Button can be clicked while disabled

[def1127]

In specific situations, buttons can be clicked while disabled. Textual responds by queuing the button click and sends it when the button is next enabled.

from textual.containers import Vertical
from textual.widgets import Button, Label
from textual import on
import asyncio

class MyApp(App):
    def compose(self) -> ComposeResult:
        # Run button
        self.run_button = Button(label="Run", variant="success", id="button")
        self.text = Label("Not Running")

        # Assemble the UI
        yield Vertical(self.run_button, self.text)

    @on(Button.Pressed, "#button")
    async def on_button_pressed(self, event: Button.Pressed) -> None:
        
        # Call the long-running function
        await MyFunction(self)
    
async def MyFunction(self):
    self.text.update("Running!")
    await asyncio.sleep(5)
    self.text.update("Not Running")

# Start the application
if __name__ == "__main__":
    MyApp().run()

When I run this example, click the button rapidly, and time the output, the label doesn't return to the "Not Running" state in the 5 seconds it should, it takes a multiple of 5 seconds.

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[def1127]

I have a suspicion that the issue originates in _button.py line 254.

async def _on_click(self, event: events.Click) -> None:
        event.stop()
        if not self.has_class("-active"):
            self.press()

    def press(self) -> Self:
        """Animate the button and send the [Pressed][textual.widgets.Button.Pressed] message.

        Can be used to simulate the button being pressed by a user.

        Returns:
            The button instance.
        """
        if self.disabled or not self.display:
            return self
        # Manage the "active" effect:
        self._start_active_affect()
        # ...and let other components know that we've just been clicked:
        self.post_message(Button.Pressed(self))
        return self

This code suggests that you can't do button.press when the button is disabled, but the async event _on_click can still create a message, and seems to wait to process the message until the button is enabled. Suggest either a check in _on_click() for if the button is disabled, or where that is inherited from widget.py

[TomJGooding]

I'm not sure I understand what you mean by a button being disabled in this context? Perhaps the docs for Async handlers help explain this behaviour?

[willmcgugan]

Your MyFunction doesn't return for 5 seconds. This means that the app's message loop will not be able to process any additional messages until that returns. Input events are queued, which is desirable -- you don't want the app to not respond to input if it ever becomes too busy.

The solution is highly dependent on what you want to implement (I don't know what work your async sleep is designed to replicate). You might want to investigate workers, but there are also timers and call_later.

If you don't want the button to be clicked while the app is busy you can set button.disabled=True

I'd also encourage you to read the guide on Events and Messages.

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