set_canvas_size
should be implemented at client level
fn set_canvas_size(&self, ctx: &Option<C>) {
// Scale the drawing canvas by [dpr] to ensure sharp rendering on
// high pixel density displays.
if let Some(ctx) = ctx {
// ctx.canvas
// ..style.width = "${w}px"
// ..style.height = "${h}px"
// ..width = scaledW
// ..height = scaledH;
// ctx.set_transform(dpr, 0, 0, dpr, 0, 0);
}
}