@material-ui/core/es/Modal/ModalManager.js

import getScrollbarSize from '../utils/getScrollbarSize';
import ownerDocument from '../utils/ownerDocument';
import ownerWindow from '../utils/ownerWindow'; // Is a vertical scrollbar displayed?

function isOverflowing(container) {
  const doc = ownerDocument(container);

  if (doc.body === container) {
    return ownerWindow(doc).innerWidth > doc.documentElement.clientWidth;
  }

  return container.scrollHeight > container.clientHeight;
}

export function ariaHidden(node, show) {
  if (show) {
    node.setAttribute('aria-hidden', 'true');
  } else {
    node.removeAttribute('aria-hidden');
  }
}

function getPaddingRight(node) {
  return parseInt(window.getComputedStyle(node)['padding-right'], 10) || 0;
}

function ariaHiddenSiblings(container, mountNode, currentNode, nodesToExclude = [], show) {
  const blacklist = [mountNode, currentNode, ...nodesToExclude];
  const blacklistTagNames = ['TEMPLATE', 'SCRIPT', 'STYLE'];
  [].forEach.call(container.children, node => {
    if (node.nodeType === 1 && blacklist.indexOf(node) === -1 && blacklistTagNames.indexOf(node.tagName) === -1) {
      ariaHidden(node, show);
    }
  });
}

function findIndexOf(containerInfo, callback) {
  let idx = -1;
  containerInfo.some((item, index) => {
    if (callback(item)) {
      idx = index;
      return true;
    }

    return false;
  });
  return idx;
}

function handleContainer(containerInfo, props) {
  const restoreStyle = [];
  const restorePaddings = [];
  const container = containerInfo.container;
  let fixedNodes;

  if (!props.disableScrollLock) {
    if (isOverflowing(container)) {
      // Compute the size before applying overflow hidden to avoid any scroll jumps.
      const scrollbarSize = getScrollbarSize();
      restoreStyle.push({
        value: container.style.paddingRight,
        key: 'padding-right',
        el: container
      }); // Use computed style, here to get the real padding to add our scrollbar width.

      container.style['padding-right'] = `${getPaddingRight(container) + scrollbarSize}px`; // .mui-fixed is a global helper.

      fixedNodes = ownerDocument(container).querySelectorAll('.mui-fixed');
      [].forEach.call(fixedNodes, node => {
        restorePaddings.push(node.style.paddingRight);
        node.style.paddingRight = `${getPaddingRight(node) + scrollbarSize}px`;
      });
    } // Improve Gatsby support
    // https://css-tricks.com/snippets/css/force-vertical-scrollbar/


    const parent = container.parentElement;
    const scrollContainer = parent.nodeName === 'HTML' && window.getComputedStyle(parent)['overflow-y'] === 'scroll' ? parent : container; // Block the scroll even if no scrollbar is visible to account for mobile keyboard
    // screensize shrink.

    restoreStyle.push({
      value: scrollContainer.style.overflow,
      key: 'overflow',
      el: scrollContainer
    });
    scrollContainer.style.overflow = 'hidden';
  }

  const restore = () => {
    if (fixedNodes) {
      [].forEach.call(fixedNodes, (node, i) => {
        if (restorePaddings[i]) {
          node.style.paddingRight = restorePaddings[i];
        } else {
          node.style.removeProperty('padding-right');
        }
      });
    }

    restoreStyle.forEach(({
      value,
      el,
      key
    }) => {
      if (value) {
        el.style.setProperty(key, value);
      } else {
        el.style.removeProperty(key);
      }
    });
  };

  return restore;
}

function getHiddenSiblings(container) {
  const hiddenSiblings = [];
  [].forEach.call(container.children, node => {
    if (node.getAttribute && node.getAttribute('aria-hidden') === 'true') {
      hiddenSiblings.push(node);
    }
  });
  return hiddenSiblings;
}
/**
 * @ignore - do not document.
 *
 * Proper state management for containers and the modals in those containers.
 * Simplified, but inspired by react-overlay's ModalManager class.
 * Used by the Modal to ensure proper styling of containers.
 */


export default class ModalManager {
  constructor() {
    // this.modals[modalIndex] = modal
    this.modals = []; // this.containers[containerIndex] = {
    //   modals: [],
    //   container,
    //   restore: null,
    // }

    this.containers = [];
  }

  add(modal, container) {
    let modalIndex = this.modals.indexOf(modal);

    if (modalIndex !== -1) {
      return modalIndex;
    }

    modalIndex = this.modals.length;
    this.modals.push(modal); // If the modal we are adding is already in the DOM.

    if (modal.modalRef) {
      ariaHidden(modal.modalRef, false);
    }

    const hiddenSiblingNodes = getHiddenSiblings(container);
    ariaHiddenSiblings(container, modal.mountNode, modal.modalRef, hiddenSiblingNodes, true);
    const containerIndex = findIndexOf(this.containers, item => item.container === container);

    if (containerIndex !== -1) {
      this.containers[containerIndex].modals.push(modal);
      return modalIndex;
    }

    this.containers.push({
      modals: [modal],
      container,
      restore: null,
      hiddenSiblingNodes
    });
    return modalIndex;
  }

  mount(modal, props) {
    const containerIndex = findIndexOf(this.containers, item => item.modals.indexOf(modal) !== -1);
    const containerInfo = this.containers[containerIndex];

    if (!containerInfo.restore) {
      containerInfo.restore = handleContainer(containerInfo, props);
    }
  }

  remove(modal) {
    const modalIndex = this.modals.indexOf(modal);

    if (modalIndex === -1) {
      return modalIndex;
    }

    const containerIndex = findIndexOf(this.containers, item => item.modals.indexOf(modal) !== -1);
    const containerInfo = this.containers[containerIndex];
    containerInfo.modals.splice(containerInfo.modals.indexOf(modal), 1);
    this.modals.splice(modalIndex, 1); // If that was the last modal in a container, clean up the container.

    if (containerInfo.modals.length === 0) {
      // The modal might be closed before it had the chance to be mounted in the DOM.
      if (containerInfo.restore) {
        containerInfo.restore();
      }

      if (modal.modalRef) {
        // In case the modal wasn't in the DOM yet.
        ariaHidden(modal.modalRef, true);
      }

      ariaHiddenSiblings(containerInfo.container, modal.mountNode, modal.modalRef, containerInfo.hiddenSiblingNodes, false);
      this.containers.splice(containerIndex, 1);
    } else {
      // Otherwise make sure the next top modal is visible to a screen reader.
      const nextTop = containerInfo.modals[containerInfo.modals.length - 1]; // as soon as a modal is adding its modalRef is undefined. it can't set
      // aria-hidden because the dom element doesn't exist either
      // when modal was unmounted before modalRef gets null

      if (nextTop.modalRef) {
        ariaHidden(nextTop.modalRef, false);
      }
    }

    return modalIndex;
  }

  isTopModal(modal) {
    return this.modals.length > 0 && this.modals[this.modals.length - 1] === modal;
  }

}