Centered popup window

gistfile1.txt

const show = ({ url }, resolve, reject) => {
  const width = Math.max(1000, Math.floor(window.outerWidth * 0.8));
  const height = Math.max(630, Math.floor(window.outerHeight * 0.5));
  const left = Math.floor(window.screenX + (window.outerWidth - width) / 2);
  const top = Math.floor(window.screenY + (window.outerHeight - height) / 8);

  const wOptions = [
    'toolbar=0',
    'scrollbars=1',
    'status=0',
    'resizable=1',
    'location=0',
    'menubar=0',
    `width=${width}`,
    `height=${height}`,
    `left=${left}`,
    `top=${top}`
  ].join(',');

  let w;
  let reply;
  let wTimeout;
  let gotmessage = false;

  const getMessage = e => {
    if (!gotmessage) {
      if (e.origin !== '/* @echo apiHost */') {
        return;
      }
      if (!e.data) {
        reply = { error: { message: 'No data' } };
      } else {
        reply = e.data;
      }
      try {
        w.close();
      } catch (_error) {}
      gotmessage = true;
      return true;
    }
  };

  const callback = data => {
    if (wTimeout) {
      clearTimeout(wTimeout);
      wTimeout = null;
    }
    if (window.removeEventListener) {
      window.removeEventListener('message', getMessage, false);
    } else if (window.detachEvent) {
      window.detachEvent('onmessage', getMessage);
    } else {
      if (document.detachEvent) {
        document.detachEvent('onmessage', getMessage);
      }
    }
    if (data.error) {
      reject(data.error);
    } else {
      resolve(data.data);
    }
  };

  if (window.attachEvent) {
    window.attachEvent('onmessage', getMessage);
  } else if (document.attachEvent) {
    document.attachEvent('onmessage', getMessage);
  } else {
    if (window.addEventListener) {
      window.addEventListener('message', getMessage, false);
    }
  }

  w = window.open(url, 'Authorization', wOptions);
  if (w) {
    w.focus();

    wTimeout = setTimeout(function() {
      reply = { error: new Error('Timeout') };
      try {
        w.close();
      } catch (_error) {}
    }, 5 * 60 * 1000);

    const closeChecker = setInterval(function() {
      let close = !w;
      try {
        if (w) {
          close = w.closed;
        }
      } catch (e) {}
      if (close) {
        clearInterval(closeChecker);
        callback(reply || { error: new Error('Window closed') });
      }
    }, 500);
  } else {
    callback({ error: new Error('Window blocked') });
  }
};

export default show;