automatically interpret color/colormap for the categorical plot

whitecanvas/canvas/_base.py

@@ -1864,7 +1864,7 @@ def add_image(
         image: ArrayLike,
         *,
         name: str | None = None,
-        cmap: ColormapType = "gray",
+        cmap: ColormapType | None = None,
         clim: tuple[float | None, float | None] | None = None,
         flip_canvas: bool = True,
         lock_aspect: bool = True,
@@ -1880,8 +1880,9 @@ def add_image(
         image : ArrayLike
             Image data. Must be 2D or 3D array. If 3D, the last dimension must be
             RGB(A). Note that the first dimension is the vertical axis.
-        cmap : ColormapType, default "gray"
-            Colormap used for the image.
+        cmap : ColormapType, optional
+            Colormap used for the image. If None, the theme default for image colormap
+            will be used.
         clim : (float or None, float or None) or None
             Contrast limits. If None, the limits are automatically determined by min and
             max of the data. You can also pass None separately to either limit to use
@@ -1896,6 +1897,7 @@ def add_image(
         Image
             The image layer.
         """
+        cmap = theme._default("colormap_image", cmap)
         layer = _l.Image(
             image, name=name, cmap=cmap, clim=clim, backend=self._get_backend()
         )

whitecanvas/canvas/_dims.py

@@ -6,6 +6,7 @@
 from psygnal import Signal, SignalGroup
 
 from whitecanvas import layers as _l
+from whitecanvas import theme
 from whitecanvas._axis import DimAxis, RangeAxis
 from whitecanvas._exceptions import ReferenceDeletedError
 from whitecanvas.layers import _ndim as _ndl
@@ -529,7 +530,7 @@ def add_image(
         image: Any,
         *,
         name: str | None = None,
-        cmap: ColormapType = "gray",
+        cmap: ColormapType | None = None,
         clim: tuple[float | None, float | None] | None = None,
         rgb: bool = False,
         flip_canvas: bool = True,
@@ -553,6 +554,7 @@ def add_image(
         """
         canvas = self._get_canvas()
         name = canvas._coerce_name(name)
+        cmap = theme._default("colormap_image", cmap)
         stack = _ndl.ImageLayerStack.from_layer_class(
             _l.Image, image, name=name, cmap=cmap, clim=clim, rgb=rgb,
             backend=canvas._get_backend(),

whitecanvas/canvas/dataframe/_feature_cat.py

@@ -11,6 +11,7 @@
 from whitecanvas.canvas.dataframe._base import BaseCatPlotter
 from whitecanvas.layers import tabular as _lt
 from whitecanvas.layers.tabular import _jitter
+from whitecanvas.layers.tabular import _plans as _p
 from whitecanvas.types import HistBinType, KdeBandWidthType, Orientation
 
 if TYPE_CHECKING:
@@ -205,7 +206,11 @@ def add_markers(
             self._df, xj, yj, name=name, color=color, hatch=hatch,
             size=size, symbol=symbol, backend=canvas._get_backend(),
         )  # fmt: skip
-        if color is not None and not layer._color_by.is_const():
+        if (
+            color is not None
+            and not layer._color_by.is_const()
+            and isinstance(layer._color_by, _p.ColorPlan)
+        ):
             layer.update_color(layer._color_by.by, palette=canvas._color_palette)
         elif color is None:
             layer.update_color(canvas._color_palette.next())
@@ -219,7 +224,6 @@ def add_hist2d(
         bins: HistBinType | tuple[HistBinType, HistBinType] = "auto",
         rangex: tuple[float, float] | None = None,
         rangey: tuple[float, float] | None = None,
-        cmap=None,  # deprecated
     ) -> _lt.DFMultiHeatmap[_DF]:
         """
         Add 2-D histogram of given x/y columns.

whitecanvas/layers/tabular/_marker_like.py

@@ -122,7 +122,7 @@ def _update_color_or_colormap(self, by: str | Iterable[str]) -> Self:
             and by in self._source
             and self._source[by].dtype.kind in "fiu"
         ):
-            return self.update_colormap(by)
+            return self.update_colormap(by, theme._default("colormap_categorical"))
         self.update_color(by)
         return self
 

whitecanvas/theme/_api.py

@@ -27,7 +27,7 @@ def get_theme(name: str | Theme | None = None) -> Theme:
     return _EXISTING_THEMES[name]
 
 
-def _default(attr: str, value) -> Any:
+def _default(attr: str, value=None) -> Any:
     if value is not None:
         return value
     out = _DEFAULT_THEME

whitecanvas/theme/_dataclasses.py

@@ -133,6 +133,8 @@ class Theme(_BaseModel):
     background_color: Color = _field(Color("white"))
     canvas_size: tuple[float, float] = _field((800, 600), _validate_canvas_size)
     palette: Colormap = _field(Colormap("tab10"), Colormap)
+    colormap_categorical: Colormap = _field(Colormap("viridis"), Colormap)
+    colormap_image: Colormap = _field(Colormap("gray"), Colormap)
 
 
 LIGHT_THEME = Theme()