look for ome_types metadata at layer.metadata['ome_types'] (#97)

* detect layer meta elsewhere

* still look for callable

src/ome_types/_napari_plugin.py

@@ -2,6 +2,8 @@
 
 from .widgets import OMETree
 
+METADATA_KEY = "ome_types"
+
 
 @napari_hook_implementation
 def napari_experimental_provide_dock_widget():

src/ome_types/widgets.py

@@ -50,15 +50,26 @@ def clear(self):
         self.headerItem().setText(0, "drag/drop file...")
         super().clear()
 
-    def _try_load_layer(self, layer):
+    def _try_load_layer(self, layer: "napari.layers.Layer"):
         """Handle napari viewer behavior"""
+        from ._napari_plugin import METADATA_KEY
+
         if layer is not None:
             path = str(layer.source.path)
-            ome = None
+
+            # deprecated... don't do this ... it should be a dict
             if callable(layer.metadata):
-                ome = layer.metadata()
+                ome_meta = layer.metadata()
             elif isinstance(layer.metadata, OME):
-                ome = layer.metadata
+                ome_meta = layer.metadata
+            else:
+                ome_meta = layer.metadata.get(METADATA_KEY)
+                if callable(ome_meta):
+                    ome_meta = ome_meta()
+
+            ome = None
+            if isinstance(ome_meta, OME):
+                ome = ome_meta
             elif path.endswith((".tiff", ".tif")) and path != self._current_path:
                 try:
                     ome = OME.from_tiff(path)