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Merge pull request #1191 from PySimpleGUI/Dev-latest 

Dev latest
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MikeTheWatchGuy 2019-03-02 17:44:34 -05:00 committed by GitHub
parent 23fc85d423 1c46c3456b
commit 4cdcda44ad
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1 changed files with 23 additions and 14 deletions
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37
DemoPrograms/Demo_Multithreaded_Queued.py
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@ -7,8 +7,17 @@ import PySimpleGUI as sg
"""
DESIGN PATTERN - Multithreaded GUI
One method for running multiple threads in a PySimpleGUI environment.
This design pattern works for all of the flavors of PySimpleGUI including the Web and also repl.it
The PySimpleGUI code, and thus the underlying GUI framework, runs as the primary, main thread
Other parts of the software are implemented as threads
A queue.Queue is used by the worker threads to communicate with code that calls PySimpleGUI directly.
The PySimpleGUI code is structured just like a typical PySimpleGUI program. A layout defined,
a Window is created, and an event loop is executed.
What's different is that within this otherwise normal PySimpleGUI Event Loop, there is a check for items
in the Queue. If there are items found, process them by making GUI changes, and continue.
This design pattern works for all of the flavors of PySimpleGUI including the Web and also repl.it
You'll find a repl.it version here: https://repl.it/@PySimpleGUI/Async-With-Queue-Communicationspy
"""
@ -21,7 +30,7 @@ def worker_thread(thread_name, run_freq, gui_queue):
:param gui_queue: Queue used to communicate with the GUI
:return:
"""
print('Strarting thread - ', thread_name)
print('Starting thread - ', thread_name)
i = 0
while True:
sleep(run_freq/1000)
@ -43,17 +52,19 @@ def the_gui(gui_queue):
window = sg.Window('Window Title').Layout(layout)
while True: # Event Loop
event, values = window.Read(timeout=200) # wait for up to 200 ms for a GUI event
event, values = window.Read(timeout=100) # wait for up to 200 ms for a GUI event
if event is None or event == 'Exit':
break
#--------------- Handle stuff coming in from threads ---------------
try: # see if something has been posted to Queue
message = gui_queue.get_nowait()
except:
message = None # indicate nothing posted
# if message received from queue, display the message in the Window
if message:
window.Element('_OUTPUT_').Update(message)
while True: # loop executes until runs out of messages in Queue
try: # see if something has been posted to Queue
message = gui_queue.get_nowait()
except: # will get exception when Queue is empty
break # break from the loop if no more messages are queued up
# if message received from queue, display the message in the Window
if message:
window.Element('_OUTPUT_').Update(message)
window.Refresh()
# if user exits the window, then close the window and exit
window.Close()
@ -63,9 +74,7 @@ if __name__ == '__main__':
#-- Create a Queue to communicate with GUI --
gui_queue = Queue() # queue used to communicate between the gui and the worker
#-- Start worker threads, one runs twice as often as the other
thread = Thread(target=worker_thread, args=('Thread 1', 1000, gui_queue,), daemon=True)
thread.start()
thread = Thread(target=worker_thread, args=('Thread 2', 500, gui_queue,), daemon=True)
thread.start()
Thread(target=worker_thread, args=('Thread 1', 500, gui_queue,), daemon=True).start()
Thread(target=worker_thread, args=('Thread 2', 200, gui_queue,), daemon=True).start()
#-- Start the GUI passing in the Queue --
the_gui(gui_queue)