Change name for subset conversion action

glue/core/regions.py

@@ -0,0 +1,41 @@
+"""
+Functions to support data that defines regions
+"""
+import numpy as np
+
+from glue.core.roi import PolygonalROI
+from glue.core.data import RegionData
+
+from glue.config import layer_action
+from glue.core.subset import RoiSubsetState, MultiOrState
+
+
+def reg_to_roi(reg):
+    if reg.geom_type == "Polygon":
+        ext_coords = np.array(reg.exterior.coords.xy)
+        roi = PolygonalROI(vx=ext_coords[0], vy=ext_coords[1])  # Need to account for interior rings
+    return roi
+
+
+@layer_action(label='Subset of regions -> Subset over region extent', single=True, subset=True)
+def layer_to_subset(layer, data_collection):
+    """
+    This should be limited to the case where subset.Data is RegionData
+    and/or return a warning when applied to some other kind of data.
+    """
+    if isinstance(layer.data, RegionData):
+
+        extended_comp = layer.data._extended_component_ids[0]
+        regions = layer[extended_comp]
+        list_of_rois = [reg_to_roi(region) for region in regions]
+
+        roisubstates = [RoiSubsetState(layer.data.ext_x,
+                                       layer.data.ext_y,
+                                       roi=roi
+                                       )
+                        for roi in list_of_rois]
+        if len(list_of_rois) > 1:
+            composite_substate = MultiOrState(roisubstates)
+        else:
+            composite_substate = roisubstates[0]
+        _ = data_collection.new_subset_group(subset_state=composite_substate)