object has no attribute 'refresh'

[DdosTheCoder]

I'm new to programming so sorry if this is actually a very easy and stupid question.

I'm trying to develop an Android training app for my friend with, because it's android, I can't create new windows, so I'm using main_window.content, and when I try to ran the app with briefcase dev I get an error in the cmd AttributeError: 'Picture' object has no attribute 'refresh'. I understand that's the error is in the fact, that the Picture class has no attribute refresh but I don't know how to fix it.

I tried:

def refresh(widget): 
pass

and

class Picture(toga.App, refresh):

but it doesn't work, I also looked in discussions and asked ChatGPT but nothing seems to work, so I came here.

This is a part of the code where I think the problem is. If you need I can send a full code here.

class Picture(toga.App):
    def startup(self):

        def barbell_bench_press(widget):

            barbell_bench_press_box = toga.Box()
            main_window.content = barbell_bench_press_box

           
            image_path =  toga.Image(self.paths.data / "C:\\Users\\ddosu\\Downloads\\barbell-bench-press.png")
            view = toga.ImageView(image_path, style=Pack(width=300, height=300))
            barbell_bench_press_box.add(view)

[rmartin16]

Please include what it is you are trying to do; it's difficult to provide advice if you don't state your relevant goals.

As far as the error is concerned, are you trying to call Picture.refresh() somewhere? If so, you'll need to define a method called refresh in your Picture class.

If you are able to provide a minimal app that reproduces the error (that only includes the code necessary to create your error), that can help since we'll have a straightforward example to commonly work from.

Also, please include the full error traceback as well; this is simplest if you just upload the log created by Briefcase. You can force this log creation with briefcase dev --log.

[DdosTheCoder]

I'm sorry for the confusion.

My goal is: add picture to the box of the exercise , my code worked just fine before I tried to add a picture.

I don't know if you need it , but here's minimal app that shows how it's supposed to work:

"""
S training - created to help
"""

import toga
from toga.style.pack import COLUMN, ROW, RIGHT, LEFT, Pack, CENTER



def startup(self):

    def barbell_bench_press(widget):

        barbell_bench_press_box = toga.Box()
        main_window.content = barbell_bench_press_box

        label = toga.Label(text="PICTURE OF THE BENCH PRESS")

        barbell_bench_press_box.add(label)


    push_box = toga.Box(style=Pack(direction=COLUMN))
    def push_list(widget):
        main_window.content = push_box

        barbell_bench_press_button = toga.Button("Barbell Bench Press", on_press=barbell_bench_press, style=Pack(flex=1, padding=0))

        push_box.add(barbell_bench_press_button, return_button)


    def return_to_main_window(widget):
        main_window.content = main_box


    main_window = toga.MainWindow(title="S training")

    toga.App.main_window = main_window
    main_window.show()


    split_box = toga.Box(style=Pack(direction=COLUMN, alignment="center"))

    dummy_box = toga.Box(style=Pack(flex=1))
    dummy_box_bottom = toga.Box(style=Pack(flex=1))

    push_button = toga.Button("Push", on_press=push_list, style=Pack(flex=1, padding=5))


    return_button = toga.Button("Go Back", on_press=return_to_main_window, style=Pack(padding_top=100))


    split_box.add(push_button)


    main_box = toga.Box(style=Pack(direction=COLUMN))
    main_box.add(dummy_box)
    main_box.add(split_box)
    main_box.add(dummy_box_bottom)

    main_window.content = main_box

    return main_box


def main():
    return toga.App("S training", "org.s_training", startup=startup, version="0.69.0")


if __name__ == "__main__":
    main().main_loop()

Here is the most minimalistic version of my code that I can think of:

"""
S training - created to help
"""

import toga
from toga.style.pack import COLUMN, ROW, RIGHT, LEFT, Pack, CENTER


class Picture(toga.App):
    def startup(self):

        def barbell_bench_press(widget):

            barbell_bench_press_box = toga.Box()
            main_window.content = barbell_bench_press_box

            image_path =  toga.Image(self.paths.data / "C:\\Users\\ddosu\\Downloads\\barbell-bench-press.png")
            view = toga.ImageView(image_path, style=Pack(width=300, height=300))
            barbell_bench_press_box.add(view)


        push_box = toga.Box(style=Pack(direction=COLUMN))
        def push_list(widget):
            main_window.content = push_box

            barbell_bench_press_button = toga.Button("Barbell Bench Press", on_press=barbell_bench_press, style=Pack(flex=1, padding=0))

            push_box.add(barbell_bench_press_button, return_button)


        def return_to_main_window(widget):
            main_window.content = main_box


        main_window = toga.MainWindow(title="S training")

        toga.App.main_window = main_window
        main_window.show()


        split_box = toga.Box(style=Pack(direction=COLUMN, alignment="center"))

        dummy_box = toga.Box(style=Pack(flex=1))
        dummy_box_bottom = toga.Box(style=Pack(flex=1))

        push_button = toga.Button("Push", on_press=push_list, style=Pack(flex=1, padding=5))


        return_button = toga.Button("Go Back", on_press=return_to_main_window, style=Pack(padding_top=100))


        split_box.add(push_button)


        main_box = toga.Box(style=Pack(direction=COLUMN))
        main_box.add(dummy_box)
        main_box.add(split_box)
        main_box.add(dummy_box_bottom)

        main_window.content = main_box

        return main_box


def main():
    return toga.App("S training", "org.s_training", startup=Picture, version="0.69.0")


if __name__ == "__main__":
    main().main_loop()

And here is the logs:
briefcase.2024_01_06-21_21_40.dev.log

[rmartin16]

Thanks.

In main(), you're returning a toga.App with startup=Picture but that's probably not going to work since invoking the object from startup needs to return a widget.

Try this instead:

def main():
    return Picture()

You'll also want to consider the use of main_box in return_to_main_window() since it won't be available in that function.

[DdosTheCoder]

Thank you for fast response, I did like you told me, and AttributeError: 'Picture' object has no attribute 'refresh' error disappeared, but now I encounter another error, TypeError: App.main_loop() missing 1 required positional argument: 'self'

I tried:

if __name__ == "__main__":
    main().main_loop(self)

but the error hasn't disappeared

Here are the logs:
briefcase.2024_01_06-22_00_01.dev.log

[DdosTheCoder]

I am very sorry it was the problem on my side, sorry that I disturbed you

[rmartin16]

Are you returning Picture or Picture() from main() in app.py? It needs to be Picture().

[DdosTheCoder]

yes, the problem was in my bad typing, I reffered to Picture(), as Picture, thank you very much for your help and patience