ant-design-vue/components/_util/hooks/useBreakpoint.ts

import { onMounted, onUnmounted, Ref, ref } from 'vue';
import ResponsiveObserve, { ScreenMap } from '../../_util/responsiveObserve';

function useBreakpoint(): Ref<ScreenMap> {
  const screens = ref<ScreenMap>({});
  let token = null;

  onMounted(() => {
    token = ResponsiveObserve.subscribe(supportScreens => {
      screens.value = supportScreens;
    });
  });

  onUnmounted(() => {
    ResponsiveObserve.unsubscribe(token);
  });

  return screens;
}

export default useBreakpoint;