wip fix group scan box

bec_widgets/widgets/control/scan_control/scan_group_box.py

@@ -271,9 +271,19 @@ class ScanGroupBox(QGroupBox):
                 continue
             if default == "_empty":
                 default = None
-            widget = widget_class(parent=self.parent(), arg_name=arg_name, default=default)
+            if widget_class is DeviceComboBox:
+                widget = widget_class(parent=self.parent(), arg_name=arg_name)
+            else:
+                widget = widget_class(parent=self.parent(), arg_name=arg_name, default=default)
             if isinstance(widget, DeviceComboBox):
-                widget.set_device_filter(BECDeviceFilter.DEVICE)
+                if item["type"] == ScanArgType.DEVICE:
+                    widget.set_device_filter(BECDeviceFilter.POSITIONER)
+                else:
+                    widget.set_device_filter(BECDeviceFilter.DEVICE)
+                if default is None:
+                    widget.set_first_element_as_empty = True
+                else:
+                    widget.set_device(default)
                 self.selected_devices[widget] = ""
                 widget.device_selected.connect(self.emit_device_selected)
             if isinstance(widget, ScanLiteralsComboBox):

tests/unit_tests/test_scan_control.py

@@ -9,6 +9,7 @@ from qtpy.QtCore import QModelIndex, Qt
 
 from bec_widgets.utils.forms_from_types.items import StrFormItem
 from bec_widgets.utils.widget_io import WidgetIO
+from bec_widgets.widgets.control.device_input.device_combobox.device_combobox import DeviceComboBox
 from bec_widgets.widgets.control.scan_control import ScanControl
 
 from .client_mocks import mocked_client
@@ -304,6 +305,10 @@ def test_on_scan_selected(scan_control, scan_name):
             assert widget is not None  # Confirm that a widget exists
             expected_widget_type = scan_control.arg_box.WIDGET_HANDLER.get(arg_value, None)
             assert isinstance(widget, expected_widget_type)  # Confirm the widget type matches
+            if isinstance(widget, DeviceComboBox):
+                assert widget.currentText() == ""
+                assert "samx" in widget.devices
+                assert "bpm3a" not in widget.devices
 
     # Check kwargs boxes
     kwargs_group = [param for param in expected_scan_info["gui_config"]["kwarg_groups"]]