Allow multiple alignment values for colorbar texts

Author: has2k1

doc/changelog.qmd

@@ -10,6 +10,9 @@ title: Changelog
 - Added [](:class:`~plotnine.composition.plot_layout`) with which you can customise the
   layout of plots in composition.
 
+- You can now pass a sequence of horizontal and vertical alignment (ha & va) values in
+  element_text for colorbars.
+
 ### Bug Fixes
 
 - Fixed [](:class:`~plotnine.geom_smooth`) / [](:class:`~plotnine.stat_smooth`) when using a linear model via "lm" with weights for the model to do a weighted regression. This bug did not affect the formula API of the linear model. ({{< issue 1005 >}})

plotnine/guides/guide.py

@@ -11,7 +11,7 @@
 from ..themes.theme import theme as Theme
 
 if TYPE_CHECKING:
-    from typing import Literal, Optional, TypeAlias
+    from typing import Literal, Optional, Sequence, TypeAlias
 
     import pandas as pd
     from matplotlib.offsetbox import PackerBase
@@ -176,6 +176,10 @@ class GuideElements:
     theme: Theme
     guide: guide
 
+    @cached_property
+    def text(self):
+        raise NotImplementedError
+
     def __post_init__(self):
         self.guide_kind = type(self.guide).__name__.split("_")[-1]
         self._elements_cls = GuideElements
@@ -275,3 +279,33 @@ def is_horizontal(self) -> bool:
         Whether the guide is horizontal
         """
         return self.direction == "horizontal"
+
+    def has(self, n: int) -> Sequence[str]:
+        """
+        Horizontal alignments per legend text
+        """
+        ha = self.text.ha
+        if isinstance(ha, (list, tuple)):
+            if len(ha) != n:
+                raise ValueError(
+                    "If `ha` is a sequence, its length should match the "
+                    f"number of texts. ({len(ha)} != {n})"
+                )
+        else:
+            ha = (ha,) * n
+        return ha
+
+    def vas(self, n: int) -> Sequence[str]:
+        """
+        Vertical alignments per legend texts
+        """
+        va = self.text.va
+        if isinstance(va, (list, tuple)):
+            if len(va) != n:
+                raise ValueError(
+                    "If `va` is a sequence, its length should match the "
+                    f"number of texts. ({len(va)} != {n})"
+                )
+        else:
+            va = (va,) * n
+        return va

plotnine/guides/guide_colorbar.py

@@ -420,7 +420,8 @@ def add_labels(
     n = len(labels)
     sep = elements.text.margin
     texts: list[Text] = []
-    props = {"ha": elements.text.ha, "va": elements.text.va}
+    has = elements.has(n)
+    vas = elements.vas(n)
 
     # The horizontal and vertical alignments are set in the theme
     # or dynamically calculates in GuideElements and added to the
@@ -437,8 +438,8 @@ def add_labels(
         else:
             ys = [elements.key_width + sep] * n
 
-    for x, y, s in zip(xs, ys, labels):
-        t = Text(x, y, s, **props)
+    for x, y, s, ha, va in zip(xs, ys, labels, has, vas):
+        t = Text(x, y, s, ha=ha, va=va)
         auxbox.add_artist(t)
         texts.append(t)
 

plotnine/themes/elements/element_text.py

@@ -86,10 +86,21 @@ def __init__(
             | None
         ) = None,
         size: float | Sequence[float] | None = None,
-        ha: Literal["center", "left", "right"] | float | None = None,
+        ha: (
+            Literal["center", "left", "right"]
+            | float
+            | Sequence[Literal["center", "left", "right"] | float]
+            | None
+        ) = None,
         va: (
             Literal["center", "top", "bottom", "baseline", "center_baseline"]
             | float
+            | Sequence[
+                Literal[
+                    "center", "top", "bottom", "baseline", "center_baseline"
+                ]
+                | float
+            ]
             | None
         ) = None,
         ma: Literal["center", "left", "right"] | float | None = None,

tests/baseline_images/test_theme/test_guide_colorbar_sequence_ha_va.png

@@ -175,6 +175,21 @@ def test_element_text_with_sequence_values():
     assert p == "element_text_with_sequence_values"
 
 
+def test_guide_colorbar_sequence_alignments():
+    p = (
+        ggplot(mtcars, aes("wt", "mpg", color="cyl"))
+        + geom_point()
+        + theme(
+            legend_text_colorbar=element_text(
+                size=12,
+                va=("bottom", "center", "center", "center", "top"),
+                ha=("left", "center", "center", "center", "right"),
+            ),
+        )
+    )
+    assert p == "test_guide_colorbar_sequence_ha_va"
+
+
 g = (
     ggplot(mtcars, aes(x="wt", y="mpg", color="factor(gear)"))
     + geom_point()