react/packages/react-devtools-shared/src/devtools/views/Components/Components.js

/**
 * Copyright (c) Facebook, Inc. and its affiliates.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 *
 * @flow
 */

import * as React from 'react';
import {
  Fragment,
  Suspense,
  useEffect,
  useLayoutEffect,
  useReducer,
  useRef,
} from 'react';
import Tree from './Tree';
import {InspectedElementContextController} from './InspectedElementContext';
import {OwnersListContextController} from './OwnersListContext';
import portaledContent from '../portaledContent';
import {SettingsModalContextController} from 'react-devtools-shared/src/devtools/views/Settings/SettingsModalContext';
import {
  localStorageGetItem,
  localStorageSetItem,
} from 'react-devtools-shared/src/storage';
import SelectedElement from './SelectedElement';
import {ModalDialog} from '../ModalDialog';
import SettingsModal from 'react-devtools-shared/src/devtools/views/Settings/SettingsModal';
import {NativeStyleContextController} from './NativeStyleEditor/context';

import styles from './Components.css';

type Orientation = 'horizontal' | 'vertical';

type ResizeActionType =
  | 'ACTION_SET_DID_MOUNT'
  | 'ACTION_SET_IS_RESIZING'
  | 'ACTION_SET_HORIZONTAL_PERCENTAGE'
  | 'ACTION_SET_VERTICAL_PERCENTAGE';

type ResizeAction = {|
  type: ResizeActionType,
  payload: any,
|};

type ResizeState = {|
  horizontalPercentage: number,
  isResizing: boolean,
  verticalPercentage: number,
|};

function Components(_: {||}) {
  const wrapperElementRef = useRef<null | HTMLElement>(null);
  const resizeElementRef = useRef<null | HTMLElement>(null);

  const [state, dispatch] = useReducer<ResizeState, any, ResizeAction>(
    resizeReducer,
    null,
    initResizeState,
  );

  const {horizontalPercentage, verticalPercentage} = state;

  useLayoutEffect(() => {
    const resizeElement = resizeElementRef.current;

    setResizeCSSVariable(
      resizeElement,
      'horizontal',
      horizontalPercentage * 100,
    );
    setResizeCSSVariable(resizeElement, 'vertical', verticalPercentage * 100);
  }, []);

  useEffect(() => {
    const timeoutID = setTimeout(() => {
      localStorageSetItem(
        LOCAL_STORAGE_KEY,
        JSON.stringify({
          horizontalPercentage,
          verticalPercentage,
        }),
      );
    }, 500);

    return () => clearTimeout(timeoutID);
  }, [horizontalPercentage, verticalPercentage]);

  const {isResizing} = state;

  const onResizeStart = () =>
    dispatch({type: 'ACTION_SET_IS_RESIZING', payload: true});

  let onResize;
  let onResizeEnd;
  if (isResizing) {
    onResizeEnd = () =>
      dispatch({type: 'ACTION_SET_IS_RESIZING', payload: false});

    onResize = event => {
      const resizeElement = resizeElementRef.current;
      const wrapperElement = wrapperElementRef.current;

      if (!isResizing || wrapperElement === null || resizeElement === null) {
        return;
      }

      event.preventDefault();

      const orientation = getOrientation(wrapperElement);

      const {height, width, left, top} = wrapperElement.getBoundingClientRect();

      const currentMousePosition =
        orientation === 'horizontal'
          ? event.clientX - left
          : event.clientY - top;

      const boundaryMin = MINIMUM_SIZE;
      const boundaryMax =
        orientation === 'horizontal'
          ? width - MINIMUM_SIZE
          : height - MINIMUM_SIZE;

      const isMousePositionInBounds =
        currentMousePosition > boundaryMin &&
        currentMousePosition < boundaryMax;

      if (isMousePositionInBounds) {
        const resizedElementDimension =
          orientation === 'horizontal' ? width : height;
        const actionType =
          orientation === 'horizontal'
            ? 'ACTION_SET_HORIZONTAL_PERCENTAGE'
            : 'ACTION_SET_VERTICAL_PERCENTAGE';
        const percentage =
          (currentMousePosition / resizedElementDimension) * 100;

        setResizeCSSVariable(resizeElement, orientation, percentage);

        dispatch({
          type: actionType,
          payload: currentMousePosition / resizedElementDimension,
        });
      }
    };
  }

  return (
    <SettingsModalContextController>
      <OwnersListContextController>
        <InspectedElementContextController>
          <div
            ref={wrapperElementRef}
            className={styles.Components}
            onMouseMove={onResize}
            onMouseLeave={onResizeEnd}
            onMouseUp={onResizeEnd}>
            <Fragment>
              <div ref={resizeElementRef} className={styles.TreeWrapper}>
                <Tree />
              </div>
              <div className={styles.ResizeBarWrapper}>
                <div onMouseDown={onResizeStart} className={styles.ResizeBar} />
              </div>
              <div className={styles.SelectedElementWrapper}>
                <NativeStyleContextController>
                  <Suspense fallback={<Loading />}>
                    <SelectedElement />
                  </Suspense>
                </NativeStyleContextController>
              </div>
              <ModalDialog />
              <SettingsModal />
            </Fragment>
          </div>
        </InspectedElementContextController>
      </OwnersListContextController>
    </SettingsModalContextController>
  );
}

function Loading() {
  return <div className={styles.Loading}>Loading...</div>;
}

const LOCAL_STORAGE_KEY = 'React::DevTools::createResizeReducer';
const VERTICAL_MODE_MAX_WIDTH = 600;
const MINIMUM_SIZE = 50;

function initResizeState(): ResizeState {
  let horizontalPercentage = 0.65;
  let verticalPercentage = 0.5;

  try {
    let data = localStorageGetItem(LOCAL_STORAGE_KEY);
    if (data != null) {
      data = JSON.parse(data);
      horizontalPercentage = data.horizontalPercentage;
      verticalPercentage = data.verticalPercentage;
    }
  } catch (error) {}

  return {
    horizontalPercentage,
    isResizing: false,
    verticalPercentage,
  };
}

function resizeReducer(state: ResizeState, action: ResizeAction): ResizeState {
  switch (action.type) {
    case 'ACTION_SET_IS_RESIZING':
      return {
        ...state,
        isResizing: action.payload,
      };
    case 'ACTION_SET_HORIZONTAL_PERCENTAGE':
      return {
        ...state,
        horizontalPercentage: action.payload,
      };
    case 'ACTION_SET_VERTICAL_PERCENTAGE':
      return {
        ...state,
        verticalPercentage: action.payload,
      };
    default:
      return state;
  }
}

function getOrientation(
  wrapperElement: null | HTMLElement,
): null | Orientation {
  if (wrapperElement != null) {
    const {width} = wrapperElement.getBoundingClientRect();
    return width > VERTICAL_MODE_MAX_WIDTH ? 'horizontal' : 'vertical';
  }
  return null;
}

function setResizeCSSVariable(
  resizeElement: null | HTMLElement,
  orientation: null | Orientation,
  percentage: number,
): void {
  if (resizeElement !== null && orientation !== null) {
    resizeElement.style.setProperty(
      `--${orientation}-resize-percentage`,
      `${percentage}%`,
    );
  }
}

export default portaledContent(Components);