Add helpers for common artist edges

Author: ksunden

Diff for: data_prototype/conversion_edge.py

@@ -7,7 +7,7 @@
 from typing import Any
 import numpy as np
 
-from data_prototype.description import Desc, desc_like
+from data_prototype.description import Desc, desc_like, ShapeSpec
 
 from matplotlib.transforms import Transform
 
@@ -112,6 +112,17 @@ def from_default_value(
     ) -> "DefaultEdge":
         return cls(name, {}, {key: output}, weight, invertable=False, value=value)
 
+    @classmethod
+    def from_rc(
+        cls, rc_name: str, key: str | None = None, coordinates: str = "display"
+    ):
+        from matplotlib import rcParams
+
+        if key is None:
+            key = rc_name.split(".")[-1]
+        scalar = Desc((), coordinates)
+        return cls.from_default_value(f"{rc_name}_rc", key, scalar, rcParams[rc_name])
+
     def evaluate(self, input: dict[str, Any]) -> dict[str, Any]:
         return {k: self.value for k in self.output}
 
@@ -428,3 +439,24 @@ def cache_key(self):
         import uuid
 
         return str(uuid.uuid4())
+
+def coord_and_default(
+    key: str,
+    shape: ShapeSpec = (),
+    coordinates: str = "display",
+    default_value: Any = None,
+    default_rc: str | None = None,
+):
+    if default_rc is not None:
+        if default_value is not None:
+            raise ValueError(
+                "Only one of 'default_value' and 'default_rc' may be specified"
+            )
+        def_edge = DefaultEdge.from_rc(default_rc, key, coordinates)
+    else:
+        scalar = Desc((), coordinates)
+        def_edge = DefaultEdge.from_default_value(
+            f"{key}_def", key, scalar, default_value
+        )
+    coord_edge = CoordinateEdge.from_coords(key, {key: Desc(shape)}, coordinates)
+    return coord_edge, def_edge

Diff for: data_prototype/text.py

@@ -4,41 +4,24 @@
 
 from .artist import Artist
 from .description import Desc
-from .conversion_edge import Graph, CoordinateEdge, DefaultEdge
+from .conversion_edge import Graph, CoordinateEdge, coord_and_default
 
 
 class Text(Artist):
     def __init__(self, container, edges=None, **kwargs):
         super().__init__(container, edges, **kwargs)
 
-        scalar = Desc((), "display")
-
         edges = [
             CoordinateEdge.from_coords(
                 "xycoords", {"x": Desc((), "auto"), "y": Desc((), "auto")}, "data"
             ),
-            CoordinateEdge.from_coords("text", {"text": Desc(())}, "display"),
-            CoordinateEdge.from_coords("color", {"color": Desc(())}, "display"),
-            CoordinateEdge.from_coords("alpha", {"alpha": Desc(())}, "display"),
-            CoordinateEdge.from_coords(
-                "fontproperties", {"fontproperties": Desc(())}, "display"
-            ),
-            CoordinateEdge.from_coords("usetex", {"usetex": Desc(())}, "display"),
-            CoordinateEdge.from_coords("rotation", {"rotation": Desc(())}, "display"),
-            CoordinateEdge.from_coords(
-                "antialiased", {"antialiased": Desc(())}, "display"
-            ),
-            DefaultEdge.from_default_value("text_def", "text", scalar, ""),
-            DefaultEdge.from_default_value("color_def", "color", scalar, "k"),
-            DefaultEdge.from_default_value("alpha_def", "alpha", scalar, 1),
-            DefaultEdge.from_default_value(
-                "fontproperties_def", "fontproperties", scalar, FontProperties()
-            ),
-            DefaultEdge.from_default_value("usetex_def", "usetex", scalar, False),
-            DefaultEdge.from_default_value("rotation_def", "rotation", scalar, 0),
-            DefaultEdge.from_default_value(
-                "antialiased_def", "antialiased", scalar, False
-            ),
+            *coord_and_default("text", default_value=""),
+            *coord_and_default("color", default_rc="text.color"),
+            *coord_and_default("alpha", default_value=1),
+            *coord_and_default("fontproperties", default_value=FontProperties()),
+            *coord_and_default("usetex", default_rc="text.usetex"),
+            *coord_and_default("rotation", default_value=0),
+            *coord_and_default("antialiased", default_rc="text.antialiased"),
         ]
 
         self._graph = self._graph + Graph(edges)