Fix slow events dialog (#207)

* Fix slow events dialog

* Add changelog entry

CHANGELOG.md

@@ -2,7 +2,7 @@
 ### Fixed
 - Remove auto-installation of `PySide2` when using `pip` ([#196](https://github.com/cbrnr/mnelab/pull/196) by [Clemens Brunner](https://github.com/cbrnr))
 - Starting MNELAB with the `mnelab` command in a terminal now also works on Windows ([#197](https://github.com/cbrnr/mnelab/pull/197) by [Clemens Brunner](https://github.com/cbrnr))
-- Removing annotations is now as fast as it should be ([#206](https://github.com/cbrnr/mnelab/pull/206) by [Clemens Brunner](https://github.com/cbrnr))
+- Removing annotations and events is now as fast as it should be ([#206](https://github.com/cbrnr/mnelab/pull/206) and [#207](https://github.com/cbrnr/mnelab/pull/207) by [Clemens Brunner](https://github.com/cbrnr))
 
 ### Changed
 - Rename `master` branch to `main` ([#193](https://github.com/cbrnr/mnelab/pull/193) by [Clemens Brunner](https://github.com/cbrnr))

mnelab/dialogs/eventsdialog.py

@@ -67,10 +67,11 @@ def __init__(self, parent, pos, desc):
     @Slot()
     def toggle_buttons(self):
         """Toggle + and - buttons."""
-        if len(self.table.selectedItems()) == 2:  # one row (2 items) selected
+        n_items = len(self.table.selectedItems())
+        if n_items == 2:  # one row (2 items) selected
             self.add_button.setEnabled(True)
             self.remove_button.setEnabled(True)
-        elif len(self.table.selectedItems()) > 2:  # more than one row selected
+        elif n_items > 2:  # more than one row selected
             self.add_button.setEnabled(False)
             self.remove_button.setEnabled(True)
         else:  # no rows selected
@@ -88,5 +89,6 @@ def add_event(self):
 
     def remove_event(self):
         rows = {index.row() for index in self.table.selectedIndexes()}
+        self.table.clearSelection()
         for row in sorted(rows, reverse=True):
             self.table.removeRow(row)