Make Inspector work even if mne-qt-browser is installed

We now explicitly request a Matploblib plotting context for
bringing up the Inspector. Otherwise, our MNE will default to
using the qt-browser, and our current implementation of the
Inspector will fail to launch.

doc/whats_new.rst

@@ -61,6 +61,8 @@ Detailed list of changes
 
 - Suppress superfluous warnings about MaxShield in many functions when handling Elekta/Neuromag/MEGIN data, by `Richard Höchenberger`_ (:gh:`1000`)
 
+- The MNE-BIDS Inspector didn't work if ``mne-qt-browser`` was installed and used as the default plotting backend, as the Inspector currently only supports the Matplotlib backend, by `Richard Höchenberger`_ (:gh:`1007`)
+
 :doc:`Find out what was new in previous releases <whats_new_previous_releases>`
 
 .. include:: authors.rst

mne_bids/inspect.py

@@ -12,6 +12,7 @@
 
 from mne.utils import logger, verbose
 from mne.fixes import _compare_version
+from mne.viz import use_browser_backend
 
 if _compare_version(mne.__version__, '<', '1.0.dev0'):  # pragma: no cover
     from mne.preprocessing import annotate_flat
@@ -155,10 +156,14 @@ def _inspect_raw(*, bids_path, l_freq, h_freq, find_flat, show_annotations):
         flat_chans = []
 
     show_options = bids_path.datatype == 'meg'
-    fig = raw.plot(title=f'{bids_path.root.name}: {bids_path.basename}',
-                   highpass=l_freq, lowpass=h_freq,
-                   show_options=show_options,
-                   block=False, show=False, verbose='warning')
+
+    with use_browser_backend('matplotlib'):
+        fig = raw.plot(
+            title=f'{bids_path.root.name}: {bids_path.basename}',
+            highpass=l_freq, lowpass=h_freq,
+            show_options=show_options,
+            block=False, show=False, verbose='warning'
+        )
 
     # Add our own event handlers so that when the MNE Raw Browser is being
     # closed, our dialog box will pop up, asking whether to save changes.