Trait Headerline 

pub trait Headerline:
    Send
    + Sync
    + 'static {
    // Required methods
    fn version(&self) -> u64;
    fn render(&self) -> Option<HeaderlineRow>;
}

Anything that can supply a sticky headerline row.

The cells worker calls version() on every tick. When the version has advanced, it calls render() to rebuild the displayed row. render() returns None to hide the row entirely (e.g. while idle).

Required Methods

fn version(&self) -> u64

Monotonic counter. Bump whenever the row content changes. The worker skips render() when the version is unchanged since the last call.

fn render(&self) -> Option<HeaderlineRow>

Build the current row. Return None to hide the header entirely. Must not block — cache results; background tasks push updates via the owning handle.

Dyn Compatibility

This trait is dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors

impl<S: Send + Sync + 'static> Headerline for SimpleHeaderline<S>