Major update of all demo programs to use new PEP8 bindings, etc

DemoPrograms old/Demo_Multithreaded_Logging.py

@@ -0,0 +1,98 @@
+import sys
+if sys.version_info[0] >= 3:
+    import PySimpleGUIQt as sg
+else:
+    import PySimpleGUI27 as sg
+
+import queue
+import logging
+import threading
+import time
+
+"""
+    This code originated in this project:
+    https://github.com/john144/MultiThreading
+    Thanks to John for writing this in the early days of PySimpleGUI
+    Demo program showing one way that a threaded application can function with PySimpleGUI
+    Events are sent from the ThreadedApp thread to the main thread, the GUI, by using a queue
+"""
+
+logger = logging.getLogger('mymain')
+
+
+def externalFunction():
+    logger.info('Hello from external app')
+    logger.info('External app sleeping 5 seconds')
+    time.sleep(5)
+    logger.info('External app waking up and exiting')
+
+
+class ThreadedApp(threading.Thread):
+    def __init__(self):
+        super().__init__()
+        self._stop_event = threading.Event()
+
+    def run(self):
+        externalFunction()
+
+    def stop(self):
+        self._stop_event.set()
+
+
+class QueueHandler(logging.Handler):
+    def __init__(self, log_queue):
+        super().__init__()
+        self.log_queue = log_queue
+
+    def emit(self, record):
+        self.log_queue.put(record)
+
+
+def main():
+    window = sg.FlexForm('Log window', default_element_size=(30, 2), font=('Helvetica', ' 10'), default_button_element_size=(8, 2), return_keyboard_events=True)
+
+    layout =  \
+        [
+            [sg.Multiline(size=(50, 15), key='Log')],
+            [sg.Button('Start', bind_return_key=True, key='_START_'), sg.Button('Exit')]
+        ]
+
+    window.Layout(layout).Read(timeout=0)
+    appStarted = False
+
+    # Setup logging and start app
+    logging.basicConfig(level=logging.DEBUG)
+    log_queue = queue.Queue()
+    queue_handler = QueueHandler(log_queue)
+    logger.addHandler(queue_handler)
+    threadedApp = ThreadedApp()
+
+    # Loop taking in user input and querying queue
+    while True:
+        # Wake every 100ms and look for work
+        event, values = window.Read(timeout=100)
+
+        if event == '_START_':
+            if appStarted is False:
+                threadedApp.start()
+                logger.debug('App started')
+                window.FindElement('_START_').Update(disabled=True)
+                appStarted = True
+        elif event in  (None, 'Exit'):
+            break
+
+        # Poll queue
+        try:
+            record = log_queue.get(block=False)
+        except queue.Empty:
+            pass
+        else:
+            msg = queue_handler.format(record)
+            window.FindElement('Log').Update(msg+'\n', append=True)
+
+    window.Close()
+    exit()
+
+
+if __name__ == '__main__':
+    main()