Don't react to second of two quick 'return' key presses

Fixes #228

app/config.py

@@ -77,9 +77,9 @@ class Config(object):
     OBS_PASSWORD = "auster"
     OBS_PORT = 4455
     PLAY_SETTLE = 500000
+    RETURN_KEY_DEBOUNCE_MS = 500
     ROOT = os.environ.get("ROOT") or "/home/kae/music"
     ROWS_FROM_ZERO = True
-    IMPORT_DESTINATION = os.path.join(ROOT, "Singles")
     SCROLL_TOP_MARGIN = 3
     START_GAP_WARNING_THRESHOLD = 300
     TEXT_NO_TRACK_NO_NOTE = "[Section header]"
@@ -90,3 +90,6 @@ class Config(object):
     WARNING_MS_BEFORE_FADE = 5500
     WARNING_MS_BEFORE_SILENCE = 5500
     WEB_ZOOM_FACTOR = 1.2
+
+    # These rely on earlier definitions
+    IMPORT_DESTINATION = os.path.join(ROOT, "Singles")

app/musicmuster.py

@@ -214,8 +214,7 @@ class Window(QMainWindow, Ui_MainWindow):
         try:
             mixer.init()
         except Exception:
-            helpers.show_warning(self, "Fatal error",
-                                 "Cannot initialise sound device")
+            helpers.show_warning(self, "Fatal error", "Cannot initialise sound device")
             sys.exit(1)
 
         self.widgetFadeVolume.hideAxis("bottom")
@@ -654,7 +653,6 @@ class Window(QMainWindow, Ui_MainWindow):
             else:
                 log.error("Failed to retrieve playlist")
 
-
     def download_played_tracks(self) -> None:
         """Download a CSV of played tracks"""
 
@@ -1098,6 +1096,13 @@ class Window(QMainWindow, Ui_MainWindow):
 
         # Check for inadvertent press of 'return'
         if self.catch_return_key:
+            # Suppress inadvertent double press
+            if (
+                track_sequence.now.start_time and track_sequence.now.start_time
+                + dt.timedelta(milliseconds=Config.RETURN_KEY_DEBOUNCE_MS)
+                > dt.datetime.now()
+            ):
+                return
             if not helpers.ask_yes_no(
                 "Track playing",
                 "Really play next track now?",