Make FuncFormatter work with non-fixed locator

mplexporter/tests/__init__.py

@@ -1,9 +1,6 @@
 import os
 
-MPLBE = os.environ.get('MPLBE', 'Agg')
-
-if MPLBE:
-    import matplotlib
+import matplotlib
+if MPLBE := os.environ.get('MPLBE', 'Agg'):
     matplotlib.use(MPLBE)
-
 import matplotlib.pyplot as plt

mplexporter/tests/test_utils.py

@@ -1,5 +1,5 @@
-from numpy.testing import assert_allclose, assert_equal
-from . import plt
+from numpy.testing import assert_, assert_allclose, assert_equal
+from . import plt, matplotlib
 from .. import utils
 
 
@@ -33,3 +33,23 @@ def test_axis_w_fixed_formatter():
     # NOTE: Issue #471
     # assert_equal(props['tickformat'], labels)
 
+
+def test_funcformatter_exports_major_ticklabels():
+    # Test both log and normal cases:
+    for scale, x, y in [
+        ("linear", [0, 1], [0, 1]),
+        ("log", [1, 10, 100], [0, 1, 2]),
+    ]:
+        fig, ax = plt.subplots()
+        ax.set_xscale(scale)
+        ax.plot([1, 10, 100], [0, 1, 2])
+        ax.xaxis.set_major_formatter(matplotlib.ticker.FuncFormatter(lambda x, pos: f"t{pos}"))
+
+        props = utils.get_axis_properties(ax.xaxis)
+        plt.close(fig)
+
+        assert_equal(props["scale"], scale)
+        assert_equal(props["tickformat_formatter"], "func")
+        assert_(props["tickvalues"] is not None)
+        assert_equal(len(props["tickvalues"]), len(props["tickformat"]))
+        assert_equal(props["tickformat"][:3], ["t0", "t1", "t2"])

mplexporter/utils.py

@@ -186,6 +186,29 @@ def get_text_style(text):
     return style
 
 
+def _tick_format_props(formatter, tickvalues, labels):
+    if isinstance(formatter, ticker.NullFormatter):
+        return "", ""
+    if isinstance(formatter, ticker.StrMethodFormatter):
+        convertor = StrMethodTickFormatterConvertor(formatter)
+        return convertor.output, "str_method"
+    if isinstance(formatter, ticker.PercentFormatter):
+        return {
+            "xmax": formatter.xmax,
+            "decimals": formatter.decimals,
+            "symbol": formatter.symbol,
+        }, "percent"
+    if hasattr(ticker, 'IndexFormatter') and isinstance(formatter, ticker.IndexFormatter):
+        return [text.get_text() for text in labels], "index"
+    if isinstance(formatter, ticker.FixedFormatter):
+        return list(formatter.seq), "fixed"
+    if isinstance(formatter, ticker.FuncFormatter) and tickvalues:
+        return [formatter(value, i) for i, value in enumerate(tickvalues)], "func"
+    if not any(label.get_visible() for label in labels):
+        return "", ""
+    return None, ""
+
+
 def get_axis_properties(axis):
     """Return the property dictionary for a matplotlib.Axis instance"""
     props = {}
@@ -207,41 +230,21 @@ def get_axis_properties(axis):
     # Use tick values if appropriate
     locator = axis.get_major_locator()
     props['nticks'] = len(locator())
-    if isinstance(locator, ticker.FixedLocator):
+    if isinstance(locator, ticker.FixedLocator) or isinstance(axis.get_major_formatter(), ticker.FuncFormatter):
         props['tickvalues'] = list(locator())
     else:
         props['tickvalues'] = None
 
+    minor_locator = axis.get_minor_locator()
+    props['minor_tickvalues'] = list(axis.get_minorticklocs()) if minor_locator else None
+    props['minorticklength'] = axis._minor_tick_kw.get('size', None)
+    props['majorticklength'] = axis._major_tick_kw.get('size', None)
+
     # Find tick formats
-    props['tickformat_formatter'] = ""
-    formatter = axis.get_major_formatter()
-    if isinstance(formatter, ticker.NullFormatter):
-        props['tickformat'] = ""
-    elif isinstance(formatter, ticker.StrMethodFormatter):
-        convertor = StrMethodTickFormatterConvertor(formatter)
-        props['tickformat'] = convertor.output
-        props['tickformat_formatter'] = "str_method"
-    elif isinstance(formatter, ticker.PercentFormatter):
-        props['tickformat'] = {
-            "xmax": formatter.xmax,
-            "decimals": formatter.decimals,
-            "symbol": formatter.symbol,
-        }
-        props['tickformat_formatter'] = "percent"
-    elif hasattr(ticker, 'IndexFormatter') and isinstance(formatter, ticker.IndexFormatter):
-        # IndexFormatter was dropped in matplotlib 3.5
-        props['tickformat'] = [text.get_text() for text in axis.get_ticklabels()]
-        props['tickformat_formatter'] = "index"
-    elif isinstance(formatter, ticker.FixedFormatter):
-        props['tickformat'] = list(formatter.seq)
-        props['tickformat_formatter'] = "fixed"
-    elif isinstance(formatter, ticker.FuncFormatter) and props['tickvalues']:
-        props['tickformat'] = [formatter(value) for value in props['tickvalues']]
-        props['tickformat_formatter'] = "func"
-    elif not any(label.get_visible() for label in axis.get_ticklabels()):
-        props['tickformat'] = ""
-    else:
-        props['tickformat'] = None
+    props['minor_tickformat'], props['minor_tickformat_formatter'] = _tick_format_props(
+        axis.get_minor_formatter(), props['minor_tickvalues'], axis.get_minorticklabels())
+    props['tickformat'], props['tickformat_formatter'] = _tick_format_props(
+        axis.get_major_formatter(), props['tickvalues'], axis.get_ticklabels())
 
     # Get axis scale
     props['scale'] = axis.get_scale()
@@ -255,26 +258,32 @@ def get_axis_properties(axis):
 
     # Get associated grid
     props['grid'] = get_grid_style(axis)
+    props['minor_grid'] = get_grid_style(axis, which='minor')
 
     # get axis visibility
     props['visible'] = axis.get_visible()
 
     return props
 
 
-def get_grid_style(axis):
-    gridlines = axis.get_gridlines()
-    if axis._major_tick_kw['gridOn'] and len(gridlines) > 0:
-        color = export_color(gridlines[0].get_color())
-        alpha = gridlines[0].get_alpha()
-        dasharray = get_dasharray(gridlines[0])
-        return dict(gridOn=True,
-                    color=color,
-                    dasharray=dasharray,
-                    alpha=alpha)
-    else:
+def get_grid_style(axis, which='major'):
+    tick_kw = axis._minor_tick_kw if which == 'minor' else axis._major_tick_kw
+
+    if not tick_kw.get('gridOn'):
         return {"gridOn": False}
 
+    rc = matplotlib.rcParams
+    color = export_color(tick_kw.get('grid_color', tick_kw.get('grid_c', rc['grid.color'])))
+    alpha = tick_kw.get('grid_alpha', rc['grid.alpha'])
+    dasharray = _dasharray_from_linestyle(tick_kw.get('grid_linestyle', tick_kw.get('grid_ls', rc['grid.linestyle'])))
+    linewidth = tick_kw.get('grid_linewidth', tick_kw.get('grid_lw', rc['grid.linewidth']))
+
+    return dict(gridOn=True,
+                color=color,
+                dasharray=dasharray,
+                linewidth=linewidth,
+                alpha=alpha)
+
 
 def get_figure_properties(fig):
     return {'figwidth': fig.get_figwidth(),