Fix geom_text & geom_label with adjust_text

Responding to adjustText>=1.0.0

doc/changelog.qmd

@@ -7,11 +7,14 @@ title: Changelog
 
 ### Bug Fixes
 
-- Fix bug in [](:class:`~plotnine.stat_smooth`) where you could not set the
+- Fixed bug in [](:class:`~plotnine.stat_smooth`) where you could not set the
   family when using a `glm`. ({{< issue 769 >}})
 
-- Fix bug in [](:class:`~plotnine.position_dodge2`) the widths of the dodged
-  objects were mixed up. ({{< issue 772 >}})
+- Fixed bug in [](:class:`~plotnine.position_dodge2`) the widths of the
+  dodged objects were mixed up. ({{< issue 772 >}})
+
+- Fixed [](:class:`~plotnine.geom_text`) to work better with
+  [adjustText](https://pypi.org/project/adjustText/) `v1.0.0` and above.
 
 ### Enhancements
 

plotnine/geoms/geom_text.py

@@ -252,8 +252,8 @@ def draw_group(
             if params["path_effects"]:
                 text_elem.set_path_effects(params["path_effects"])
 
-        _adjust = params["adjust_text"]
-        if _adjust:
+        # TODO: Do adjust text per panel
+        if _adjust := params["adjust_text"]:
             from adjustText import adjust_text
 
             if params["zorder"] == 1:
@@ -263,10 +263,20 @@ def draw_group(
                     PlotnineWarning,
                 )
 
-            arrowprops = _adjust.pop("arrowprops", {})
+            _adjust = _adjust.copy()
+            arrowprops = _adjust.pop("arrowprops", {}).copy()
             if "color" not in arrowprops:
                 arrowprops["color"] = color[0]
 
+            # The head_length, tail_length and tail_width of the arrow are
+            # specified on the same scale as the fontsize, but their default
+            # values are in the [0, 1] range. The true values are obtained by
+            # multiplying by the mutation_scale. The default value of
+            # mutation_scale is 1, so the arrow is effectively invisible.
+            # A good default for this usecase is the size of text.
+            if "mutation_scale" not in arrowprops:
+                arrowprops["mutation_scale"] = data["size"].mean()
+
             adjust_text(texts, ax=ax, arrowprops=arrowprops, **_adjust)
 
     @staticmethod

tests/test_geom_text_label.py

@@ -39,7 +39,7 @@
 )
 
 adjust_text = {
-    "expand_points": (2, 2),
+    "expand": (2, 2),
     "arrowprops": {"arrowstyle": "->", "color": "red"},
 }