crossdesk/application/remote_desk/demo/Win32WindowEnumeration.h

#pragma once
#include <dwmapi.h>

struct Window {
public:
  Window(nullptr_t) {}
  Window(HWND hwnd, std::wstring const &title, std::wstring &className) {
    m_hwnd = hwnd;
    m_title = title;
    m_className = className;
  }

  HWND Hwnd() const noexcept { return m_hwnd; }
  std::wstring Title() const noexcept { return m_title; }
  std::wstring ClassName() const noexcept { return m_className; }

private:
  HWND m_hwnd;
  std::wstring m_title;
  std::wstring m_className;
};

std::wstring GetClassName(HWND hwnd) {
  std::array<WCHAR, 1024> className;

  ::GetClassName(hwnd, className.data(), (int)className.size());

  std::wstring title(className.data());
  return title;
}

std::wstring GetWindowText(HWND hwnd) {
  std::array<WCHAR, 1024> windowText;

  ::GetWindowText(hwnd, windowText.data(), (int)windowText.size());

  std::wstring title(windowText.data());
  return title;
}

bool IsAltTabWindow(Window const &window) {
  HWND hwnd = window.Hwnd();
  HWND shellWindow = GetShellWindow();

  auto title = window.Title();
  auto className = window.ClassName();

  if (hwnd == shellWindow) {
    return false;
  }

  if (title.length() == 0) {
    return false;
  }

  if (!IsWindowVisible(hwnd)) {
    return false;
  }

  if (GetAncestor(hwnd, GA_ROOT) != hwnd) {
    return false;
  }

  LONG style = GetWindowLong(hwnd, GWL_STYLE);
  if (!((style & WS_DISABLED) != WS_DISABLED)) {
    return false;
  }

  DWORD cloaked = FALSE;
  HRESULT hrTemp =
      DwmGetWindowAttribute(hwnd, DWMWA_CLOAKED, &cloaked, sizeof(cloaked));
  if (SUCCEEDED(hrTemp) && cloaked == DWM_CLOAKED_SHELL) {
    return false;
  }

  return true;
}

BOOL CALLBACK EnumWindowsProc(HWND hwnd, LPARAM lParam) {
  auto class_name = GetClassName(hwnd);
  auto title = GetWindowText(hwnd);

  auto window = Window(hwnd, title, class_name);

  if (!IsAltTabWindow(window)) {
    return TRUE;
  }

  std::vector<Window> &windows =
      *reinterpret_cast<std::vector<Window> *>(lParam);
  windows.push_back(window);

  return TRUE;
}

const std::vector<Window> EnumerateWindows() {
  std::vector<Window> windows;
  EnumWindows(EnumWindowsProc, reinterpret_cast<LPARAM>(&windows));

  return windows;
}