feat: auto-centering row with apply-after-mount, grid button raster-only

Auto Centering moves out of the experiment tabs to its own row between
Manual sample and Exp. Config., with an apply-after-mount checkbox that
re-runs it on every detected sample mount (guarded against firing on GUI
startup). Draw a Grid now only shows on the Raster scan tab.

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

src/aare/gui/panels/data_collection_settings.py

@@ -3,6 +3,7 @@ from aarecommon.math.sample_geometry import SampleGeometryModel
 from aarecommon.models.models import DAQStatusModel
 from PySide6.QtCore import Signal, Slot
 from PySide6.QtWidgets import (
+    QCheckBox,
     QDoubleSpinBox,
     QFrame,
     QHBoxLayout,
@@ -55,9 +56,24 @@ class DataCollectionSettings(QFrame):
         self.manual_sample_panel = ManualSamplePanel(self)
         v_layout.addWidget(self.manual_sample_panel)
 
-        # QTabBar + QStackedWidget instead of QTabWidget: the loop-centering
-        # button row must sit BETWEEN the tab bar and the pages, which a
-        # QTabWidget cannot host.
+        # Auto Centering applies to every scan type, so it lives outside the
+        # experiment tabs, between Manual sample and Exp. Config. The checkbox
+        # arms an automatic run after each sample mount (see update_daq_status).
+        self.find_tip = QPushButton("Auto Centering", parent=self)
+        self.auto_center_after_mount = QCheckBox("apply after mount", parent=self)
+        self.auto_center_after_mount.setToolTip(
+            "Run Auto Centering automatically after each sample mount"
+        )
+        auto_center_row = QWidget(self)
+        auto_center_layout = QHBoxLayout(auto_center_row)
+        auto_center_layout.setContentsMargins(0, 0, 0, 0)
+        auto_center_layout.addWidget(self.find_tip, 1)
+        auto_center_layout.addWidget(self.auto_center_after_mount)
+        v_layout.addWidget(auto_center_row)
+
+        # QTabBar + QStackedWidget instead of QTabWidget: the grid button
+        # must sit BETWEEN the tab bar and the pages, which a QTabWidget
+        # cannot host.
         self._tab_bar = QTabBar(self)
         self._stack = QStackedWidget(self)
 
@@ -76,14 +92,9 @@ class DataCollectionSettings(QFrame):
             self._stack.addWidget(panel)
             self._tab_bar.addTab(label)
 
-        # Ex-"Loop centering" panel buttons; always visible, whatever the tab.
-        self.find_tip = QPushButton("Auto Centering", parent=self)
+        # Only meaningful for raster scans; hidden on the other tabs
+        # (_on_tab_changed).
         self.bounding_box = QPushButton("Draw a Grid", parent=self)
-        centering_row = QWidget(self)
-        centering_layout = QHBoxLayout(centering_row)
-        centering_layout.setContentsMargins(0, 0, 0, 0)
-        centering_layout.addWidget(self.find_tip)
-        centering_layout.addWidget(self.bounding_box)
 
         # Live readout mirrored from the Beamline setup panel, same reason:
         # "what is" and "what to set" must not share one ambiguous row.
@@ -120,7 +131,7 @@ class DataCollectionSettings(QFrame):
         # No bottom padding: the pages' own bottom margins breathe inside the
         # border, and the Abort button should hug the pane.
         pane_layout.setContentsMargins(6, 6, 6, 0)
-        pane_layout.addWidget(centering_row)
+        pane_layout.addWidget(self.bounding_box)
         pane_layout.addWidget(current_energy_row)
         pane_layout.addWidget(energy_row)
         pane_layout.addWidget(self._stack)
@@ -163,6 +174,10 @@ class DataCollectionSettings(QFrame):
         self.file_path_panel.path_updated.connect(self.screening.update_filename)
         self.file_path_panel.path_updated.connect(self.simple.update_filename)
         self._sample_id = None
+        # False until the first DAQ status: a sample already mounted at GUI
+        # startup must not trigger an auto-centering (hardware would move
+        # uninvited on every restart).
+        self._status_seen = False
 
         self._tab_bar.currentChanged.connect(self._stack.setCurrentIndex)
         self._tab_bar.currentChanged.connect(self._on_tab_changed)
@@ -208,12 +223,27 @@ class DataCollectionSettings(QFrame):
         self.raster.update_daq_status(s)
         self.screening.update_daq_status(s)
         self.simple.update_daq_status(s)
-        if s.sample is not None and s.sample.db_id != self._sample_id:
-            self._sample_id = s.sample.db_id
+        self._track_sample(None if s.sample is None else s.sample.db_id)
+
+    def _track_sample(self, db_id: int | None):
+        # Separate from update_daq_status so tests can drive mount detection
+        # without building a full DAQStatusModel.
+        if db_id is None:
+            # Forget on unmount so remounting the same sample counts as a
+            # fresh mount below.
+            self._sample_id = None
+        elif db_id != self._sample_id:
+            self._sample_id = db_id
             self._tab_bar.setCurrentIndex(0)
+            if self._status_seen and self.auto_center_after_mount.isChecked():
+                # Reuse the button wiring (clicked -> daq.center_loop in
+                # main_window) instead of a second signal path.
+                self.find_tip.click()
+        self._status_seen = True
 
     @Slot(int)
     def _on_tab_changed(self, idx: int):
+        self.bounding_box.setVisible(idx == 0)
         # 0: Raster, 1: Rotation (incl. screening), 2: Simple (rotation wrapper), 3: XRF (ignore)
         kind = "rotation"
         if idx == 0:

tests/unit/gui/test_data_collection_settings.py

@@ -12,6 +12,7 @@ from aarecommon.math.coordinate import Coordinate, SmargonCoordinate
 from aarecommon.math.diffraction_geometry import DiffractionGeometry
 from aarecommon.models.models import SampleGeometryModel
 
+from aare.gui.panels.data_collection_settings import DataCollectionSettings
 from aare.gui.panels.raster_data_collection import RasterDataCollectionPanel
 from aare.gui.panels.rotation_data_collection import RotationDataCollectionPanel
 from aare.gui.scan_logic.raster_grid_manager import RasterGridManager
@@ -171,8 +172,8 @@ def test_user_override_persists_across_samples(panel, diffraction):
 
 
 @pytest.fixture
-def raster_panel(qapp, diffraction):
-    geom = SampleGeometryModel(
+def geom():
+    return SampleGeometryModel(
         beam_location_pxl=Coordinate(x=500, y=500),
         pixel_in_mm=0.001,
         aerotech=Coordinate(x=0, y=0, z=0),
@@ -181,6 +182,10 @@ def raster_panel(qapp, diffraction):
         omega_deg=0.0,
         beam_size_mm=Coordinate(x=0.01, y=0.01),
     )
+
+
+@pytest.fixture
+def raster_panel(qapp, diffraction, geom):
     mgr = RasterGridManager(geom)
     return RasterDataCollectionPanel(raster_mgr=mgr, diffraction=diffraction)
 
@@ -212,3 +217,53 @@ def test_grid_size_field_shares_panel_toggle(raster_panel):
     _edit(raster_panel.high_res_enter, "2.50")
     assert raster_panel._source == DbOverrideLineEdit.SOURCE_MINE
     assert raster_panel.width_enter.source() == DbOverrideLineEdit.SOURCE_MINE
+
+
+# ---------------------------------------------------------------------------
+# DataCollectionSettings: per-tab grid button + auto-center after mount
+# ---------------------------------------------------------------------------
+
+
+@pytest.fixture
+def settings_panel(qapp, diffraction, geom):
+    return DataCollectionSettings(geom, RasterGridManager(geom), diffraction)
+
+
+def test_grid_button_only_on_raster_tab(settings_panel):
+    assert not settings_panel.bounding_box.isHidden()  # Raster is the default tab
+    for idx in (1, 2, 3):
+        settings_panel._tab_bar.setCurrentIndex(idx)
+        assert settings_panel.bounding_box.isHidden()
+    settings_panel._tab_bar.setCurrentIndex(0)
+    assert not settings_panel.bounding_box.isHidden()
+
+
+def test_auto_center_fires_on_mount_only_when_armed(settings_panel):
+    clicks = []
+    settings_panel.find_tip.clicked.connect(lambda: clicks.append(1))
+    settings_panel.auto_center_after_mount.setChecked(True)
+
+    # First status with a sample already mounted = GUI (re)start: hardware
+    # must not move, only the id is recorded.
+    settings_panel._track_sample(1)
+    assert not clicks
+
+    # Real mount after an unmount fires the centering.
+    settings_panel._track_sample(None)
+    settings_panel._track_sample(2)
+    assert len(clicks) == 1
+
+    # Direct sample exchange (no unmount tick in between) also fires.
+    settings_panel._track_sample(3)
+    assert len(clicks) == 2
+
+    # Remounting the SAME sample counts as a fresh mount.
+    settings_panel._track_sample(None)
+    settings_panel._track_sample(3)
+    assert len(clicks) == 3
+
+    # Disarmed: mounts no longer trigger.
+    settings_panel.auto_center_after_mount.setChecked(False)
+    settings_panel._track_sample(None)
+    settings_panel._track_sample(4)
+    assert len(clicks) == 3