fixes for napari 0.6.1 (#103)

Author: tlambert03

pyproject.toml

@@ -101,6 +101,8 @@ include = ["/src", "/tests", "CHANGELOG.md"]
 line-length = 88
 target-version = "py39"
 src = ["src"]
+fix = true
+unsafe-fixes = true
 
 [tool.ruff.lint]
 pydocstyle = { convention = "numpy" }

src/cmap/_colormap.py

@@ -239,11 +239,13 @@ def __init__(
             bad = info.bad if bad is None else bad
             self.info = info
             if isinstance(info.data, list):
+                if not info.data:  # pragma: no cover
+                    raise ValueError(f"Catalog colormap {info.name!r} has no data")
                 ld = len(info.data[0])
                 if ld == 2:
                     # if it's a list of tuples, it's a list of color stops
                     stops = ColorStops._from_uniform_stops(info.data)
-                elif ld == 3:
+                elif ld in (3, 4):
                     stops = ColorStops._from_colorarray_like(info.data)
                 else:  # pragma: no cover
                     raise ValueError(

src/cmap/_external.py

@@ -3,6 +3,7 @@
 from __future__ import annotations
 
 import contextlib
+from functools import cache
 from typing import TYPE_CHECKING
 
 import numpy as np
@@ -82,16 +83,39 @@ def to_plotly(cm: Colormap) -> list[list[float | str]]:
     return [[pos, color.rgba_string] for pos, color in cm.color_stops]
 
 
+@cache
+def _napari_colormap_param_names() -> set[str]:
+    from napari.utils.colormaps import Colormap
+
+    if hasattr(Colormap, "__fields__"):
+        return set(Colormap.__fields__)
+    elif hasattr(Colormap, "model_fields"):
+        return set(Colormap.model_fields)
+    return set()
+
+
 def to_napari(cm: Colormap) -> NapariColormap:
     """Return a napari colormap."""
     from napari.utils.colormaps import Colormap
 
-    return Colormap(
-        colors=cm.color_stops.color_array,
-        controls=cm.color_stops.stops,
-        name=cm.identifier or "custom colormap",
-        display_name=cm.name,
-    )
+    kwargs = {
+        "colors": cm.color_stops.color_array,
+        "controls": cm.color_stops.stops,
+        "name": cm.identifier or "custom colormap",
+        "display_name": cm.name,
+    }
+    if param_names := _napari_colormap_param_names():
+        if "interpolation" in param_names:
+            kwargs["interpolation"] = (
+                "zero" if cm.interpolation == "nearest" else "linear"
+            )
+        if "nan_color" in param_names and cm.bad_color is not None:
+            kwargs["nan_color"] = cm.bad_color.rgba
+        if "high_color" in param_names and cm.over_color is not None:
+            kwargs["nan_color"] = cm.over_color.rgba
+        if "low_color" in param_names and cm.under_color is not None:
+            kwargs["low_color"] = cm.under_color.rgba
+    return Colormap(**kwargs)
 
 
 def to_bokeh(cm: Colormap, N: int = 256) -> BokehLinearColorMapper:

src/cmap/data/napari/record.json

@@ -0,0 +1,59 @@
+{
+  "colormaps": {
+    "HiLo": {
+      "category": "miscellaneous",
+      "data": [
+        [
+          0.0,
+          0.0,
+          0.0,
+          1.0
+        ],
+        [
+          1.0,
+          1.0,
+          1.0,
+          1.0
+        ]
+      ],
+      "over": [
+        1.0,
+        0.0,
+        0.0,
+        1.0
+      ],
+      "under": [
+        0.0,
+        0.0,
+        1.0,
+        1.0
+      ]
+    },
+    "nan": {
+      "bad": [
+        1.0,
+        0.0,
+        0.0,
+        1.0
+      ],
+      "category": "miscellaneous",
+      "data": [
+        [
+          0.0,
+          0.0,
+          0.0,
+          1.0
+        ],
+        [
+          1.0,
+          1.0,
+          1.0,
+          1.0
+        ]
+      ]
+    }
+  },
+  "license": "BSD-3-Clause",
+  "namespace": "napari",
+  "source": "https://github.com/napari/napari"
+}