Method draw_cursor

std/src/console/graphics.rs:387–403

Draws the cursor at the current position and saves the previous contents of the screen so that `clear_cursor` can restore them. Does not present the canvas.

(&mut self)

    ///
    /// Does not present the canvas.
    fn draw_cursor(&mut self) -> io::Result<()> {
        if !self.cursor_visible {
            return Ok(());
        }

        let x1y1 = self.cursor_pos.clamped_mul(self.glyph_size);

        assert!(self.cursor_backup.is_none());
        self.cursor_backup = Some(self.raster_ops.read_pixels(x1y1, self.glyph_size)?);

        // TODO(jmmv): It would be nice to draw the cursor with alpha blending so that the letters
        // under it are visible.  This was done before in the HTML canvas but was lost when I added
        // the GraphicsConsole abstraction.  Maybe all RGB colors should switch to RGBA.  Or maybe
        // we should special-case the cursor drawing.
        self.raster_ops.set_draw_color(self.fg_color);
        self.raster_ops.draw_rect_filled(x1y1, self.glyph_size)
    }

    /// Clears the cursor at the current position by restoring the contents of the screen saved by
    /// an earlier call to `draw_cursor`.