Display ellipsis when Rich Layout scrolls past end of screen/console

Question

Is it possible to configure rich.Layout() to indicate when the number of items in the layout has exceeded the display size of the current layout?

I would like to be able to tell programmatically when the code is attempting to display too many items for the current Table/Layout to display in order to display ellipsis or a message such as "...and 200 further items". This would allow the program to alert the user that some items are not being displayed.

There is a size attribute in Layout, but that value appears to be an input to constrain the layout to a fixed size rather than an indicator of the current Layout size. In my current application, I would rather not constrain the size of the Layout in order to use the full available layout size, whatever that value may be.

#!/usr/bin/env python3

from rich.console import Console
from rich.layout import Layout
from rich.table import Table
from rich.pretty import Pretty

# Make too many lines for the Layout/Table to display on the current screen size
MAX_LINES = 1000

def fill_table():
    table = Table()
    for li in range(MAX_LINES):
        table.add_row(Pretty(li))
    return table


console = Console()
layout = Layout(name="root")
layout["root"].update(fill_table())
console.print(layout)

vvolhejn · Answer 1 · 2022-03-29T13:27:51.840

I'm a bit late to the party, but I've just had to solve a similar issue. The trick is to use Layout's .render() function like so:

#!/usr/bin/env python3

from rich.console import Console
from rich.layout import Layout
from rich.table import Table
from rich.pretty import Pretty
from rich import print as pprint

# Make too many lines for the Layout/Table to display on the current screen size
MAX_LINES = 1000


def fill_table(max_height):
    rows = [Pretty(li) for li in range(MAX_LINES)]

    # Subtract 4 lines - that's how many the table's header and footer takes  
    n_rows = max_height - 4
    if len(rows) > n_rows:
        rows = rows[: n_rows - 1] + [f"...and {len(rows) - n_rows + 1} further items"]

    table = Table()
    for row in rows:
        table.add_row(row)

    return table


console = Console()
layout = Layout(name="root")

render_map = layout.render(console, console.options)
pprint("Region of the layout:", render_map[layout].region)

table = fill_table(render_map[layout].region.height)
layout["root"].update(table)

console.print(layout)

I didn't figure out how to measure the Table directly, but measuring Layout does the trick. I still needed to manually input the number of rows that the table's header+footer takes, which might fail if there is a multi-line column name.

EDIT: I've posted an answer to a similar problem which also takes into account multi-line rows.

Display ellipsis when Rich Layout scrolls past end of screen/console

1 Answers1