[Question] How to handle events in event loop ?

[ViviNewbie]

Type of Issue (Enhancement, Error, Bug, Question)

Can't cycle the layout with the button

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Operating System

Windows 10

PySimpleGUI Port (tkinter, Qt, Wx, Web)

tkinter

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Versions

Version information can be obtained by calling sg.main_get_debug_data()
Or you can print each version shown in ()

Python version (sg.sys.version)

3.8.0

PySimpleGUI Version (sg.__version__)

4.41.2

GUI Version (tkinter (sg.tclversion_detailed), PySide2, WxPython, Remi)

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Your Experience In Months or Years (optional)

1.5 Years Python programming experience

1.5 Years Programming experience overall

Have used another Python GUI Framework? (tkinter, Qt, etc) (no is fine)

Anything else you think would be helpful? i'm a beginner and I'm not a developer. I use python for statistical analysis usually but am starting a new project for the students

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Troubleshooting

These items may solve your problem. Please check those you've done by changing - [ ] to - [X]

• [x ] Searched main docs for your problem www.PySimpleGUI.org
• [x ] Looked for Demo Programs that are similar to your goal Demos.PySimpleGUI.org
• If not tkinter - looked for Demo Programs for specific port
• For non tkinter - Looked at readme for your specific port if not PySimpleGUI (Qt, WX, Remi)
• [x ] Run your program outside of your debugger (from a command line)
• [x ] Searched through Issues (open and closed) to see if already reported Issues.PySimpleGUI.org
• [x ] Tried using the PySimpleGUI.py file on GitHub. Your problem may have already been fixed but not released

Detailed Description

Hi everyone,
I managed to perform cycle layout thanks to your help but I am stuck with a problem for a while now.
I think my last loop is not good: I would like when the user answers "E", to update the output with "good answer". Then the user has a to click on OK to go back to the first layout.
But it doesn't work: it creates an endless loop.
Why is my loop wrong?

Code To Duplicate

A short program that isolates and demonstrates the problem (Do not paste your massive program, but instead 10-20 lines that clearly show the problem)

This pre-formatted code block is all set for you to paste in your bit of code:

import PySimpleGUI as sg
# import PySimpleGUIQt as sg

# ----------- Create the 3 layouts this Window will display -----------
layout1 = [[sg.Text('Layout 1')],
           [sg.CB("A", key="A"), sg.CB("B", key="B")]]

layout2 = [[sg.Text('Layout 2')],
           [sg.CB("C", key="C"), sg.CB("D", key="D")]]

layout3 = [[sg.Text('Layout 3')],
           [sg.CB("E", key="E"), sg.CB("F", key="F")],
           [sg.Text(key="OUTPUT")]]

# ----------- Create actual layout using Columns and a row of Buttons
layout = [[sg.Column(layout1, key='-COL1-'), sg.Column(layout2, visible=False, key='-COL2-'), sg.Column(layout3, visible=False, key='-COL3-')],
          [sg.Button('OK'), sg.Button('Exit')]]

window = sg.Window('Swapping the contents of a window', layout)

layout = 1  # The currently visible layout
while True:
    event, values = window.read()
    print(event, values)
    if event in (sg.WIN_CLOSED, 'Exit'):
        break
    if event == 'OK' and values["A"]==True and values["B"]==False:
        window[f'-COL1-'].update(visible=False)
        window[f'-COL2-'].update(visible=True)
        if event=="OK" and values["C"]==True and values["D"]==False:
            window[f'-COL2-'].update(visible=False)
            window[f'-COL3-'].update(visible=True)
            if event =="OK" and values["E"]==True and values["F"]==False:
                window['OUTPUT'].update("Good answer")
                if event=="OK":
                    window[f'-COL3-'].update(visible=False)
                    window[f'-COL1-'].update(visible=True)
                
    
window.close()

Screenshot, Sketch, or Drawing

[jason990420]

It looks like this issue is about python programming logic, not about PySimpleGUI.

There are only theree events generated, and last two events will break the event loop and close window.

• 'OK'
• 'Exit'
• sg.WINDOW_CLOSED

For event ''OK'', we need to confirm which layout visible ? so one variable layout to indicate which layout visible. There are three layouts, so each time event 'OK' happened, we need to check which layout is, then what to do. Your event loop is a while loop which is going to read window about what event happened and what values for some elements. You won't get the new event and new values of window if no window read.

Code revised as following

import PySimpleGUI as sg
# import PySimpleGUIQt as sg

sg.theme('DarkBlue3')
sg.set_options(font=('Courier New', 16))

# ----------- Create the 3 layouts this Window will display -----------
layout1 = [
    [sg.Text('Layout 1')],
    [sg.CB("A", key="A"), sg.CB("B", key="B")],]

layout2 = [
    [sg.Text('Layout 2')],
    [sg.CB("C", key="C"), sg.CB("D", key="D")],]

layout3 = [
    [sg.Text('Layout 3')],
    [sg.CB("E", key="E"), sg.CB("F", key="F")],]

# ----------- Create actual layout using Columns and a row of Buttons
layout = [
    [sg.Column(layout1, key='-COL1-'),
     sg.Column(layout2, visible=False, key='-COL2-'),
     sg.Column(layout3, visible=False, key='-COL3-')],
    [sg.Text(size=(15, 1), key="OUTPUT")],
    [sg.Button('OK'), sg.Button('Exit')]]

window = sg.Window('Swapping the contents of a window', layout)

layout = 1  # The currently visible layout

while True:

    event, values = window.read()
    if event in (sg.WINDOW_CLOSED, 'Exit'):
        break
    elif event == 'OK':
        if layout == 1 and values['A'] and not values['B']:
            window['-COL1-'].update(visible=False)
            window['-COL2-'].update(visible=True)
            layout = 2
        elif layout == 2 and values['C'] and not values['D']:
            window['-COL2-'].update(visible=False)
            window['-COL3-'].update(visible=True)
            layout = 3
        elif layout == 3 and values['E'] and not values['F']:
            window['OUTPUT'].update(value="Good answer")
            layout = 4
        elif layout == 4:
            window['-COL3-'].update(visible=False)
            window['-COL1-'].update(visible=True)
            layout = 1

window.close()

If your layout at all the same format as here, you may just update the text of your elements, then it will be a new question for only one layout required and also no switching of layouts required.

[jason990420]

Here's my way to do it,

import PySimpleGUI as sg

def update_question(window, question):
    window['QUESTION'].update(value=questions[question]['question'])
    window['A'].update(value=False)
    window['B'].update(value=False)

sg.theme('DarkBlue3')
sg.set_options(font=('Courier New', 16))

questions = {
    1: {'question': 'question 1', 'answer':(True, False)},
    2: {'question': 'question 2', 'answer':(True, False)},
    3: {'question': 'question 3', 'answer':(True, False)},
}

question = 1
layout = [
    [sg.Text(questions[question]['question'], size=(0, 1), key='QUESTION')],
    [sg.CB("A", key="A"), sg.CB("B", key="B")],
    [sg.Button('OK'), sg.Button('Exit')]
]

window = sg.Window('Questions', layout)

while True:

    event, values = window.read()
    if event in (sg.WINDOW_CLOSED, 'Exit'):
        break
    answers = (values['A'], values['B'])
    if event == 'OK':
        if answers == questions[question]['answer']:
            question += 1
            if question not in questions:
                sg.popup("Good answer !")
                question = 1
            update_question(window, question)

window.close()