pika-welcome/src/main.rs

// GTK crates
mod config;

use std::env;
use adw::prelude::*;
use adw::*;
use gdk::Display;
/// Use all gtk4 libraries (gtk4 -> gtk because cargo)
/// Use all libadwaita libraries (libadwaita -> adw because cargo)
use gtk::*;
use single_instance::SingleInstance;
use glib::*;
use glib::prelude::*;

use std::boxed::Box;
use users::*;
use config::{APP_ID};

// application crates
mod build_ui;
use crate::build_ui::build_ui;
mod save_window_size;
/// first setup crates
mod welcome_content_page;

// Init translations for current crate.
#[macro_use]
extern crate rust_i18n;
i18n!("locales", fallback = "en_US");

/// main function
fn main() {
    let current_locale = match env::var_os("LANG") {
        Some(v) => v.into_string().unwrap(),
        None => panic!("$LANG is not set"),
    };
    rust_i18n::set_locale(current_locale.strip_suffix(".UTF-8").unwrap());
    let application = adw::Application::new(
        Some(APP_ID),
        Default::default(),
    );
    application.connect_startup(|app| {
        // The CSS "magic" happens here.
        let provider = CssProvider::new();
        provider.load_from_string(include_str!("style.css"));
        // We give the CssProvided to the default screen so the CSS rules we added
        // can be applied to our window.
        gtk::style_context_add_provider_for_display(
            &Display::default().expect("Could not connect to a display."),
            &provider,
            STYLE_PROVIDER_PRIORITY_APPLICATION,
        );
        app.connect_activate(build_ui);
    });

    let instance = SingleInstance::new(APP_ID).unwrap();
    assert!(instance.is_single());

    if get_current_username().unwrap() != "pikaos" {
        application.run();
    } else {
        println!("Error: This program can only be run via an installed system user");
        std::process::exit(1)
    }

}