fix: clear x/y positions for absolute grid plans in MDASequence and PositionTable (#509)

Author: tlambert03

src/pymmcore_widgets/useq_widgets/_mda_sequence.py

@@ -125,14 +125,26 @@ def usedAxes(self) -> tuple[str, ...]:
 
     def value(self) -> useq.MDASequence:
         """Return the current sequence as a [`useq.MDASequence`][]."""
+        grid_plan = self.grid_plan.value() if self.isAxisUsed("g") else None
+        positions = self.stage_positions.value() if self.isAxisUsed("p") else ()
+
+        # If a global absolute grid plan is used, x/y on positions are
+        # meaningless (the grid defines them). Clear them to avoid useq
+        # validation warnings.
+        if grid_plan is not None and not grid_plan.is_relative and positions:
+            positions = tuple(
+                pos.replace(x=None, y=None)
+                if pos.x is not None or pos.y is not None
+                else pos
+                for pos in positions
+            )
+
         return useq.MDASequence(
             z_plan=self.z_plan.value() if self.isAxisUsed("z") else None,
             time_plan=self.time_plan.value() if self.isAxisUsed("t") else None,
-            stage_positions=(
-                self.stage_positions.value() if self.isAxisUsed("p") else ()
-            ),
+            stage_positions=positions,
             channels=self.channels.value() if self.isAxisUsed("c") else (),
-            grid_plan=self.grid_plan.value() if self.isAxisUsed("g") else None,
+            grid_plan=grid_plan,
             metadata={PYMMCW_METADATA_KEY: {"version": pymmcore_widgets.__version__}},
         )
 

src/pymmcore_widgets/useq_widgets/_positions.py

@@ -245,6 +245,15 @@ def value(
                     # update the sub-sequence dict in the record
                     r["sequence"] = sub_seq
 
+            # If a sub-sequence uses an absolute grid plan, x/y on the
+            # position are meaningless (the grid defines them). Clear them
+            # to avoid useq validation warnings.
+            sub = r.get("sequence")
+            if isinstance(sub, useq.MDASequence) and sub.grid_plan is not None:
+                if not sub.grid_plan.is_relative:
+                    r.pop("x", None)
+                    r.pop("y", None)
+
             pos = useq.Position(**r)
             out.append(pos)
 

tests/test_useq_core_widgets.py

@@ -1071,8 +1071,6 @@ def test_sub_wdg_channel_tab(qtbot: QtBot, global_mmcore: CMMCorePlus) -> None:
         ),
         stage_positions=(
             useq.AbsolutePosition(
-                x=1,
-                y=2,
                 z=3,
                 name="pos1",
                 sequence=useq.MDASequence(grid_plan=poly1),