style(Pack(visibility=VISIBLE) does not work

Expected Behavior

self.busy_label.style=Pack(visibility=VISIBLE) should work

Current Behavior

I had a label: self.busy_label = toga.Label('Fetching data...Please wait...', style=Pack(visibility=HIDDEN))

Later I tried to hide it: self.busy_label.style=Pack(visibility=VISIBLE)

This did not work. Resizing the window did not help.

This. did work: self.busy_label.style.visibility = VISIBLE

Steps to reproduce

If you click the 2nd or 3rd buttons, everything works fine, but as soon as you click the 1st button, everything is broken.

import toga
from toga.style import Pack
from toga.constants import ROW, COLUMN, HIDDEN, VISIBLE, CENTER

class BugApp(toga.App):

    def startup(self):
        # Main window of the application with title and size
        self.main_window = toga.MainWindow(title=self.name, size=(500, 500))

        self.busy_label = toga.Label('Fetching data...Please wait...', style=Pack(visibility=HIDDEN))

        self.button1 = toga.Button(label='style=Pack(visibility=VISIBLE)', on_press=self.clicked)
        self.button2 = toga.Button(label='style.visibility = VISIBLE', on_press=self.clicked)
        self.button3 = toga.Button(label='Hide Label', on_press=self.clicked)
        button_box = toga.Box(children=[self.button1, self.button2, self.button3], style=Pack(direction=ROW, padding=20, alignment=CENTER))
        label_box = toga.Box(children=[self.busy_label], style=Pack(direction=COLUMN, padding=20, alignment=CENTER))
        box = toga.Box(children=[button_box, label_box], style=Pack(direction=COLUMN, padding=20))

        self.main_window.content = box
        self.main_window.show()

    def clicked(self, button):
        if 'Pack' in button.label:
            self.busy_label.style=Pack(visibility=VISIBLE)
        elif 'Hide' in button.label:
            self.busy_label.style.visibility = HIDDEN
        else:
            self.busy_label.style.visibility = VISIBLE

        self.busy_label.refresh()

def main():
    # App name and namespace
    return BugApp('BugApp', 'mybugapp')


if __name__ == '__main__':
    app = main()
    app.main_loop()

Your Environment

• Python Version: 3.7.7

• Operating System and Version (select from the following and list the specific version number; if your OS is not listed, list that as well)

  • macOS - version: 10.15.5

• Toga Version: 0.2.15

• Toga Target (the type of app you are trying to generate)

  • cocoa

[freakboy3742]

@swapniljha001 We need to establish a patch that does trigger the application of the style change, but doesn’t require removal of the overall optimization. I’m not sure if @Vipul-Cariappa is still looking at this problem (it’s been a few months since the last update); any investigation/exploration you want to do would be helpful.

[swapniljha001]

What can I do to help resolve this issue?