Skip to content

Collapse: measure a flow-root content wrapper #9

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
microbit-matt-hillsdon merged 1 commit into from
Jul 30, 2026
Merged

Collapse: measure a flow-root content wrapper #9

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
14 changes: 13 additions & 1 deletion packages/ui/src/Collapse.tsx
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -162,7 +162,19 @@ export const Collapse = ({
...style,
}}
>
<div ref={contentRef}>{children}</div>
<div
ref={contentRef}
// flow-root: the measured element must be a block formatting
// context, or children's margins collapse through it and
// scrollHeight under-measures — the outer (overflow: hidden)
// wrapper IS a BFC and needs the full height, so the mismatch
// clips the last line of margined content (python-editor's API
// docs). Rendering is unchanged: the margins always displayed
// inside the outer BFC.
className={css({ display: "flow-root" })}
>
{children}
</div>
</div>
);
};