allow_focus doesn't work as expected

[TomJGooding]

Initially I wasn't sure if I'd just misunderstood the allow_focus method, but following on from #5605 it sounds like this might not be working as expected.

I've created this as a separate issue as its somewhat tangential. but feel free to close this as a duplicate if you'd prefer to just re-open the original issue.

Here's another minimal example:

from textual.app import App, ComposeResult
from textual.containers import VerticalScroll
from textual.widget import Widget
from textual.widgets import Static


class Focusable(Widget, can_focus=False):
    def allow_focus(self) -> bool:
        return True

    def compose(self) -> ComposeResult:
        for _ in range(100):
            yield Static("Focusable")


class NonFocusable(VerticalScroll, can_focus=True):
    def allow_focus(self) -> bool:
        return False

    def compose(self) -> ComposeResult:
        for _ in range(100):
            yield Static("NonFocusable")


class ExampleApp(App):
    CSS = """
    Focusable, NonFocusable {
        height: 1fr;
        border: tall red;
        &:focus {
            border: tall green;
        }
    }
    """

    def compose(self) -> ComposeResult:
        yield Focusable()
        yield NonFocusable()


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

[github-actions]

We found the following entries in the FAQ which you may find helpful:

• How can I select and copy text in a Textual app?
• How do I center a widget in a screen?
• Why do some key combinations never make it to my app?

Feel free to close this issue if you found an answer in the FAQ. Otherwise, please give us a little time to review.

This is an automated reply, generated by FAQtory

[mzebrak]

It looks like in this MRE, the can_focus takes precedence over allow_focus which may be the intended behavior, but also may not be, IDK.

But there is also another problem with allow_focus as you mentioned? In the MRE you mentioned in the #5605 (comment) it doesn't look like it shows the same thing; there is no can_focus. Or am I missing something? This one is more about "allow_focus is not called when widget is mounted for the first time"

---

Edit

I think I get the point - you also wanted to show that allow_focus is not called when the widget is mounted. But actually it is interesting which one can_focus or allow_focus should take precedence in that example.

[TomJGooding]

Right, this is just another example. Remember in the original example that VerticalScroll will have inherited can_focus=True.