screensaver/main.cpp

//
// main.cpp
// screensaver
//
// Created by Bob Polis at 2020-10-23
// Copyright (c) 2020 SwiftCoder. All rights reserved.
//

#include <iostream>
#include <cstdlib>
#include <string>
#include <stdexcept>
#include <getopt.h>
#include <libscgui.hpp>
#include <unistd.h>
#include <cairo/cairo.h>

void print_help() {
    std::cout << "usage: screensaver [-h|--version]\n";
    std::cout << "  -h, --help    show this help text and exit\n";
    std::cout << "  --version     show version number and exit\n";
}

void print_version() {
    std::cout << "screensaver version 1.0\n";
}

void draw(sc::gui::Window& window) {
    SDL_Surface* s {SDL_CreateRGBSurface(0, 700, 700, 32, 0x00ff0000, 0x0000ff00, 0x000000ff, 0)};
    sc::gui::Image image {s};
    SDL_FillRect(s, nullptr, SDL_MapRGB(s->format, 255, 255, 255));
    SDL_Rect rect { 300, 300, 100, 100 };
    SDL_FillRect(s, &rect, SDL_MapRGB(s->format, 255, 128, 0));
    sc::gui::ImageLock lock {image};
    cairo_surface_t* cs {cairo_image_surface_create_for_data(static_cast<unsigned char*>(s->pixels),
                                                             CAIRO_FORMAT_RGB24, s->w, s->h, s->pitch)};
    cairo_t* cr {cairo_create(cs)};
    cairo_set_line_width(cr, 0.1);
    cairo_set_source_rgb(cr, 0, 0, 0);
    cairo_rectangle(cr, 200, 200, 100, 100);
    cairo_fill(cr);
    window.show_image(image);
    cairo_surface_destroy(cs);
    cairo_destroy(cr);
}

int main(int argc, const char * argv[]) {
    try {
        // RAII instances
        sc::gui::SDLWrapper sdl2;
        sc::gui::SDLImageWrapper sdl_image;

        // main window
        sc::gui::Window& window {sc::gui::Window::new_window("screensaver")};

        int opt_char, opt_val;
        struct option long_options[] = {
            {"help", no_argument, nullptr, 'h'},
            {"version", no_argument, &opt_val, 1},
            {nullptr, 0, nullptr, 0}
        };
        while ((opt_char = getopt_long(argc, const_cast<char* const *>(argv), "h", long_options, nullptr)) != -1) {
            std::string arg {optarg ? optarg : ""};
            switch (opt_char) {
                case 0: {
                    // handle long-only options here
                    switch (opt_val) {
                        case 1:
                            print_version();
                            return EXIT_SUCCESS;
                    }
                    break;
                }
                case 'h':
                    print_help();
                    return EXIT_SUCCESS;
                case '?':
                    throw std::runtime_error("unrecognized option");
            }
        }
        if (optind == argc) {
            // here when no file args
        }
        for (int i = optind; i < argc; ++i) {
            try {
                // process file argv[i]
            } catch (const std::runtime_error& ex) {
                std::cerr << "screensaver: " << ex.what() << '\n';
            }
        }

        draw(window);
        sc::gui::app().run();

    } catch (const std::exception& ex) {
        std::cerr << "screensaver: " << ex.what() << '\n';
        return EXIT_FAILURE;
    }
    return EXIT_SUCCESS;
}