Struct Timeline 

pub struct Timeline { /* private fields */ }

multi-track timeline with integer frame-aligned intervals.

Authoring builders retain diagnostics; try_* variants report immediately. Empty timelines last zero ticks; trailing gaps contribute duration. An explicit duration clips or extends all tracks without retiming their scenes. This is the canonical root Timeline. Nested output clips the child viewport before centered contain mapping into its parent’s design space; child frame rate does not retime parent ticks.

Implementations

impl Timeline

pub fn new(size: Size, rate: impl Into<FrameRate>) -> Self

Creates an authoring timeline; invalid dimensions/rates are reported by validate().

pub fn validate(&self) -> Result<()>

Validates every retained authoring diagnostic and nested scene before execution.

pub fn track(self, build: impl FnOnce(TrackBuilder) -> TrackBuilder) -> Self

Constructs one track while accumulating all invalid operations.

pub fn audio(self, clip: AudioClip) -> Self

Adds timeline audio, deferring validation failures to execution.

pub fn master(self, master: Master) -> Self

Sets optional master processing, shared by preview and export.

pub fn audio_bus(self, bus: AudioBus) -> Self

Declares a named offline submix before the master.

pub fn audio_master(&self) -> Master

Immutable master settings at the audio execution boundary.

pub fn audio_buses(&self) -> &[AudioBus]

Declared submixes in deterministic insertion order.

pub fn duration(self, duration: Duration) -> Self

Overrides output duration, deferring validation failures to execution.

pub fn try_new(size: Size, rate: impl Into<FrameRate>) -> Result<Self>

Creates a timeline without discovering fonts, devices or encoders. Rates above one frame per tick cannot define a distinct frame grid.

pub fn background(self, color: Color) -> Self

Adds a full-design background below every track; alpha is retained.

pub fn try_audio(self, clip: AudioClip) -> Result<Self>

Adds audio without snapping its placement to the video grid. Audio extends inferred output to the next frame boundary, never trims its tail.

pub fn try_track( self, build: impl FnOnce(TrackBuilder) -> Result<TrackBuilder>, ) -> Result<Self>

Atomically builds one track; all tracks together admit at most 16384 clips, 256 tracks and 65536 frame-adjustment warnings per snapshot.

pub fn try_duration(self, duration: Duration) -> Result<Self>

Overrides total duration on the nearest frame grid; zero is intentionally empty.

pub fn size(&self) -> Size

Logical timeline viewport; supply this to composition rendering.

pub fn frame_rate(&self) -> FrameRate

Frame grid used for all schedule boundary adjustments.

pub fn total_duration(&self) -> Duration

Finite inferred/overridden duration, independent of any parent clip duration.

pub fn frame_count(&self) -> u64

Exact output frame count. Existing Composition needs checked u32 conversion.

pub fn tracks(&self) -> &[Track]

Immutable tracks in bottom-to-top paint order.

pub fn adjustments(&self) -> &[BoundaryAdjustment]

Accumulated structured boundary warnings, without stderr side effects.

pub fn resolve_audio( &self, resolve: impl FnMut(&AudioClip) -> Result<AudioClip>, ) -> Result<Self>

Resolves flattened audio at an I/O boundary while preserving visual scene clocks.

Trait Implementations

impl Clone for Timeline

fn clone(&self) -> Self

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Timeline

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Scene for Timeline

fn audio_composition(&self) -> Option<&Timeline>

Optional nested timeline ownership, preserved when its audio is relocated.

fn validate(&self) -> Result<()>

Validates deferred authoring errors without evaluating a frame.

fn duration(&self) -> Option<Duration>

Natural finite duration, or None when a caller must provide one.

fn audio_clips(&self) -> Result<Vec<AudioClip>>

Returns pure audio metadata for precomposition/export, not playback. Default scenes are silent; callers must preserve local clip coordinates.

fn render(&self, context: &SceneContext<'_>) -> Node

Builds one snapshot without retaining previous-frame state.

fn with_duration(self, duration: Duration) -> WithDuration<Self>

where Self: Sized,

Overrides clip metadata without retiming or clamping the callback.