Refactor camera config dialog and reduce code duplication (#46)

* Extract camera loaders; refactor preview UI state

Move camera worker and preview state logic into a new module (dlclivegui/gui/camera_loaders.py) and refactor the CameraConfigDialog to use it. Added DetectCamerasWorker, CameraProbeWorker, CameraLoadWorker, PreviewState enum and PreviewSession dataclass to centralize loader/backend/timer intent. Removed the embedded worker classes from camera_config_dialog.py and replaced multiple booleans/flags with a single PreviewSession, an epoch-based signal invalidation mechanism, coalesced preview restarts, and unified scan/preview UI syncing. Also adjusted loader signal handlers to be epoch-aware, simplified start/stop flows, and made small docstring/comment tweaks in basler_backend.py regarding fast_start.

* Refactor camera config into package

Move camera configuration code into a dedicated gui/camera_config package and extract UI construction into a new ui_blocks module. Renamed camera_config_dialog.py and camera_loaders.py to camera_config/camera_config_dialog.py and camera_config/loaders.py respectively, replaced the large _setup_ui implementation with setup_camera_config_dialog_ui(dlg) from ui_blocks.py, and added ui_blocks.py to build the dialog UI. Updated relative imports in __init__.py, main_window.py, and affected modules/tests to the new paths. This refactor improves modularity and keeps the dialog file focused on logic rather than bulky widget construction.

* Refactor camera config dialog & add identity utils

Move camera identity utilities into cameras.factory (apply_detected_identity, camera_identity_key) and add CameraSettings.check_diff for concise settings diffs. Major refactor of CameraConfigDialog: reorganize UI/state helpers, probe/preview lifecycle, auto-apply pending edits, improved scan/probe cancellation and dialog reject handling, duplicate-camera checks, add reorder/add/remove safety, and split preview helpers into a new preview module; also remove unused cv2 import. These changes centralize identity handling, improve preview & probe UX, and add safer settings application and logging. Tests updated to match the new contracts.

* Centralize camera dialog cleanup and fixes

Add a unified _on_close_cleanup and closeEvent to ensure preview/worker shutdown and UI reset on dialog close/cancel. Make cleanup idempotent with a _cleanup_done guard, shorten worker wait times to reduce UI freeze, and defensively reset scan UI widgets. Connect scan cancel button handler. Initialize _multi_camera_settings fallback, tighten type annotations, and note eventFilter UI assignments. Refactor form/apply flow to build a new CameraSettings model, compute diffs, replace the working camera entry and update the active list item (apply now returns a truthy value). Call _reconcile_fps_from_backend when loading settings, remove exc_info from a loader error log, and invoke cleanup before accepting the dialog. These changes improve robustness during shutdown and reduce UI hangs.

* Refactor preview helpers into controller

Move preview state and session datatypes into preview.py and refactor low-level image ops into MultiCameraController static methods. preview.py now delegates rotation, crop, resize and pixmap conversion to MultiCameraController (with proper type hints and QTimer usage). loaders.py removes duplicate PreviewState/PreviewSession definitions and cleans imports. camera_config_dialog uses getattr to safely read backend.actual_fps and updates imports to match the refactor. MultiCameraController gains apply_rotation/apply_crop/apply_resize/ensure_color_* and to_display_pixmap utilities (default: no upscale when resizing).

* Update tests to use PreviewState and dialog._preview

Adapt camera config GUI tests to the refactored preview API: import PreviewState and replace checks against legacy dialog attributes (_loader, _preview_active, _preview_backend, _preview_timer) with dialog._preview.loader, dialog._preview.state (using PreviewState.*), dialog._preview.backend, and dialog._preview.timer. Update waitUntil conditions and assertions across test_cam_dialog_e2e.py to reflect the new preview state machine and object structure.

Author: C-Achard

dlclivegui/__init__.py

@@ -7,7 +7,7 @@
     MultiCameraSettings,
     RecordingSettings,
 )
-from .gui.camera_config_dialog import CameraConfigDialog
+from .gui.camera_config.camera_config_dialog import CameraConfigDialog
 from .gui.main_window import DLCLiveMainWindow
 from .main import main
 from .services.multi_camera_controller import MultiCameraController, MultiFrameData

dlclivegui/cameras/backends/basler_backend.py

@@ -30,7 +30,8 @@ def __init__(self, settings):
 
         self._props: dict = settings.properties if isinstance(settings.properties, dict) else {}
 
-        # Optional fast-start hint for probe workers (best-effort; doesn't change behavior yet)
+        # Optional fast-start hint for probe workers
+        # (may skip StartGrabbing and converter setup for faster capability probing; not suitable for normal capture)
         self._fast_start: bool = bool(self.ns.get("fast_start", False))
 
         # Stable identity (serial-based). Prefer new namespace; fall back to legacy keys read-only.

dlclivegui/cameras/factory.py

@@ -415,3 +415,49 @@ def _resolve_backend(name: str) -> type[CameraBackend]:
                 "Tip: enable strict import failures with DLC_CAMERA_BACKENDS_STRICT_IMPORT=1"
             )
             raise RuntimeError(msg) from exc
+
+
+# -------------------------------
+# Camera identity utilities
+# -------------------------------
+
+
+def apply_detected_identity(cam: CameraSettings, detected: DetectedCamera, backend: str) -> None:
+    """Persist stable identity from a detected camera into cam.properties under backend namespace."""
+    if not isinstance(cam.properties, dict):
+        cam.properties = {}
+
+    ns = cam.properties.get(backend.lower())
+    if not isinstance(ns, dict):
+        ns = {}
+        cam.properties[backend.lower()] = ns
+
+    # Store whatever we have (backend-specific but written generically)
+    if getattr(detected, "device_id", None):
+        ns["device_id"] = detected.device_id
+    if getattr(detected, "vid", None) is not None:
+        ns["device_vid"] = int(detected.vid)
+    if getattr(detected, "pid", None) is not None:
+        ns["device_pid"] = int(detected.pid)
+    if getattr(detected, "path", None):
+        ns["device_path"] = detected.path
+
+    # Optional: store human name for matching fallback
+    if getattr(detected, "label", None):
+        ns["device_name"] = detected.label
+
+    # Optional: store backend_hint if you expose it (e.g., CAP_DSHOW)
+    if getattr(detected, "backend_hint", None) is not None:
+        ns["backend_hint"] = int(detected.backend_hint)
+
+
+def camera_identity_key(cam: CameraSettings) -> tuple:
+    backend = (cam.backend or "").lower()
+    props = cam.properties if isinstance(cam.properties, dict) else {}
+    ns = props.get(backend, {}) if isinstance(props, dict) else {}
+    device_id = ns.get("device_id")
+
+    # Prefer stable identity if present, otherwise fallback
+    if device_id:
+        return (backend, "device_id", device_id)
+    return (backend, "index", int(cam.index))

dlclivegui/config.py

@@ -140,6 +140,32 @@ def apply_defaults(self) -> CameraSettings:
 
         return self
 
+    @staticmethod
+    def check_diff(old: CameraSettings, new: CameraSettings) -> dict:
+        keys = (
+            "width",
+            "height",
+            "fps",
+            "exposure",
+            "gain",
+            "rotation",
+            "crop_x0",
+            "crop_y0",
+            "crop_x1",
+            "crop_y1",
+            "enabled",
+        )
+        out = {}
+        for k in keys:
+            try:
+                ov = getattr(old, k, None)
+                nv = getattr(new, k, None)
+                if ov != nv:
+                    out[k] = (ov, nv)
+            except Exception:
+                pass
+        return out
+
 
 class MultiCameraSettings(BaseModel):
     cameras: list[CameraSettings] = Field(default_factory=list)