Dialogs.h

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//
//  Portable File Dialogs
//
//  Copyright © 2018–2022 Sam Hocevar <sam@hocevar.net>
//
//  This library is free software. It comes without any warranty, to
//  the extent permitted by applicable law. You can redistribute it
//  and/or modify it under the terms of the Do What the Fuck You Want
//  to Public License, Version 2, as published by the WTFPL Task Force.
//  See http://www.wtfpl.net/ for more details.
//
 
#pragma once
 
#if _WIN32
#ifndef WIN32_LEAN_AND_MEAN
#define WIN32_LEAN_AND_MEAN 1
#endif
#include <commdlg.h>
#include <shellapi.h>
#include <shlobj.h>
#include <shobjidl.h>  // IFileDialog
#include <strsafe.h>
#include <userenv.h>  // GetUserProfileDirectory()
#include <windows.h>
#include <future>  // std::async
 
#elif __EMSCRIPTEN__
#include <emscripten.h>
 
#else
#ifndef _POSIX_C_SOURCE
#define _POSIX_C_SOURCE 2  // for popen()
#endif
#ifdef __APPLE__
#ifndef _DARWIN_C_SOURCE
#define _DARWIN_C_SOURCE
#endif
#endif
#include <fcntl.h>     // fcntl()
#include <pwd.h>       // getpwnam()
#include <sys/stat.h>  // stat()
#include <sys/wait.h>  // waitpid()
#include <unistd.h>    // read(), pipe(), dup2(), getuid()
#include <csignal>     // ::kill, std::signal
#include <cstdio>      // popen()
#include <cstdlib>     // std::getenv()
#endif
 
#include <chrono>    // std::chrono
#include <iostream>  // std::ostream
#include <map>       // std::map
#include <memory>    // std::shared_ptr
#include <regex>     // std::regex
#include <set>       // std::set
#include <string>    // std::string
#include <thread>    // std::mutex, std::this_thread
 
// Versions of mingw64 g++ up to 9.3.0 do not have a complete IFileDialog
#ifndef PFD_HAS_IFILEDIALOG
#define PFD_HAS_IFILEDIALOG 1
#if (defined __MINGW64__ || defined __MINGW32__) && defined __GXX_ABI_VERSION
#if __GXX_ABI_VERSION <= 1013
#undef PFD_HAS_IFILEDIALOG
#define PFD_HAS_IFILEDIALOG 0
#endif
#endif
#endif
 
namespace pfd {
 
enum class button {
  cancel = -1,
  ok,
  yes,
  no,
  abort,
  retry,
  ignore,
};
 
enum class choice {
  ok = 0,
  ok_cancel,
  yes_no,
  yes_no_cancel,
  retry_cancel,
  abort_retry_ignore,
};
 
enum class icon {
  info = 0,
  warning,
  error,
  question,
};
 
// Additional option flags for various dialog constructors
enum class opt : uint8_t {
  none = 0,
  // For file open, allow multiselect.
  multiselect = 0x1,
  // For file save, force overwrite and disable the confirmation dialog.
  force_overwrite = 0x2,
  // For folder select, force path to be the provided argument instead
  // of the last opened directory, which is the Microsoft-recommended,
  // user-friendly behaviour.
  force_path = 0x4,
};
 
inline opt operator|(opt a, opt b) {
  return opt(uint8_t(a) | uint8_t(b));
}
inline bool operator&(opt a, opt b) {
  return bool(uint8_t(a) & uint8_t(b));
}
 
// The settings class, only exposing to the user a way to set verbose mode
// and to force a rescan of installed desktop helpers (zenity, kdialog…).
class settings {
 public:
  static bool available();
 
  static void verbose(bool value);
  static void rescan();
 
 protected:
  explicit settings(bool resync = false);
 
  bool check_program(std::string const& program);
 
  inline bool is_osascript() const;
  inline bool is_zenity() const;
  inline bool is_kdialog() const;
 
  enum class flag {
    is_scanned = 0,
    is_verbose,
 
    has_zenity,
    has_matedialog,
    has_qarma,
    has_kdialog,
    is_vista,
 
    max_flag,
  };
 
  // Static array of flags for internal state
  bool const& flags(flag in_flag) const;
 
  // Non-const getter for the static array of flags
  bool& flags(flag in_flag);
};
 
// Internal classes, not to be used by client applications
namespace internal {
 
  // Process wait timeout, in milliseconds
  static int const default_wait_timeout = 20;
 
  class executor {
    friend class dialog;
 
   public:
    // High level function to get the result of a command
    std::string result(int* exit_code = nullptr);
 
    // High level function to abort
    bool kill();
 
#if _WIN32
    void                 start_func(std::function<std::string(int*)> const& fun);
    static BOOL CALLBACK enum_windows_callback(HWND hwnd, LPARAM lParam);
#elif __EMSCRIPTEN__
    void start(int exit_code);
#else
    void start_process(std::vector<std::string> const& command);
#endif
 
    ~executor();
 
   protected:
    bool ready(int timeout = default_wait_timeout);
    void stop();
 
   private:
    bool        m_running = false;
    std::string m_stdout;
    int         m_exit_code = -1;
#if _WIN32
    std::future<std::string> m_future;
    std::set<HWND>           m_windows;
    std::condition_variable  m_cond;
    std::mutex               m_mutex;
    DWORD                    m_tid;
#elif __EMSCRIPTEN__ || __NX__
    // FIXME: do something
#else
    pid_t m_pid = 0;
    int   m_fd  = -1;
#endif
  };
 
  class platform {
   protected:
#if _WIN32
    // Helper class around LoadLibraryA() and GetProcAddress() with some safety
    class dll {
     public:
      dll(std::string const& name);
      ~dll();
 
      template <typename T>
      class proc {
       public:
        proc(dll const& lib, std::string const& sym)
            : m_proc(reinterpret_cast<T*>((void*) ::GetProcAddress(lib.handle, sym.c_str()))) {}
 
        operator bool() const { return m_proc != nullptr; }
        operator T*() const { return m_proc; }
 
       private:
        T* m_proc;
      };
 
     private:
      HMODULE handle;
    };
 
    // Helper class around CoInitialize() and CoUnInitialize()
    class ole32_dll : public dll {
     public:
      ole32_dll();
      ~ole32_dll();
      bool is_initialized();
 
     private:
      HRESULT m_state;
    };
 
    // Helper class around CreateActCtx() and ActivateActCtx()
    class new_style_context {
     public:
      new_style_context();
      ~new_style_context();
 
     private:
      HANDLE    create();
      ULONG_PTR m_cookie = 0;
    };
#endif
  };
 
  class dialog : protected settings, protected platform {
   public:
    bool ready(int timeout = default_wait_timeout) const;
    bool kill() const;
 
   protected:
    explicit dialog();
 
    std::vector<std::string> desktop_helper() const;
    static std::string       buttons_to_name(choice _choice);
    static std::string       get_icon_name(icon _icon);
 
    std::string powershell_quote(std::string const& str) const;
    std::string osascript_quote(std::string const& str) const;
    std::string shell_quote(std::string const& str) const;
 
    // Keep handle to executing command
    std::shared_ptr<executor> m_async;
  };
 
  class file_dialog : public dialog {
   protected:
    enum type {
      open,
      save,
      folder,
    };
 
    file_dialog(type in_type, std::string const& title, std::string const& default_path = "",
                std::vector<std::string> const& filters = {}, opt options = opt::none);
 
   protected:
    std::string              string_result();
    std::vector<std::string> vector_result();
 
#if _WIN32
    static int CALLBACK bffcallback(HWND hwnd, UINT uMsg, LPARAM, LPARAM pData);
#if PFD_HAS_IFILEDIALOG
    std::string select_folder_vista(IFileDialog* ifd, bool force_path);
#endif
 
    std::wstring m_wtitle;
    std::wstring m_wdefault_path;
 
    std::vector<std::string> m_vector_result;
#endif
  };
 
}  // namespace internal
 
//
// The path class provides some platform-specific path constants
//
 
class path : protected internal::platform {
 public:
  static std::string home();
  static std::string separator();
};
 
//
// The notify widget
//
 
class notify : public internal::dialog {
 public:
  notify(std::string const& title, std::string const& message, icon _icon = icon::info);
};
 
//
// The message widget
//
 
class message : public internal::dialog {
 public:
  message(std::string const& title, std::string const& text, choice _choice = choice::ok_cancel,
          icon _icon = icon::info);
 
  button result();
 
 private:
  // Some extra logic to map the exit code to button number
  std::map<int, button> m_mappings;
};
 
//
// The open_file, save_file, and open_folder widgets
//
 
class open_file : public internal::file_dialog {
 public:
  open_file(std::string const& title, std::string const& default_path = "",
            std::vector<std::string> const& filters = {"All Files", "*"}, opt options = opt::none);
 
#if defined(__has_cpp_attribute)
#if __has_cpp_attribute(deprecated)
  // Backwards compatibility
  [[deprecated("Use pfd::opt::multiselect instead of allow_multiselect")]]
#endif
#endif
  open_file(std::string const& title, std::string const& default_path,
            std::vector<std::string> const& filters, bool allow_multiselect);
 
  std::vector<std::string> result();
};
 
class save_file : public internal::file_dialog {
 public:
  save_file(std::string const& title, std::string const& default_path = "",
            std::vector<std::string> const& filters = {"All Files", "*"}, opt options = opt::none);
 
#if defined(__has_cpp_attribute)
#if __has_cpp_attribute(deprecated)
  // Backwards compatibility
  [[deprecated("Use pfd::opt::force_overwrite instead of confirm_overwrite")]]
#endif
#endif
  save_file(std::string const& title, std::string const& default_path,
            std::vector<std::string> const& filters, bool confirm_overwrite);
 
  std::string result();
};
 
class select_folder : public internal::file_dialog {
 public:
  select_folder(std::string const& title, std::string const& default_path = "",
                opt options = opt::none);
 
  std::string result();
};
 
//
// Below this are all the method implementations. You may choose to define the
// macro PFD_SKIP_IMPLEMENTATION everywhere before including this header except
// in one place. This may reduce compilation times.
//
 
#if !defined PFD_SKIP_IMPLEMENTATION
 
// internal free functions implementations
 
namespace internal {
 
#if _WIN32
  static inline std::wstring str2wstr(std::string const& str) {
    int          len = MultiByteToWideChar(CP_UTF8, 0, str.c_str(), (int) str.size(), nullptr, 0);
    std::wstring ret(len, '\0');
    MultiByteToWideChar(CP_UTF8, 0, str.c_str(), (int) str.size(), (LPWSTR) ret.data(),
                        (int) ret.size());
    return ret;
  }
 
  static inline std::string wstr2str(std::wstring const& str) {
    int len = WideCharToMultiByte(CP_UTF8, 0, str.c_str(), (int) str.size(), nullptr, 0, nullptr,
                                  nullptr);
    std::string ret(len, '\0');
    WideCharToMultiByte(CP_UTF8, 0, str.c_str(), (int) str.size(), (LPSTR) ret.data(),
                        (int) ret.size(), nullptr, nullptr);
    return ret;
  }
 
  static inline bool is_vista() {
    OSVERSIONINFOEXW osvi;
    memset(&osvi, 0, sizeof(osvi));
    DWORDLONG const mask = VerSetConditionMask(
        VerSetConditionMask(VerSetConditionMask(0, VER_MAJORVERSION, VER_GREATER_EQUAL),
                            VER_MINORVERSION, VER_GREATER_EQUAL),
        VER_SERVICEPACKMAJOR, VER_GREATER_EQUAL);
    osvi.dwOSVersionInfoSize = sizeof(osvi);
    osvi.dwMajorVersion      = HIBYTE(_WIN32_WINNT_VISTA);
    osvi.dwMinorVersion      = LOBYTE(_WIN32_WINNT_VISTA);
    osvi.wServicePackMajor   = 0;
 
    return VerifyVersionInfoW(&osvi, VER_MAJORVERSION | VER_MINORVERSION | VER_SERVICEPACKMAJOR,
                              mask) != FALSE;
  }
#endif
 
  // This is necessary until C++20 which will have std::string::ends_with() etc.
 
  static inline bool ends_with(std::string const& str, std::string const& suffix) {
    return suffix.size() <= str.size() &&
           str.compare(str.size() - suffix.size(), suffix.size(), suffix) == 0;
  }
 
  static inline bool starts_with(std::string const& str, std::string const& prefix) {
    return prefix.size() <= str.size() && str.compare(0, prefix.size(), prefix) == 0;
  }
 
  // This is necessary until C++17 which will have std::filesystem::is_directory
 
  static inline bool is_directory(std::string const& path) {
#if _WIN32
    auto attr = GetFileAttributesA(path.c_str());
    return attr != INVALID_FILE_ATTRIBUTES && (attr & FILE_ATTRIBUTE_DIRECTORY);
#elif __EMSCRIPTEN__
    // TODO
    return false;
#else
    struct stat s;
    return stat(path.c_str(), &s) == 0 && S_ISDIR(s.st_mode);
#endif
  }
 
  // This is necessary because getenv is not thread-safe
 
  static inline std::string getenv(std::string const& str) {
#if _MSC_VER
    char*  buf  = nullptr;
    size_t size = 0;
    if (_dupenv_s(&buf, &size, str.c_str()) == 0 && buf) {
      std::string ret(buf);
      free(buf);
      return ret;
    }
    return "";
#else
    auto buf = std::getenv(str.c_str());
    return buf ? buf : "";
#endif
  }
 
}  // namespace internal
 
// settings implementation
 
inline settings::settings(bool resync) {
  flags(flag::is_scanned) &= !resync;
 
  if (flags(flag::is_scanned)) return;
 
  auto pfd_verbose = internal::getenv("PFD_VERBOSE");
  auto match_no    = std::regex("(|0|no|false)", std::regex_constants::icase);
  if (!std::regex_match(pfd_verbose, match_no)) flags(flag::is_verbose) = true;
 
#if _WIN32
  flags(flag::is_vista) = internal::is_vista();
#elif !__APPLE__
  flags(flag::has_zenity)     = check_program("zenity");
  flags(flag::has_matedialog) = check_program("matedialog");
  flags(flag::has_qarma)      = check_program("qarma");
  flags(flag::has_kdialog)    = check_program("kdialog");
 
  // If multiple helpers are available, try to default to the best one
  if (flags(flag::has_zenity) && flags(flag::has_kdialog)) {
    auto desktop_name = internal::getenv("XDG_SESSION_DESKTOP");
    if (desktop_name == std::string("gnome"))
      flags(flag::has_kdialog) = false;
    else if (desktop_name == std::string("KDE"))
      flags(flag::has_zenity) = false;
  }
#endif
 
  flags(flag::is_scanned) = true;
}
 
inline bool settings::available() {
#if _WIN32
  return true;
#elif __APPLE__
  return true;
#elif __EMSCRIPTEN__
  // FIXME: Return true after implementation is complete.
  return false;
#else
  settings tmp;
  return tmp.flags(flag::has_zenity) || tmp.flags(flag::has_matedialog) ||
         tmp.flags(flag::has_qarma) || tmp.flags(flag::has_kdialog);
#endif
}
 
inline void settings::verbose(bool value) {
  settings().flags(flag::is_verbose) = value;
}
 
inline void settings::rescan() {
  settings(/* resync = */ true);
}
 
// Check whether a program is present using “which”.
inline bool settings::check_program(std::string const& program) {
#if _WIN32
  (void) program;
  return false;
#elif __EMSCRIPTEN__
  (void) program;
  return false;
#else
  int                exit_code = -1;
  internal::executor async;
  async.start_process({"/bin/sh", "-c", "which " + program});
  async.result(&exit_code);
  return exit_code == 0;
#endif
}
 
inline bool settings::is_osascript() const {
#if __APPLE__
  return true;
#else
  return false;
#endif
}
 
inline bool settings::is_zenity() const {
  return flags(flag::has_zenity) || flags(flag::has_matedialog) || flags(flag::has_qarma);
}
 
inline bool settings::is_kdialog() const {
  return flags(flag::has_kdialog);
}
 
inline bool const& settings::flags(flag in_flag) const {
  static bool flags[size_t(flag::max_flag)];
  return flags[size_t(in_flag)];
}
 
inline bool& settings::flags(flag in_flag) {
  return const_cast<bool&>(static_cast<settings const*>(this)->flags(in_flag));
}
 
// path implementation
inline std::string path::home() {
#if _WIN32
  // First try the USERPROFILE environment variable
  auto user_profile = internal::getenv("USERPROFILE");
  if (user_profile.size() > 0) return user_profile;
  // Otherwise, try GetUserProfileDirectory()
  HANDLE token         = nullptr;
  DWORD  len           = MAX_PATH;
  char   buf[MAX_PATH] = {'\0'};
  if (OpenProcessToken(GetCurrentProcess(), TOKEN_QUERY, &token)) {
    dll                                            userenv("userenv.dll");
    dll::proc<BOOL WINAPI(HANDLE, LPSTR, LPDWORD)> get_user_profile_directory(
        userenv, "GetUserProfileDirectoryA");
    get_user_profile_directory(token, buf, &len);
    CloseHandle(token);
    if (*buf) return buf;
  }
#elif __EMSCRIPTEN__
  return "/";
#else
  // First try the HOME environment variable
  auto home = internal::getenv("HOME");
  if (home.size() > 0) return home;
  // Otherwise, try getpwuid_r()
  size_t len = 4096;
#if defined(_SC_GETPW_R_SIZE_MAX)
  auto size_max = sysconf(_SC_GETPW_R_SIZE_MAX);
  if (size_max != -1) len = size_t(size_max);
#endif
  std::vector<char> buf(len);
  struct passwd     pwd, *result;
  if (getpwuid_r(getuid(), &pwd, buf.data(), buf.size(), &result) == 0) return result->pw_dir;
#endif
  return "/";
}
 
inline std::string path::separator() {
#if _WIN32
  return "\\";
#else
  return "/";
#endif
}
 
// executor implementation
 
inline std::string internal::executor::result(int* exit_code /* = nullptr */) {
  stop();
  if (exit_code) *exit_code = m_exit_code;
  return m_stdout;
}
 
inline bool internal::executor::kill() {
#if _WIN32
  if (m_future.valid()) {
    // Close all windows that weren’t open when we started the future
    auto previous_windows = m_windows;
    EnumWindows(&enum_windows_callback, (LPARAM) this);
    for (auto hwnd : m_windows)
      if (previous_windows.find(hwnd) == previous_windows.end()) {
        SendMessage(hwnd, WM_CLOSE, 0, 0);
        // Also send IDNO in case of a Yes/No or Abort/Retry/Ignore messagebox
        SendMessage(hwnd, WM_COMMAND, IDNO, 0);
      }
  }
#elif __EMSCRIPTEN__ || __NX__
  // FIXME: do something
  return false;  // cannot kill
#else
  ::kill(m_pid, SIGKILL);
#endif
  stop();
  return true;
}
 
#if _WIN32
inline BOOL CALLBACK internal::executor::enum_windows_callback(HWND hwnd, LPARAM lParam) {
  auto that = (executor*) lParam;
 
  DWORD pid;
  auto  tid = GetWindowThreadProcessId(hwnd, &pid);
  if (tid == that->m_tid) that->m_windows.insert(hwnd);
  return TRUE;
}
#endif
 
#if _WIN32
inline void internal::executor::start_func(std::function<std::string(int*)> const& fun) {
  stop();
 
  auto trampoline = [fun, this]() {
    // Save our thread id so that the caller can cancel us
    m_tid = GetCurrentThreadId();
    EnumWindows(&enum_windows_callback, (LPARAM) this);
    m_cond.notify_all();
    return fun(&m_exit_code);
  };
 
  std::unique_lock<std::mutex> lock(m_mutex);
  m_future = std::async(std::launch::async, trampoline);
  m_cond.wait(lock);
  m_running = true;
}
 
#elif __EMSCRIPTEN__
inline void internal::executor::start(int exit_code) {
  m_exit_code = exit_code;
}
 
#else
inline void internal::executor::start_process(std::vector<std::string> const& command) {
  stop();
  m_stdout.clear();
  m_exit_code = -1;
 
  int in[2], out[2];
  if (pipe(in) != 0 || pipe(out) != 0) return;
 
  m_pid = fork();
  if (m_pid < 0) return;
 
  close(in[m_pid ? 0 : 1]);
  close(out[m_pid ? 1 : 0]);
 
  if (m_pid == 0) {
    dup2(in[0], STDIN_FILENO);
    dup2(out[1], STDOUT_FILENO);
 
    // Ignore stderr so that it doesn’t pollute the console (e.g. GTK+ errors from zenity)
    int fd = open("/src/null", O_WRONLY);
    dup2(fd, STDERR_FILENO);
    close(fd);
 
    std::vector<char*> args;
    std::transform(command.cbegin(), command.cend(), std::back_inserter(args),
                   [](std::string const& s) { return const_cast<char*>(s.c_str()); });
    args.push_back(nullptr);  // null-terminate argv[]
 
    execvp(args[0], args.data());
    exit(1);
  }
 
  close(in[1]);
  m_fd       = out[0];
  auto flags = fcntl(m_fd, F_GETFL);
  fcntl(m_fd, F_SETFL, flags | O_NONBLOCK);
 
  m_running = true;
}
#endif
 
inline internal::executor::~executor() {
  stop();
}
 
inline bool internal::executor::ready(int timeout /* = default_wait_timeout */) {
  if (!m_running) return true;
 
#if _WIN32
  if (m_future.valid()) {
    auto status = m_future.wait_for(std::chrono::milliseconds(timeout));
    if (status != std::future_status::ready) {
      // On Windows, we need to run the message pump. If the async
      // thread uses a Windows API dialog, it may be attached to the
      // main thread and waiting for messages that only we can dispatch.
      MSG msg;
      while (PeekMessage(&msg, nullptr, 0, 0, PM_REMOVE)) {
        TranslateMessage(&msg);
        DispatchMessage(&msg);
      }
      return false;
    }
 
    m_stdout = m_future.get();
  }
#elif __EMSCRIPTEN__ || __NX__
  // FIXME: do something
  (void) timeout;
#else
  char    buf[BUFSIZ];
  ssize_t received = read(m_fd, buf, BUFSIZ);  // Flawfinder: ignore
  if (received > 0) {
    m_stdout += std::string(buf, received);
    return false;
  }
 
  // Reap child process if it is dead. It is possible that the system has already reaped it
  // (this happens when the calling application handles or ignores SIG_CHLD) and results in
  // waitpid() failing with ECHILD. Otherwise we assume the child is running and we sleep for
  // a little while.
  int   status;
  pid_t child = waitpid(m_pid, &status, WNOHANG);
  if (child != m_pid && (child >= 0 || errno != ECHILD)) {
    // FIXME: this happens almost always at first iteration
    std::this_thread::sleep_for(std::chrono::milliseconds(timeout));
    return false;
  }
 
  close(m_fd);
  m_exit_code = WEXITSTATUS(status);
#endif
 
  m_running = false;
  return true;
}
 
inline void internal::executor::stop() {
  // Loop until the user closes the dialog
  while (!ready());
}
 
// dll implementation
 
#if _WIN32
inline internal::platform::dll::dll(std::string const& name)
    : handle(::LoadLibraryA(name.c_str())) {}
 
inline internal::platform::dll::~dll() {
  if (handle) ::FreeLibrary(handle);
}
#endif  // _WIN32
 
// ole32_dll implementation
 
#if _WIN32
inline internal::platform::ole32_dll::ole32_dll() : dll("ole32.dll") {
  // Use COINIT_MULTITHREADED because COINIT_APARTMENTTHREADED causes crashes.
  // See https://github.com/samhocevar/portable-file-dialogs/issues/51
  auto coinit = proc<HRESULT WINAPI(LPVOID, DWORD)>(*this, "CoInitializeEx");
  m_state     = coinit(nullptr, COINIT_MULTITHREADED);
}
 
inline internal::platform::ole32_dll::~ole32_dll() {
  if (is_initialized()) proc<void WINAPI()>(*this, "CoUninitialize")();
}
 
inline bool internal::platform::ole32_dll::is_initialized() {
  return m_state == S_OK || m_state == S_FALSE;
}
#endif
 
// new_style_context implementation
 
#if _WIN32
inline internal::platform::new_style_context::new_style_context() {
  // Only create one activation context for the whole app lifetime.
  static HANDLE hctx = create();
 
  if (hctx != INVALID_HANDLE_VALUE) ActivateActCtx(hctx, &m_cookie);
}
 
inline internal::platform::new_style_context::~new_style_context() {
  DeactivateActCtx(0, m_cookie);
}
 
inline HANDLE internal::platform::new_style_context::create() {
  // This “hack” seems to be necessary for this code to work on windows XP.
  // Without it, dialogs do not show and close immediately. GetError()
  // returns 0 so I don’t know what causes this. I was not able to reproduce
  // this behavior on Windows 7 and 10 but just in case, let it be here for
  // those versions too.
  // This hack is not required if other dialogs are used (they load comdlg32
  // automatically), only if message boxes are used.
  dll comdlg32("comdlg32.dll");
 
  // Using approach as shown here: https://stackoverflow.com/a/10444161
  UINT        len = ::GetSystemDirectoryA(nullptr, 0);
  std::string sys_dir(len, '\0');
  ::GetSystemDirectoryA(&sys_dir[0], len);
 
  ACTCTXA act_ctx = {
      // Do not set flag ACTCTX_FLAG_SET_PROCESS_DEFAULT, since it causes a
      // crash with error “default context is already set”.
      sizeof(act_ctx),
      ACTCTX_FLAG_RESOURCE_NAME_VALID | ACTCTX_FLAG_ASSEMBLY_DIRECTORY_VALID,
      "shell32.dll",
      0,
      0,
      sys_dir.c_str(),
      (LPCSTR) 124,
      nullptr,
      0,
  };
 
  return ::CreateActCtxA(&act_ctx);
}
#endif  // _WIN32
 
// dialog implementation
 
inline bool internal::dialog::ready(int timeout /* = default_wait_timeout */) const {
  return m_async->ready(timeout);
}
 
inline bool internal::dialog::kill() const {
  return m_async->kill();
}
 
inline internal::dialog::dialog() : m_async(std::make_shared<executor>()) {}
 
inline std::vector<std::string> internal::dialog::desktop_helper() const {
#if __APPLE__
  return {"osascript"};
#else
  return {flags(flag::has_zenity)       ? "zenity"
          : flags(flag::has_matedialog) ? "matedialog"
          : flags(flag::has_qarma)      ? "qarma"
          : flags(flag::has_kdialog)    ? "kdialog"
                                        : "echo"};
#endif
}
 
inline std::string internal::dialog::buttons_to_name(choice _choice) {
  switch (_choice) {
    case choice::ok_cancel:
      return "okcancel";
    case choice::yes_no:
      return "yesno";
    case choice::yes_no_cancel:
      return "yesnocancel";
    case choice::retry_cancel:
      return "retrycancel";
    case choice::abort_retry_ignore:
      return "abortretryignore";
    /* case choice::ok: */ default:
      return "ok";
  }
}
 
inline std::string internal::dialog::get_icon_name(icon _icon) {
  switch (_icon) {
    case icon::warning:
      return "warning";
    case icon::error:
      return "error";
    case icon::question:
      return "question";
    // Zenity wants "information" but WinForms wants "info"
    /* case icon::info: */ default:
#if _WIN32
      return "info";
#else
      return "information";
#endif
  }
}
 
// This is only used for debugging purposes
inline std::ostream& operator<<(std::ostream& s, std::vector<std::string> const& v) {
  int not_first = 0;
  for (auto& e : v) s << (not_first++ ? " " : "") << e;
  return s;
}
 
// Properly quote a string for Powershell: replace ' or " with '' or ""
// FIXME: we should probably get rid of newlines!
// FIXME: the \" sequence seems unsafe, too!
// XXX: this is no longer used but I would like to keep it around just in case
inline std::string internal::dialog::powershell_quote(std::string const& str) const {
  return "'" + std::regex_replace(str, std::regex("['\"]"), "$&$&") + "'";
}
 
// Properly quote a string for osascript: replace \ or " with \\ or \"
// XXX: this also used to replace ' with \' when popen was used, but it would be
// smarter to do shell_quote(osascript_quote(...)) if this is needed again.
inline std::string internal::dialog::osascript_quote(std::string const& str) const {
  return "\"" + std::regex_replace(str, std::regex("[\\\\\"]"), "\\$&") + "\"";
}
 
// Properly quote a string for the shell: just replace ' with '\''
// XXX: this is no longer used but I would like to keep it around just in case
inline std::string internal::dialog::shell_quote(std::string const& str) const {
  return "'" + std::regex_replace(str, std::regex("'"), "'\\''") + "'";
}
 
// file_dialog implementation
 
inline internal::file_dialog::file_dialog(type in_type, std::string const& title,
                                          std::string const&              default_path /* = "" */,
                                          std::vector<std::string> const& filters /* = {} */,
                                          opt options /* = opt::none */) {
#if _WIN32
  std::string filter_list;
  std::regex  whitespace("  *");
  for (size_t i = 0; i + 1 < filters.size(); i += 2) {
    filter_list += filters[i] + '\0';
    filter_list += std::regex_replace(filters[i + 1], whitespace, ";") + '\0';
  }
  filter_list += '\0';
 
  m_async->start_func(
      [this, in_type, title, default_path, filter_list, options](int* exit_code) -> std::string {
        (void) exit_code;
        m_wtitle          = internal::str2wstr(title);
        m_wdefault_path   = internal::str2wstr(default_path);
        auto wfilter_list = internal::str2wstr(filter_list);
 
        // Initialise COM. This is required for the new folder selection window,
        // (see https://github.com/samhocevar/portable-file-dialogs/pull/21)
        // and to avoid random crashes with GetOpenFileNameW() (see
        // https://github.com/samhocevar/portable-file-dialogs/issues/51)
        ole32_dll ole32;
 
        // Folder selection uses a different method
        if (in_type == type::folder) {
#if PFD_HAS_IFILEDIALOG
          if (flags(flag::is_vista)) {
            // On Vista and higher we should be able to use IFileDialog for folder selection
            IFileDialog* ifd;
            HRESULT hr = dll::proc<HRESULT WINAPI(REFCLSID, LPUNKNOWN, DWORD, REFIID, LPVOID*)>(
                ole32, "CoCreateInstance")(CLSID_FileOpenDialog, nullptr, CLSCTX_INPROC_SERVER,
                                           IID_PPV_ARGS(&ifd));
 
            // In case CoCreateInstance fails (which it should not), try legacy approach
            if (SUCCEEDED(hr)) return select_folder_vista(ifd, options & opt::force_path);
          }
#endif
 
          BROWSEINFOW bi;
          memset(&bi, 0, sizeof(bi));
 
          bi.lpfn   = &bffcallback;
          bi.lParam = (LPARAM) this;
 
          if (flags(flag::is_vista)) {
            if (ole32.is_initialized()) bi.ulFlags |= BIF_NEWDIALOGSTYLE;
            bi.ulFlags |= BIF_EDITBOX;
            bi.ulFlags |= BIF_STATUSTEXT;
          }
 
          auto*       list = SHBrowseForFolderW(&bi);
          std::string ret;
          if (list) {
            auto buffer = new wchar_t[MAX_PATH];
            SHGetPathFromIDListW(list, buffer);
            dll::proc<void WINAPI(LPVOID)>(ole32, "CoTaskMemFree")(list);
            ret = internal::wstr2str(buffer);
            delete[] buffer;
          }
          return ret;
        }
 
        OPENFILENAMEW ofn;
        memset(&ofn, 0, sizeof(ofn));
        ofn.lStructSize = sizeof(OPENFILENAMEW);
        ofn.hwndOwner   = GetActiveWindow();
 
        ofn.lpstrFilter = wfilter_list.c_str();
 
        auto woutput  = std::wstring(MAX_PATH * 256, L'\0');
        ofn.lpstrFile = (LPWSTR) woutput.data();
        ofn.nMaxFile  = (DWORD) woutput.size();
        if (!m_wdefault_path.empty()) {
          // If a directory was provided, use it as the initial directory. If
          // a valid path was provided, use it as the initial file. Otherwise,
          // let the Windows API decide.
          auto path_attr = GetFileAttributesW(m_wdefault_path.c_str());
          if (path_attr != INVALID_FILE_ATTRIBUTES && (path_attr & FILE_ATTRIBUTE_DIRECTORY))
            ofn.lpstrInitialDir = m_wdefault_path.c_str();
          else if (m_wdefault_path.size() <= woutput.size())
            // second argument is size of buffer, not length of string
            StringCchCopyW(ofn.lpstrFile, MAX_PATH * 256 + 1, m_wdefault_path.c_str());
          else {
            ofn.lpstrFileTitle = (LPWSTR) m_wdefault_path.data();
            ofn.nMaxFileTitle  = (DWORD) m_wdefault_path.size();
          }
        }
        ofn.lpstrTitle = m_wtitle.c_str();
        ofn.Flags      = OFN_NOCHANGEDIR | OFN_EXPLORER;
 
        dll comdlg32("comdlg32.dll");
 
        // Apply new visual style (required for windows XP)
        new_style_context ctx;
 
        if (in_type == type::save) {
          if (!(options & opt::force_overwrite)) ofn.Flags |= OFN_OVERWRITEPROMPT;
 
          dll::proc<BOOL WINAPI(LPOPENFILENAMEW)> get_save_file_name(comdlg32, "GetSaveFileNameW");
          if (get_save_file_name(&ofn) == 0) return "";
          return internal::wstr2str(woutput.c_str());
        } else {
          if (options & opt::multiselect) ofn.Flags |= OFN_ALLOWMULTISELECT;
          ofn.Flags |= OFN_PATHMUSTEXIST;
 
          dll::proc<BOOL WINAPI(LPOPENFILENAMEW)> get_open_file_name(comdlg32, "GetOpenFileNameW");
          if (get_open_file_name(&ofn) == 0) return "";
        }
 
        std::string prefix;
        for (wchar_t const* p = woutput.c_str(); *p;) {
          auto filename = internal::wstr2str(p);
          p += wcslen(p);
          // In multiselect mode, we advance p one wchar further and
          // check for another filename. If there is one and the
          // prefix is empty, it means we just read the prefix.
          if ((options & opt::multiselect) && *++p && prefix.empty()) {
            prefix = filename + "/";
            continue;
          }
 
          m_vector_result.push_back(prefix + filename);
        }
 
        return "";
      });
#elif __EMSCRIPTEN__
  // FIXME: do something
  (void) in_type;
  (void) title;
  (void) default_path;
  (void) filters;
  (void) options;
#else
  auto command = desktop_helper();
 
  if (is_osascript()) {
    std::string script = "set ret to choose";
    switch (in_type) {
      case type::save:
        script += " file name";
        break;
      case type::open:
      default:
        script += " file";
        if (options & opt::multiselect) script += " with multiple selections allowed";
        break;
      case type::folder:
        script += " folder";
        break;
    }
 
    if (default_path.size()) {
      if (in_type == type::folder || is_directory(default_path))
        script += " default location ";
      else
        script += " default name ";
      script += osascript_quote(default_path);
    }
 
    script += " with prompt " + osascript_quote(title);
 
    if (in_type == type::open) {
      // Concatenate all user-provided filter patterns
      std::string patterns;
      for (size_t i = 0; i < filters.size() / 2; ++i) patterns += " " + filters[2 * i + 1];
 
      // Split the pattern list to check whether "*" is in there; if it
      // is, we have to disable filters because there is no mechanism in
      // OS X for the user to override the filter.
      std::regex                 sep("\\s+");
      std::string                filter_list;
      bool                       has_filter = true;
      std::sregex_token_iterator iter(patterns.begin(), patterns.end(), sep, -1);
      std::sregex_token_iterator end;
      for (; iter != end; ++iter) {
        auto pat = iter->str();
        if (pat == "*" || pat == "*.*")
          has_filter = false;
        else if (internal::starts_with(pat, "*."))
          filter_list += "," + osascript_quote(pat.substr(2, pat.size() - 2));
      }
 
      if (has_filter && filter_list.size() > 0) {
        // There is a weird AppleScript bug where file extensions of length != 3 are
        // ignored, e.g. type{"txt"} works, but type{"json"} does not. Fortunately if
        // the whole list starts with a 3-character extension, everything works again.
        // We use "///" for such an extension because we are sure it cannot appear in
        // an actual filename.
        script += " of type {\"///\"" + filter_list + "}";
      }
    }
 
    if (in_type == type::open && (options & opt::multiselect)) {
      script += "\nset s to \"\"";
      script += "\nrepeat with i in ret";
      script += "\n  set s to s & (POSIX path of i) & \"\\n\"";
      script += "\nend repeat";
      script += "\ncopy s to stdout";
    } else {
      script += "\nPOSIX path of ret";
    }
 
    command.push_back("-e");
    command.push_back(script);
  } else if (is_zenity()) {
    command.push_back("--file-selection");
 
    // If the default path is a directory, make sure it ends with "/" otherwise zenity will
    // open the file dialog in the parent directory.
    auto filename_arg = "--filename=" + default_path;
    if (in_type != type::folder && !ends_with(default_path, "/") &&
        internal::is_directory(default_path))
      filename_arg += "/";
    command.push_back(filename_arg);
 
    command.push_back("--title");
    command.push_back(title);
    command.push_back("--separator=\n");
 
    for (size_t i = 0; i < filters.size() / 2; ++i) {
      command.push_back("--file-filter");
      command.push_back(filters[2 * i] + "|" + filters[2 * i + 1]);
    }
 
    if (in_type == type::save) command.push_back("--save");
    if (in_type == type::folder) command.push_back("--directory");
    if (!(options & opt::force_overwrite)) command.push_back("--confirm-overwrite");
    if (options & opt::multiselect) command.push_back("--multiple");
  } else if (is_kdialog()) {
    switch (in_type) {
      case type::save:
        command.push_back("--getsavefilename");
        break;
      case type::open:
        command.push_back("--getopenfilename");
        break;
      case type::folder:
        command.push_back("--getexistingdirectory");
        break;
    }
    if (options & opt::multiselect) {
      command.push_back("--multiple");
      command.push_back("--separate-output");
    }
 
    command.push_back(default_path);
 
    std::string filter;
    for (size_t i = 0; i < filters.size() / 2; ++i)
      filter += (i == 0 ? "" : " | ") + filters[2 * i] + "(" + filters[2 * i + 1] + ")";
    command.push_back(filter);
 
    command.push_back("--title");
    command.push_back(title);
  }
 
  if (flags(flag::is_verbose)) std::cerr << "pfd: " << command << std::endl;
 
  m_async->start_process(command);
#endif
}
 
inline std::string internal::file_dialog::string_result() {
#if _WIN32
  return m_async->result();
#else
  auto ret = m_async->result();
  // Strip potential trailing newline (zenity). Also strip trailing slash
  // added by osascript for consistency with other backends.
  while (!ret.empty() && (ret.back() == '\n' || ret.back() == '/')) ret.pop_back();
  return ret;
#endif
}
 
inline std::vector<std::string> internal::file_dialog::vector_result() {
#if _WIN32
  m_async->result();
  return m_vector_result;
#else
  std::vector<std::string> ret;
  auto                     result = m_async->result();
  for (;;) {
    // Split result along newline characters
    auto i = result.find('\n');
    if (i == 0 || i == std::string::npos) break;
    ret.push_back(result.substr(0, i));
    result = result.substr(i + 1, result.size());
  }
  return ret;
#endif
}
 
#if _WIN32
// Use a static function to pass as BFFCALLBACK for legacy folder select
inline int CALLBACK internal::file_dialog::bffcallback(HWND hwnd, UINT uMsg, LPARAM, LPARAM pData) {
  auto inst = (file_dialog*) pData;
  switch (uMsg) {
    case BFFM_INITIALIZED:
      SendMessage(hwnd, BFFM_SETSELECTIONW, TRUE, (LPARAM) inst->m_wdefault_path.c_str());
      break;
  }
  return 0;
}
 
#if PFD_HAS_IFILEDIALOG
inline std::string internal::file_dialog::select_folder_vista(IFileDialog* ifd, bool force_path) {
  std::string result;
 
  IShellItem* folder;
 
  // Load library at runtime so app doesn't link it at load time (which will fail on windows XP)
  dll                                                          shell32("shell32.dll");
  dll::proc<HRESULT WINAPI(PCWSTR, IBindCtx*, REFIID, void**)> create_item(
      shell32, "SHCreateItemFromParsingName");
 
  if (!create_item) return "";
 
  auto hr = create_item(m_wdefault_path.c_str(), nullptr, IID_PPV_ARGS(&folder));
 
  // Set default folder if found. This only sets the default folder. If
  // Windows has any info about the most recently selected folder, it
  // will display it instead. Generally, calling SetFolder() to set the
  // current directory “is not a good or expected user experience and
  // should therefore be avoided”:
  // https://docs.microsoft.com/windows/win32/api/shobjidl_core/nf-shobjidl_core-ifiledialog-setfolder
  if (SUCCEEDED(hr)) {
    if (force_path)
      ifd->SetFolder(folder);
    else
      ifd->SetDefaultFolder(folder);
    folder->Release();
  }
 
  // Set the dialog title and option to select folders
  ifd->SetOptions(FOS_PICKFOLDERS | FOS_FORCEFILESYSTEM);
  ifd->SetTitle(m_wtitle.c_str());
 
  hr = ifd->Show(GetActiveWindow());
  if (SUCCEEDED(hr)) {
    IShellItem* item;
    hr = ifd->GetResult(&item);
    if (SUCCEEDED(hr)) {
      wchar_t* wname = nullptr;
      // This is unlikely to fail because we use FOS_FORCEFILESYSTEM, but try
      // to output a debug message just in case.
      if (SUCCEEDED(item->GetDisplayName(SIGDN_FILESYSPATH, &wname))) {
        result = internal::wstr2str(std::wstring(wname));
        dll::proc<void WINAPI(LPVOID)>(ole32_dll(), "CoTaskMemFree")(wname);
      } else {
        if (SUCCEEDED(item->GetDisplayName(SIGDN_NORMALDISPLAY, &wname))) {
          auto name = internal::wstr2str(std::wstring(wname));
          dll::proc<void WINAPI(LPVOID)>(ole32_dll(), "CoTaskMemFree")(wname);
          std::cerr << "pfd: failed to get path for " << name << std::endl;
        } else
          std::cerr << "pfd: item of unknown type selected" << std::endl;
      }
 
      item->Release();
    }
  }
 
  ifd->Release();
 
  return result;
}
#endif
#endif
 
// notify implementation
 
inline notify::notify(std::string const& title, std::string const& message,
                      icon _icon /* = icon::info */) {
  if (_icon == icon::question)  // Not supported by notifications
    _icon = icon::info;
 
#if _WIN32
  // Use a static shared pointer for notify_icon so that we can delete
  // it whenever we need to display a new one, and we can also wait
  // until the program has finished running.
  struct notify_icon_data : public NOTIFYICONDATAW {
    ~notify_icon_data() { Shell_NotifyIconW(NIM_DELETE, this); }
  };
 
  static std::shared_ptr<notify_icon_data> nid;
 
  // Release the previous notification icon, if any, and allocate a new
  // one. Note that std::make_shared() does value initialization, so there
  // is no need to memset the structure.
  nid = nullptr;
  nid = std::make_shared<notify_icon_data>();
 
  // For XP support
  nid->cbSize = NOTIFYICONDATAW_V2_SIZE;
  nid->hWnd   = nullptr;
  nid->uID    = 0;
 
  // Flag Description:
  // - NIF_ICON    The hIcon member is valid.
  // - NIF_MESSAGE The uCallbackMessage member is valid.
  // - NIF_TIP     The szTip member is valid.
  // - NIF_STATE   The dwState and dwStateMask members are valid.
  // - NIF_INFO    Use a balloon ToolTip instead of a standard ToolTip. The szInfo, uTimeout,
  // szInfoTitle, and dwInfoFlags members are valid.
  // - NIF_GUID    Reserved.
  nid->uFlags = NIF_MESSAGE | NIF_ICON | NIF_INFO;
 
  // Flag Description
  // - NIIF_ERROR     An error icon.
  // - NIIF_INFO      An information icon.
  // - NIIF_NONE      No icon.
  // - NIIF_WARNING   A warning icon.
  // - NIIF_ICON_MASK Version 6.0. Reserved.
  // - NIIF_NOSOUND   Version 6.0. Do not play the associated sound. Applies only to balloon
  // ToolTips
  switch (_icon) {
    case icon::warning:
      nid->dwInfoFlags = NIIF_WARNING;
      break;
    case icon::error:
      nid->dwInfoFlags = NIIF_ERROR;
      break;
    /* case icon::info: */ default:
      nid->dwInfoFlags = NIIF_INFO;
      break;
  }
 
  ENUMRESNAMEPROC icon_enum_callback = [](HMODULE, LPCTSTR, LPTSTR lpName,
                                          LONG_PTR lParam) -> BOOL {
    ((NOTIFYICONDATAW*) lParam)->hIcon = ::LoadIcon(GetModuleHandle(nullptr), lpName);
    return false;
  };
 
  nid->hIcon = ::LoadIcon(nullptr, IDI_APPLICATION);
  ::EnumResourceNames(nullptr, RT_GROUP_ICON, icon_enum_callback, (LONG_PTR) nid.get());
 
  nid->uTimeout = 5000;
 
  StringCchCopyW(nid->szInfoTitle, ARRAYSIZE(nid->szInfoTitle), internal::str2wstr(title).c_str());
  StringCchCopyW(nid->szInfo, ARRAYSIZE(nid->szInfo), internal::str2wstr(message).c_str());
 
  // Display the new icon
  Shell_NotifyIconW(NIM_ADD, nid.get());
#elif __EMSCRIPTEN__
  // FIXME: do something
  (void) title;
  (void) message;
#else
  auto command = desktop_helper();
 
  if (is_osascript()) {
    command.push_back("-e");
    command.push_back("display notification " + osascript_quote(message) + " with title " +
                      osascript_quote(title));
  } else if (is_zenity()) {
    command.push_back("--notification");
    command.push_back("--window-icon");
    command.push_back(get_icon_name(_icon));
    command.push_back("--text");
    command.push_back(title + "\n" + message);
  } else if (is_kdialog()) {
    command.push_back("--icon");
    command.push_back(get_icon_name(_icon));
    command.push_back("--title");
    command.push_back(title);
    command.push_back("--passivepopup");
    command.push_back(message);
    command.push_back("5");
  }
 
  if (flags(flag::is_verbose)) std::cerr << "pfd: " << command << std::endl;
 
  m_async->start_process(command);
#endif
}
 
// message implementation
 
inline message::message(std::string const& title, std::string const& text,
                        choice _choice /* = choice::ok_cancel */, icon _icon /* = icon::info */) {
#if _WIN32
  // Use MB_SYSTEMMODAL rather than MB_TOPMOST to ensure the message window is brought
  // to front. See https://github.com/samhocevar/portable-file-dialogs/issues/52
  UINT style = MB_SYSTEMMODAL;
  switch (_icon) {
    case icon::warning:
      style |= MB_ICONWARNING;
      break;
    case icon::error:
      style |= MB_ICONERROR;
      break;
    case icon::question:
      style |= MB_ICONQUESTION;
      break;
    /* case icon::info: */ default:
      style |= MB_ICONINFORMATION;
      break;
  }
 
  switch (_choice) {
    case choice::ok_cancel:
      style |= MB_OKCANCEL;
      break;
    case choice::yes_no:
      style |= MB_YESNO;
      break;
    case choice::yes_no_cancel:
      style |= MB_YESNOCANCEL;
      break;
    case choice::retry_cancel:
      style |= MB_RETRYCANCEL;
      break;
    case choice::abort_retry_ignore:
      style |= MB_ABORTRETRYIGNORE;
      break;
    /* case choice::ok: */ default:
      style |= MB_OK;
      break;
  }
 
  m_mappings[IDCANCEL] = button::cancel;
  m_mappings[IDOK]     = button::ok;
  m_mappings[IDYES]    = button::yes;
  m_mappings[IDNO]     = button::no;
  m_mappings[IDABORT]  = button::abort;
  m_mappings[IDRETRY]  = button::retry;
  m_mappings[IDIGNORE] = button::ignore;
 
  m_async->start_func([text, title, style](int* exit_code) -> std::string {
    auto wtext  = internal::str2wstr(text);
    auto wtitle = internal::str2wstr(title);
    // Apply new visual style (required for all Windows versions)
    new_style_context ctx;
    *exit_code = MessageBoxW(GetActiveWindow(), wtext.c_str(), wtitle.c_str(), style);
    return "";
  });
 
#elif __EMSCRIPTEN__
  std::string full_message;
  switch (_icon) {
    case icon::warning:
      full_message = "⚠️";
      break;
    case icon::error:
      full_message = "⛔";
      break;
    case icon::question:
      full_message = "❓";
      break;
    /* case icon::info: */ default:
      full_message = "ℹ";
      break;
  }
 
  full_message += ' ' + title + "\n\n" + text;
 
  // This does not really start an async task; it just passes the
  // EM_ASM_INT return value to a fake start() function.
  m_async->start(EM_ASM_INT(
      {
        if ($1) return window.confirm(UTF8ToString($0)) ? 0 : -1;
        alert(UTF8ToString($0));
        return 0;
      },
      full_message.c_str(), _choice == choice::ok_cancel));
#else
  auto command = desktop_helper();
 
  if (is_osascript()) {
    std::string script =
        "display dialog " + osascript_quote(text) + " with title " + osascript_quote(title);
    auto if_cancel = button::cancel;
    switch (_choice) {
      case choice::ok_cancel:
        script +=
            "buttons {\"OK\", \"Cancel\"}"
            " default button \"OK\""
            " cancel button \"Cancel\"";
        break;
      case choice::yes_no:
        script +=
            "buttons {\"Yes\", \"No\"}"
            " default button \"Yes\""
            " cancel button \"No\"";
        if_cancel = button::no;
        break;
      case choice::yes_no_cancel:
        script +=
            "buttons {\"Yes\", \"No\", \"Cancel\"}"
            " default button \"Yes\""
            " cancel button \"Cancel\"";
        break;
      case choice::retry_cancel:
        script +=
            "buttons {\"Retry\", \"Cancel\"}"
            " default button \"Retry\""
            " cancel button \"Cancel\"";
        break;
      case choice::abort_retry_ignore:
        script +=
            "buttons {\"Abort\", \"Retry\", \"Ignore\"}"
            " default button \"Abort\""
            " cancel button \"Retry\"";
        if_cancel = button::retry;
        break;
      case choice::ok:
      default:
        script +=
            "buttons {\"OK\"}"
            " default button \"OK\""
            " cancel button \"OK\"";
        if_cancel = button::ok;
        break;
    }
    m_mappings[1]   = if_cancel;
    m_mappings[256] = if_cancel;  // XXX: I think this was never correct
    script += " with icon ";
    switch (_icon) {
#define PFD_OSX_ICON(n)                                         \
  "alias ((path to library folder from system domain) as text " \
  "& \"CoreServices:CoreTypes.bundle:Contents:Resources:" n ".icns\")"
      case icon::info:
      default:
        script += PFD_OSX_ICON("ToolBarInfo");
        break;
      case icon::warning:
        script += "caution";
        break;
      case icon::error:
        script += "stop";
        break;
      case icon::question:
        script += PFD_OSX_ICON("GenericQuestionMarkIcon");
        break;
#undef PFD_OSX_ICON
    }
 
    command.push_back("-e");
    command.push_back(script);
  } else if (is_zenity()) {
    switch (_choice) {
      case choice::ok_cancel:
        command.insert(command.end(), {"--question", "--cancel-label=Cancel", "--ok-label=OK"});
        break;
      case choice::yes_no:
        // Do not use standard --question because it causes “No” to return -1,
        // which is inconsistent with the “Yes/No/Cancel” mode below.
        command.insert(command.end(),
                       {"--question", "--switch", "--extra-button=No", "--extra-button=Yes"});
        break;
      case choice::yes_no_cancel:
        command.insert(command.end(), {"--question", "--switch", "--extra-button=Cancel",
                                       "--extra-button=No", "--extra-button=Yes"});
        break;
      case choice::retry_cancel:
        command.insert(command.end(),
                       {"--question", "--switch", "--extra-button=Cancel", "--extra-button=Retry"});
        break;
      case choice::abort_retry_ignore:
        command.insert(command.end(), {"--question", "--switch", "--extra-button=Ignore",
                                       "--extra-button=Abort", "--extra-button=Retry"});
        break;
      case choice::ok:
      default:
        switch (_icon) {
          case icon::error:
            command.push_back("--error");
            break;
          case icon::warning:
            command.push_back("--warning");
            break;
          default:
            command.push_back("--info");
            break;
        }
    }
 
    command.insert(command.end(),
                   {"--title", title, "--width=300", "--height=0",  // sensible defaults
                    "--no-markup",  // do not interpret text as Pango markup
                    "--text", text, "--icon-name=dialog-" + get_icon_name(_icon)});
  } else if (is_kdialog()) {
    if (_choice == choice::ok) {
      switch (_icon) {
        case icon::error:
          command.push_back("--error");
          break;
        case icon::warning:
          command.push_back("--sorry");
          break;
        default:
          command.push_back("--msgbox");
          break;
      }
    } else {
      std::string flag = "--";
      if (_icon == icon::warning || _icon == icon::error) flag += "warning";
      flag += "yesno";
      if (_choice == choice::yes_no_cancel) flag += "cancel";
      command.push_back(flag);
      if (_choice == choice::yes_no || _choice == choice::yes_no_cancel) {
        m_mappings[0]   = button::yes;
        m_mappings[256] = button::no;
      }
    }
 
    command.push_back(text);
    command.push_back("--title");
    command.push_back(title);
 
    // Must be after the above part
    if (_choice == choice::ok_cancel)
      command.insert(command.end(), {"--yes-label", "OK", "--no-label", "Cancel"});
  }
 
  if (flags(flag::is_verbose)) std::cerr << "pfd: " << command << std::endl;
 
  m_async->start_process(command);
#endif
}
 
inline button message::result() {
  int  exit_code;
  auto ret = m_async->result(&exit_code);
  // osascript will say "button returned:Cancel\n"
  // and others will just say "Cancel\n"
  if (internal::ends_with(ret, "Cancel\n")) return button::cancel;
  if (internal::ends_with(ret, "OK\n")) return button::ok;
  if (internal::ends_with(ret, "Yes\n")) return button::yes;
  if (internal::ends_with(ret, "No\n")) return button::no;
  if (internal::ends_with(ret, "Abort\n")) return button::abort;
  if (internal::ends_with(ret, "Retry\n")) return button::retry;
  if (internal::ends_with(ret, "Ignore\n")) return button::ignore;
  if (m_mappings.count(exit_code) != 0) return m_mappings[exit_code];
  return exit_code == 0 ? button::ok : button::cancel;
}
 
// open_file implementation
 
inline open_file::open_file(std::string const& title, std::string const& default_path /* = "" */,
                            std::vector<std::string> const& filters /* = { "All Files", "*" } */,
                            opt                             options /* = opt::none */)
    : file_dialog(type::open, title, default_path, filters, options) {}
 
inline open_file::open_file(std::string const& title, std::string const& default_path,
                            std::vector<std::string> const& filters, bool allow_multiselect)
    : open_file(title, default_path, filters, (allow_multiselect ? opt::multiselect : opt::none)) {}
 
inline std::vector<std::string> open_file::result() {
  return vector_result();
}
 
// save_file implementation
 
inline save_file::save_file(std::string const& title, std::string const& default_path /* = "" */,
                            std::vector<std::string> const& filters /* = { "All Files", "*" } */,
                            opt                             options /* = opt::none */)
    : file_dialog(type::save, title, default_path, filters, options) {}
 
inline save_file::save_file(std::string const& title, std::string const& default_path,
                            std::vector<std::string> const& filters, bool confirm_overwrite)
    : save_file(title, default_path, filters,
                (confirm_overwrite ? opt::none : opt::force_overwrite)) {}
 
inline std::string save_file::result() {
  return string_result();
}
 
// select_folder implementation
 
inline select_folder::select_folder(std::string const& title,
                                    std::string const& default_path /* = "" */,
                                    opt                options /* = opt::none */)
    : file_dialog(type::folder, title, default_path, {}, options) {}
 
inline std::string select_folder::result() {
  return string_result();
}
 
#endif  // PFD_SKIP_IMPLEMENTATION
 
}  // namespace pfd