[BUG, MRG] Fix topomap extra plot generated, add util to check a range

doc/changes/latest.inc

@@ -64,6 +64,7 @@ Bugs
 - Fix :func:`mne.io.read_raw` for file names containing multiple dots (:gh:`11521` by `Clemens Brunner`_)
 - Fix bug in :func:`mne.export.export_raw` when exporting to EDF with a physical range set smaller than the data range (:gh:`11569` by `Mathieu Scheltienne`_)
 - Fix bug in :func:`mne.concatenate_raws` where two raws could not be merged if the order of the bad channel lists did not match (:gh:`11502` by `Moritz Gerster`_)
+- Fix bug where :meth:`mne.Evoked.plot_topomap` opened an extra figure (:gh:`11607` by `Alex Rockhill`_)
 
 
 API changes

mne/utils/__init__.py

@@ -11,7 +11,7 @@
                     _check_pandas_index_arguments,
                     _check_event_id, _check_ch_locs, _check_compensation_grade,
                     _check_if_nan, _is_numeric, _ensure_int, _check_preload,
-                    _validate_type, _check_info_inv,
+                    _validate_type, _check_range, _check_info_inv,
                     _check_channels_spatial_filter, _check_one_ch_type,
                     _check_rank, _check_option, _check_depth, _check_combine,
                     _path_like, _check_src_normal, _check_stc_units,

mne/utils/check.py

@@ -551,6 +551,37 @@ def _validate_type(item, types=None, item_name=None, type_name=None, *,
             f"got {type(item)} instead.")
 
 
+def _check_range(val, min_val, max_val, name, min_inclusive=True,
+                 max_inclusive=True):
+    """Check that item is within range.
+
+    Parameters
+    ----------
+    val : int | float
+        The value to be checked.
+    min_val : int | float
+        The minimum value allowed.
+    max_val : int | float
+        The maximum value allowed.
+    name : str
+        The name of the value.
+    min_inclusive : bool
+        Whether ``val`` is allowed to be ``min_val``.
+    max_inclusive : bool
+        Whether ``val`` is allowed to be ``max_val``.
+    """
+    below_min = val < min_val if min_inclusive else val <= min_val
+    above_max = val > max_val if max_inclusive else val >= max_val
+    if below_min or above_max:
+        error_str = f'The value of {name} must be between {min_val} '
+        if min_inclusive:
+            error_str += 'inclusive '
+        error_str += f'and {max_val}'
+        if max_inclusive:
+            error_str += 'inclusive '
+        raise ValueError(error_str)
+
+
 def _path_like(item):
     """Validate that `item` is `path-like`.
 

mne/utils/tests/test_check.py

@@ -18,7 +18,8 @@
 from mne.utils import (check_random_state, _check_fname, check_fname, _suggest,
                        _check_subject, _check_info_inv, _check_option, Bunch,
                        check_version, _path_like, _validate_type, _on_missing,
-                       _safe_input, _check_ch_locs, _check_sphere)
+                       _safe_input, _check_ch_locs, _check_sphere,
+                       _check_range)
 
 data_path = testing.data_path(download=False)
 base_dir = data_path / "MEG" / "sample"
@@ -184,6 +185,15 @@ def test_validate_type():
         _validate_type(False, 'int-like')
 
 
+def test_check_range():
+    """Test _check_range."""
+    _check_range(10, 1, 100, 'value')
+    with pytest.raises(ValueError, match='must be between'):
+        _check_range(0, 1, 10, 'value')
+    with pytest.raises(ValueError, match='must be between'):
+        _check_range(1, 1, 10, 'value', False, False)
+
+
 @testing.requires_testing_data
 def test_suggest():
     """Test suggestions."""

mne/viz/topomap.py

@@ -908,7 +908,6 @@ def _plot_topomap(
         border=_BORDER_DEFAULT, res=64, cmap=None, vmin=None, vmax=None,
         cnorm=None, show=True, onselect=None):
     from matplotlib.colors import Normalize
-    import matplotlib.pyplot as plt
     from matplotlib.widgets import RectangleSelector
     data = np.asarray(data)
     logger.debug(f'Plotting topomap for {ch_type} data shape {data.shape}')
@@ -1050,7 +1049,7 @@ def _plot_topomap(
                       verticalalignment='center', size='x-small')
 
     if not axes.figure.get_constrained_layout():
-        plt.subplots_adjust(top=.95)
+        axes.figure.subplots_adjust(top=.95)
 
     if onselect is not None:
         lim = axes.dataLim