Threaded class methods updating progressbar

DemoPrograms/Demo_Threaded_Progressbar.py

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+#! /usr/bin/env python
+#  -*- coding: utf-8 -*-
+
+"""
+Quick and dirty threading example for PySimpleGUI progress bar executing class methods
+Written in 2018 by Orsiris de Jong, www.netpower.fr, works with Python 3+
+"""
+
+from threading import Thread
+from concurrent.futures import Future
+from time import time, sleep
+import PySimpleGUI as Sg
+
+# Helper functions for threading class functions with return values using future from https://stackoverflow.com/a/19846691/2635443
+def call_with_future(fn, future, args, kwargs):
+    try:
+        result = fn(*args, **kwargs)
+        future.set_result(result)
+    except Exception as exc:
+        future.set_exception(exc)
+
+def threaded(fn):
+    def wrapper(*args, **kwargs):
+        future = Future()
+        Thread(target=call_with_future, args=(fn, future, args, kwargs)).start()
+        return future
+    return wrapper
+
+# Some fancy class which functions should be threaded or not using decorator
+class SomeFancyClass:
+    def __init__(self):
+        self.somevar = 'Some initial class variable'
+
+    # Adding this decoroator to thread the function below
+    @threaded
+    def func_to_be_threaded(self):
+        print(self.somevar)
+        sleep(7)
+        self.somevar = 'New value'
+        return('Return from func_to_be_threaded is ' + self.somevar)
+
+
+    @threaded
+    def another_thread_function(self):
+        print(self.somevar)
+        sleep(3)
+        return ('Return from another_thread_function is ' + self.somevar)
+
+    def non_threaded_function(self):
+        print('waiting')
+        sleep(5)
+        print('finished waiting')
+
+# The main progress bar method
+def progressbar(myClass):
+    maxwait = 10  # Wait for 10 seconds max with the progress bar before asking to cancel
+    progress = 0
+    startTime = 0
+    currentTime = 0
+
+    function_one = None
+    function_two = None
+    function_one_done = False
+    function_two_done = False
+
+    # layout of the progress bar window
+    layout = [[Sg.Text('Launching threads')],
+              [Sg.ProgressBar(100, orientation='h', size=(20, 20), key='progressbar')],
+              [Sg.Cancel()]]
+
+    # create the progress bar
+    window = Sg.Window('Init', text_justification='center').Layout(layout)
+
+    startTime = time()
+
+    while True:
+        event, values = window.Read(timeout=1)
+        if event == 'Cancel' or event is None:
+            window.Close()
+            exit()
+
+        if function_one == None:
+            # Launch first threaded function
+            function_one = myClass.func_to_be_threaded()
+
+        if function_two == None:
+            # Launch second threaded function
+            function_two = myClass.another_thread_function()
+
+        print('function_one is done: ' + str(function_one.done()))
+        print('function_two is done: ' + str(function_two.done()))
+
+        if function_one.done() == True and function_one_done == False:
+            function_one_done = True
+            print(function_one.result())
+            progress += 70
+
+        if function_two.done() == True and function_two_done == False:
+            function_two_done = True
+            print(function_two.result())
+            progress += 30
+
+        window.FindElement('progressbar').UpdateBar(progress)
+        sleep(.3) # Arbitrary time between loops so UI stays snappy
+
+        currentTime = time()
+        if (currentTime - startTime) > maxwait:
+            action = Sg.Popup('Seems that it takes too long, shall we continue the program',custom_text=('No', 'Yes'))
+            if action == 'No':
+                function_one.cancel()
+                function_two.cancel()
+                break
+            elif action == 'Yes':
+                startTime = time() # Lets give another 10 seconds or check if functions must be stopped
+                """
+                TODO: We could relaunch the functions with
+                function_one.cancel()
+                if function_one.cancelled():
+                    function_one = myClass.func_to_be_threaded()
+                """
+
+        if progress >= 100:
+            break
+    window.Close()
+
+def main():
+    myClass = SomeFancyClass()
+    progressbar(myClass)
+
+
+if __name__ == '__main__':
+    main()