Trait TaskPresenter 

pub trait TaskPresenter: Send + Sync {
    // Required methods
    fn prefix(&self, task: &TaskId) -> Vec<u8> ;
    fn summary_completed(
        &self,
        task: &TaskId,
        record: &CompletedRecord,
        duration: Duration,
    ) -> Option<Vec<u8>>;
    fn summary_skipped(
        &self,
        task: &TaskId,
        record: &SkipRecord,
    ) -> Option<Vec<u8>>;
    fn summary_cancelled(
        &self,
        task: &TaskId,
        record: &CancelledRecord,
        duration: Option<Duration>,
    ) -> Option<Vec<u8>>;
}

Strategy object the crate::output observers consult for presentation-policy bytes.

Implementations decide how to render the bearing-task prefix and the optional terminal summary line. The trait is intentionally narrow: it does not see the observer’s sinks, any timing source other than the duration the observer hands it, or any byte the task wrote. A presenter is a pure function of the lifecycle event plus its own configuration (palette, glyph set, etc.).

Send + Sync lets the observers store the presenter behind an Arc<dyn TaskPresenter> and share it across concurrent on_* calls without further coordination.

Required Methods

fn prefix(&self, task: &TaskId) -> Vec<u8>

Bytes that prefix each captured line of task in live mode. Buffered observers ignore this method; the prefix has no role when the task’s bytes flush as a single block.

The returned slice MUST NOT contain a trailing newline: the observer concatenates it with the captured line plus \n.

fn summary_completed( &self, task: &TaskId, record: &CompletedRecord, duration: Duration, ) -> Option<Vec<u8>>

Bytes of the summary line for a task whose lookup-then- spawn pipeline completed (succeeded or failed per EXEC-009). Returning None suppresses the line; the observer emits nothing for the terminal callback.

duration is the wall-clock elapsed between crate::run_task::RunObserver::on_task_started and the terminal callback the observer is currently handling.

The returned bytes MUST be a complete line including the trailing newline; the observer writes them verbatim.

fn summary_skipped(&self, task: &TaskId, record: &SkipRecord) -> Option<Vec<u8>>

Bytes of the summary line for a task the scheduler cascade-skipped per EXEC-010 / EXEC-011. No duration is associated with a skip: the task never entered the pipeline.

Same None / newline contract as Self::summary_completed.

fn summary_cancelled( &self, task: &TaskId, record: &CancelledRecord, duration: Option<Duration>, ) -> Option<Vec<u8>>

Bytes of the summary line for a task whose terminal state was reached through the cancellation flow per EXEC-012..EXEC-015.

duration is Some for CancelledRecord::SignaledInFlight (the task ran for duration before the signal). For the other two variants (UpstreamCancelled, RunCancelled) the task never entered the spawn step, so duration is None.

Same None / newline contract as Self::summary_completed.

Dyn Compatibility

This trait is dyn compatible.

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

Implementors

impl TaskPresenter for PlainPresenter