fix(stop_button): enhance emergency stop functionality and update button behavior

bec_widgets/widgets/control/buttons/stop_button/stop_button.py

@@ -1,5 +1,5 @@
 from bec_qthemes import material_icon
-from qtpy.QtCore import Qt
+from qtpy.QtCore import Qt, QTimer
 from qtpy.QtWidgets import QHBoxLayout, QPushButton, QSizePolicy, QToolButton, QWidget
 
 from bec_widgets.utils.bec_widget import BECWidget
@@ -12,6 +12,9 @@ class StopButton(BECWidget, QWidget):
     PLUGIN = True
     ICON_NAME = "dangerous"
     RPC = False
+    ABORT_LABEL = "Stop"
+    EMERGENCY_STOP_LABEL = "Emergency Stop"
+    EMERGENCY_STOP_TIMEOUT_MS = 2000
 
     def __init__(self, parent=None, client=None, config=None, gui_id=None, toolbar=False, **kwargs):
         super().__init__(parent=parent, client=client, gui_id=gui_id, config=config, **kwargs)
@@ -22,15 +25,19 @@ class StopButton(BECWidget, QWidget):
         self.layout.setSpacing(0)
         self.layout.setContentsMargins(0, 0, 0, 0)
         self.layout.setAlignment(Qt.AlignmentFlag.AlignVCenter)
+        self._emergency_stop_active = False
+        self._reset_timer = QTimer(self)
+        self._reset_timer.setSingleShot(True)
+        self._reset_timer.timeout.connect(self._deactivate_emergency_stop)
 
         if toolbar:
             icon = material_icon("stop", color="#cc181e", filled=True, convert_to_pixmap=False)
             self.button = QToolButton(icon=icon)
-            self.button.setToolTip("Stop the scan queue")
+            self.button.setToolTip(self.ABORT_LABEL)
         else:
             self.button = QPushButton()
             self.button.setSizePolicy(QSizePolicy.Policy.Minimum, QSizePolicy.Policy.Fixed)
-            self.button.setText("Stop")
+            self.button.setText(self.ABORT_LABEL)
             self.button.setProperty("variant", "danger")
         self.button.clicked.connect(self.stop_scan)
 
@@ -41,12 +48,39 @@ class StopButton(BECWidget, QWidget):
         self,
     ):  # , scan_id: str | None = None): #FIXME scan_id will be added when combining with Queue widget
         """
-        Stop the scan.
+        Abort the scan by default, then temporarily offer an emergency stop.
 
         Args:
-            scan_id(str|None): The scan id to stop. If None, the current scan will be stopped.
+            scan_id(str|None): The scan id to stop. If None, the current scan will be targeted.
         """
-        self.queue.request_scan_halt()
+        if self._emergency_stop_active:
+            self.queue.request_scan_halt()
+            self._activate_emergency_stop()
+            return
+
+        self.queue.request_scan_abortion()
+        self._activate_emergency_stop()
+
+    def _activate_emergency_stop(self) -> None:
+        self._emergency_stop_active = True
+        self._set_button_label(self.EMERGENCY_STOP_LABEL)
+        self._reset_timer.start(self.EMERGENCY_STOP_TIMEOUT_MS)
+
+    def _deactivate_emergency_stop(self) -> None:
+        self._emergency_stop_active = False
+        self._set_button_label(self.ABORT_LABEL)
+
+    def _set_button_label(self, label: str) -> None:
+        if hasattr(self.button, "setText"):
+            self.button.setText(label)
+        self.button.setToolTip(label)
+
+    def cleanup(self):
+        """Stop and dispose the emergency-stop reset timer before widget teardown."""
+        self._reset_timer.stop()
+        self._reset_timer.timeout.disconnect(self._deactivate_emergency_stop)
+        self._reset_timer.deleteLater()
+        super().cleanup()
 
 
 if __name__ == "__main__":  # pragma: no cover

tests/unit_tests/test_stop_button.py

@@ -1,5 +1,7 @@
 # pylint: disable=missing-function-docstring, missing-module-docstring, unused-import
 
+from unittest.mock import MagicMock
+
 import pytest
 
 from bec_widgets.widgets.control.buttons.stop_button.stop_button import StopButton
@@ -10,13 +12,48 @@ from .client_mocks import mocked_client
 @pytest.fixture
 def stop_button(qtbot, mocked_client):
     widget = StopButton(client=mocked_client)
+    widget.queue = MagicMock()
     qtbot.addWidget(widget)
     qtbot.waitExposed(widget)
-    yield widget
+    yield widget, qtbot
 
 
 def test_stop_button(stop_button):
-    assert stop_button.button.text() == "Stop"
-    stop_button.button.click()
-    assert stop_button.queue.request_scan_halt.called
-    stop_button.close()
+    widget, qtbot = stop_button
+
+    assert widget.button.text() == "Stop"
+
+    widget.button.click()
+
+    assert widget.queue.request_scan_abortion.called
+    assert widget.button.text() == "Emergency Stop"
+
+    qtbot.wait(widget.EMERGENCY_STOP_TIMEOUT_MS // 2)
+    widget.button.click()
+
+    assert widget.queue.request_scan_halt.called
+
+    qtbot.wait((widget.EMERGENCY_STOP_TIMEOUT_MS // 2) + 100)
+    assert widget.button.text() == "Emergency Stop"
+
+    qtbot.wait((widget.EMERGENCY_STOP_TIMEOUT_MS // 2) + 100)
+    assert widget.button.text() == "Stop"
+
+    widget.close()
+
+
+def test_stop_button_click_extends_emergency_timeout(stop_button):
+    widget, qtbot = stop_button
+
+    widget.button.click()
+    qtbot.wait(widget.EMERGENCY_STOP_TIMEOUT_MS - 250)
+
+    widget.button.click()
+    assert widget.button.text() == "Emergency Stop"
+
+    qtbot.wait(200)
+    assert widget.button.text() == "Emergency Stop"
+
+    qtbot.wait(widget.EMERGENCY_STOP_TIMEOUT_MS - 100)
+    assert widget.button.text() == "Stop"
+    widget.close()