matches tiler).
+    # Reference aspect is based on the first frame in display order (matches tiler).
     h0, w0 = frames_list[0].shape[:2]
     frame_aspect = (w0 / h0) if h0 > 0 else 1.0
 
@@ -135,7 +135,7 @@ def compute_tile_info(
 
     Critical robustness fix:
     - Tile dimensions are computed from the same reference used by create_tiled_frame()
-      (first frame in sorted order), so offsets/scales match the actual tiling.
+      (first frame in display order), so offsets/scales match the actual tiling.
     """
     if not frames:
         return (0, 0), (1.0, 1.0)

From d602c1ecb6970a8041c9925f590f672701952b7a Mon Sep 17 00:00:00 2001
From: Cyril Achard <cyril.achard@epfl.ch>
Date: Thu, 28 May 2026 15:01:30 +0200
Subject: [PATCH 06/20] tests: preserve display order and add MultiCamera tests

Update display tests to assert that tiling and tile computations preserve frame insertion/display order (no longer sorting by camera ID) and add coverage for tile offsets, scaling, and tiled frame content. Add a suite of unit tests for MultiCameraController utilities and behavior: get_camera_id, trigger role aliasing, camera start priority, preserving user display order on start, frame_ready emission order, clearing display order on stop, hardware trigger timeouts (non-fatal), and non-trigger timeouts (fatal). Also import newly-tested helper functions from multi_camera_controller.
---
 tests/services/test_multicam_controller.py | 300 +++++++++++++++++++++
 tests/utils/test_display.py                | 111 +++++++-
 2 files changed, 398 insertions(+), 13 deletions(-)

diff --git a/tests/services/test_multicam_controller.py b/tests/services/test_multicam_controller.py
index 0893bd9..e8f94f6 100644
--- a/tests/services/test_multicam_controller.py
+++ b/tests/services/test_multicam_controller.py
@@ -6,6 +6,12 @@
 # from dlclivegui.config import CameraSettings
 from dlclivegui.config import CameraSettings
 from dlclivegui.services.multi_camera_controller import MultiCameraController, get_display_id
+from dlclivegui.services.multi_camera_controller import (
+    MultiCameraController,
+    _camera_start_priority,
+    _trigger_role_from_settings,
+    get_camera_id,
+)
 
 
 @pytest.mark.unit
@@ -95,3 +101,297 @@ def _create(_settings):
     # Expect initialization_failed with the camera id
     with qtbot.waitSignals([mc.initialization_failed, mc.all_stopped], timeout=2000) as _:
         mc.start([cam])
+
+
+@pytest.mark.unit
+def test_get_camera_id_prefers_stable_device_id():
+    cam = CameraSettings(
+        name="GenTL Cam",
+        backend="gentl",
+        index=0,
+        properties={
+            "gentl": {
+                "device_id": "serial:30220469",
+                "serial_number": "30220469",
+            }
+        },
+    ).apply_defaults()
+
+    assert get_camera_id(cam) == "gentl:serial:30220469"
+
+
+@pytest.mark.unit
+def test_get_camera_id_falls_back_to_index_without_stable_identity():
+    cam = CameraSettings(
+        name="Cam",
+        backend="opencv",
+        index=2,
+    ).apply_defaults()
+
+    assert get_camera_id(cam) == "opencv:index:2"
+
+
+@pytest.mark.unit
+@pytest.mark.parametrize(
+    ("role", "expected"),
+    [
+        ("off", "off"),
+        ("disabled", "off"),
+        ("on", "external"),
+        ("triggered", "external"),
+        ("external", "external"),
+        ("follower", "follower"),
+        ("slave", "follower"),
+        ("master", "master"),
+        ("main", "master"),
+    ],
+)
+def test_trigger_role_from_settings_aliases(role, expected):
+    cam = CameraSettings(
+        name="C",
+        backend="gentl",
+        index=0,
+        properties={
+            "gentl": {
+                "trigger": {
+                    "role": role,
+                }
+            }
+        },
+    ).apply_defaults()
+
+    assert _trigger_role_from_settings(cam) == expected
+
+
+@pytest.mark.unit
+def test_camera_start_priority_orders_trigger_roles():
+    external = CameraSettings(
+        name="External",
+        backend="gentl",
+        index=0,
+        properties={"gentl": {"trigger": {"role": "external"}}},
+    ).apply_defaults()
+
+    normal = CameraSettings(
+        name="Normal",
+        backend="gentl",
+        index=1,
+        properties={"gentl": {"trigger": {"role": "off"}}},
+    ).apply_defaults()
+
+    master = CameraSettings(
+        name="Master",
+        backend="gentl",
+        index=2,
+        properties={"gentl": {"trigger": {"role": "master"}}},
+    ).apply_defaults()
+
+    assert _camera_start_priority(external) == 0
+    assert _camera_start_priority(normal) == 1
+    assert _camera_start_priority(master) == 2
+
+
+@pytest.mark.unit
+def test_start_preserves_user_display_order_even_when_trigger_start_order_differs(qtbot, patch_factory):
+    mc = MultiCameraController()
+
+    # User wants master first in tiled view, follower second.
+    # Startup order should still be follower first internally.
+    master = CameraSettings(
+        name="Master",
+        backend="opencv",
+        index=0,
+        enabled=True,
+        properties={
+            "opencv": {
+                "device_id": "master-cam",
+                "trigger": {"role": "master"},
+            }
+        },
+    ).apply_defaults()
+
+    follower = CameraSettings(
+        name="Follower",
+        backend="opencv",
+        index=1,
+        enabled=True,
+        properties={
+            "opencv": {
+                "device_id": "follower-cam",
+                "trigger": {"role": "follower"},
+            }
+        },
+    ).apply_defaults()
+
+    expected_display_order = [get_camera_id(master), get_camera_id(follower)]
+
+    try:
+        with qtbot.waitSignal(mc.all_started, timeout=1500):
+            mc.start([master, follower])
+
+        assert mc._camera_display_order == expected_display_order
+
+    finally:
+        with qtbot.waitSignal(mc.all_stopped, timeout=2000):
+            mc.stop(wait=True)
+
+
+@pytest.mark.unit
+def test_frame_ready_emits_frames_in_user_configured_order(qtbot, patch_factory):
+    mc = MultiCameraController()
+
+    cam_a = CameraSettings(
+        name="A",
+        backend="opencv",
+        index=0,
+        enabled=True,
+        properties={"opencv": {"device_id": "cam-a"}},
+    ).apply_defaults()
+
+    cam_b = CameraSettings(
+        name="B",
+        backend="opencv",
+        index=1,
+        enabled=True,
+        properties={"opencv": {"device_id": "cam-b"}},
+    ).apply_defaults()
+
+    expected_order = [get_camera_id(cam_a), get_camera_id(cam_b)]
+    seen_orders: list[list[str]] = []
+
+    def on_ready(mfd):
+        if len(mfd.frames) >= 2:
+            seen_orders.append(list(mfd.frames.keys()))
+
+    mc.frame_ready.connect(on_ready)
+
+    try:
+        with qtbot.waitSignal(mc.all_started, timeout=1500):
+            mc.start([cam_a, cam_b])
+
+        qtbot.waitUntil(lambda: bool(seen_orders), timeout=2500)
+
+        assert seen_orders[-1] == expected_order
+
+    finally:
+        with qtbot.waitSignal(mc.all_stopped, timeout=2000):
+            mc.stop(wait=True)
+
+
+@pytest.mark.unit
+def test_display_order_is_cleared_on_stop(qtbot, patch_factory):
+    mc = MultiCameraController()
+
+    cam = CameraSettings(
+        name="C",
+        backend="opencv",
+        index=0,
+        enabled=True,
+        properties={"opencv": {"device_id": "cam-0"}},
+    ).apply_defaults()
+
+    try:
+        with qtbot.waitSignal(mc.all_started, timeout=1500):
+            mc.start([cam])
+
+        assert mc._camera_display_order == [get_camera_id(cam)]
+
+    finally:
+        with qtbot.waitSignal(mc.all_stopped, timeout=2000):
+            mc.stop(wait=True)
+
+    assert mc._camera_display_order == []
+
+
+@pytest.mark.unit
+def test_hardware_trigger_timeouts_are_not_fatal(qtbot, monkeypatch):
+    class WaitingTriggerBackend:
+        waits_for_hardware_trigger = True
+
+        def __init__(self, settings):
+            self.settings = settings
+            self.opened = False
+            self.closed = False
+
+        def open(self):
+            self.opened = True
+
+        def read(self):
+            raise TimeoutError("waiting for hardware trigger")
+
+        def close(self):
+            self.closed = True
+
+    def _create(settings):
+        return WaitingTriggerBackend(settings)
+
+    monkeypatch.setattr(CameraFactory, "create", staticmethod(_create))
+
+    mc = MultiCameraController()
+    cam = CameraSettings(
+        name="Triggered",
+        backend="gentl",
+        index=0,
+        enabled=True,
+        properties={
+            "gentl": {
+                "device_id": "serial:30220469",
+                "trigger": {"role": "external", "timeout": 0.1},
+            }
+        },
+    ).apply_defaults()
+
+    errors: list[tuple[str, str]] = []
+    mc.camera_error.connect(lambda cam_id, msg: errors.append((cam_id, msg)))
+
+    try:
+        with qtbot.waitSignal(mc.all_started, timeout=1500):
+            mc.start([cam])
+
+        # Let several timeout cycles happen.
+        qtbot.wait(500)
+
+        assert mc.is_running()
+        assert errors == []
+
+    finally:
+        with qtbot.waitSignal(mc.all_stopped, timeout=2000):
+            mc.stop(wait=True)
+
+
+@pytest.mark.unit
+def test_non_trigger_timeouts_are_fatal_after_retries(qtbot, monkeypatch):
+    class TimeoutBackend:
+        waits_for_hardware_trigger = False
+
+        def __init__(self, settings):
+            self.settings = settings
+
+        def open(self):
+            pass
+
+        def read(self):
+            raise TimeoutError("camera timeout")
+
+        def close(self):
+            pass
+
+    def _create(settings):
+        return TimeoutBackend(settings)
+
+    monkeypatch.setattr(CameraFactory, "create", staticmethod(_create))
+
+    mc = MultiCameraController()
+    cam = CameraSettings(name="TimeoutCam", backend="opencv", index=0, enabled=True).apply_defaults()
+
+    with qtbot.waitSignal(mc.camera_error, timeout=3000) as blocker:
+        mc.start([cam])
+
+    cam_id, msg = blocker.args
+    assert cam_id == get_camera_id(cam)
+    assert "Camera read timeout" in msg
+
+    # Cleanup if still running.
+    if mc.is_running():
+        with qtbot.waitSignal(mc.all_stopped, timeout=2000):
+            mc.stop(wait=True)
diff --git a/tests/utils/test_display.py b/tests/utils/test_display.py
index 9ce8d49..559aa15 100644
--- a/tests/utils/test_display.py
+++ b/tests/utils/test_display.py
@@ -41,7 +41,9 @@ def test_compute_tiling_geometry_single_frame_respects_max_canvas_and_min_tile()
 def test_compute_tiling_geometry_two_frames_is_1x2():
     frames = {"camB": _frame(480, 640, 3), "camA": _frame(480, 640, 3)}
     cam_ids, rows, cols, tile_w, tile_h = compute_tiling_geometry(frames, max_canvas=(1200, 800))
-    assert cam_ids == ["camA", "camB"]  # sorted
+
+    # Preserve insertion/display order, do not sort by camera ID.
+    assert cam_ids == ["camB", "camA"]
     assert (rows, cols) == (1, 2)
     assert tile_w >= 160 and tile_h >= 120
 
@@ -49,25 +51,106 @@ def test_compute_tiling_geometry_two_frames_is_1x2():
 def test_compute_tiling_geometry_three_frames_is_2x2():
     frames = {"c3": _frame(480, 640, 3), "c1": _frame(480, 640, 3), "c2": _frame(480, 640, 3)}
     cam_ids, rows, cols, tile_w, tile_h = compute_tiling_geometry(frames, max_canvas=(1200, 800))
-    assert cam_ids == ["c1", "c2", "c3"]
+
+    # Preserve insertion/display order.
+    assert cam_ids == ["c3", "c1", "c2"]
     assert (rows, cols) == (2, 2)
     assert tile_w >= 160 and tile_h >= 120
 
 
-def test_compute_tiling_geometry_reference_aspect_is_first_sorted_cam():
-    # camA has aspect 2.0 (w/h), camB has aspect 0.5
+def test_compute_tiling_geometry_reference_aspect_is_first_display_order_cam():
+    # camB is first in insertion/display order and has aspect 0.5.
+    # camA has aspect 2.0.
     frames = {
-        "camB": _frame(400, 200, 3),
-        "camA": _frame(200, 400, 3),
+        "camB": _frame(400, 200, 3),  # aspect = 200 / 400 = 0.5
+        "camA": _frame(200, 400, 3),  # aspect = 400 / 200 = 2.0
     }
+
     cam_ids, rows, cols, tile_w, tile_h = compute_tiling_geometry(frames, max_canvas=(1200, 800))
-    assert cam_ids == ["camA", "camB"]
+
+    assert cam_ids == ["camB", "camA"]
 
     # For 2 cams, rows=1 cols=2 => initial tile_w=600 tile_h=800 => tile_aspect=0.75
-    # frame_aspect for camA = 400/200 = 2.0 > 0.75 => tile_h adjusted to tile_w/frame_aspect = 600/2 = 300
+    # frame_aspect for camB = 0.5 <= 0.75 => tile_w adjusted to tile_h * frame_aspect = 800 * 0.5 = 400
+    assert (rows, cols) == (1, 2)
+    assert tile_w == 400
+    assert tile_h == 800
+
+
+def test_compute_tiling_geometry_preserves_frame_insertion_order():
+    frames = {
+        "gentl:serial:30220469": np.zeros((10, 20, 3), dtype=np.uint8),
+        "gentl:serial:10620051": np.zeros((10, 20, 3), dtype=np.uint8),
+    }
+
+    cam_ids, rows, cols, tile_w, tile_h = compute_tiling_geometry(frames)
+
+    assert cam_ids == ["gentl:serial:30220469", "gentl:serial:10620051"]
+    assert rows == 1
+    assert cols == 2
+    assert tile_w > 0
+    assert tile_h > 0
+
+
+def test_compute_tiling_geometry_preserves_reversed_insertion_order():
+    frames = {
+        "gentl:serial:10620051": np.zeros((10, 20, 3), dtype=np.uint8),
+        "gentl:serial:30220469": np.zeros((10, 20, 3), dtype=np.uint8),
+    }
+
+    cam_ids, *_ = compute_tiling_geometry(frames)
+
+    assert cam_ids == ["gentl:serial:10620051", "gentl:serial:30220469"]
+
+
+def test_compute_tile_info_uses_display_order_for_offsets():
+    cam0 = "gentl:serial:30220469"
+    cam1 = "gentl:serial:10620051"
+
+    frames = {
+        cam0: np.zeros((100, 200, 3), dtype=np.uint8),
+        cam1: np.zeros((100, 200, 3), dtype=np.uint8),
+    }
+
+    cam_ids, rows, cols, tile_w, tile_h = compute_tiling_geometry(frames)
+
+    offset0, scale0 = compute_tile_info(cam0, frames[cam0], frames)
+    offset1, scale1 = compute_tile_info(cam1, frames[cam1], frames)
+
+    assert cam_ids == [cam0, cam1]
+    assert offset0 == (0, 0)
+    assert offset1 == (tile_w, 0)
+    assert scale0[0] > 0
+    assert scale0[1] > 0
+    assert scale1[0] > 0
+    assert scale1[1] > 0
+
+
+def test_create_tiled_frame_preserves_display_order_by_tile_content():
+    # First frame is blue-ish, second is red-ish.
+    first = np.zeros((100, 100, 3), dtype=np.uint8)
+    first[:, :] = (255, 0, 0)  # BGR blue
+
+    second = np.zeros((100, 100, 3), dtype=np.uint8)
+    second[:, :] = (0, 0, 255)  # BGR red
+
+    frames = {
+        "gentl:serial:30220469": first,
+        "gentl:serial:10620051": second,
+    }
+
+    cam_ids, rows, cols, tile_w, tile_h = compute_tiling_geometry(frames, max_canvas=(400, 200))
+    out = create_tiled_frame(frames, max_canvas=(400, 200))
+
+    assert cam_ids == ["gentl:serial:30220469", "gentl:serial:10620051"]
     assert (rows, cols) == (1, 2)
-    assert tile_w == 600
-    assert tile_h == 300
+
+    # Sample away from text label area.
+    left_sample = out[tile_h // 2, tile_w // 2]
+    right_sample = out[tile_h // 2, tile_w + tile_w // 2]
+
+    assert left_sample[0] > left_sample[2]  # blue tile first
+    assert right_sample[2] > right_sample[0]  # red tile second
 
 
 def test_create_tiled_frame_empty_returns_default_canvas():
@@ -110,16 +193,18 @@ def test_create_tiled_frame_canvas_shape_matches_geometry():
 
 
 def test_compute_tile_info_offset_and_scale_matches_tiling():
-    # 2 frames => 1x2 tiling, cam ids sorted: ["cam1", "cam2"]
+    # 2 frames => 1x2 tiling, preserving insertion/display order: ["cam2", "cam1"]
     frames = {"cam2": _frame(200, 400, 3), "cam1": _frame(200, 400, 3)}
     cam_ids, rows, cols, tile_w, tile_h = compute_tiling_geometry(frames, max_canvas=(1200, 800))
 
     original = _frame(200, 400, 3)
     (ox, oy), (sx, sy) = compute_tile_info("cam2", original, frames, max_canvas=(1200, 800))
 
-    # cam2 is index 1 -> row 0 col 1
+    assert cam_ids == ["cam2", "cam1"]
     assert (rows, cols) == (1, 2)
-    assert ox == tile_w
+
+    # cam2 is first in display order => row 0 col 0
+    assert ox == 0
     assert oy == 0
     assert sx == pytest.approx(tile_w / 400)
     assert sy == pytest.approx(tile_h / 200)

From cf7a23795b7f2106b95fcade860b945bdd13ed27 Mon Sep 17 00:00:00 2001
From: Cyril Achard <cyril.achard@epfl.ch>
Date: Thu, 28 May 2026 15:08:00 +0200
Subject: [PATCH 07/20] Mock _maybe_allow_keyboard_interrupt in GUI tests

Patch tests/gui/test_app_entrypoint.py to monkeypatch appmod._maybe_allow_keyboard_interrupt with a MagicMock in both test_main_with_splash and test_main_without_splash. This prevents the real interrupt-handling helper from running during GUI tests and avoids side effects on global keyboard/signal handling.
---
 tests/gui/test_app_entrypoint.py | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/tests/gui/test_app_entrypoint.py b/tests/gui/test_app_entrypoint.py
index 0a68bb2..b6b1c60 100644
--- a/tests/gui/test_app_entrypoint.py
+++ b/tests/gui/test_app_entrypoint.py
@@ -31,6 +31,7 @@ def set_use_splash_false(monkeypatch):
 @pytest.mark.gui
 def test_main_with_splash(monkeypatch, set_use_splash_true):
     appmod = _import_fresh()
+    monkeypatch.setattr(appmod, "_maybe_allow_keyboard_interrupt", MagicMock(name="_maybe_allow_keyboard_interrupt"))
 
     # --- Patch Qt app & icon in the entry module's namespace ---
     QApplication_cls = MagicMock(name="QApplication")
@@ -101,6 +102,7 @@ def immediate_single_shot(ms, fn):
 @pytest.mark.gui
 def test_main_without_splash(monkeypatch, set_use_splash_false):
     appmod = _import_fresh()
+    monkeypatch.setattr(appmod, "_maybe_allow_keyboard_interrupt", MagicMock(name="_maybe_allow_keyboard_interrupt"))
 
     # Patch Qt app creation & window icon
     QApplication_cls = MagicMock(name="QApplication")

From f56710362203ed66d3effc6096387785a2051528 Mon Sep 17 00:00:00 2001
From: Cyril Achard <cyril.achard@epfl.ch>
Date: Thu, 28 May 2026 15:21:09 +0200
Subject: [PATCH 08/20] Support strict GenTL trigger and defaults

GenTLCameraBackend: add handling for a 'strict' flag when parsing GenTL trigger config so invalid configs raise in strict mode but fall back with a warning otherwise. Preserve the original exception when raising, and improve the warning text to mention strict mode. Return whether LineSelector was actually set and skip configuring trigger output if selection failed to avoid driving an unintended GPIO line.

DLCLiveMainWindow: introduce _with_camera_trigger_defaults_for_save to ensure gentl trigger defaults are stored per camera, refactor _with_camera_defaults_for_save to apply that per-camera, and adjust _current_config to use the first camera with defaults applied. This ensures trigger settings are persisted and validated consistently.
---
 dlclivegui/cameras/backends/gentl_backend.py | 32 ++++++++++++++--
 dlclivegui/gui/main_window.py                | 39 ++++++++++++--------
 2 files changed, 53 insertions(+), 18 deletions(-)

diff --git a/dlclivegui/cameras/backends/gentl_backend.py b/dlclivegui/cameras/backends/gentl_backend.py
index 18c17d2..d97da49 100644
--- a/dlclivegui/cameras/backends/gentl_backend.py
+++ b/dlclivegui/cameras/backends/gentl_backend.py
@@ -106,10 +106,20 @@ def __init__(self, settings):
             self._gain = self._positive_float(ns.get("gain", props.get("gain")))
 
         self._timeout: float = float(ns.get("timeout", props.get("timeout", 2.0)))
+        raw_trigger = ns.get("trigger", props.get("trigger"))
+        raw_trigger_strict = isinstance(raw_trigger, dict) and bool(raw_trigger.get("strict", False))
+
         try:
-            self._trigger = CameraTriggerSettings.from_any(ns.get("trigger", props.get("trigger")))
+            self._trigger = CameraTriggerSettings.from_any(raw_trigger)
         except Exception as exc:
-            LOG.warning("Invalid GenTL trigger config; falling back to trigger role=off: %s", exc)
+            if raw_trigger_strict:
+                raise ValueError(f"Strict mode failure - Invalid GenTL trigger configuration: {exc}") from exc
+
+            LOG.warning(
+                "Invalid GenTL trigger config; falling back to trigger role=off: %s. "
+                "Enable strict mode to force this to raise.",
+                exc,
+            )
             self._trigger = CameraTriggerSettings()
 
         trigger_timeout = self._positive_float(self._trigger_attr(self._trigger, "timeout", None))
@@ -1145,7 +1155,23 @@ def _configure_trigger_master(self, node_map, cfg, *, strict: bool = False) -> N
         # Master camera runs freerun and exposes an output signal.
         self._configure_trigger_off(node_map, strict=False)
 
-        self._set_enum_node(node_map, "LineSelector", output_line, strict=strict)
+        line_selected = self._set_enum_node(
+            node_map,
+            "LineSelector",
+            output_line,
+            strict=strict,
+        )
+
+        # In non-strict mode, do not continue configuring output behavior if the
+        # requested line could not be selected. Otherwise we may accidentally drive
+        # whichever GPIO line the camera had selected previously/defaulted to.
+        if not line_selected:
+            LOG.warning(
+                "Could not select GenTL output line '%s'; skipping trigger output configuration.",
+                output_line,
+            )
+            return
+
         self._set_enum_node(node_map, "LineMode", "Output", strict=strict)
         self._set_enum_node(node_map, "LineSource", output_source, strict=strict)
 
diff --git a/dlclivegui/gui/main_window.py b/dlclivegui/gui/main_window.py
index def6094..2951681 100644
--- a/dlclivegui/gui/main_window.py
+++ b/dlclivegui/gui/main_window.py
@@ -855,31 +855,40 @@ def _apply_config(self, config: ApplicationSettings) -> None:
         # Update recording path preview
         self._update_recording_path_preview()
 
-    def _with_camera_defaults_for_save(self, settings: MultiCameraSettings) -> MultiCameraSettings:
-        out = settings.model_copy(deep=True)
+    def _with_camera_trigger_defaults_for_save(self, cam: CameraSettings) -> CameraSettings:
+        out = cam.model_copy(deep=True)
 
-        for cam in out.cameras:
-            backend = (cam.backend or "").lower()
-            if backend != "gentl":
-                continue
+        backend = (out.backend or "").lower()
+        if backend != "gentl":
+            return out
 
-            if not isinstance(cam.properties, dict):
-                cam.properties = {}
+        if not isinstance(out.properties, dict):
+            out.properties = {}
 
-            ns = cam.properties.setdefault("gentl", {})
-            if not isinstance(ns, dict):
-                ns = {}
-                cam.properties["gentl"] = ns
+        ns = out.properties.setdefault("gentl", {})
+        if not isinstance(ns, dict):
+            ns = {}
+            out.properties["gentl"] = ns
 
-            ns.setdefault("trigger", CameraTriggerSettings().model_dump(exclude_none=True))
+        ns.setdefault("trigger", CameraTriggerSettings().model_dump(exclude_none=True))
+
+        return out
+
+    def _with_camera_defaults_for_save(self, settings: MultiCameraSettings) -> MultiCameraSettings:
+        out = settings.model_copy(deep=True)
+
+        out.cameras = [self._with_camera_trigger_defaults_for_save(cam) for cam in out.cameras]
 
         return out
 
     def _current_config(self, *, allow_empty_model_path=False) -> ApplicationSettings:
         # Get the first camera from multi-camera config for backward compatibility
         multi_camera = self._with_camera_defaults_for_save(self._config.multi_camera)
-        active_cameras = self._config.multi_camera.get_active_cameras()
-        camera = active_cameras[0] if active_cameras else CameraSettings()
+        camera = (
+            multi_camera.cameras[0].model_copy(deep=True)
+            if multi_camera.cameras
+            else self._with_camera_trigger_defaults_for_save(self._config.camera)
+        )
 
         return ApplicationSettings(
             camera=camera,

From ea49e5abaa2f04852ec3d4de0fd64fd0ecc2831c Mon Sep 17 00:00:00 2001
From: Cyril Achard <cyril.achard@epfl.ch>
Date: Thu, 28 May 2026 15:30:07 +0200
Subject: [PATCH 09/20] Apply gentl trigger defaults when saving

Add with_save_defaults helpers to CameraSettings and MultiCameraSettings and use them when serializing ApplicationSettings so gentl "trigger" defaults are applied to saved configs. Remove duplicated camera-default helper logic from DLCLiveMainWindow and simplify _current_config to rely on model methods. Add unit tests to verify gentl trigger defaults are included for top-level and multi-camera cases.
---
 dlclivegui/config.py          | 44 +++++++++++++++++++++++++++++++----
 dlclivegui/gui/main_window.py | 32 ++-----------------------
 tests/test_config.py          | 36 ++++++++++++++++++++++++++++
 3 files changed, 77 insertions(+), 35 deletions(-)
 create mode 100644 tests/test_config.py

diff --git a/dlclivegui/config.py b/dlclivegui/config.py
index 154eabf..c7a474b 100644
--- a/dlclivegui/config.py
+++ b/dlclivegui/config.py
@@ -190,6 +190,25 @@ def set_trigger_settings(self, trigger: CameraTriggerSettings, backend: str | No
             self.properties[str(key).lower()] = ns
         ns["trigger"] = trigger.to_properties()
 
+    def with_save_defaults(self) -> CameraSettings:
+        out = self.model_copy(deep=True)
+
+        backend = (out.backend or "").lower()
+        if backend != "gentl":
+            return out
+
+        if not isinstance(out.properties, dict):
+            out.properties = {}
+
+        ns = out.properties.setdefault("gentl", {})
+        if not isinstance(ns, dict):
+            ns = {}
+            out.properties["gentl"] = ns
+
+        ns.setdefault("trigger", CameraTriggerSettings().to_properties())
+
+        return out
+
 
 class CameraTriggerSettings(BaseModel):
     """
@@ -302,12 +321,19 @@ def from_dict(cls, data: dict[str, Any]) -> MultiCameraSettings:
         return cls(cameras=cameras, max_cameras=max_cameras, tile_layout=tile_layout)
 
     def to_dict(self) -> dict[str, Any]:
+        out = self.with_save_defaults()
         return {
-            "cameras": [cam.model_dump() for cam in self.cameras],
-            "max_cameras": self.max_cameras,
-            "tile_layout": self.tile_layout,
+            "cameras": [cam.model_dump() for cam in out.cameras],
+            "max_cameras": out.max_cameras,
+            "tile_layout": out.tile_layout,
         }
 
+    def with_save_defaults(self) -> MultiCameraSettings:
+        """Return a copy with save defaults applied to all cameras."""
+        out = self.model_copy(deep=True)
+        out.cameras = [cam.with_save_defaults() for cam in out.cameras]
+        return out
+
 
 class DynamicCropModel(BaseModel):
     enabled: bool = False
@@ -473,10 +499,18 @@ def from_dict(cls, data: dict[str, Any]) -> ApplicationSettings:
         )
 
     def to_dict(self) -> dict[str, Any]:
+        multi_camera = self.multi_camera.with_save_defaults()
+        active_cameras = multi_camera.get_active_cameras()
+
+        if active_cameras:
+            camera = active_cameras[0].model_copy(deep=True)
+        else:
+            camera = self.camera.with_save_defaults()
+
         return {
             "version": self.version,
-            "camera": self.camera.model_dump(),
-            "multi_camera": self.multi_camera.to_dict(),
+            "camera": camera.model_dump(),
+            "multi_camera": multi_camera.to_dict(),
             "dlc": self.dlc.model_dump(),
             "recording": self.recording.model_dump(),
             "bbox": self.bbox.model_dump(),
diff --git a/dlclivegui/gui/main_window.py b/dlclivegui/gui/main_window.py
index 2951681..4dbf830 100644
--- a/dlclivegui/gui/main_window.py
+++ b/dlclivegui/gui/main_window.py
@@ -56,7 +56,6 @@
     ApplicationSettings,
     BoundingBoxSettings,
     CameraSettings,
-    CameraTriggerSettings,
     DLCProcessorSettings,
     MultiCameraSettings,
     RecordingSettings,
@@ -855,39 +854,12 @@ def _apply_config(self, config: ApplicationSettings) -> None:
         # Update recording path preview
         self._update_recording_path_preview()
 
-    def _with_camera_trigger_defaults_for_save(self, cam: CameraSettings) -> CameraSettings:
-        out = cam.model_copy(deep=True)
-
-        backend = (out.backend or "").lower()
-        if backend != "gentl":
-            return out
-
-        if not isinstance(out.properties, dict):
-            out.properties = {}
-
-        ns = out.properties.setdefault("gentl", {})
-        if not isinstance(ns, dict):
-            ns = {}
-            out.properties["gentl"] = ns
-
-        ns.setdefault("trigger", CameraTriggerSettings().model_dump(exclude_none=True))
-
-        return out
-
-    def _with_camera_defaults_for_save(self, settings: MultiCameraSettings) -> MultiCameraSettings:
-        out = settings.model_copy(deep=True)
-
-        out.cameras = [self._with_camera_trigger_defaults_for_save(cam) for cam in out.cameras]
-
-        return out
-
     def _current_config(self, *, allow_empty_model_path=False) -> ApplicationSettings:
-        # Get the first camera from multi-camera config for backward compatibility
-        multi_camera = self._with_camera_defaults_for_save(self._config.multi_camera)
+        multi_camera = self._config.multi_camera
         camera = (
             multi_camera.cameras[0].model_copy(deep=True)
             if multi_camera.cameras
-            else self._with_camera_trigger_defaults_for_save(self._config.camera)
+            else self._config.camera.model_copy(deep=True)
         )
 
         return ApplicationSettings(
diff --git a/tests/test_config.py b/tests/test_config.py
new file mode 100644
index 0000000..f0165f4
--- /dev/null
+++ b/tests/test_config.py
@@ -0,0 +1,36 @@
+import pytest
+
+from dlclivegui.config import ApplicationSettings, CameraSettings, MultiCameraSettings
+
+
+@pytest.mark.unit
+def test_save_applies_gentl_trigger_defaults_to_top_level_camera():
+    cam = CameraSettings(
+        backend="gentl",
+        properties={"gentl": {}},
+    )
+
+    settings = ApplicationSettings(
+        camera=cam,
+        multi_camera=MultiCameraSettings(cameras=[cam]),
+    )
+
+    data = settings.to_dict()
+
+    assert "trigger" in data["camera"]["properties"]["gentl"]
+
+
+@pytest.mark.unit
+def test_save_applies_gentl_trigger_defaults_to_multi_camera():
+    cam = CameraSettings(
+        backend="gentl",
+        properties={"gentl": {}},
+    )
+
+    settings = ApplicationSettings(
+        multi_camera=MultiCameraSettings(cameras=[cam]),
+    )
+
+    data = settings.to_dict()
+
+    assert "trigger" in data["multi_camera"]["cameras"][0]["properties"]["gentl"]

From b073ce3a27b39f905adbd8c5fa68d08826696d68 Mon Sep 17 00:00:00 2001
From: Cyril Achard <cyril.achard@epfl.ch>
Date: Thu, 28 May 2026 15:36:54 +0200
Subject: [PATCH 10/20] Don't sort available camera IDs

Remove sorting when building available_ids so the original frame key order is preserved. The DLC camera selection relies on the first active camera in frame_data.frames; using list(...) keeps the insertion/order semantics (dict order) instead of reordering keys with sorted(). This avoids unintended changes to camera priority caused by alphabetical/numeric sorting.
---
 dlclivegui/gui/main_window.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/dlclivegui/gui/main_window.py b/dlclivegui/gui/main_window.py
index 4dbf830..0b8a215 100644
--- a/dlclivegui/gui/main_window.py
+++ b/dlclivegui/gui/main_window.py
@@ -1384,7 +1384,7 @@ def _on_multi_frame_ready(self, frame_data: MultiFrameData) -> None:
 
         # Determine DLC camera (first active camera)
         selected_id = self._inference_camera_id
-        available_ids = sorted(frame_data.frames.keys())
+        available_ids = list(frame_data.frames.keys())
         if selected_id in frame_data.frames:
             dlc_cam_id = selected_id
         else:

From cd562d54b78e9755e1e2d225fc26b6887f5f0dea Mon Sep 17 00:00:00 2001
From: Cyril Achard <cyril.achard@epfl.ch>
Date: Thu, 28 May 2026 16:02:13 +0200
Subject: [PATCH 11/20] Preserve DLC config using model_copy

Initialize an existing DLC config (falling back to DEFAULT_CONFIG if unset) and use its model_copy(update=...) to return settings. This replaces explicit field-by-field construction so only model_path (and model_type when set) are changed, preserving other DLC options and avoiding duplication.
---
 dlclivegui/gui/main_window.py | 38 ++++++++++++++++++-----------------
 1 file changed, 20 insertions(+), 18 deletions(-)

diff --git a/dlclivegui/gui/main_window.py b/dlclivegui/gui/main_window.py
index 0b8a215..4f07bd7 100644
--- a/dlclivegui/gui/main_window.py
+++ b/dlclivegui/gui/main_window.py
@@ -883,19 +883,23 @@ def _dlc_settings_from_ui(self, *, allow_empty_model_path=False) -> DLCProcessor
             # IMPORTANT NOTE: DLClive expects a directory for TensorFlow models,
             # so if user selects a .pb file, we should pass the parent directory to DLCLive
             model_path = str(Path(model_path).parent)
+
+        existing_dlc = (  # explicitly init from default if unset
+            self._config.dlc.model_copy(deep=True)
+            if getattr(self._config, "dlc", None) is not None
+            else DEFAULT_CONFIG.dlc.model_copy(deep=True)
+        )
         if not model_path:
             if allow_empty_model_path:
-                return DLCProcessorSettings(
-                    model_path="",
-                    model_directory=self._config.dlc.model_directory,  # Preserve from config
-                    device=self._config.dlc.device,  # Preserve from config
-                    dynamic=self._config.dlc.dynamic,  # Preserve from config
-                    resize=self._config.dlc.resize,  # Preserve from config
-                    precision=self._config.dlc.precision,  # Preserve from config
-                    model_type=None,
-                    # additional_options=self._parse_json(self.additional_options_edit.toPlainText()),
+                # Preserve all existing DLC settings and only clear the model path.
+                return existing_dlc.model_copy(
+                    update={
+                        "model_path": "",
+                    }
                 )
+
             raise ValueError("Model path cannot be empty. Please enter a valid path to a DLCLive model file.")
+
         try:
             model_bknd = DLCLiveProcessor.get_model_backend(model_path)
         except Exception as e:
@@ -904,15 +908,13 @@ def _dlc_settings_from_ui(self, *, allow_empty_model_path=False) -> DLCProcessor
                 "Please ensure the model file is valid and has an appropriate extension "
                 "(.pt, .pth for PyTorch or model directory for TensorFlow)."
             ) from e
-        return DLCProcessorSettings(
-            model_path=model_path,
-            model_directory=self._config.dlc.model_directory,  # Preserve from config
-            device=self._config.dlc.device,  # Preserve from config
-            dynamic=self._config.dlc.dynamic,  # Preserve from config
-            resize=self._config.dlc.resize,  # Preserve from config
-            precision=self._config.dlc.precision,  # Preserve from config
-            model_type=model_bknd,
-            # additional_options=self._parse_json(self.additional_options_edit.toPlainText()),
+
+        # Preserve all unchanged DLC settings and only update values derived from the UI.
+        return existing_dlc.model_copy(
+            update={
+                "model_path": model_path,
+                "model_type": model_bknd,
+            }
         )
 
     def _recording_settings_from_ui(self) -> RecordingSettings:

From 0cc318ba2a5d6839754fc80b97d815f7a1989d7b Mon Sep 17 00:00:00 2001
From: Cyril Achard <cyril.achard@epfl.ch>
Date: Thu, 28 May 2026 16:56:14 +0200
Subject: [PATCH 12/20] Warn when GenTL TriggerMode fails to enable

Add a warning log when setting GenTL TriggerMode to 'On' fails in non-strict mode. Previously the code only raised an exception in strict mode; now it emits a warning to inform users that the trigger mode may not be correctly configured when continuing without strict enforcement.
---
 dlclivegui/cameras/backends/gentl_backend.py | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/dlclivegui/cameras/backends/gentl_backend.py b/dlclivegui/cameras/backends/gentl_backend.py
index d97da49..d7811fc 100644
--- a/dlclivegui/cameras/backends/gentl_backend.py
+++ b/dlclivegui/cameras/backends/gentl_backend.py
@@ -1139,6 +1139,8 @@ def _configure_trigger_input(self, node_map, cfg, *, strict: bool = False) -> No
         if not self._set_enum_node(node_map, "TriggerMode", "On", strict=strict):
             if strict:
                 raise RuntimeError("Could not enable GenTL TriggerMode=On")
+            else:
+                LOG.warning("Could not enable GenTL TriggerMode=On; trigger mode may not be correctly configured.")
 
         LOG.info(
             "GenTL trigger input configured: role=%s selector=%s source=%s activation=%s",

From 973d69fe67e709bdcbc91723d6632e8d67803879 Mon Sep 17 00:00:00 2001
From: C-Achard <cyril.achard@epfl.ch>
Date: Thu, 28 May 2026 17:47:00 +0200
Subject: [PATCH 13/20] Improve GenTL trigger routing safety and tests

Make GenTLCameraBackend trigger configuration more robust and adjust tests.

- Use the waits_for_hardware_trigger property when converting GenTL timeouts to user-facing errors instead of inferring from the role string.
- Read and record the configured trigger role early in _configure_trigger_input.
- Check results when setting TriggerSelector, TriggerSource and TriggerActivation (selector_ok, source_ok, activation_ok). If selector/source routing fails in non-strict mode, disable the trigger, reset internal trigger state and log a warning to avoid arming the camera on a previous/default input line. If activation fails, warn and continue using the camera default.
- If enabling TriggerMode=On fails, disable the trigger and reset internal state instead of only warning.
- Validate LineMode and LineSource when configuring master output and log if configuration is incomplete.

Tests updated to reflect safety changes:
- Expect waits_for_hardware_trigger to be set for external input configuration.
- Rename and change a non-strict invalid-source test to assert the trigger is disabled, waits_for_hardware_trigger is False, and trigger_actual is persisted as off.
- Add a new test ensuring an invalid selector in non-strict mode disables the trigger and persists the off state.

These changes prevent the camera from being left armed on an unintended/default input if routing nodes could not be applied, improving safety and predictability.
---
 dlclivegui/cameras/backends/gentl_backend.py | 64 ++++++++++++++++----
 tests/cameras/backends/test_gentl_trigger.py | 49 +++++++++++++--
 2 files changed, 98 insertions(+), 15 deletions(-)

diff --git a/dlclivegui/cameras/backends/gentl_backend.py b/dlclivegui/cameras/backends/gentl_backend.py
index d7811fc..a09a273 100644
--- a/dlclivegui/cameras/backends/gentl_backend.py
+++ b/dlclivegui/cameras/backends/gentl_backend.py
@@ -498,8 +498,7 @@ def read(self) -> tuple[np.ndarray, float]:
                 except ValueError:
                     frame = array.copy()
         except HarvesterTimeoutError as exc:
-            role = str(self._trigger_attr(getattr(self, "_trigger", None), "role", "off") or "off").lower()
-            if role in {"external", "follower"}:
+            if self.waits_for_hardware_trigger:
                 raise TimeoutError(str(exc) + " (GenTL timeout; waiting for hardware trigger?)") from exc
             raise TimeoutError(str(exc) + " (GenTL timeout)") from exc
 
@@ -1123,6 +1122,7 @@ def _configure_trigger_off(self, node_map, *, strict: bool = False) -> None:
         self._set_enum_node(node_map, "TriggerMode", "Off", strict=strict)
 
     def _configure_trigger_input(self, node_map, cfg, *, strict: bool = False) -> None:
+        role = str(self._trigger_attr(cfg, "role", "external") or "external").strip().lower()
         selector = str(self._trigger_attr(cfg, "selector", "FrameStart") or "FrameStart")
         source = str(self._trigger_attr(cfg, "source", "Line0") or "Line0")
         activation = str(self._trigger_attr(cfg, "activation", "RisingEdge") or "RisingEdge")
@@ -1130,17 +1130,51 @@ def _configure_trigger_input(self, node_map, cfg, *, strict: bool = False) -> No
         # Disable trigger while changing trigger-related nodes.
         self._set_enum_node(node_map, "TriggerMode", "Off", strict=False)
 
-        self._set_enum_node(node_map, "TriggerSelector", selector, strict=strict)
-        self._set_enum_node(node_map, "TriggerSource", source, strict=strict)
-        self._set_enum_node(node_map, "TriggerActivation", activation, strict=strict)
+        selector_ok = self._set_enum_node(node_map, "TriggerSelector", selector, strict=strict)
+        source_ok = self._set_enum_node(node_map, "TriggerSource", source, strict=strict)
+        activation_ok = self._set_enum_node(node_map, "TriggerActivation", activation, strict=strict)
+
+        # TriggerSelector and TriggerSource are required routing nodes.
+        # If either failed in non-strict mode, do not arm TriggerMode=On.
+        # Otherwise the camera may wait on a previous/default input line.
+        if not (selector_ok and source_ok):
+            LOG.warning(
+                "Could not apply GenTL trigger input routing "
+                "(selector_ok=%s, source_ok=%s); disabling trigger. "
+                "requested role=%s selector=%s source=%s activation=%s",
+                selector_ok,
+                source_ok,
+                role,
+                selector,
+                source,
+                activation,
+            )
+            self._configure_trigger_off(node_map, strict=False)
+            self._trigger = CameraTriggerSettings()
+            return
+
+        if not activation_ok:
+            LOG.warning(
+                "Could not apply GenTL TriggerActivation=%s; using camera default/current activation.",
+                activation,
+            )
 
         self._set_enum_node(node_map, "AcquisitionMode", "Continuous", strict=False)
 
         if not self._set_enum_node(node_map, "TriggerMode", "On", strict=strict):
-            if strict:
-                raise RuntimeError("Could not enable GenTL TriggerMode=On")
-            else:
-                LOG.warning("Could not enable GenTL TriggerMode=On; trigger mode may not be correctly configured.")
+            LOG.warning("Could not enable GenTL TriggerMode=On; disabling trigger.")
+            self._configure_trigger_off(node_map, strict=False)
+            self._trigger = CameraTriggerSettings()
+            return
+
+        LOG.info(
+            "GenTL trigger input configured: role=%s selector=%s source=%s activation=%s activation_ok=%s",
+            role,
+            selector,
+            source,
+            activation,
+            activation_ok,
+        )
 
         LOG.info(
             "GenTL trigger input configured: role=%s selector=%s source=%s activation=%s",
@@ -1174,8 +1208,16 @@ def _configure_trigger_master(self, node_map, cfg, *, strict: bool = False) -> N
             )
             return
 
-        self._set_enum_node(node_map, "LineMode", "Output", strict=strict)
-        self._set_enum_node(node_map, "LineSource", output_source, strict=strict)
+        mode_ok = self._set_enum_node(node_map, "LineMode", "Output", strict=strict)
+        source_ok = self._set_enum_node(node_map, "LineSource", output_source, strict=strict)
+
+        if not (mode_ok and source_ok):
+            LOG.warning(
+                "GenTL trigger master output configuration incomplete (LineMode ok=%s, LineSource ok=%s).",
+                mode_ok,
+                source_ok,
+            )
+            return
 
         LOG.info(
             "GenTL trigger master configured: output_line=%s output_source=%s",
diff --git a/tests/cameras/backends/test_gentl_trigger.py b/tests/cameras/backends/test_gentl_trigger.py
index f0d5f45..5d774af 100644
--- a/tests/cameras/backends/test_gentl_trigger.py
+++ b/tests/cameras/backends/test_gentl_trigger.py
@@ -75,6 +75,7 @@ def test_trigger_external_configures_input_line_and_timeout(patch_gentl_sdk, gen
     assert nm.TriggerSource.value == "Line0"
     assert nm.TriggerActivation.value == "RisingEdge"
     assert nm.TriggerMode.value == "On"
+    assert be.waits_for_hardware_trigger is True
     assert be._timeout == pytest.approx(10.0)
 
     ns = settings.properties["gentl"]
@@ -140,7 +141,7 @@ def test_trigger_master_configures_output_line_and_keeps_trigger_off(patch_gentl
     be.close()
 
 
-def test_trigger_invalid_source_non_strict_does_not_crash(patch_gentl_sdk, gentl_settings_factory):
+def test_trigger_invalid_source_non_strict_disables_trigger(patch_gentl_sdk, gentl_settings_factory):
     gb = patch_gentl_sdk
 
     settings = _gentl_trigger_settings(
@@ -158,9 +159,17 @@ def test_trigger_invalid_source_non_strict_does_not_crash(patch_gentl_sdk, gentl
 
     # Source was unsupported, so the fake node should retain its default.
     assert nm.TriggerSource.value == "Line0"
-    # Non-strict mode should still allow opening; TriggerMode may be enabled
-    # because TriggerSource failure is best-effort in this mode.
-    assert be._acquirer is not None
+
+    # Safety behavior: do not arm TriggerMode on the previous/default source.
+    assert nm.TriggerMode.value == "Off"
+
+    # Controller should not treat timeouts as expected trigger waits.
+    assert be.waits_for_hardware_trigger is False
+
+    # trigger_actual is persisted after _configure_trigger(); since we reset
+    # self._trigger to off, the effective trigger state is off.
+    actual = settings.properties["gentl"]["trigger_actual"]
+    assert actual["role"] == "off"
 
     be.close()
 
@@ -331,3 +340,35 @@ def test_trigger_actual_is_persisted_for_debugging(patch_gentl_sdk, gentl_settin
     assert actual["timeout"] == pytest.approx(9.0)
 
     be.close()
+
+
+def test_trigger_invalid_selector_non_strict_disables_trigger(patch_gentl_sdk, gentl_settings_factory):
+    gb = patch_gentl_sdk
+
+    settings = _gentl_trigger_settings(
+        gentl_settings_factory,
+        {
+            "role": "external",
+            "selector": "NotARealSelector",
+            "source": "Line1",
+            "strict": False,
+        },
+    )
+    be = gb.GenTLCameraBackend(settings)
+
+    be.open()
+    nm = be._acquirer.remote_device.node_map
+
+    # Selector was unsupported, so the fake node should retain its default.
+    assert nm.TriggerSelector.value == "FrameStart"
+
+    # Source may have been applied, but trigger must not be armed because
+    # the required selector routing failed.
+    assert nm.TriggerSource.value == "Line1"
+    assert nm.TriggerMode.value == "Off"
+    assert be.waits_for_hardware_trigger is False
+
+    actual = settings.properties["gentl"]["trigger_actual"]
+    assert actual["role"] == "off"
+
+    be.close()

From 7942066c9067f0773f39775e93c1e547272b7c4f Mon Sep 17 00:00:00 2001
From: C-Achard <cyril.achard@epfl.ch>
Date: Thu, 28 May 2026 17:54:22 +0200
Subject: [PATCH 14/20] Cap hardware-trigger fetch timeout and update tests

Introduce a MAX_HARDWARE_TRIGGER_FETCH_TIMEOUT and cap Harvester.fetch() timeouts when the trigger role waits for external hardware (roles: external, follower) to keep individual fetch calls short and allow prompt shutdown. Preserve legacy behavior for non-waiting roles (e.g. master). Remove a noisy Trigger input LOG.info call. Update tests to expect the capped fetch timeout, verify the original requested timeout is still persisted in trigger_actual, add a test that master mode is not capped, and make test resource cleanup more robust (use try/finally around open/close).
---
 dlclivegui/cameras/backends/gentl_backend.py |  24 +++--
 tests/cameras/backends/test_gentl_trigger.py | 106 ++++++++++++++-----
 2 files changed, 93 insertions(+), 37 deletions(-)

diff --git a/dlclivegui/cameras/backends/gentl_backend.py b/dlclivegui/cameras/backends/gentl_backend.py
index a09a273..1c63c60 100644
--- a/dlclivegui/cameras/backends/gentl_backend.py
+++ b/dlclivegui/cameras/backends/gentl_backend.py
@@ -76,6 +76,11 @@ class GenTLCameraBackend(CameraBackend):
     _CTI_FILES_SOURCE_AUTO: ClassVar[str] = "auto"
     _CTI_FILES_SOURCE_USER: ClassVar[str] = "user"
 
+    # Keep individual Harvester.fetch() calls short enough that controller
+    # shutdown can stop worker threads promptly. Hardware-trigger waits are
+    # handled by repeated polling in SingleCameraWorker.
+    _MAX_HARDWARE_TRIGGER_FETCH_TIMEOUT: ClassVar[float] = 1.0
+
     def __init__(self, settings):
         super().__init__(settings)
 
@@ -124,7 +129,16 @@ def __init__(self, settings):
 
         trigger_timeout = self._positive_float(self._trigger_attr(self._trigger, "timeout", None))
         if trigger_timeout is not None:
-            self._timeout = float(trigger_timeout)
+            role = str(self._trigger_attr(self._trigger, "role", "off") or "off").strip().lower()
+
+            if role in {"external", "follower"}:
+                # Do not let a long hardware-trigger wait block shutdown.
+                # SingleCameraWorker treats these fetch timeouts as expected
+                # polling misses while waits_for_hardware_trigger is true.
+                self._timeout = min(float(trigger_timeout), self._MAX_HARDWARE_TRIGGER_FETCH_TIMEOUT)
+            else:
+                # For non-trigger-waiting modes, preserve legacy behavior.
+                self._timeout = float(trigger_timeout)
 
         self._requested_resolution: tuple[int, int] | None = self._get_requested_resolution_or_none()
 
@@ -1176,14 +1190,6 @@ def _configure_trigger_input(self, node_map, cfg, *, strict: bool = False) -> No
             activation_ok,
         )
 
-        LOG.info(
-            "GenTL trigger input configured: role=%s selector=%s source=%s activation=%s",
-            self._trigger_attr(cfg, "role", "external"),
-            selector,
-            source,
-            activation,
-        )
-
     def _configure_trigger_master(self, node_map, cfg, *, strict: bool = False) -> None:
         output_line = str(self._trigger_attr(cfg, "output_line", "Line2") or "Line2")
         output_source = str(self._trigger_attr(cfg, "output_source", "ExposureActive") or "ExposureActive")
diff --git a/tests/cameras/backends/test_gentl_trigger.py b/tests/cameras/backends/test_gentl_trigger.py
index 5d774af..e060035 100644
--- a/tests/cameras/backends/test_gentl_trigger.py
+++ b/tests/cameras/backends/test_gentl_trigger.py
@@ -63,7 +63,7 @@ def test_trigger_external_configures_input_line_and_timeout(patch_gentl_sdk, gen
             "selector": "FrameStart",
             "source": "Line0",
             "activation": "RisingEdge",
-            "timeout": 10.0,
+            "timeout": gb.GenTLCameraBackend._MAX_HARDWARE_TRIGGER_FETCH_TIMEOUT,
         },
     )
     be = gb.GenTLCameraBackend(settings)
@@ -76,7 +76,7 @@ def test_trigger_external_configures_input_line_and_timeout(patch_gentl_sdk, gen
     assert nm.TriggerActivation.value == "RisingEdge"
     assert nm.TriggerMode.value == "On"
     assert be.waits_for_hardware_trigger is True
-    assert be._timeout == pytest.approx(10.0)
+    assert be._timeout == pytest.approx(gb.GenTLCameraBackend._MAX_HARDWARE_TRIGGER_FETCH_TIMEOUT)
 
     ns = settings.properties["gentl"]
     assert ns["trigger_actual"]["role"] == "external"
@@ -265,8 +265,12 @@ def test_trigger_alias_on_maps_to_external(patch_gentl_sdk, gentl_settings_facto
     be.close()
 
 
-def test_trigger_timeout_overrides_default_fetch_timeout(patch_gentl_sdk, gentl_settings_factory):
+def test_trigger_timeout_is_capped_for_hardware_trigger_fetch_polling(
+    patch_gentl_sdk,
+    gentl_settings_factory,
+):
     gb = patch_gentl_sdk
+    expected_fetch_timeout = gb.GenTLCameraBackend._MAX_HARDWARE_TRIGGER_FETCH_TIMEOUT
 
     settings = _gentl_trigger_settings(
         gentl_settings_factory,
@@ -277,18 +281,30 @@ def test_trigger_timeout_overrides_default_fetch_timeout(patch_gentl_sdk, gentl_
     )
     be = gb.GenTLCameraBackend(settings)
 
-    be.open()
-    assert be._timeout == pytest.approx(7.5)
+    try:
+        be.open()
 
-    # Fake acquisition is started, so read should pass and record the timeout.
-    frame, _ = be.read()
-    assert frame is not None
-    assert be._acquirer.fetch_calls[-1] == pytest.approx(7.5)
+        # Hardware-trigger fetch calls are intentionally capped so stop(wait=True)
+        # is not blocked by a long user trigger timeout.
+        assert be._timeout == pytest.approx(expected_fetch_timeout)
 
-    be.close()
+        # Fake acquisition is started, so read should pass and record the capped timeout.
+        frame, _ = be.read()
+        assert frame is not None
+        assert be._acquirer.fetch_calls[-1] == pytest.approx(expected_fetch_timeout)
+
+        # The requested trigger timeout is still preserved in persisted trigger_actual.
+        actual = settings.properties["gentl"]["trigger_actual"]
+        assert actual["timeout"] == pytest.approx(7.5)
 
+    finally:
+        be.close()
 
-def test_trigger_timeout_error_mentions_hardware_trigger_when_waiting(patch_gentl_sdk, gentl_settings_factory):
+
+def test_trigger_timeout_error_mentions_hardware_trigger_when_waiting(
+    patch_gentl_sdk,
+    gentl_settings_factory,
+):
     gb = patch_gentl_sdk
 
     settings = _gentl_trigger_settings(
@@ -297,22 +313,27 @@ def test_trigger_timeout_error_mentions_hardware_trigger_when_waiting(patch_gent
             "role": "external",
             "timeout": 3.0,
         },
-        # fast_start keeps acquisition stopped; fake fetch then raises timeout.
-        # This lets us assert the backend timeout message without hardware.
     )
+    # fast_start keeps acquisition stopped; fake fetch then raises timeout.
+    # This lets us assert the backend timeout message without hardware.
     settings.properties["gentl"]["fast_start"] = True
+
     be = gb.GenTLCameraBackend(settings)
 
-    be.open()
+    try:
+        be.open()
 
-    with pytest.raises(TimeoutError) as ei:
-        be.read()
+        assert be._timeout == pytest.approx(gb.GenTLCameraBackend._MAX_HARDWARE_TRIGGER_FETCH_TIMEOUT)
 
-    msg = str(ei.value).lower()
-    assert "gentl timeout" in msg
-    assert "hardware trigger" in msg or "trigger" in msg
+        with pytest.raises(TimeoutError) as ei:
+            be.read()
 
-    be.close()
+        msg = str(ei.value).lower()
+        assert "gentl timeout" in msg
+        assert "hardware trigger" in msg or "trigger" in msg
+
+    finally:
+        be.close()
 
 
 def test_trigger_actual_is_persisted_for_debugging(patch_gentl_sdk, gentl_settings_factory):
@@ -330,16 +351,22 @@ def test_trigger_actual_is_persisted_for_debugging(patch_gentl_sdk, gentl_settin
     )
     be = gb.GenTLCameraBackend(settings)
 
-    be.open()
+    try:
+        be.open()
 
-    actual = settings.properties["gentl"].get("trigger_actual")
-    assert isinstance(actual, dict)
-    assert actual["role"] == "follower"
-    assert actual["source"] == "Line1"
-    assert actual["activation"] == "FallingEdge"
-    assert actual["timeout"] == pytest.approx(9.0)
+        # Requested timeout remains in trigger_actual for debugging/config visibility.
+        actual = settings.properties["gentl"].get("trigger_actual")
+        assert isinstance(actual, dict)
+        assert actual["role"] == "follower"
+        assert actual["source"] == "Line1"
+        assert actual["activation"] == "FallingEdge"
+        assert actual["timeout"] == pytest.approx(9.0)
 
-    be.close()
+        # But each blocking Harvester.fetch() call is capped for responsive shutdown.
+        assert be._timeout == pytest.approx(gb.GenTLCameraBackend._MAX_HARDWARE_TRIGGER_FETCH_TIMEOUT)
+
+    finally:
+        be.close()
 
 
 def test_trigger_invalid_selector_non_strict_disables_trigger(patch_gentl_sdk, gentl_settings_factory):
@@ -372,3 +399,26 @@ def test_trigger_invalid_selector_non_strict_disables_trigger(patch_gentl_sdk, g
     assert actual["role"] == "off"
 
     be.close()
+
+
+def test_trigger_timeout_not_capped_for_master_mode(patch_gentl_sdk, gentl_settings_factory):
+    gb = patch_gentl_sdk
+
+    settings = _gentl_trigger_settings(
+        gentl_settings_factory,
+        {
+            "role": "master",
+            "timeout": 7.5,
+        },
+    )
+    be = gb.GenTLCameraBackend(settings)
+
+    try:
+        be.open()
+
+        # Master is free-running / trigger-generating, not waiting for hardware input.
+        assert be.waits_for_hardware_trigger is False
+        assert be._timeout == pytest.approx(7.5)
+
+    finally:
+        be.close()

From 93c2a730d794c834fbbbf7b19595a729390102e7 Mon Sep 17 00:00:00 2001
From: Cyril Achard <cyril.achard@epfl.ch>
Date: Fri, 29 May 2026 10:19:58 +0200
Subject: [PATCH 15/20] Interruptible camera waits; simplify config save

Make SingleCameraWorker sleep calls interruptible by using self._stop_event.wait() instead of time.sleep(), and add a small _trigger_timeout_delay to allow early exit during trigger/wait cycles. This prevents the worker from being unresponsive to stop requests during retry and trigger waits. Also simplify ApplicationSettings.to_dict() to always start from self.camera.with_save_defaults() and stop overriding it with active multi-camera selection, ensuring consistent camera settings are saved.
---
 dlclivegui/config.py                           |  7 +------
 dlclivegui/services/multi_camera_controller.py | 14 ++++++++++----
 2 files changed, 11 insertions(+), 10 deletions(-)

diff --git a/dlclivegui/config.py b/dlclivegui/config.py
index c7a474b..6f204ac 100644
--- a/dlclivegui/config.py
+++ b/dlclivegui/config.py
@@ -499,13 +499,8 @@ def from_dict(cls, data: dict[str, Any]) -> ApplicationSettings:
         )
 
     def to_dict(self) -> dict[str, Any]:
+        camera = self.camera.with_save_defaults()
         multi_camera = self.multi_camera.with_save_defaults()
-        active_cameras = multi_camera.get_active_cameras()
-
-        if active_cameras:
-            camera = active_cameras[0].model_copy(deep=True)
-        else:
-            camera = self.camera.with_save_defaults()
 
         return {
             "version": self.version,
diff --git a/dlclivegui/services/multi_camera_controller.py b/dlclivegui/services/multi_camera_controller.py
index 17af14e..cd13ae0 100644
--- a/dlclivegui/services/multi_camera_controller.py
+++ b/dlclivegui/services/multi_camera_controller.py
@@ -4,7 +4,6 @@
 
 import copy
 import logging
-import time
 from dataclasses import dataclass
 from threading import Event, Lock
 
@@ -49,6 +48,7 @@ def __init__(self, camera_id: str, settings: CameraSettings):
         self._backend: CameraBackend | None = None
         self._max_consecutive_errors = 5
         self._retry_delay = 0.1
+        self._trigger_timeout_delay = 0.05
 
     @Slot()
     def run(self) -> None:
@@ -93,7 +93,8 @@ def run(self) -> None:
                             self._camera_id, "Too many empty frames.\nWas the device disconnected ?"
                         )
                         break
-                    time.sleep(self._retry_delay)
+                    if self._stop_event.wait(self._retry_delay):
+                        break
                     continue
 
                 consecutive_errors = 0
@@ -113,13 +114,17 @@ def run(self) -> None:
                         exc,
                     )
                     consecutive_errors = 0
+
+                    if self._stop_event.wait(self._trigger_timeout_delay):
+                        break  # Stop event set during wait
                     continue
 
                 consecutive_errors += 1
                 if consecutive_errors >= self._max_consecutive_errors:
                     self.error_occurred.emit(self._camera_id, f"Camera read timeout: {exc}")
                     break
-                time.sleep(self._retry_delay)
+                if self._stop_event.wait(self._retry_delay):
+                    break
                 continue
 
             except Exception as exc:
@@ -129,7 +134,8 @@ def run(self) -> None:
                 if consecutive_errors >= self._max_consecutive_errors:
                     self.error_occurred.emit(self._camera_id, f"Camera read error: {exc}")
                     break
-                time.sleep(self._retry_delay)
+                if self._stop_event.wait(self._retry_delay):
+                    break
                 continue
 
         # Cleanup

From 96354ec363efcea931762fe45a7bcd14540eac3d Mon Sep 17 00:00:00 2001
From: Cyril Achard <cyril.achard@epfl.ch>
Date: Fri, 29 May 2026 10:32:12 +0200
Subject: [PATCH 16/20] Potential fix for pull request finding

Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>
---
 dlclivegui/gui/main_window.py | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/dlclivegui/gui/main_window.py b/dlclivegui/gui/main_window.py
index 4f07bd7..673e801 100644
--- a/dlclivegui/gui/main_window.py
+++ b/dlclivegui/gui/main_window.py
@@ -856,11 +856,15 @@ def _apply_config(self, config: ApplicationSettings) -> None:
 
     def _current_config(self, *, allow_empty_model_path=False) -> ApplicationSettings:
         multi_camera = self._config.multi_camera
+        active_cameras = multi_camera.get_active_cameras()
         camera = (
-            multi_camera.cameras[0].model_copy(deep=True)
-            if multi_camera.cameras
-            else self._config.camera.model_copy(deep=True)
-        )
+            active_cameras[0].model_copy(deep=True)
+            if active_cameras
+            else (
+                multi_camera.cameras[0].model_copy(deep=True)
+                if multi_camera.cameras
+                else self._config.camera.model_copy(deep=True)
+            )
 
         return ApplicationSettings(
             camera=camera,

From fe826a1872a2774c8e79ef3341aa8a95e90b9c8d Mon Sep 17 00:00:00 2001
From: Cyril Achard <cyril.achard@epfl.ch>
Date: Fri, 29 May 2026 10:34:52 +0200
Subject: [PATCH 17/20] Fix broken suggestion

---
 dlclivegui/gui/main_window.py | 1 +
 1 file changed, 1 insertion(+)

diff --git a/dlclivegui/gui/main_window.py b/dlclivegui/gui/main_window.py
index 673e801..c16964b 100644
--- a/dlclivegui/gui/main_window.py
+++ b/dlclivegui/gui/main_window.py
@@ -865,6 +865,7 @@ def _current_config(self, *, allow_empty_model_path=False) -> ApplicationSetting
                 if multi_camera.cameras
                 else self._config.camera.model_copy(deep=True)
             )
+        )
 
         return ApplicationSettings(
             camera=camera,

From d44bf18814d6c6786221df224680af2290e5f13b Mon Sep 17 00:00:00 2001
From: Cyril Achard <cyril.achard@epfl.ch>
Date: Fri, 29 May 2026 10:55:11 +0200
Subject: [PATCH 18/20] Resolve 'auto' trigger source in GenTL backend

Add resolution logic for trigger source: implement _resolve_trigger_source to map the model-level default 'auto' to the first supported camera line (Line0/Line1/Line2/Any), return whether the resolved value is supported, and log/warn or raise depending on strict mode. Integrate this into _configure_pixel_format/_configure trigger flow so TriggerSource is only set if resolution succeeded. Change CameraTriggerSettings default source to 'auto' and add a field validator to coerce common aliases (e.g. 'default', 'automatic', 'device', 'camera') to 'auto'. Update tests and fixtures: adjust fake node default TriggerSource to Line1, update expectations, and add unit tests for auto-selection behavior and strict-mode error. This makes trigger configuration more robust across cameras with differing GenICam enum symbolics.
---
 dlclivegui/cameras/backends/gentl_backend.py | 48 +++++++++++++++++++-
 dlclivegui/config.py                         | 20 +++++++-
 tests/cameras/backends/conftest.py           |  2 +-
 tests/cameras/backends/test_gentl_trigger.py | 38 +++++++++++++++-
 tests/test_config.py                         |  9 +++-
 5 files changed, 112 insertions(+), 5 deletions(-)

diff --git a/dlclivegui/cameras/backends/gentl_backend.py b/dlclivegui/cameras/backends/gentl_backend.py
index 1c63c60..0992db0 100644
--- a/dlclivegui/cameras/backends/gentl_backend.py
+++ b/dlclivegui/cameras/backends/gentl_backend.py
@@ -1056,6 +1056,51 @@ def _trigger_to_dict(trigger) -> dict[str, Any]:
                 pass
         return {}
 
+    def _resolve_trigger_source(self, node_map, requested: str, *, strict: bool) -> tuple[str, bool]:
+        """Resolve TriggerSource against the camera-supported GenICam enum values.
+
+        Model-level default is "auto"; this backend maps it to the first preferred
+        source supported by the actual camera.
+        """
+        requested = str(requested or "auto").strip()
+        node = self._node(node_map, "TriggerSource")
+        available = self._node_symbolics(node)
+
+        if not available:
+            if strict:
+                raise RuntimeError("GenICam node 'TriggerSource' is not available or has no symbolics")
+            LOG.warning("GenICam node 'TriggerSource' is not available; disabling trigger input.")
+            return requested, False
+
+        if requested in available:
+            return requested, True
+
+        if requested.lower() == "auto":
+            for candidate in ("Line0", "Line1", "Line2", "Any"):
+                if candidate in available:
+                    LOG.info(
+                        "GenTL TriggerSource auto-selected '%s'. Available: %s",
+                        candidate,
+                        available,
+                    )
+                    return candidate, True
+
+            LOG.warning(
+                "Could not auto-select a GenTL TriggerSource. Available: %s",
+                available,
+            )
+            return requested, False
+
+        if strict:
+            raise RuntimeError(f"GenICam node 'TriggerSource' does not support '{requested}'. Available: {available}")
+
+        LOG.warning(
+            "GenTL TriggerSource '%s' is not available. Available: %s",
+            requested,
+            available,
+        )
+        return requested, False
+
     def _configure_pixel_format(self, node_map) -> None:
         try:
             pixel_format_node = getattr(node_map, "PixelFormat", None)
@@ -1145,7 +1190,8 @@ def _configure_trigger_input(self, node_map, cfg, *, strict: bool = False) -> No
         self._set_enum_node(node_map, "TriggerMode", "Off", strict=False)
 
         selector_ok = self._set_enum_node(node_map, "TriggerSelector", selector, strict=strict)
-        source_ok = self._set_enum_node(node_map, "TriggerSource", source, strict=strict)
+        source, source_resolved = self._resolve_trigger_source(node_map, source, strict=strict)
+        source_ok = source_resolved and self._set_enum_node(node_map, "TriggerSource", source, strict=strict)
         activation_ok = self._set_enum_node(node_map, "TriggerActivation", activation, strict=strict)
 
         # TriggerSelector and TriggerSource are required routing nodes.
diff --git a/dlclivegui/config.py b/dlclivegui/config.py
index 6f204ac..1153016 100644
--- a/dlclivegui/config.py
+++ b/dlclivegui/config.py
@@ -224,7 +224,7 @@ class CameraTriggerSettings(BaseModel):
 
     # Input trigger config: external/follower
     selector: str = "FrameStart"
-    source: str = "Line0"
+    source: str = "auto"
     activation: TriggerActivation | str = "RisingEdge"
 
     # Output config: master
@@ -272,6 +272,24 @@ def _coerce_timeout(cls, v):
             return None
         return fv if fv > 0 else None
 
+    @field_validator("source", mode="before")
+    @classmethod
+    def _coerce_source(cls, v):
+        if v is None:
+            return "auto"
+
+        s = str(v).strip()
+        if not s:
+            return "auto"
+
+        aliases = {
+            "default": "auto",
+            "automatic": "auto",
+            "device": "auto",
+            "camera": "auto",
+        }
+        return aliases.get(s.lower(), s)
+
     @classmethod
     def from_any(cls, value) -> CameraTriggerSettings:
         if isinstance(value, cls):
diff --git a/tests/cameras/backends/conftest.py b/tests/cameras/backends/conftest.py
index f21bf48..f0a0b6b 100644
--- a/tests/cameras/backends/conftest.py
+++ b/tests/cameras/backends/conftest.py
@@ -603,7 +603,7 @@ def __init__(
         self.AcquisitionMode = _FakeNode("Continuous", symbolics=["Continuous", "SingleFrame"])
         self.TriggerSelector = _FakeNode("FrameStart", symbolics=["FrameStart"])
         self.TriggerMode = _FakeNode("Off", symbolics=["Off", "On"])
-        self.TriggerSource = _FakeNode("Line0", symbolics=["Line0", "Line1", "Software"])
+        self.TriggerSource = _FakeNode("Line1", symbolics=["Line0", "Line1", "Software"])
         self.TriggerActivation = _FakeNode("RisingEdge", symbolics=["RisingEdge", "FallingEdge"])
 
         # GPIO output nodes for master/follower setups
diff --git a/tests/cameras/backends/test_gentl_trigger.py b/tests/cameras/backends/test_gentl_trigger.py
index e060035..57339a1 100644
--- a/tests/cameras/backends/test_gentl_trigger.py
+++ b/tests/cameras/backends/test_gentl_trigger.py
@@ -158,7 +158,7 @@ def test_trigger_invalid_source_non_strict_disables_trigger(patch_gentl_sdk, gen
     nm = be._acquirer.remote_device.node_map
 
     # Source was unsupported, so the fake node should retain its default.
-    assert nm.TriggerSource.value == "Line0"
+    assert nm.TriggerSource.value == "Line1"
 
     # Safety behavior: do not arm TriggerMode on the previous/default source.
     assert nm.TriggerMode.value == "Off"
@@ -422,3 +422,39 @@ def test_trigger_timeout_not_capped_for_master_mode(patch_gentl_sdk, gentl_setti
 
     finally:
         be.close()
+
+
+def test_resolve_trigger_source_auto_selects_supported_line(
+    patch_gentl_sdk,
+    gentl_settings_factory,
+):
+    gb = patch_gentl_sdk
+    be = gb.GenTLCameraBackend(gentl_settings_factory())
+
+    class Node:
+        symbolics = ["Line1", "Software", "Any"]
+
+    class NodeMap:
+        TriggerSource = Node()
+
+    source, ok = be._resolve_trigger_source(NodeMap(), "auto", strict=False)
+
+    assert ok is True
+    assert source == "Line1"
+
+
+def test_resolve_trigger_source_strict_raises_for_unsupported_explicit_line(
+    patch_gentl_sdk,
+    gentl_settings_factory,
+):
+    gb = patch_gentl_sdk
+    be = gb.GenTLCameraBackend(gentl_settings_factory())
+
+    class Node:
+        symbolics = ["Line1", "Software", "Any"]
+
+    class NodeMap:
+        TriggerSource = Node()
+
+    with pytest.raises(RuntimeError, match="TriggerSource.*Line0"):
+        be._resolve_trigger_source(NodeMap(), "Line0", strict=True)
diff --git a/tests/test_config.py b/tests/test_config.py
index f0165f4..9f82017 100644
--- a/tests/test_config.py
+++ b/tests/test_config.py
@@ -1,6 +1,6 @@
 import pytest
 
-from dlclivegui.config import ApplicationSettings, CameraSettings, MultiCameraSettings
+from dlclivegui.config import ApplicationSettings, CameraSettings, CameraTriggerSettings, MultiCameraSettings
 
 
 @pytest.mark.unit
@@ -34,3 +34,10 @@ def test_save_applies_gentl_trigger_defaults_to_multi_camera():
     data = settings.to_dict()
 
     assert "trigger" in data["multi_camera"]["cameras"][0]["properties"]["gentl"]
+
+
+@pytest.mark.unit
+def test_trigger_source_defaults_to_auto():
+    trigger = CameraTriggerSettings()
+
+    assert trigger.source == "auto"

From 662313a3efa2c013b128c36625c1b5d7c9bc87eb Mon Sep 17 00:00:00 2001
From: Cyril Achard <cyril.achard@epfl.ch>
Date: Fri, 29 May 2026 18:03:57 +0200
Subject: [PATCH 19/20] Fix display tests

---
 tests/services/test_multicam_controller.py | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/tests/services/test_multicam_controller.py b/tests/services/test_multicam_controller.py
index e8f94f6..99047be 100644
--- a/tests/services/test_multicam_controller.py
+++ b/tests/services/test_multicam_controller.py
@@ -11,6 +11,7 @@
     _camera_start_priority,
     _trigger_role_from_settings,
     get_camera_id,
+    get_display_id,
 )
 
 
@@ -256,7 +257,7 @@ def test_frame_ready_emits_frames_in_user_configured_order(qtbot, patch_factory)
         properties={"opencv": {"device_id": "cam-b"}},
     ).apply_defaults()
 
-    expected_order = [get_camera_id(cam_a), get_camera_id(cam_b)]
+    expected_order = [get_display_id(cam_a), get_display_id(cam_b)]
     seen_orders: list[list[str]] = []
 
     def on_ready(mfd):
@@ -388,7 +389,7 @@ def _create(settings):
         mc.start([cam])
 
     cam_id, msg = blocker.args
-    assert cam_id == get_camera_id(cam)
+    assert cam_id == get_display_id(cam)
     assert "Camera read timeout" in msg
 
     # Cleanup if still running.

From 3edb48ce1f2f3f7ce16f5f34a6d71a03f5413a6d Mon Sep 17 00:00:00 2001
From: Cyril Achard <cyril.achard@epfl.ch>
Date: Fri, 29 May 2026 18:05:01 +0200
Subject: [PATCH 20/20] Update test_multicam_controller.py

---
 tests/services/test_multicam_controller.py | 1 -
 1 file changed, 1 deletion(-)

diff --git a/tests/services/test_multicam_controller.py b/tests/services/test_multicam_controller.py
index 99047be..d41befe 100644
--- a/tests/services/test_multicam_controller.py
+++ b/tests/services/test_multicam_controller.py
@@ -5,7 +5,6 @@
 
 # from dlclivegui.config import CameraSettings
 from dlclivegui.config import CameraSettings
-from dlclivegui.services.multi_camera_controller import MultiCameraController, get_display_id
 from dlclivegui.services.multi_camera_controller import (
     MultiCameraController,
     _camera_start_priority,