extern crate icns;
use icns::{IconFamily, IconType, Image};
use std::fs::File;
use std::io::{BufReader, BufWriter};

fn main() {
    // Load an icon family from an ICNS file.
    let file = BufReader::new(File::open("16.icns").unwrap());
    let mut icon_family = IconFamily::read(file).unwrap();

    // Extract an icon from the family and save it as a PNG.
    let image = icon_family.get_icon_with_type(IconType::RGB24_16x16).unwrap();
    let file = BufWriter::new(File::create("16.png").unwrap());
    image.write_png(file).unwrap();

    // Read in another icon from a PNG file, and add it to the icon family.
    let file = BufReader::new(File::open("32.png").unwrap());
    let image = Image::read_png(file).unwrap();
    icon_family.add_icon(&image).unwrap();

    // Save the updated icon family to a new ICNS file.
    let file = BufWriter::new(File::create("16-and-32.icns").unwrap());
    icon_family.write(file).unwrap();
}