Shared Surface functionality

[mikowitz]

For non-NI functions, there is cairo::Surface which is a shared impl for the surface types.

use cairo::{Format, ImageSurface, PdfSurface};

pub fn test() {
    let surface = ImageSurface::create(Format::ARgb32, 100, 100).expect("ok");

    let pdf = PdfSurface::new(100., 100., "test.pdf").expect("ok");

    foo(&surface);
    foo(&pdf);
}

fn foo(surface: &cairo::Surface) {
    println!("{:#?}", surface);
    println!("  {:#?}", surface.type_());
}

Perhaps a surface wrapper enum, like

enum Surface {
  Image(cairo::ImageSurface)
  Pdf(cairo::PdfSurface)
  ...
}

that can be passed as a reference up to Elixir, then passed back, matched on, and the surface passed directly to the helper functions.

• create_similar
• create_for_rectangle
• mime_data
• device
• set_(device_offset)
• set_(device_scale)
• set_(fallback_resolution)
• status
• flush
• finish
• type_

Device

implement this as a struct, I think?

Enums

• Content
• SurfaceType