How do I change the DataTable cursor from "cell" to "row"

[evanpolster]

The DataTable cursor defaults to "cell".

I have derived a class from DataTable so I can override default behavior.

I cannot figure out though how to change the DataTable cursor_type from "cell" to "row".

This is probably because I do not fully understand Reactive variables.

[TomJGooding]

You just need to assign the cursor_type, like this:

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

ROWS = [
    ("lane", "swimmer", "country", "time"),
    (4, "Joseph Schooling", "Singapore", 50.39),
    (2, "Michael Phelps", "United States", 51.14),
    (5, "Chad le Clos", "South Africa", 51.14),
    (6, "László Cseh", "Hungary", 51.14),
    (3, "Li Zhuhao", "China", 51.26),
    (8, "Mehdy Metella", "France", 51.58),
    (7, "Tom Shields", "United States", 51.73),
    (1, "Aleksandr Sadovnikov", "Russia", 51.84),
    (10, "Darren Burns", "Scotland", 51.84),
]


class CustomDataTable(DataTable):
    ...


class ExampleApp(App):
    def compose(self) -> ComposeResult:
        yield CustomDataTable()

    def on_mount(self) -> None:
        table = self.query_one(CustomDataTable)
        table.cursor_type = "row"

        table.add_columns(*ROWS[0])
        table.add_rows(ROWS[1:])


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

[evanpolster]

Ah! I was trying to set the cursor type from the derived class's init function by using self.cursor_type = "row" and PyCharm was signalling an error. Apparently you can't assign the parent's variables during construction. Thanks for your quick reply.

[TomJGooding]

I think that would actually also work, but generally it is probably better to set reactives this way.

You mentioned you don't fully understand reactive attributes. I'd recommend the Reactivity guide in the docs if you haven't read this already.