Fix passing colormap objects

Author: aeisenbarth

src/spatialdata_plot/pl/utils.py

@@ -344,7 +344,12 @@ def _prepare_cmap_norm(
     **kwargs: Any,
 ) -> CmapParams:
     is_default = cmap is None
-    cmap = copy(matplotlib.colormaps[rcParams["image.cmap"] if cmap is None else cmap])
+    if cmap is None:
+        cmap = rcParams["image.cmap"]
+    if isinstance(cmap, str):
+        cmap = matplotlib.colormaps[cmap]
+
+    cmap = copy(cmap)
     cmap.set_bad("lightgray" if na_color is None else na_color)
 
     if isinstance(norm, Normalize) or not norm:

tests/_images/Images_can_pass_cmap_to_render_images.png renamed to tests/_images/Images_can_pass_cmap_name_to_render_images.png

@@ -24,9 +24,12 @@ class TestImages(PlotTester, metaclass=PlotTesterMeta):
     def test_plot_can_render_image(self, sdata_blobs: SpatialData):
         sdata_blobs.pl.render_images(elements="blobs_image").pl.show()
 
-    def test_plot_can_pass_cmap_to_render_images(self, sdata_blobs: SpatialData):
+    def test_plot_can_pass_cmap_name_to_render_images(self, sdata_blobs: SpatialData):
         sdata_blobs.pl.render_images(elements="blobs_image", cmap="seismic").pl.show()
 
+    def test_plot_can_pass_cmap_object_to_render_images(self, sdata_blobs: SpatialData):
+        sdata_blobs.pl.render_images(elements="blobs_image", cmap=matplotlib.colormaps["seismic"]).pl.show()
+
     def test_plot_can_render_a_single_channel_from_image(self, sdata_blobs: SpatialData):
         sdata_blobs.pl.render_images(elements="blobs_image", channel=0).pl.show()