Passing focus to a different widget and hiding causes screen regions not to be redrawn.

[lyovushka]

Here is an example to reproduce the issue. Press "ctrl+f", type some letters (it makes the program scroll randomly), then press "escape". Quite often the screen is not redrawn properly.

Textual version: 6.4.0
Terminal's tried: kitty, foot
Operating system: linux

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()

Originally posted by @lyovushka in #6176

[willmcgugan]

I can reproduce this, but only very rarely. Barely 1 in 20 times, which makes it hard to test.

Have you established what parts of that code are required to reproduce the issue? i.e. do you need the checkboxes, the border etc? Is focusing the third child significant?

[willmcgugan]

Ok, I can reproduce it more reliably by setting top=True on the scroll_to_region. Without it, the scroll rarely occurs, as the random region may already be in the view.

[github-actions]

I hope I solved your issue!

Consider sponsoring my work to continue to maintain and develop Textual.

• Will McGugan

[lyovushka]

Thanks @willmcgugan! Can't reproduce it any more with 6.5.0