fix: connect core roiSet signal to MDAWidget _core_grid and _core_position (#406)

* add mmc.events.roiSet connection

* add test

* update + test

Author: fdrgsp

src/pymmcore_widgets/mda/_core_grid.py

@@ -45,6 +45,7 @@ def __init__(
 
         self._mmc.events.systemConfigurationLoaded.connect(self._update_fov_size)
         self._mmc.events.pixelSizeChanged.connect(self._update_fov_size)
+        self._mmc.events.roiSet.connect(self._update_fov_size)
         self._update_fov_size()
 
     def _update_fov_size(self) -> None:

src/pymmcore_widgets/mda/_core_positions.py

@@ -17,7 +17,7 @@
     QWizard,
 )
 from superqt.utils import signals_blocked
-from useq import WellPlatePlan
+from useq import MDASequence, WellPlatePlan
 
 from pymmcore_widgets import HCSWizard
 from pymmcore_widgets.useq_widgets import PositionTable
@@ -112,6 +112,8 @@ def __init__(
         # connect
         self._mmc.events.systemConfigurationLoaded.connect(self._on_sys_config_loaded)
         self._mmc.events.propertyChanged.connect(self._on_property_changed)
+        self._mmc.events.roiSet.connect(self._update_fov_size)
+        self._mmc.events.pixelSizeChanged.connect(self._update_fov_size)
 
         self.destroyed.connect(self._disconnect)
 
@@ -455,3 +457,30 @@ def _disconnect(self) -> None:
             self._on_sys_config_loaded
         )
         self._mmc.events.propertyChanged.disconnect(self._on_property_changed)
+
+    def _update_fov_size(self) -> None:
+        """Update the FOV size of any grid plan subsequence."""
+        if not (pos_list := self.value()):
+            return
+
+        # get updated FOV size
+        px = self._mmc.getPixelSizeUm()
+        fov_w = self._mmc.getImageWidth() * px
+        fov_h = self._mmc.getImageHeight() * px
+
+        new_pos_list = []
+        for pos in pos_list:
+            # skip if there is not a subsequence
+            if pos.sequence is None:
+                new_pos_list.append(pos)
+                continue
+            # skip if there is not a grid plan
+            if (gp := pos.sequence.grid_plan) is None:
+                new_pos_list.append(pos)
+                continue
+            # update the FOV size
+            new_gp = gp.model_copy(update={"fov_width": fov_w, "fov_height": fov_h})
+            new_pos = pos.model_copy(update={"sequence": MDASequence(grid_plan=new_gp)})
+            new_pos_list.append(new_pos)
+        # update the table
+        self.setValue(new_pos_list)

tests/test_useq_core_widgets.py

@@ -983,3 +983,64 @@ def _qmsgbox(*args, **kwargs):
         # AF column should be hidden
         assert pos_table.table().isColumnHidden(af_col)
         assert pos_table.table().isColumnHidden(af_btn_col)
+
+
+def test_grid_plan_fov_update(qtbot: QtBot, global_mmcore: CMMCorePlus) -> None:
+    mmc = global_mmcore
+    wdg = MDAWidget()
+    qtbot.addWidget(wdg)
+    wdg.show()
+
+    wdg.tab_wdg.setChecked(wdg.grid_plan, True)
+    grid_plan = useq.GridRowsColumns(rows=2, columns=1)
+    wdg.grid_plan.setValue(grid_plan)
+
+    assert wdg.value().grid_plan.fov_height == 512
+    assert wdg.value().grid_plan.fov_width == 512
+
+    with qtbot.waitSignal(mmc.events.roiSet):
+        mmc.setROI(0, 0, 100, 150)
+    assert wdg.value().grid_plan.fov_width == 100
+    assert wdg.value().grid_plan.fov_height == 150
+
+    with qtbot.waitSignal(mmc.events.pixelSizeChanged):
+        mmc.setPixelSizeConfig("Res20x")
+    assert wdg.value().grid_plan.fov_width == 50
+    assert wdg.value().grid_plan.fov_height == 75
+
+
+def test_grid_plan_subsequence_fov_update(
+    qtbot: QtBot, global_mmcore: CMMCorePlus
+) -> None:
+    mmc = global_mmcore
+    wdg = MDAWidget()
+    qtbot.addWidget(wdg)
+    wdg.show()
+
+    pos = useq.AbsolutePosition(
+        x=0.0,
+        y=0.0,
+        z=0.0,
+        sequence=useq.MDASequence(
+            grid_plan=useq.GridRowsColumns(
+                fov_width=512.0, fov_height=512.0, rows=3, columns=1
+            )
+        ),
+    )
+    wdg.tab_wdg.setChecked(wdg.stage_positions, True)
+    wdg.stage_positions.setValue([pos])
+
+    sp = wdg.stage_positions
+    assert sp.value()[0].sequence.grid_plan.fov_width == 512
+    assert sp.value()[0].sequence.grid_plan.fov_height == 512
+
+    with qtbot.waitSignal(mmc.events.roiSet):
+        mmc.setROI(0, 0, 100, 150)
+
+    assert sp.value()[0].sequence.grid_plan.fov_width == 100
+    assert sp.value()[0].sequence.grid_plan.fov_height == 150
+
+    with qtbot.waitSignal(mmc.events.pixelSizeChanged):
+        mmc.setPixelSizeConfig("Res20x")
+    assert sp.value()[0].sequence.grid_plan.fov_width == 50
+    assert sp.value()[0].sequence.grid_plan.fov_height == 75