preferences_window.py: Add a descriptive comment to length check

To remind us what this is for.

1 files changed, 2 insertions, 0 deletions

diff --git a/preferences_window.py b/preferences_window.py
index 10dbf1b..a40ce48 100644
--- a/preferences_window.py
+++ b/preferences_window.py
@@ -21,6 +21,8 @@ class PreferencesWindow(object):
     def edit_text_callback(self, sender):
         value = sender.get()
 
+        # Only allow a single character to be entered because this is
+        # supposed to be a hotkey
         if len(value) > 1:
             value = value[0]