watch for file changes

bigtext.py

@@ -1,5 +1,7 @@
 import math
+import os
 import re
+import time
 from typing import Optional, List
 import PyQt6.QtGui
 from PyQt6 import QtGui
@@ -18,13 +20,60 @@ from logFileModel import LogFileModel
 import re
 
 from settings import Settings
+from watchdog.observers import Observer
+from watchdog.events import FileSystemEventHandler
+import threading
+
+
+class FileObserver(FileSystemEventHandler):
+    counter = 0
+    def __init__(self, big_text):
+        super(FileObserver, self).__init__()
+        self.big_text = big_text
+
+    def on_modified(self, event):
+        #print("file modified ", self.counter," ", time.time())
+        self.counter+=1
+        time.sleep(0.5)
+        self.big_text.update()
+
+
+class FileWatchdogThread(QRunnable):
+
+    observer = None
+
+    def __init__(self, big_text, file: str):
+        super(FileWatchdogThread, self).__init__()
+        self.file = file
+        self.big_text = big_text
+
+    def run(self) -> None:
+        print("observer started for file ", self.file)
+        if self.observer:
+            print("observer already exists")
+        self.observer = Observer()
+        self.observer.schedule(FileObserver(self.big_text), self.file)
+        self.observer.start()
+
+    def destruct(self):
+        self.observer.stop()
+        try:
+            self.observer.join()
+        except:
+            # probably: RuntimeError: cannot join thread before it is started
+            pass
 
 
 class BigText(QWidget):
+
     def __init__(self, model: LogFileModel):
         super(BigText, self).__init__()
 
         self.model = model
+
+        self.watchdog = FileWatchdogThread(self, model.get_file())
+        QThreadPool.globalInstance().start(self.watchdog)
+
         self.grid = QGridLayout()
         self.grid.setContentsMargins(0, 0, 0, 0)
         self.grid.setHorizontalSpacing(0)
@@ -51,7 +100,7 @@ class BigText(QWidget):
         return self.model.get_file()
 
     def destruct(self):
-        pass
+        self.watchdog.destruct()
 
 
 class InnerBigText(QWidget):
@@ -82,7 +131,7 @@ class InnerBigText(QWidget):
 
     def keyPressEvent(self, e: QKeyEvent) -> None:
 
-        #print("%s + %s" % (e.keyCombination().keyboardModifiers(), e.key()))
+        # print("%s + %s" % (e.keyCombination().keyboardModifiers(), e.key()))
         if e.modifiers() == Qt.KeyboardModifier.NoModifier:
             lines_to_scroll = math.floor(self.lines_shown()) - 1
             if e.key() == Qt.Key.Key_PageUp:
@@ -186,6 +235,7 @@ class InnerBigText(QWidget):
             cb.setText(selected_text)
 
     def paintEvent(self, event: QPaintEvent) -> None:
+        #print("paintEvent")
         painter = QPainter(self)
         painter.setFont(self.model.settings.font())
         painter.setPen(QColor(0, 0, 0))