Screen redrawing issue after upgrading to 6.0.0

[lyovushka]

I tried to upgrade to latest textual (v6.3.0) in netbook, but I got an issue with redrawing that seems to have appeared in v6.0.0. It is triggered by the search functionality. Although I am able to reproduce it quite consistently, the trigger conditions are a bit involved.

I have a demo below. Essentially after I scroll the main container back and forth and hide the search widget (triggered by pressing escape) the main container is not properly redrawn. The scrolling part is important as the problem isn't triggered without it.

Screencast.From.2025-10-13.21-21-45.mp4

I am still trying to come up with a minimal example, but maybe this would ring some bells as to what the problem might be.

Edit: I was able to modify @TomJGooding 's example to reproduce the issue. It seems to be caused by a combination of scrolling and setting focus to another widget before hiding the search widget. To reproduce: press ctrl+f, type some keys, then press escape. It doesn't happen all the time, but happens consistently enough.

from textual.app import App, ComposeResult
from textual.containers import HorizontalGroup, VerticalScroll
from textual.widgets import Checkbox, Input
from textual.geometry import Region
from textual.binding import Binding
import random


class ExampleFind(HorizontalGroup):
    BINDINGS = [("escape", "dismiss")]

    DEFAULT_CSS = """
    ExampleFind {
        border-top: tall $accent;
        padding: 0 1 1 1;
        Input { width: 1fr; }

        &.hidden {
            display: none;
        }
    }
    """

    def on_input_changed(self, message: Input.Changed) -> None:
        scroll: VerticalScroll = self.parent.query_one(VerticalScroll)
        region = Region(random.randint(5, 100), random.randint(5, 100), width=3, height=1)
        scroll.scroll_to_region(region, immediate=True, animate=False)

    def compose(self) -> ComposeResult:
        yield Input(placeholder="Find")
        yield Checkbox("Match case")
        yield Checkbox("Whole word")

    def action_dismiss(self) -> None:
        scroll: VerticalScroll = self.parent.query_one(VerticalScroll)
        scroll.children[3].focus(False)
        self.add_class("hidden")


class ExampleApp(App):
    BINDINGS = [Binding("ctrl+f", "find", priority=True)]

    def compose(self) -> ComposeResult:
        with VerticalScroll():
            for i in range(100):
                yield Input(placeholder=str(i))

        yield ExampleFind(classes="hidden")

    def action_find(self) -> None:
        find = self.query_one(ExampleFind)
        find.remove_class("hidden")
        find_input = find.query_one(Input)
        find_input.focus()


if __name__ == "__main__":
    app = ExampleApp()
    app.run()

[Zaloog]

I could reproduce it, but looking into the code, couldnt find anything that looks odd (besides the absense of from imports which makes some sections quite more challenging to read, e.g. textual.reactive.reactive instead of just reactive :P ).

I remember I had some issues with the custom hidden class which sets display: none; when it came to some focusing behavior...
I switched it just to widget.display = True/False, which just does the same though (I just checked the source).

I also cloned netbook and tried it with the widget.display method, but could still reproduce the issue.
Maybe someone else has some more insights.

[lyovushka]

Thanks for taking a look! And for bearing with my coding style ;)

[TomJGooding]

FWIW, I quickly tried creating an MRE but can't reproduce this.

Perhaps this simple example will help clarify what else your app might be doing to cause this rendering issue. I'm afraid your code is too complex to expect anyone to help debug this for you, so this really does needs a MRE.

Have you tried checking the changes in Textual v6.0.0 in case that sheds some light? There's nothing that jumps out to me, but obviously you're more familiar with your code!

import random

from textual import on
from textual.app import App, ComposeResult
from textual.containers import HorizontalGroup, VerticalScroll
from textual.message import Message
from textual.widgets import Checkbox, Input


class ExampleFind(HorizontalGroup):
    BINDINGS = [("escape", "dismiss")]

    DEFAULT_CSS = """
    ExampleFind {
        border-top: tall $accent;
        padding: 0 1 1 1;
        display: none;
        Input { width: 1fr; }
    }
    """

    class Submitted(Message):
        def __init__(self) -> None:
            super().__init__()

    def compose(self) -> ComposeResult:
        yield Input(placeholder="Find")
        yield Checkbox("Match case")
        yield Checkbox("Whole word")

    def on_input_submitted(self, event: Input.Submitted) -> None:
        event.stop()
        self.post_message(self.Submitted())

    def action_dismiss(self) -> None:
        self.display = False


class ExampleApp(App):
    BINDINGS = [("ctrl+f", "find")]

    def compose(self) -> ComposeResult:
        with VerticalScroll(id="inputs-scroll"):
            for i in range(100):
                yield Input(placeholder=str(i))

        yield ExampleFind()

    @on(ExampleFind.Submitted)
    def on_find_submitted(self) -> None:
        # Scroll to a random input widget
        inputs_scroll = self.query_one("#inputs-scroll", VerticalScroll)
        all_inputs = inputs_scroll.query(Input)
        random_input = random.choice(all_inputs)
        inputs_scroll.scroll_to_widget(random_input)

    def action_find(self) -> None:
        find = self.query_one(ExampleFind)
        find.display = True
        find_input = find.query_one(Input)
        find_input.focus()


if __name__ == "__main__":
    app = ExampleApp()
    app.run()

[lyovushka]

Thank you @TomJGooding for having a look. I think the part where the VerticalScroll is being scrolled back and forth by the Find widget is important. It seems like it makes the framework think that some parts are not visible and don't need to be redrawn.

v6.0.0 is a largish change. Hard to know what might have caused it.

[TomJGooding]

I quickly tried updating my example so submitting the Find input just scrolls to a random widget, but still couldn't reproduce this rendering issue I'm afraid.

[lyovushka]

Thanks @TomJGooding ! I was able to modify your example to reproduce the issue. It seems like a combination of scrolling and setting the focus before hiding is what is causing the problem.

[TomJGooding]

Glad this helped you create a reproducible example.

Can I just check if you're also able to reproduce this in Textual v5.0.1?

[lyovushka]

Actually using the example code I am able to reproduce the issue going all the way back to Textual v1.0.0. On netbook I am only able to reproduce the issue starting at v6.0.0. It might be that the two issues are related but not identical.