Summary
Add a new grid_cols_max_content GPUI styling API that uses minmax(0,
max-content) for grid column sizing. This allows columns to
automatically size based on their content width while remaining
responsive when the container shrinks.
Applied the fix to both markdown preview (markdown_renderer.rs) and
agent panel (markdown.rs) table rendering. Table borders now wrap
tightly around content instead of stretching to full container width.
Fixes#50044
Approach
A new grid_cols_max_content API is added (as discussed with
@MikaylaMaki):
style.rs — New grid_cols_max_content: Option<u16> field
styled.rs — New .grid_cols_max_content(cols) builder method
taffy.rs — New to_grid_repeat_max_content() using minmax(0, max-content)
markdown_renderer.rs — Swapped .grid_cols() → .grid_cols_max_content(),
moved border to grid div, wrapped in v_flex().items_start() so border
hugs content
markdown.rs — Applied same fix for agent panel tables:
grid_cols_max_content, border on grid div, wrapped in
div().flex().flex_col().items_start() container
Screenshots
Before (equal-width columns, border stretches full width):
<img width="1386" height="890" alt="Screenshot 2026-03-06 at 2 17 54 PM"
src="https://github.com/user-attachments/assets/42cf76c4-6eba-4919-9b16-78c7fc823315"
/>
<img width="2555" height="1308" alt="original issue"
src="https://github.com/user-attachments/assets/22b0fc02-5203-48bb-8f03-7aa8255197cc"
/>
After — Markdown Preview and Agent Panel
<img width="2554" height="1317" alt="Screenshot 2026-03-07 at 2 29
28 PM"
src="https://github.com/user-attachments/assets/8849988e-9ba8-4388-9c29-a255e0ecc52b"
/>
Before you mark this PR as ready for review, make sure that you have:
Added a solid test coverage and/or screenshots from doing manual testing
Done a self-review taking into account security and performance aspects
Aligned any UI changes with the UI checklist
Release Notes:
Fixed markdown table columns to use content-based auto-width instead of
equal-width distribution in both markdown preview and agent panel
(#50044).
---------
Co-authored-by: Mikayla Maki <mikayla.c.maki@gmail.com>
