diff --git a/DemoPrograms/Demo_Multithreaded_Long_Task_Simple.py b/DemoPrograms/Demo_Multithreaded_Long_Task_Simple.py index 27303845..ca8808f9 100644 --- a/DemoPrograms/Demo_Multithreaded_Long_Task_Simple.py +++ b/DemoPrograms/Demo_Multithreaded_Long_Task_Simple.py @@ -5,42 +5,38 @@ import PySimpleGUI as sg """ DESIGN PATTERN - Multithreaded Long Tasks GUI using shared global variables - + Presents one method for running long-running operations in a PySimpleGUI environment. The PySimpleGUI code, and thus the underlying GUI framework, runs as the primary, main thread The "long work" is contained in the thread that is being started. Communicating is done (carefully) using global variables - There are 2 ways "progress" is being reported to the user. If a the amount of time is known ahead of time and - the work can be broek down into countable units, then a progress bar is used. If a task is one long chunk - of time that cannot be broken down into smaller units, then an animated GIF is shown that spins as - long as the task is running. + There are 2 ways "progress" is being reported to the user. + You can simulate the 2 different scenarios that happen with worker threads. + 1. If a the amount of time is known ahead of time or the work can be broken down into countable units, then a progress bar is used. + 2. If a task is one long chunk of time that cannot be broken down into smaller units, then an animated GIF is shown that spins as + long as the task is running. """ -thread_done = 1 -message = '' -thread_counter = 0 -total = 100 -progress = 0 +total = 100 # number of units that are used with the progress bar +message = '' # used by thread to send back a message to the main thread +progress = 0 # current progress up to a maximum of "total" + def long_operation_thread(seconds): """ - A worker thread that communicates with the GUI through a global variable + A worker thread that communicates with the GUI through a global message variable This thread can block for as long as it wants and the GUI will not be affected :param seconds: (int) How long to sleep, the ultimate blocking call - :return: """ - global thread_done, message, thread_counter, progress + global message, progress print('Thread started - will sleep for {} seconds'.format(seconds)) - thread_counter += 1 - for i in range(int(seconds*10)): - time.sleep(.1) # sleep for a while - progress += total/(seconds*10) - - message = f'***This is a message from the thread {thread_counter} ***' - thread_done = True + for i in range(int(seconds * 10)): + time.sleep(.1) # sleep for a while + progress += total / (seconds * 10) + message = f'*** The thread says.... "I am finished" ***' def the_gui(): """ @@ -48,53 +44,50 @@ def the_gui(): Reads data from a global variable and displays Returns when the user exits / closes the window """ - global thread_done, message, progress + global message, progress sg.theme('Light Brown 3') layout = [[sg.Text('Long task to perform example')], [sg.Output(size=(80, 12))], [sg.Text('Number of seconds your task will take'), - sg.Input(key='-SECONDS-', size=(5, 1)), - sg.Button('Do Long Task', bind_return_key=True), - sg.CBox('ONE chunk, cannot break apart', key='-ONE CHUNK-')], - [sg.Text('Work progress'), sg.ProgressBar(total, size=(20,20), orientation='h', key='-PROG-')], + sg.Input(key='-SECONDS-', size=(5, 1)), + sg.Button('Do Long Task', bind_return_key=True), + sg.CBox('ONE chunk, cannot break apart', key='-ONE CHUNK-')], + [sg.Text('Work progress'), sg.ProgressBar(total, size=(20, 20), orientation='h', key='-PROG-')], [sg.Button('Click Me'), sg.Button('Exit')], ] - window = sg.Window('Multithreaded Window', layout) + window = sg.Window('Multithreaded Demonstration Window', layout) - one_chunk = False - sg.popup_animated(None) + thread = None # --------------------- EVENT LOOP --------------------- while True: event, values = window.read(timeout=100) if event in (None, 'Exit'): break - elif event.startswith('Do'): - seconds = float(values['-SECONDS-']) - one_chunk = values['-ONE CHUNK-'] - print('Thread Starting! Long work....sending value of {} seconds'.format(seconds)) - threading.Thread(target=long_operation_thread, args=(seconds, ), daemon=True).start() + elif event.startswith('Do') and not thread: + print('Thread Starting! Long work....sending value of {} seconds'.format(float(values['-SECONDS-']))) + thread = threading.Thread(target=long_operation_thread, args=(float(values['-SECONDS-']),), daemon=True) + thread.start() elif event == 'Click Me': print('Your GUI is alive and well') - # --------------- Check for incoming messages from threads --------------- - if thread_done is True: - print('The thread has finished!') - print(f'message = {message}') - # reset everything for the next run - sg.popup_animated(None) # just in case one's running, stop it - thread_done = one_chunk = False - message, progress = '', 0 - window['-PROG-'].update_bar(total, total) # show the bar as maxed out - if one_chunk: # flag signifies the thread is taking to take one big chunk of time - sg.popup_animated(sg.DEFAULT_BASE64_LOADING_GIF, background_color='white', transparent_color='white', time_between_frames=100) - elif progress != 0: - window['-PROG-'].update_bar(progress, total) # update the progress bar if non-zero - # if user exits the window, then close the window and exit the GUI func + if thread: # If thread is running + if values['-ONE CHUNK-']: # If one big operation, show an animated GIF + sg.popup_animated(sg.DEFAULT_BASE64_LOADING_GIF, background_color='white', transparent_color='white', time_between_frames=100) + else: # Not one big operation, so update a progress bar instead + window['-PROG-'].update_bar(progress, total) + thread.join(timeout=0) + if not thread.is_alive(): # the thread finished + print(f'message = {message}') + sg.popup_animated(None) # stop animination in case one is running + thread, message, progress = None, '', 0 # reset variables for next run + window['-PROG-'].update_bar(0,0) # clear the progress bar + window.close() + if __name__ == '__main__': the_gui() print('Exiting Program')