Canvas is not full screen when using ScreenInteractive

[niosus]

I might be doing something completely wrong but I am breaking my brain on this for a while now.

I'm trying to create a single full-screen canvas so that I could draw into it at any point in the terminal. I expect that when I create a ftxui::ScreenInteractive::Fullscreen() interactive screen, it should initialize its size to the full size of the terminal, which, I believe it doesn't. Then, when I create a canvas it is initialized to an even smaller size, so that I can effectively draw in only part of the screen.

It feels like the task should be fairly simple, so I wonder what I might be doing wrong here. The code I use to test this out is below:

#include <ftxui/component/screen_interactive.hpp>
#include <ftxui/screen/string.hpp>
#include <string>

#include "ftxui/component/component.hpp"
#include "ftxui/component/event.hpp"
#include "ftxui/component/loop.hpp"
#include "ftxui/dom/elements.hpp"
#include "ftxui/screen/color.hpp"

namespace {
const ftxui::Color kYellowishColor = ftxui::Color::RGB(255, 200, 100);
}

int main() {
  auto screen = ftxui::ScreenInteractive::Fullscreen();

  int x{};
  int y{};

  auto component = ftxui::Renderer([&] {
    auto c = ftxui::Canvas{screen.dimx(), screen.dimy()};
    c.DrawBlock(x, y, true, kYellowishColor);
    c.DrawBlock(x + 1, y, true, kYellowishColor);
    return ftxui::vbox(
        {ftxui::hbox({ftxui::text("canvas: " + std::to_string(screen.dimx()) +
                                  " " + std::to_string(screen.dimy())),
                      ftxui::separator(),
                      ftxui::text("pos: " + std::to_string(x) + " " +
                                  std::to_string(y))}),
         ftxui::canvas(std::move(c))});
  });

  component |= ftxui::CatchEvent([&](ftxui::Event event) {
    if (event.is_character()) {
      if (event.character()[0] == 'q') { screen.Exit(); }
    }
    if (event == ftxui::Event::ArrowRight) { x += 2; }
    if (event == ftxui::Event::ArrowLeft) { x -= 2; }
    if (event == ftxui::Event::ArrowDown) { y++; }
    if (event == ftxui::Event::ArrowUp) { y--; }
    return true;
  });

  ftxui::Loop loop{&screen, component};
  while (!loop.HasQuitted()) {
    loop.RunOnce();
    std::this_thread::sleep_for(std::chrono::milliseconds(10));
  }

  return EXIT_SUCCESS;
}

[niosus]

This is probably related to #344
But the question for me remains of how I could create a canvas that fits the size of the current terminal.