Method new

web/src/canvas.rs:103–145

Creates a new canvas console backed by the `canvas` HTML element and that receives input events from `input`.

(
        canvas: HtmlCanvasElement,
        font: &'static Font,
        yielder: WebYielder,
    )

    /// Creates a new canvas console backed by the `canvas` HTML element and that receives input
    /// events from `input`.
    pub(crate) fn new(
        canvas: HtmlCanvasElement,
        font: &'static Font,
        yielder: WebYielder,
    ) -> io::Result<Self> {
        let size_pixels = {
            let width = match u16::try_from(canvas.width()) {
                Ok(v) => v,
                Err(_) => {
                    return Err(io::Error::new(
                        io::ErrorKind::InvalidInput,
                        format!("Canvas is too wide at {} pixels", canvas.width()),
                    ));
                }
            };
            let height = match u16::try_from(canvas.height()) {
                Ok(v) => v,
                Err(_) => {
                    return Err(io::Error::new(
                        io::ErrorKind::InvalidInput,
                        format!("Canvas is too tall at {} pixels", canvas.height()),
                    ));
                }
            };
            SizeInPixels::new(width, height)
        };

        let context = html_canvas_to_2d_context(canvas)?;
        context.set_image_smoothing_enabled(false);
        context.set_text_baseline("middle");

        // The actual values are irrelevant but need to be different than the initial values we use
        // below.
        let fill_color = (10, 10, 10);
        let stroke_color = (100, 100, 100);

        let mut raster_ops = Self { context, font, yielder, size_pixels, fill_color, stroke_color };

        raster_ops.set_fill_style_rgb((0, 0, 0));
        raster_ops.set_stroke_style_rgb((255, 255, 255));

        Ok(raster_ops)
    }

    /// Returns true if the point falls within the canvas bounds.
    fn contains_pixel(&self, xy: PixelsXY) -> bool {