skip update of big text if file was not modified

src/ui/bigtext/bigtext.py

@@ -1,3 +1,4 @@
+import logging
 import math
 import os
 import time
@@ -26,20 +27,31 @@ from watchdog.observers import Observer
 from watchdog.events import FileSystemEventHandler
 from src.i18n import _
 
+log = logging.getLogger("bigtext")
 
 class FileObserver(FileSystemEventHandler):
 
     def __init__(self, big_text):
         super(FileObserver, self).__init__()
         self.big_text = big_text
+        self._last_mtime = -1
 
     def on_modified(self, event):
         # slow down the updates. This is needed, because the file is modified
         # constantly, which would lead to constant re-rendering, which would
         # block the UI thread and make the UI unresponsive.
         # Note: we don't miss events, because they are queued and de-duplicated
+        if not event.is_directory:
+            try:
+                mtime = os.stat(event.src_path).st_mtime
+                if mtime != self._last_mtime:
+                    self._last_mtime = mtime
                     time.sleep(0.5)
                     self.big_text.trigger_update.emit()
+            except FileNotFoundError:
+                # ignore: happens when closing the application, because tmp files are deleted,
+                # which triggers a modification event
+                pass
 
 
 class FileWatchdogThread(QRunnable):