From b5615883934cc398962face8d5947d03081e595b Mon Sep 17 00:00:00 2001
From: veghp <pvegh@posteo.uk>
Date: Thu, 9 Jan 2025 13:14:00 +0000
Subject: [PATCH] Fix #91

---
 .../GraphicRecord/MatplotlibPlottableMixin.py | 31 ++++++++++++++++---
 1 file changed, 26 insertions(+), 5 deletions(-)

diff --git a/dna_features_viewer/GraphicRecord/MatplotlibPlottableMixin.py b/dna_features_viewer/GraphicRecord/MatplotlibPlottableMixin.py
index f3f5601..31d33c6 100644
--- a/dna_features_viewer/GraphicRecord/MatplotlibPlottableMixin.py
+++ b/dna_features_viewer/GraphicRecord/MatplotlibPlottableMixin.py
@@ -157,7 +157,12 @@ def plot_feature(self, ax, feature, level, linewidth=1.0):
             head_length = 0.001
         else:
             width_pixel = self._get_ax_width(ax, unit="pixel")
-            head_length = 0.5 * width_pixel * feature.length / self.sequence_length
+            head_length = (
+                0.5
+                * width_pixel
+                * feature.length
+                / (ax.get_xlim()[1] - ax.get_xlim()[0])
+            )
             head_length = min(head_length, 0.6 * feature.thickness)
 
         arrowstyle = mpatches.ArrowStyle.Simple(
@@ -274,7 +279,7 @@ def place_annotation(
         max_label_length,
         indicate_strand_in_label=False,
     ):
-        """"Place an annotation in the figure. Decide on inline vs. outline.
+        """ "Place an annotation in the figure. Decide on inline vs. outline.
 
         Parameters
         ----------
@@ -464,7 +469,16 @@ def strand_in_label(f):
             self.plot_feature(ax=ax, feature=feature, level=level)
             if feature.label is None:
                 continue
-            (text, overflowing, nlines, (x1, x2,), height,) = self.place_annotation(
+            (
+                text,
+                overflowing,
+                nlines,
+                (
+                    x1,
+                    x2,
+                ),
+                height,
+            ) = self.place_annotation(
                 feature=feature,
                 ax=ax,
                 level=level,
@@ -573,10 +587,17 @@ def plot_legend(
             text = feature.legend_text
             if text is None:
                 continue
-            parameters = dict(label=text, facecolor=feature.color, edgecolor="black",)
+            parameters = dict(
+                label=text,
+                facecolor=feature.color,
+                edgecolor="black",
+            )
             if include_edge:
                 parameters.update(
-                    dict(linewidth=feature.linewidth, edgecolor=feature.linecolor,)
+                    dict(
+                        linewidth=feature.linewidth,
+                        edgecolor=feature.linecolor,
+                    )
                 )
             if text in features_parameters:
                 previous_parameters = features_parameters[text]