FTXUI/src/ftxui/screen/terminal.cpp
2022-03-31 02:17:43 +02:00

128 lines
3.6 KiB
C++

#include <cstdlib> // for getenv
#include <string> // for string, allocator
#include "ftxui/screen/terminal.hpp"
#if defined(_WIN32)
#define WIN32_LEAN_AND_MEAN
#ifndef NOMINMAX
#define NOMINMAX
#endif
#include <Windows.h>
#else
#include <sys/ioctl.h> // for winsize, ioctl, TIOCGWINSZ
#include <unistd.h> // for STDOUT_FILENO
#endif
namespace ftxui {
namespace {
Dimensions& FallbackSize() {
#if defined(__EMSCRIPTEN__)
// This dimension was chosen arbitrarily to be able to display:
// https://arthursonzogni.com/FTXUI/examples
// This will have to be improved when someone has time to implement and need
// it.
constexpr int fallback_width = 140;
constexpr int fallback_height = 43;
#else
// The terminal size in VT100 was 80x24. It is still used nowadays by
// default in many terminal emulator. That's a good choice for a fallback
// value.
constexpr int fallback_width = 80;
constexpr int fallback_height = 24;
#endif
static Dimensions g_fallback_size{fallback_width, fallback_height};
return g_fallback_size;
}
const char* Safe(const char* c) {
return (c != nullptr) ? c : "";
}
bool Contains(const std::string& s, const char* key) {
return s.find(key) != std::string::npos;
}
Terminal::Color ComputeColorSupport() {
#if defined(__EMSCRIPTEN__)
return Terminal::Color::TrueColor;
#endif
std::string COLORTERM = Safe(std::getenv("COLORTERM")); // NOLINT
if (Contains(COLORTERM, "24bit") || Contains(COLORTERM, "truecolor")) {
return Terminal::Color::TrueColor;
}
std::string TERM = Safe(std::getenv("TERM")); // NOLINT
if (Contains(COLORTERM, "256") || Contains(TERM, "256")) {
return Terminal::Color::Palette256;
}
#if defined(FTXUI_MICROSOFT_TERMINAL_FALLBACK)
// Microsoft terminals do not properly declare themselve supporting true
// colors: https://github.com/microsoft/terminal/issues/1040
// As a fallback, assume microsoft terminal are the ones not setting those
// variables, and enable true colors.
if (TERM == "" && COLORTERM == "") {
return Terminal::Color::TrueColor;
}
#endif
return Terminal::Color::Palette16;
}
} // namespace
Dimensions Terminal::Size() {
#if defined(__EMSCRIPTEN__)
// This dimension was chosen arbitrarily to be able to display:
// https://arthursonzogni.com/FTXUI/examples
// This will have to be improved when someone has time to implement and need
// it.
return FallbackSize();
#elif defined(_WIN32)
CONSOLE_SCREEN_BUFFER_INFO csbi;
if (GetConsoleScreenBufferInfo(GetStdHandle(STD_OUTPUT_HANDLE), &csbi)) {
return Dimensions{csbi.srWindow.Right - csbi.srWindow.Left + 1,
csbi.srWindow.Bottom - csbi.srWindow.Top + 1};
}
return FallbackSize();
#else
winsize w{};
const int status = ioctl(STDOUT_FILENO, TIOCGWINSZ, &w); // NOLINT
// The ioctl return value result should be checked. Some operating systems
// don't support TIOCGWINSZ.
if (w.ws_col == 0 || w.ws_row == 0 || status < 0) {
return FallbackSize();
}
return Dimensions{w.ws_col, w.ws_row};
#endif
}
/// @brief Override terminal size in case auto-detection fails
/// @param fallbackSize Terminal dimensions to fallback to
void Terminal::SetFallbackSize(const Dimensions& fallbackSize) {
FallbackSize() = fallbackSize;
}
Terminal::Color Terminal::ColorSupport() {
static bool cached = false;
static Terminal::Color cached_supported_color;
if (!cached) {
cached = true;
cached_supported_color = ComputeColorSupport();
}
return cached_supported_color;
}
} // namespace ftxui
// Copyright 2020 Arthur Sonzogni. All rights reserved.
// Use of this source code is governed by the MIT license that can be found in
// the LICENSE file.