menu_window.cpp

/*
* cpp-terminal
* C++ library for writing multi-platform terminal applications.
*
* SPDX-FileCopyrightText: 2019-2025 cpp-terminal
*
* SPDX-License-Identifier: MIT
*/

#include "cpp-terminal/exception.hpp"
#include "cpp-terminal/input.hpp"
#include "cpp-terminal/iostream.hpp"
#include "cpp-terminal/key.hpp"
#include "cpp-terminal/screen.hpp"
#include "cpp-terminal/terminal.hpp"
#include "cpp-terminal/tty.hpp"
#include "cpp-terminal/window.hpp"

static std::string render(Term::Window& scr, const std::size_t& rows, const std::size_t& cols, const std::size_t& menuheight, const std::size_t& menuwidth, const std::size_t& menupos)
{
  scr.clear();
  const std::size_t menux0 = ((cols - menuwidth) / 2) + 1;
  const std::size_t menuy0 = ((rows - menuheight) / 2) + 1;
  scr.print_rect(menux0, menuy0, menux0 + menuwidth + 1, menuy0 + menuheight + 1);

  for(std::size_t i = 1; i <= menuheight; ++i)
  {
    const std::string item = std::to_string(i) + ": item";
    scr.print_str(menux0 + 1, menuy0 + i, item);
    if(i == menupos)
    {
      scr.fill_fg(menux0 + 1, menuy0 + i, menux0 + item.size(), menuy0 + i, Term::Color::Name::Red);  // FG
      scr.fill_bg(menux0 + 1, menuy0 + i, menux0 + menuwidth, menuy0 + i, Term::Color::Name::Gray);   // BG
      scr.fill_style(menux0 + 1, menuy0 + i, menux0 + item.size(), menuy0 + i, Term::Style::Bold);
    }
    else
    {
      scr.fill_fg(menux0 + 1, menuy0 + i, menux0 + item.size(), menuy0 + i, Term::Color::Name::Blue);
      scr.fill_bg(menux0 + 1, menuy0 + i, menux0 + menuwidth, menuy0 + i, Term::Color::Name::Green);
    }
  }

  const std::size_t y = menuy0 + menuheight + 5;
  scr.print_str(1, y, "Selected item: " + std::to_string(menupos));
  scr.print_str(1, y + 1, "Menu width: " + std::to_string(menuwidth));
  scr.print_str(1, y + 2, "Menu height: " + std::to_string(menuheight));
  scr.print_str(1, y + 3, "Unicode test: Ondřej Čertík, ἐξήκοι");

  return scr.render(1, 1, false);
}

int main()
{
  try
  {
    // check if the terminal is capable of handling input
    if(!Term::is_stdin_a_tty())
    {
      Term::cout << "The terminal is not attached to a TTY and therefore can't catch user input. Exiting...\n";
      return 1;
    }
    Term::terminal.setOptions(Term::Option::ClearScreen, Term::Option::NoSignalKeys, Term::Option::NoCursor, Term::Option::Raw);
    Term::Screen term_size = Term::screen_size();
    std::size_t  pos{5};
    std::size_t  h{10};
    std::size_t  w{10};
    bool         on = true;
    Term::Window scr(term_size);
    bool         need_to_render{true};
    while(on)
    {
      if(need_to_render)
      {
        Term::cout << ::render(scr, term_size.rows(), term_size.columns(), h, w, pos) << std::flush;
        need_to_render = false;
      }
      Term::Key key = Term::read_event();
      switch(key)
      {
        case Term::Key::ArrowLeft:
          if(w > 10) { --w; }
          need_to_render = true;
          break;
        case Term::Key::ArrowRight:
          if(w < (term_size.columns() - 5)) { ++w; }
          need_to_render = true;
          break;
        case Term::Key::ArrowUp:
          if(pos > 1) { --pos; }
          need_to_render = true;
          break;
        case Term::Key::ArrowDown:
          if(pos < h) { ++pos; }
          need_to_render = true;
          break;
        case Term::Key::Home:
          pos            = 1;
          need_to_render = true;
          break;
        case Term::Key::End:
          pos            = h;
          need_to_render = true;
          break;
        case Term::Key::q:
        case Term::Key::Esc:
        case Term::Key::Ctrl_C: on = false; break;
        default: break;
      }
    }
  }
  catch(const Term::Exception& re)
  {
    Term::cerr << "cpp-terminal error: " << re.what() << std::endl;
    return 2;
  }
  catch(...)
  {
    Term::cerr << "Unknown error." << std::endl;
    return 1;
  }
  return 0;
}