PromucFlow_constructor/app/client/src/widgets/useDropdown.tsx

import React, { useCallback, useRef } from "react";
import { getMainCanvas } from "./WidgetUtils";
import styled from "styled-components";
import Select from "rc-select";
import { LabelValueType } from "rc-select/lib/interface/generator";
import { RenderMode, RenderModes } from "constants/WidgetConstants";

const BackDropContainer = styled.div`
  position: fixed;
  width: 100vw;
  height: 100vh;
  background: transparent;
  top: 0;
  left: 0;
`;

type useDropdownProps = {
  selectRef: React.MutableRefObject<Select<LabelValueType[]> | null>;
  inputRef: React.RefObject<HTMLInputElement>;
  renderMode?: RenderMode;
};
const FOCUS_TIMEOUT = 500;

// TODO: Refactor More functionalities in MultiSelect, MultiTreeSelect and TreeSelect Components
const useDropdown = ({ inputRef, renderMode, selectRef }: useDropdownProps) => {
  const popupContainer = useRef<HTMLElement>(getMainCanvas());

  const closeBackDrop = useCallback(() => {
    if (selectRef.current) {
      selectRef.current.blur();
    }
  }, []);

  // Avoid scrolls when Popup is opened
  function BackDrop() {
    return <BackDropContainer onClick={closeBackDrop} />;
  }
  // Get PopupContainer on main Canvas
  const getPopupContainer = useCallback(() => popupContainer.current, []);

  // When Dropdown is opened disable scrolling within the app except the list of options
  const onOpen = useCallback((open: boolean) => {
    if (open) {
      setTimeout(() => inputRef.current?.focus(), FOCUS_TIMEOUT);
      if (popupContainer.current && renderMode === RenderModes.CANVAS) {
        popupContainer.current.style.overflowY = "hidden";
      }
    } else {
      if (popupContainer.current && renderMode === RenderModes.CANVAS) {
        popupContainer.current.style.overflowY = "auto";
      }
    }
  }, []);

  return {
    BackDrop,
    getPopupContainer,
    onOpen,
  };
};

export default useDropdown;