Setting/getting size

[davidbrochart]

I'm trying to set the size of the terminal, but the application takes the size of my terminal anyway. Also, printing the size of the widget shows Size(width=0, height=0):

from textual.app import App, ComposeResult
from textual.widgets import Static


class MyStatic(Static):
    def on_mount(self):
        print(self.size)


class MyApp(App):

    def compose(self) -> ComposeResult:
        yield MyStatic("\n".join([f"{i} " * 100 for i in range(100)]))


if __name__ == "__main__":
    app = MyApp()
    app.run(size=(10, 10))

[willmcgugan]

The size argument was mainly for situations where there isn't a physical terminal, like testing. We could make that clearer in the docs.

The widget size will be (0, 0) on mount because you get the mount prior to the first layout.

What behaviour were you expecting by setting the size on run?

[davidbrochart]

So how would I get the size available to the widget? Here I'm expecting a height of 7, since it's in a container of height 10, and 3 rows are taken by the tabs.

[willmcgugan]

I have a feeling this may be an XY problem. Can we step back and help me understand what you are trying to accomplish?

[davidbrochart]

I'm trying to have a container with two widgets aligned vertically, a Tabs and a Static. In my particular case, the Static will show a terminal emulator, so I need to get the available height of the Static and report it back to the backend. But it seems that the reported height includes the 3 rows of the Tabs.

[willmcgugan]

You can set the height of your widget to 1fr, which will tell it to fill the remaining space. If the container has height 10, and the tables take up 3 rows, the widget will get the height of 7.

You could then implement on_size on your Widget to get the size when it changes.

[davidbrochart]

Great, thanks!