Struct Drawing 

pub struct Drawing { /* private fields */ }

A recorded drawing at a fixed size: what a canvas would replay, kept for export.

Write the drawing once as a plain function and call it from the canvas and from export:

fn draw_chart(d: &mut Draw, size: Size, series: &[f64]) { /* … */ }

canvas(move |d, size| draw_chart(d, size, &series.get()))           // on screen
let drawing = Drawing::record(Size::new(600.0, 400.0), |d, size| {
    draw_chart(d, size, &series.get_untracked())
});
day::task(async move {
    if let Ok(png) = drawing.to_png(2.0).await { /* save it */ }
});

Rendering goes through the toolkit’s own canvas painter (Core Graphics, cairo, QPainter, an android Canvas, …), so an export matches the screen. Probe canvas_exports before offering a command.

Implementations

impl Drawing

pub fn record(size: Size, draw: impl FnOnce(&mut Draw, Size)) -> Drawing

Run draw once, untracked, at size points. Signal reads inside it subscribe nothing, so recording from a binding or a menu action is safe.

pub fn from_ops(size: Size, ops: Vec<DrawOp>) -> Drawing

A drawing of ops recorded elsewhere, at size points.

pub fn size(&self) -> Size

The size the drawing was recorded at, in points.

pub fn ops(&self) -> &[DrawOp]

The recorded display list.

pub fn to_bitmap(&self, scale: f64) -> RenderBitmap

Render to a bitmap of size × scale pixels whose info().scale is scale, so image(&bitmap) shows it at the drawing’s point size. Await it inside day::task.

Err(ExportError::Unsupported) where the toolkit has no offscreen painter (Cap::CanvasBitmap); Err(ExportError::TooLarge) above 16,384 pixels a side or 64 megapixels.

pub fn to_png( &self, scale: f64, ) -> impl Future<Output = Result<Vec<u8>, ExportError>> + 'static

Render to a bitmap and encode it as PNG: Drawing::to_bitmap then Bitmap::encode. Err(ExportError::Unsupported) where either half is missing (CanvasExports::png answers that up front).

pub fn to_pdf(&self) -> RenderPdf

A one-page PDF the size of the drawing. Err(ExportError::Unsupported) where the platform has no PDF writer (Cap::CanvasPdf).

Trait Implementations

impl Clone for Drawing

fn clone(&self) -> Drawing

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Drawing

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

Formats the value using the given formatter.

impl PartialEq for Drawing

fn eq(&self, other: &Drawing) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for Drawing