Technician tool v0.6

Imported from the Google Drive folder 004-technician_tool/v0.6.

kota_tech/ui/sd_tab.py

@@ -7,7 +7,6 @@ from pathlib import Path
 
 from PySide6.QtCore import QObject, QSettings, Qt, Signal
 from PySide6.QtWidgets import (
-    QApplication,
     QCheckBox,
     QFileDialog,
     QFormLayout,
@@ -34,6 +33,7 @@ DEFAULT_TEMPLATE = Path(__file__).resolve().parents[4] / "002-SD_card_format" /
 
 class _Bridge(QObject):
     done = Signal(object)
+    listed = Signal(object)
 
 
 def _secret_field() -> tuple[QLineEdit, QCheckBox]:
@@ -52,6 +52,7 @@ class SdTab(QWidget):
         self._settings = QSettings("KOTA", "TechnicianTool")
         self._cards: list[Disk] = []
         self._busy = False
+        self._listing = False
 
         # --- 1. settings
         sbox = QGroupBox("1. Settings written to the card (ENV.TXT)")
@@ -135,6 +136,7 @@ class SdTab(QWidget):
 
         self._bridge = _Bridge()
         self._bridge.done.connect(self._on_done)
+        self._bridge.listed.connect(self._on_listed)
         for w in (self.url, self.token, self.ssid, self.password):
             w.textChanged.connect(self._update)
         self.wifi_box.toggled.connect(self._update)
@@ -199,13 +201,28 @@ class SdTab(QWidget):
         super().showEvent(event)
 
     def refresh_cards(self) -> None:
-        if self._busy:
+        """List cards in the background: the UI never waits for a slow card reader."""
+        if self._busy or self._listing:
+            return
+        self._listing = True
+        self.others.setText("Looking for SD cards...")
+
+        def worker():
+            try:
+                result = list_cards()
+            except Exception as exc:        # show it, never leave the tab stuck
+                result = ([], [], str(exc))
+            self._bridge.listed.emit(result)
+
+        threading.Thread(target=worker, daemon=True, name="sd-list").start()
+
+    def _on_listed(self, result) -> None:
+        self._listing = False
+        self._cards, others = result[0], result[1]
+        if len(result) > 2:
+            self.others.setText(f"Could not list cards: {result[2]}")
+            self._update()
             return
-        QApplication.setOverrideCursor(Qt.CursorShape.WaitCursor)
-        try:
-            self._cards, others = list_cards()
-        finally:
-            QApplication.restoreOverrideCursor()
         self.card_list.clear()
         for d in self._cards:
             self.card_list.addItem(QListWidgetItem(d.label))