Make Run the master stop switch; add Log button disabled/recording styling

Run/Stop previously only paused acquisition — control outputs (motor
speed, switches, PWM duty) kept whatever value was last written, so
stopping the run loop didn't stop a running motor. Adds
ControlWidget.safe_stop() (per-widget override, default zeros the
output) and ControlPanel.safe_stop_all(), called from _toggle_run's
Stop branch before engine.stop().

Per-widget behavior is deliberately not uniform:
- OnOffSwitch/MotorControl/PwmControl have a latched running/enabled
  state, so safe_stop() drives their own toggle handler (consistent UI
  + write in one path) and, for Motor/PWM, zeroes the slider too.
- SetpointControl/AnalogOutputControl only write on an explicit user
  action and have no universally safe forced value (e.g. 0 isn't
  necessarily "off" for an arbitrary process setpoint or analog
  output) — Stop leaves them untouched rather than guessing.

Log button: added a :disabled QSS rule so "can't log yet" reads as
clearly inert rather than a duller version of the enabled look, and a
600ms blink (toggling a "recording" dynamic property the QSS keys off)
while a recording is active, so it reads as live/recording rather than
a static pressed button. Master Stop now calls _toggle_log(False)
explicitly when forcing the button off, since QPushButton.setChecked()
doesn't emit clicked — without this the blink would keep running after
a master Stop even though logging itself already halted via
engine.stop()'s internal stop_logging() call.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

1 files changed, 40 insertions, 0 deletions

diff --git a/ui/control_panel.py b/ui/control_panel.py
index 2b936c4..4db18e3 100644
--- a/ui/control_panel.py
+++ b/ui/control_panel.py
@@ -154,6 +154,21 @@ class ControlWidget(QFrame):
             except Exception as e:
                 print(f"[Control '{self.title}'] script error: {e}")
 
+    def safe_stop(self):
+        """
+        Called on every control when the master Stop is pressed.
+
+        Default: zero the output. Widgets with a latched running/enabled
+        state (OnOffSwitch, MotorControl, PwmControl) override this to go
+        through their own toggle handler, so UI state and the write stay
+        consistent. Widgets that only write on an explicit user action
+        (SetpointControl, AnalogOutputControl) override with a no-op —
+        there's no universally "safe" value to force onto an arbitrary
+        process setpoint or analog output, so Stop leaves them alone
+        rather than guessing.
+        """
+        self._write(0.0)
+
 
 # ══════════════════════════════════════════════════════════════════════════════
 #  On/Off Switch
@@ -207,6 +222,9 @@ class OnOffSwitch(ControlWidget):
             w.style().unpolish(w); w.style().polish(w)
         self._write(self._logic_level(checked))
 
+    def safe_stop(self):
+        self._btn.setChecked(False)  # routes through _on_toggle: updates UI + writes off
+
 
 # ══════════════════════════════════════════════════════════════════════════════
 #  Motor Control
@@ -294,6 +312,10 @@ class MotorControl(ControlWidget):
         else:
             self._on_speed(self._slider.value())
 
+    def safe_stop(self):
+        self._run_btn.setChecked(False)  # routes through _on_run: stops + writes 0
+        self._slider.setValue(0)
+
 
 # ══════════════════════════════════════════════════════════════════════════════
 #  Setpoint Control
@@ -386,6 +408,9 @@ class SetpointControl(ControlWidget):
     def _decrement(self):
         self._sp_spin.setValue(self._sp_spin.value() - self.step)
 
+    def safe_stop(self):
+        pass  # no safe universal value for an arbitrary process setpoint — leave it
+
 
 # ══════════════════════════════════════════════════════════════════════════════
 #  PWM Control
@@ -455,6 +480,10 @@ class PwmControl(ControlWidget):
         self._en_btn.style().polish(self._en_btn)
         self._write(float(self._dc_slider.value()) if en else 0.0)
 
+    def safe_stop(self):
+        self._en_btn.setChecked(False)  # routes through _on_enable: disables + writes 0
+        self._dc_slider.setValue(0)
+
 
 # ══════════════════════════════════════════════════════════════════════════════
 #  Generic Analog Output
@@ -509,6 +538,9 @@ class AnalogOutputControl(ControlWidget):
         self._slider.setValue(max(0, min(1000, norm)))
         self._slider.blockSignals(False)
 
+    def safe_stop(self):
+        pass  # only writes on explicit SET click — no safe universal value to force
+
 
 # ══════════════════════════════════════════════════════════════════════════════
 #  Control Panel container
@@ -566,6 +598,14 @@ class ControlPanel(QWidget):
 
     # ── Widget management ─────────────────────────────────────────────────────
 
+    def safe_stop_all(self):
+        """Master Stop — tell every control widget to go to a safe state."""
+        for w in self._widgets:
+            try:
+                w.safe_stop()
+            except Exception as e:
+                print(f"[Control '{w.title}'] safe_stop failed: {e}")
+
     def _make_wrapper(self, widget: ControlWidget, spec) -> QFrame:
         """Wrap a ControlWidget with Edit / Remove / reorder buttons."""
         wrapper = QFrame(); wrapper.setObjectName("controlWidgetWrapper")