Force the size of a widget in its loading state to use the loading widget's size

[NSPC911]

Hey guys, so this kind of confused me quite a bit. Take a look at this code

from textual import on
from textual.app import App, ComposeResult
from textual.containers import HorizontalGroup, VerticalGroup
from textual.widgets import Button, Static


class Application(App):
    CSS = """
    HorizontalGroup#labels {
        height: 1fr;
    }
    HorizontalGroup#labels > Static {
        border: solid $accent;
        width: 1fr;
        height: 1fr;
    }
    """

    def compose(self) -> ComposeResult:
        with VerticalGroup():
            with HorizontalGroup(id="labels"):
                yield Static("One")
                yield Static("Two", id="middle")
                yield Static("Three")
            with HorizontalGroup():
                yield Button("toggle middle one", id="toggle")
                yield Button("get middle one size", id="size")

    @on(Button.Pressed, "#toggle")
    def toggle_loading(self) -> None:
        middle = self.query_one("#middle", Static)
        middle.loading = not middle.loading

    @on(Button.Pressed, "#size")
    def toggle_size(self) -> None:
        middle = self.query_one("#middle", Static)
        self.notify(f"Middle size: {middle.size}")


Application().run()

now run it

so far, nothing looks wrong, you can click on the 'get middle one size' button and it will return its size

current size is `(35, 34)`

notice what happens when i set it into loading mode

okay so the borders are gone, thanks to Textual v6.9 (you can test this out yourself pre-6.7), but the size (visually) is still the same

but what if we check the size again?

the size is now `(0, 0)` which is really weird, because it still takes up the same amount of space as before, but it just doesn't have a size?

i'm thinking that this happens since the real widget gets psuedo-hidden, and the loading widget is taking up the same space as the real widget, but since the real widget is hidden, it has a size of (0, 0) even though it still takes up space in the layout

so now what i'm proposing is for the size property of the widget to check if the widget is in the loading mode, and if so, return the loading widget's size rather than the main widget's size (to be more consistent with the visual representation of the widget)

[TomJGooding]

i'm thinking that this happens since the real widget gets psuedo-hidden, and the loading widget is taking up the same space as the real widget, but since the real widget is hidden, it has a size of (0, 0) even though it still takes up space in the layout

Pretty much. When the widget is put into a loading state, it gets "covered" by the LoadingIndicator. Since the widget isn't visible, its content size is zero.

I'm curious what's your use case for needing the size? But here's a possible workaround in the meantime:

size = my_widget._render_widget.size

[NSPC911]

I'm curious what's your use case for needing the size?

currently using it for rovr where when the file preview is in the loading state, it grabs the file content, gets enough lines to fill the container without using word wrap, display it, then hide the loading state

currently instead of that, i just cache it before i send it into the loading state, but yours works just as well

[TomJGooding]

Out of curiosity, presumably you aren't reading the file again after every resize?