Method MessageHandler

example/windows/runner/win32_window.cpp:152–194

}

LRESULT
Win32Window::MessageHandler(HWND hwnd,
                            UINT const message,
                            WPARAM const wparam,
                            LPARAM const lparam) noexcept {
  switch (message) {
    case WM_DESTROY:
      window_handle_ = nullptr;
      Destroy();
      if (quit_on_close_) {
        PostQuitMessage(0);
      }
      return 0;

    case WM_DPICHANGED: {
      auto newRectSize = reinterpret_cast<RECT*>(lparam);
      LONG newWidth = newRectSize->right - newRectSize->left;
      LONG newHeight = newRectSize->bottom - newRectSize->top;

      SetWindowPos(hwnd, nullptr, newRectSize->left, newRectSize->top, newWidth,
                   newHeight, SWP_NOZORDER | SWP_NOACTIVATE);

      return 0;
    }
    case WM_SIZE: {
      RECT rect = GetClientArea();
      if (child_content_ != nullptr) {
        // Size and position the child window.
        MoveWindow(child_content_, rect.left, rect.top, rect.right - rect.left,
                   rect.bottom - rect.top, TRUE);
      }
      return 0;
    }

    case WM_ACTIVATE:
      if (child_content_ != nullptr) {
        SetFocus(child_content_);
      }
      return 0;
  }

  return DefWindowProc(window_handle_, message, wparam, lparam);
}

void Win32Window::Destroy() {
  OnDestroy();