Modal.js

import React from 'react';
import ReactDOM from 'react-dom';
import PropTypes from 'prop-types';
import { getThemeProps, useTheme } from '@material-ui/styles';
import { elementAcceptingRef } from '@material-ui/utils';
import ownerDocument from '../utils/ownerDocument';
import Portal from '../Portal';
import createChainedFunction from '../utils/createChainedFunction';
import useForkRef from '../utils/useForkRef';
import useEventCallback from '../utils/useEventCallback';
import zIndex from '../styles/zIndex';
import ModalManager, { ariaHidden } from './ModalManager';
import TrapFocus from './TrapFocus';
import SimpleBackdrop from './SimpleBackdrop';

function getContainer(container) {
  container = typeof container === 'function' ? container() : container;
  return ReactDOM.findDOMNode(container);
}

function getHasTransition(props) {
  return props.children ? props.children.props.hasOwnProperty('in') : false;
}

// A modal manager used to track and manage the state of open Modals.
// Modals don't open on the server so this won't conflict with concurrent requests.
const defaultManager = new ModalManager();

export const styles = theme => ({
  /* Styles applied to the root element. */
  root: {
    position: 'fixed',
    zIndex: theme.zIndex.modal,
    right: 0,
    bottom: 0,
    top: 0,
    left: 0,
  },
  /* Styles applied to the root element if the `Modal` has exited. */
  hidden: {
    visibility: 'hidden',
  },
});

/**
 * Modal is a lower-level construct that is leveraged by the following components:
 *
 * - [Dialog](/api/dialog/)
 * - [Drawer](/api/drawer/)
 * - [Menu](/api/menu/)
 * - [Popover](/api/popover/)
 *
 * If you are creating a modal dialog, you probably want to use the [Dialog](/api/dialog/) component
 * rather than directly using Modal.
 *
 * This component shares many concepts with [react-overlays](https://react-bootstrap.github.io/react-overlays/#modals).
 */
const Modal = React.forwardRef(function Modal(inProps, ref) {
  const theme = useTheme();
  const props = getThemeProps({ name: 'MuiModal', props: { ...inProps }, theme });
  const {
    BackdropComponent = SimpleBackdrop,
    BackdropProps,
    children,
    closeAfterTransition = false,
    container,
    disableAutoFocus = false,
    disableBackdropClick = false,
    disableEnforceFocus = false,
    disableEscapeKeyDown = false,
    disablePortal = false,
    disableRestoreFocus = false,
    disableScrollLock = false,
    hideBackdrop = false,
    keepMounted = false,
    manager = defaultManager,
    onBackdropClick,
    onClose,
    onEscapeKeyDown,
    onRendered,
    open,
    ...other
  } = props;

  const [exited, setExited] = React.useState(true);
  const modal = React.useRef({});
  const mountNodeRef = React.useRef(null);
  const modalRef = React.useRef(null);
  const handleRef = useForkRef(modalRef, ref);
  const hasTransition = getHasTransition(props);

  const getDoc = () => ownerDocument(mountNodeRef.current);
  const getModal = () => {
    modal.current.modalRef = modalRef.current;
    modal.current.mountNode = mountNodeRef.current;
    return modal.current;
  };

  const handleMounted = () => {
    manager.mount(getModal(), { disableScrollLock });

    // Fix a bug on Chrome where the scroll isn't initially 0.
    modalRef.current.scrollTop = 0;
  };

  const handleOpen = useEventCallback(() => {
    const resolvedContainer = getContainer(container) || getDoc().body;

    manager.add(getModal(), resolvedContainer);

    // The element was already mounted.
    if (modalRef.current) {
      handleMounted();
    }
  });

  const isTopModal = React.useCallback(() => manager.isTopModal(getModal()), [manager]);

  const handlePortalRef = useEventCallback(node => {
    mountNodeRef.current = node;

    if (!node) {
      return;
    }

    if (onRendered) {
      onRendered();
    }

    if (open && isTopModal()) {
      handleMounted();
    } else {
      ariaHidden(modalRef.current, true);
    }
  });

  const handleClose = React.useCallback(() => {
    manager.remove(getModal());
  }, [manager]);

  React.useEffect(() => {
    return () => {
      handleClose();
    };
  }, [handleClose]);

  React.useEffect(() => {
    if (open) {
      handleOpen();
    } else if (!hasTransition || !closeAfterTransition) {
      handleClose();
    }
  }, [open, handleClose, hasTransition, closeAfterTransition, handleOpen]);

  if (!keepMounted && !open && (!hasTransition || exited)) {
    return null;
  }

  const handleEnter = () => {
    setExited(false);
  };

  const handleExited = () => {
    setExited(true);

    if (closeAfterTransition) {
      handleClose();
    }
  };

  const handleBackdropClick = event => {
    if (event.target !== event.currentTarget) {
      return;
    }

    if (onBackdropClick) {
      onBackdropClick(event);
    }

    if (!disableBackdropClick && onClose) {
      onClose(event, 'backdropClick');
    }
  };

  const handleKeyDown = event => {
    // The handler doesn't take event.defaultPrevented into account:
    //
    // event.preventDefault() is meant to stop default behaviours like
    // clicking a checkbox to check it, hitting a button to submit a form,
    // and hitting left arrow to move the cursor in a text input etc.
    // Only special HTML elements have these default behaviors.
    if (event.key !== 'Escape' || !isTopModal()) {
      return;
    }

    // Swallow the event, in case someone is listening for the escape key on the body.
    event.stopPropagation();

    if (onEscapeKeyDown) {
      onEscapeKeyDown(event);
    }

    if (!disableEscapeKeyDown && onClose) {
      onClose(event, 'escapeKeyDown');
    }
  };

  const inlineStyle = styles(theme || { zIndex });
  const childProps = {};
  if (children.props.tabIndex === undefined) {
    childProps.tabIndex = children.props.tabIndex || '-1';
  }

  // It's a Transition like component
  if (hasTransition) {
    childProps.onEnter = createChainedFunction(handleEnter, children.props.onEnter);
    childProps.onExited = createChainedFunction(handleExited, children.props.onExited);
  }

  return (
    <Portal ref={handlePortalRef} container={container} disablePortal={disablePortal}>
      {/*
          Marking an element with the role presentation indicates to assistive technology
          that this element should be ignored; it exists to support the web application and
          is not meant for humans to interact with directly.
          https://github.com/evcohen/eslint-plugin-jsx-a11y/blob/master/docs/rules/no-static-element-interactions.md
        */}
      <div
        data-mui-test="Modal"
        ref={handleRef}
        onKeyDown={handleKeyDown}
        role="presentation"
        {...other}
        style={{
          ...inlineStyle.root,
          ...(!open && exited ? inlineStyle.hidden : {}),
          ...other.style,
        }}
      >
        {hideBackdrop ? null : (
          <BackdropComponent open={open} onClick={handleBackdropClick} {...BackdropProps} />
        )}
        <TrapFocus
          disableEnforceFocus={disableEnforceFocus}
          disableAutoFocus={disableAutoFocus}
          disableRestoreFocus={disableRestoreFocus}
          getDoc={getDoc}
          isEnabled={isTopModal}
          open={open}
        >
          {React.cloneElement(children, childProps)}
        </TrapFocus>
      </div>
    </Portal>
  );
});

Modal.propTypes = {
  /**
   * A backdrop component. This prop enables custom backdrop rendering.
   */
  BackdropComponent: PropTypes.elementType,
  /**
   * Props applied to the [`Backdrop`](/api/backdrop/) element.
   */
  BackdropProps: PropTypes.object,
  /**
   * A single child content element.
   */
  children: elementAcceptingRef.isRequired,
  /**
   * When set to true the Modal waits until a nested Transition is completed before closing.
   */
  closeAfterTransition: PropTypes.bool,
  /**
   * A node, component instance, or function that returns either.
   * The `container` will have the portal children appended to it.
   */
  container: PropTypes.oneOfType([PropTypes.object, PropTypes.func]),
  /**
   * If `true`, the modal will not automatically shift focus to itself when it opens, and
   * replace it to the last focused element when it closes.
   * This also works correctly with any modal children that have the `disableAutoFocus` prop.
   *
   * Generally this should never be set to `true` as it makes the modal less
   * accessible to assistive technologies, like screen readers.
   */
  disableAutoFocus: PropTypes.bool,
  /**
   * If `true`, clicking the backdrop will not fire any callback.
   */
  disableBackdropClick: PropTypes.bool,
  /**
   * If `true`, the modal will not prevent focus from leaving the modal while open.
   *
   * Generally this should never be set to `true` as it makes the modal less
   * accessible to assistive technologies, like screen readers.
   */
  disableEnforceFocus: PropTypes.bool,
  /**
   * If `true`, hitting escape will not fire any callback.
   */
  disableEscapeKeyDown: PropTypes.bool,
  /**
   * Disable the portal behavior.
   * The children stay within it's parent DOM hierarchy.
   */
  disablePortal: PropTypes.bool,
  /**
   * If `true`, the modal will not restore focus to previously focused element once
   * modal is hidden.
   */
  disableRestoreFocus: PropTypes.bool,
  /**
   * Disable the scroll lock behavior.
   */
  disableScrollLock: PropTypes.bool,
  /**
   * If `true`, the backdrop is not rendered.
   */
  hideBackdrop: PropTypes.bool,
  /**
   * Always keep the children in the DOM.
   * This prop can be useful in SEO situation or
   * when you want to maximize the responsiveness of the Modal.
   */
  keepMounted: PropTypes.bool,
  /**
   * @ignore
   */
  manager: PropTypes.object,
  /**
   * Callback fired when the backdrop is clicked.
   */
  onBackdropClick: PropTypes.func,
  /**
   * Callback fired when the component requests to be closed.
   * The `reason` parameter can optionally be used to control the response to `onClose`.
   *
   * @param {object} event The event source of the callback.
   * @param {string} reason Can be: `"escapeKeyDown"`, `"backdropClick"`.
   */
  onClose: PropTypes.func,
  /**
   * Callback fired when the escape key is pressed,
   * `disableEscapeKeyDown` is false and the modal is in focus.
   */
  onEscapeKeyDown: PropTypes.func,
  /**
   * Callback fired once the children has been mounted into the `container`.
   * It signals that the `open={true}` prop took effect.
   *
   * This prop will be deprecated and removed in v5, the ref can be used instead.
   */
  onRendered: PropTypes.func,
  /**
   * If `true`, the modal is open.
   */
  open: PropTypes.bool.isRequired,
};

export default Modal;