Motion capture: camera selection dropdown

Replace camera index spinbox with a combo listing detected cameras by
name. On Linux enumerates /dev/video* and reads device names from sysfs
(fast, no probing). Fallback probes cv2.VideoCapture indices 0-7 on
other platforms. Simulation entry always appended as last option.

Also adds explicit simulation mode (index -1) to tracker.start() and a
rescan button (⟳) in both the main window and the Settings > Plugins
widget.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

1 files changed, 41 insertions, 10 deletions

diff --git a/plugins/motion_capture/window.py b/plugins/motion_capture/window.py
index 082a8f6..40b436f 100644
--- a/plugins/motion_capture/window.py
+++ b/plugins/motion_capture/window.py
@@ -15,8 +15,8 @@ from __future__ import annotations
 from PyQt6.QtCore import Qt, QTimer, pyqtSignal
 from PyQt6.QtGui import QCloseEvent, QImage, QMouseEvent, QPixmap
 from PyQt6.QtWidgets import (
-    QDoubleSpinBox, QFrame, QHBoxLayout, QLabel, QPushButton,
-    QSizePolicy, QSpinBox, QVBoxLayout, QWidget,
+    QComboBox, QDoubleSpinBox, QFrame, QHBoxLayout, QLabel, QPushButton,
+    QSizePolicy, QVBoxLayout, QWidget,
 )
 
 import numpy as np
@@ -92,11 +92,19 @@ class MotionCaptureWindow(QWidget):
         ctrl.setContentsMargins(10, 6, 10, 6); ctrl.setSpacing(6)
 
         ctrl.addWidget(QLabel("Camera:"))
-        self._cam_spin = QSpinBox()
-        self._cam_spin.setRange(0, 9); self._cam_spin.setValue(0)
-        self._cam_spin.setObjectName("traceWidthSpin")
-        self._cam_spin.setFixedWidth(52)
-        ctrl.addWidget(self._cam_spin)
+        self._cam_combo = QComboBox()
+        self._cam_combo.setObjectName("channelPickerCb")
+        self._cam_combo.setMinimumWidth(200)
+        ctrl.addWidget(self._cam_combo)
+
+        self._refresh_btn = QPushButton("⟳")
+        self._refresh_btn.setObjectName("configButton")
+        self._refresh_btn.setFixedWidth(28)
+        self._refresh_btn.setToolTip("Rescan cameras")
+        self._refresh_btn.clicked.connect(self._scan_cameras)
+        ctrl.addWidget(self._refresh_btn)
+
+        self._scan_cameras()   # populate on open
 
         self._conn_btn = QPushButton("Connect")
         self._conn_btn.setObjectName("applyButton")
@@ -136,6 +144,21 @@ class MotionCaptureWindow(QWidget):
 
     # ── Actions ───────────────────────────────────────────────────────────
 
+    def _scan_cameras(self):
+        from tracker import list_cameras
+        current_idx = self.get_camera_index()
+        self._cam_combo.blockSignals(True)
+        self._cam_combo.clear()
+        self._cameras = list_cameras()   # [(index, label), ...]
+        for _, label in self._cameras:
+            self._cam_combo.addItem(label)
+        # Restore selection by index if still present
+        for i, (idx, _) in enumerate(self._cameras):
+            if idx == current_idx:
+                self._cam_combo.setCurrentIndex(i)
+                break
+        self._cam_combo.blockSignals(False)
+
     def _toggle_connect(self):
         if self._connected:
             self._tracker.stop()
@@ -150,7 +173,7 @@ class MotionCaptureWindow(QWidget):
             self._sim_badge.setVisible(False)
             self._status.setText("Disconnected")
         else:
-            ok = self._tracker.start(self._cam_spin.value())
+            ok = self._tracker.start(self.get_camera_index())
             if ok:
                 self._connected = True
                 self._conn_btn.setText("Disconnect")
@@ -243,10 +266,18 @@ class MotionCaptureWindow(QWidget):
     # ── State accessors (used by plugin for save/restore) ─────────────────
 
     def get_camera_index(self) -> int:
-        return self._cam_spin.value()
+        i = self._cam_combo.currentIndex()
+        cameras = getattr(self, "_cameras", [])
+        if 0 <= i < len(cameras):
+            return cameras[i][0]
+        return 0
 
     def set_camera_index(self, v: int):
-        self._cam_spin.setValue(v)
+        cameras = getattr(self, "_cameras", [])
+        for i, (idx, _) in enumerate(cameras):
+            if idx == v:
+                self._cam_combo.setCurrentIndex(i)
+                return
 
     def get_px_per_mm(self) -> float:
         return self._pxmm_spin.value()