fltk-sys example

main.rs

#![feature(concat_idents)]

use fltk_sys::{fl::*, frame::*, window::*, group::*, button::{self, *}};
use std::os::raw::*;

macro_rules! fstr {
    ($s:literal) => {
        concat!($s, "\0").as_ptr() as _
    }
}

macro_rules! default {
    ($i:ident, $s:literal) => {
        concat_idents!($i, _new)(0, 0, 0, 0, fstr!($s))
    };
    ($i:ident) => {
        default!($i, "")
    };
}

macro_rules! default_fill {
    ($i:ident, $s:literal) => {
        {
            let g = Fl_Group_current();
            concat_idents!($i, _new)(0, 0, Fl_Group_width(g), Fl_Group_height(g), fstr!($s))
        }
    };
    ($i:ident) => {
        default_fill!($i, "")
    }
}

unsafe extern "C" fn btn_cb(_w: *mut button::Fl_Widget, data: *mut c_void) {
    Fl_Window_set_label(data as _, fstr!("Works"));
}


fn main() {
    unsafe {
        let win = Fl_Window_new(100, 100, 400, 300, fstr!("Hello"));
        let flex = default_fill!(Fl_Flex);
        Fl_Flex_set_type(flex, 1);
        default!(Fl_Box);
        let btn = default!(Fl_Button, "Click");
        default!(Fl_Box);
        Fl_Flex_end(flex);
        Fl_Window_end(win);
        Fl_Window_show(win);
        Fl_Button_set_callback(btn, Some(btn_cb), win as _);
        Fl_run();
    }
}