Struct PrepareResult 

pub struct PrepareResult {
    pub needs_redraw: bool,
    pub next_redraw_in: Option<Duration>,
    pub next_layout_redraw_in: Option<Duration>,
    pub next_paint_redraw_in: Option<Duration>,
    pub timings: PrepareTimings,
}

Reported back from each backend’s prepare(...) per frame.

Two redraw deadlines:

• Self::next_layout_redraw_in — the next frame that needs a full rebuild + layout pass. Driven by widget crate::tree::El::redraw_within requests, animations still settling, and pending tooltip / toast fades. The host must call the backend’s full prepare(...) (build → layout → paint → render) when this elapses.
• Self::next_paint_redraw_in — the next frame a time-driven shader needs but layout state is unchanged (e.g. spinner / skeleton / progress-indeterminate / samples_time=true custom shaders). The host can call the backend’s lighter repaint(...) path which reuses the cached DrawOp list, advances frame.time, and skips rebuild + layout. Skipping the layout path is only safe when no input has been processed since the last full prepare; hosts must upgrade to the full path on any input event.

Legacy aggregates Self::needs_redraw and Self::next_redraw_in fold both lanes (OR / min) for hosts that don’t want to split paths.

Fields

needs_redraw: bool

Legacy “any redraw needed?” — OR of next_layout_redraw_in.is_some() and next_paint_redraw_in.is_some(), plus animation-settling / tooltip-pending bools the runtime tracks internally.

next_redraw_in: Option<Duration>

Legacy combined deadline — min(next_layout_redraw_in, next_paint_redraw_in). Hosts that don’t distinguish layout from paint-only redraws can keep reading this.

next_layout_redraw_in: Option<Duration>

Tightest deadline among signals that need a full rebuild + layout: widget redraw_within, animations still settling, tooltip / toast pending. Some(ZERO) for “now.”

next_paint_redraw_in: Option<Duration>

Tightest deadline among time-driven shaders. The host can service this with a paint-only frame (reuse cached ops, just advance frame.time). Some(ZERO) for “every frame” (the default for is_continuous() shaders today).

timings: PrepareTimings

Trait Implementations

impl Clone for PrepareResult

fn clone(&self) -> PrepareResult

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for PrepareResult

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

Formats the value using the given formatter.

impl Default for PrepareResult

fn default() -> PrepareResult

Returns the “default value” for a type.

impl Copy for PrepareResult