Trait PartPainter 

pub trait PartPainter: Send + Sync {
    // Required method
    fn paint(
        &self,
        part: Part,
        size: Size,
        state: PartState,
        progress: f32,
        tokens: &PartTokens,
    ) -> Option<PaintedPart>;

    // Provided methods
    fn params(&self) -> Vec<ParamSpec> { ... }
    fn transition(&self, part: Part, from: States, to: States) -> Transition { ... }
}

A painter set: how a theme draws every part.

Every method is a pure function of its arguments: no clock, no I/O, no state kept between calls. The toolkit caches what it returns and calls it again only when an argument changes.

Required Methods

fn paint( &self, part: Part, size: Size, state: PartState, progress: f32, tokens: &PartTokens, ) -> Option<PaintedPart>

Draw part at size (logical pixels, origin at its top left), in state, progress of the way through the transition from state.was to state.now (1 when settled), with tokens.

None leaves the part to the built-in Default set, so a theme draws only the parts it changes.

Provided Methods

fn params(&self) -> Vec<ParamSpec>

The parameters this set takes from a theme document. A document naming the set may state these and no others; the toolkit hands the stated values to every call in PartTokens::params.

fn transition(&self, part: Part, from: States, to: States) -> Transition

How part moves from from to to. The toolkit runs it on its clock; Transition::Inherit takes the toolkit’s own motion.

Implementors

impl PartPainter for WasmPainter