mapbox.ts

import {transformToViewState, compareViewStateWithTransform} from '../utils/transform';
import {ProxyTransform, createProxyTransform} from './proxy-transform';
import {normalizeStyle} from '../utils/style-utils';
import {deepEqual} from '../utils/deep-equal';

import type {
  ViewState,
  Point,
  PointLike,
  PaddingOptions,
  ImmutableLike,
  LngLatBoundsLike,
  MapGeoJSONFeature
} from '../types/common';
import type {
  StyleSpecification,
  LightSpecification,
  TerrainSpecification,
  FogSpecification,
  ProjectionSpecification
} from '../types/style-spec';
import type {MapInstance} from '../types/lib';
import type {Transform} from '../types/internal';
import type {
  MapCallbacks,
  ViewStateChangeEvent,
  MapEvent,
  ErrorEvent,
  MapMouseEvent
} from '../types/events';

export type MapboxProps = Partial<ViewState> &
  MapCallbacks & {
    // Init options
    mapboxAccessToken?: string;

    /** Camera options used when constructing the Map instance */
    initialViewState?: Partial<ViewState> & {
      /** The initial bounds of the map. If bounds is specified, it overrides longitude, latitude and zoom options. */
      bounds?: LngLatBoundsLike;
      /** A fitBounds options object to use only when setting the bounds option. */
      fitBoundsOptions?: {
        offset?: PointLike;
        minZoom?: number;
        maxZoom?: number;
        padding?: number | PaddingOptions;
      };
    };

    /** If provided, render into an external WebGL context */
    gl?: WebGLRenderingContext;

    /** For external controller to override the camera state */
    viewState?: ViewState & {
      width: number;
      height: number;
    };

    // Styling

    /** Mapbox style */
    mapStyle?: string | StyleSpecification | ImmutableLike<StyleSpecification>;
    /** Enable diffing when the map style changes
     * @default true
     */
    styleDiffing?: boolean;
    /** The projection property of the style. Must conform to the Projection Style Specification.
     * @default 'mercator'
     */
    projection?: ProjectionSpecification | ProjectionSpecification['name'];
    /** The fog property of the style. Must conform to the Fog Style Specification .
     * If `undefined` is provided, removes the fog from the map. */
    fog?: FogSpecification;
    /** Light properties of the map. */
    light?: LightSpecification;
    /** Terrain property of the style. Must conform to the Terrain Style Specification .
     * If `undefined` is provided, removes terrain from the map. */
    terrain?: TerrainSpecification;

    /** Default layers to query on pointer events */
    interactiveLayerIds?: string[];
    /** CSS cursor */
    cursor?: string;
  };

const DEFAULT_STYLE = {version: 8, sources: {}, layers: []} as StyleSpecification;

const DEFAULT_SETTINGS = {
  minZoom: 0,
  maxZoom: 22,
  minPitch: 0,
  maxPitch: 85,
  maxBounds: [-180, -85.051129, 180, 85.051129],
  projection: 'mercator',
  renderWorldCopies: true
};

const pointerEvents = {
  mousedown: 'onMouseDown',
  mouseup: 'onMouseUp',
  mouseover: 'onMouseOver',
  mousemove: 'onMouseMove',
  click: 'onClick',
  dblclick: 'onDblClick',
  mouseenter: 'onMouseEnter',
  mouseleave: 'onMouseLeave',
  mouseout: 'onMouseOut',
  contextmenu: 'onContextMenu',
  touchstart: 'onTouchStart',
  touchend: 'onTouchEnd',
  touchmove: 'onTouchMove',
  touchcancel: 'onTouchCancel'
};
const cameraEvents = {
  movestart: 'onMoveStart',
  move: 'onMove',
  moveend: 'onMoveEnd',
  dragstart: 'onDragStart',
  drag: 'onDrag',
  dragend: 'onDragEnd',
  zoomstart: 'onZoomStart',
  zoom: 'onZoom',
  zoomend: 'onZoomEnd',
  rotatestart: 'onRotateStart',
  rotate: 'onRotate',
  rotateend: 'onRotateEnd',
  pitchstart: 'onPitchStart',
  pitch: 'onPitch',
  pitchend: 'onPitchEnd'
};
const otherEvents = {
  wheel: 'onWheel',
  boxzoomstart: 'onBoxZoomStart',
  boxzoomend: 'onBoxZoomEnd',
  boxzoomcancel: 'onBoxZoomCancel',
  resize: 'onResize',
  load: 'onLoad',
  render: 'onRender',
  idle: 'onIdle',
  remove: 'onRemove',
  data: 'onData',
  styledata: 'onStyleData',
  sourcedata: 'onSourceData',
  error: 'onError'
};
const settingNames = [
  'minZoom',
  'maxZoom',
  'minPitch',
  'maxPitch',
  'maxBounds',
  'projection',
  'renderWorldCopies'
];
const handlerNames = [
  'scrollZoom',
  'boxZoom',
  'dragRotate',
  'dragPan',
  'keyboard',
  'doubleClickZoom',
  'touchZoomRotate',
  'touchPitch'
];

/**
 * A wrapper for mapbox-gl's Map class
 */
export default class Mapbox {
  private _MapClass: {new (options: any): MapInstance};
  /** mapboxgl.Map instance */
  private _map: MapInstance = null;
  /** User-supplied props */
  props: MapboxProps;

  /** The transform that replaces native map.transform to resolve changes vs. React props
   * See proxy-transform.ts
   */
  private _proxyTransform: ProxyTransform;

  // Internal states
  /** Making updates driven by React props. Do not trigger React callbacks to avoid infinite loop */
  private _internalUpdate: boolean = false;
  /** Map is currently rendering */
  private _inRender: boolean = false;
  /** Map features under the pointer */
  private _hoveredFeatures: MapGeoJSONFeature[] = null;
  /** View state changes driven by React props
   * They still need to fire move/etc. events because controls such as marker/popup
   * subscribe to the move event internally to update their position
   * React callbacks like onMove are not called for these */
  private _deferredEvents: {
    move: boolean;
    zoom: boolean;
    pitch: boolean;
    rotate: boolean;
  } = {
    move: false,
    zoom: false,
    pitch: false,
    rotate: false
  };

  static savedMaps: Mapbox[] = [];

  constructor(
    MapClass: {new (options: any): MapInstance},
    props: MapboxProps,
    container: HTMLDivElement
  ) {
    this._MapClass = MapClass;
    this.props = props;
    this._initialize(container);
  }

  get map(): MapInstance {
    return this._map;
  }

  get transform(): Transform {
    return this._map.transform;
  }

  setProps(props: MapboxProps) {
    const oldProps = this.props;
    this.props = props;

    const settingsChanged = this._updateSettings(props, oldProps);
    if (settingsChanged) {
      this._createProxyTransform(this._map);
    }
    const sizeChanged = this._updateSize(props);
    const viewStateChanged = this._updateViewState(props, true);
    this._updateStyle(props, oldProps);
    this._updateStyleComponents(props, oldProps);
    this._updateHandlers(props, oldProps);

    // If 1) view state has changed to match props and
    //    2) the props change is not triggered by map events,
    // it's driven by an external state change. Redraw immediately
    if (settingsChanged || sizeChanged || (viewStateChanged && !this._map.isMoving())) {
      this.redraw();
    }
  }

  static reuse(props: MapboxProps, container: HTMLDivElement): Mapbox {
    const that = Mapbox.savedMaps.pop();
    if (!that) {
      return null;
    }

    const map = that.map;
    // When reusing the saved map, we need to reparent the map(canvas) and other child nodes
    // intoto the new container from the props.
    // Step 1: reparenting child nodes from old container to new container
    const oldContainer = map.getContainer();
    container.className = oldContainer.className;
    while (oldContainer.childNodes.length > 0) {
      container.appendChild(oldContainer.childNodes[0]);
    }
    // Step 2: replace the internal container with new container from the react component
    // @ts-ignore
    map._container = container;

    // Step 4: apply new props
    that.setProps({...props, styleDiffing: false});
    map.resize();
    const {initialViewState} = props;
    if (initialViewState) {
      if (initialViewState.bounds) {
        map.fitBounds(initialViewState.bounds, {...initialViewState.fitBoundsOptions, duration: 0});
      } else {
        that._updateViewState(initialViewState, false);
      }
    }

    // Simulate load event
    if (map.isStyleLoaded()) {
      map.fire('load');
    } else {
      map.once('styledata', () => map.fire('load'));
    }

    // Force reload
    // @ts-ignore
    map._update();
    return that;
  }

  /* eslint-disable complexity,max-statements */
  _initialize(container: HTMLDivElement) {
    const {props} = this;
    const {mapStyle = DEFAULT_STYLE} = props;
    const mapOptions = {
      ...props,
      ...props.initialViewState,
      accessToken: props.mapboxAccessToken || getAccessTokenFromEnv() || null,
      container,
      style: normalizeStyle(mapStyle)
    };

    const viewState = mapOptions.initialViewState || mapOptions.viewState || mapOptions;
    Object.assign(mapOptions, {
      center: [viewState.longitude || 0, viewState.latitude || 0],
      zoom: viewState.zoom || 0,
      pitch: viewState.pitch || 0,
      bearing: viewState.bearing || 0
    });

    if (props.gl) {
      // eslint-disable-next-line
      const getContext = HTMLCanvasElement.prototype.getContext;
      // Hijack canvas.getContext to return our own WebGLContext
      // This will be called inside the mapboxgl.Map constructor
      // @ts-expect-error
      HTMLCanvasElement.prototype.getContext = () => {
        // Unhijack immediately
        HTMLCanvasElement.prototype.getContext = getContext;
        return props.gl;
      };
    }

    const map = new this._MapClass(mapOptions);
    // Props that are not part of constructor options
    if (viewState.padding) {
      map.setPadding(viewState.padding);
    }
    if (props.cursor) {
      map.getCanvas().style.cursor = props.cursor;
    }
    this._createProxyTransform(map);

    // Hack
    // Insert code into map's render cycle
    // eslint-disable-next-line @typescript-eslint/unbound-method
    const renderMap = map._render;
    map._render = (arg: number) => {
      // Hijacked to set this state flag
      this._inRender = true;
      renderMap.call(map, arg);
      this._inRender = false;
    };
    // eslint-disable-next-line @typescript-eslint/unbound-method
    const runRenderTaskQueue = map._renderTaskQueue.run;
    map._renderTaskQueue.run = (arg: number) => {
      // This is where camera updates from input handler/animation happens
      // And where all view state change events are fired
      this._proxyTransform.$internalUpdate = true;
      runRenderTaskQueue.call(map._renderTaskQueue, arg);
      this._proxyTransform.$internalUpdate = false;
      this._fireDefferedEvents();
    };
    // eslint-disable-next-line @typescript-eslint/unbound-method
    const jumpTo = map.jumpTo;
    map.jumpTo = (...args: Parameters<MapInstance['jumpTo']>) => {
      // This method will fire view state change events immediately
      this._proxyTransform.$internalUpdate = true;
      jumpTo.apply(map, args);
      this._proxyTransform.$internalUpdate = false;
      return map;
    };
    // Insert code into map's event pipeline
    // eslint-disable-next-line @typescript-eslint/unbound-method
    const fireEvent = map.fire;
    map.fire = this._fireEvent.bind(this, fireEvent);

    // add listeners
    map.on('styledata', () => {
      this._updateStyleComponents(this.props, {});
    });
    map.on('sourcedata', () => {
      this._updateStyleComponents(this.props, {});
    });
    for (const eventName in pointerEvents) {
      map.on(eventName, this._onPointerEvent);
    }
    for (const eventName in cameraEvents) {
      map.on(eventName, this._onCameraEvent);
    }
    for (const eventName in otherEvents) {
      map.on(eventName, this._onEvent);
    }
    this._map = map;
  }
  /* eslint-enable complexity,max-statements */

  recycle() {
    // Clean up unnecessary elements before storing for reuse.
    const container = this.map.getContainer();
    const children = container.querySelector('[mapboxgl-children]');
    children?.remove();

    Mapbox.savedMaps.push(this);
  }

  destroy() {
    this._map.remove();
  }

  // Force redraw the map now. Typically resize() and jumpTo() is reflected in the next
  // render cycle, which is managed by Mapbox's animation loop.
  // This removes the synchronization issue caused by requestAnimationFrame.
  redraw() {
    const map = this._map as any;
    // map._render will throw error if style does not exist
    // https://github.com/mapbox/mapbox-gl-js/blob/fb9fc316da14e99ff4368f3e4faa3888fb43c513
    //   /src/ui/map.js#L1834
    if (!this._inRender && map.style) {
      // cancel the scheduled update
      if (map._frame) {
        map._frame.cancel();
        map._frame = null;
      }
      // the order is important - render() may schedule another update
      map._render();
    }
  }

  _createProxyTransform(map: any) {
    const proxyTransform = createProxyTransform(map.transform);
    map.transform = proxyTransform;
    map.painter.transform = proxyTransform;
    this._proxyTransform = proxyTransform;
  }

  /* Trigger map resize if size is controlled
     @param {object} nextProps
     @returns {bool} true if size has changed
   */
  _updateSize(nextProps: MapboxProps): boolean {
    // Check if size is controlled
    const {viewState} = nextProps;
    if (viewState) {
      const map = this._map;
      if (viewState.width !== map.transform.width || viewState.height !== map.transform.height) {
        map.resize();
        return true;
      }
    }
    return false;
  }

  // Adapted from map.jumpTo
  /* Update camera to match props
     @param {object} nextProps
     @param {bool} triggerEvents - should fire camera events
     @returns {bool} true if anything is changed
   */
  _updateViewState(nextProps: MapboxProps, triggerEvents: boolean): boolean {
    const viewState: Partial<ViewState> = nextProps.viewState || nextProps;
    const tr = this._proxyTransform;
    const {zoom, pitch, bearing} = tr;
    const changed = compareViewStateWithTransform(this._proxyTransform, viewState);
    tr.$reactViewState = viewState;

    if (changed && triggerEvents) {
      const deferredEvents = this._deferredEvents;
      // Delay DOM control updates to the next render cycle
      deferredEvents.move = true;
      deferredEvents.zoom ||= zoom !== tr.zoom;
      deferredEvents.rotate ||= bearing !== tr.bearing;
      deferredEvents.pitch ||= pitch !== tr.pitch;
    }

    return changed;
  }

  /* Update camera constraints and projection settings to match props
     @param {object} nextProps
     @param {object} currProps
     @returns {bool} true if anything is changed
   */
  _updateSettings(nextProps: MapboxProps, currProps: MapboxProps): boolean {
    const map = this._map;
    let changed = false;
    for (const propName of settingNames) {
      const propPresent = propName in nextProps || propName in currProps;

      if (propPresent && !deepEqual(nextProps[propName], currProps[propName])) {
        changed = true;
        const nextValue = propName in nextProps ? nextProps[propName] : DEFAULT_SETTINGS[propName];
        const setter = map[`set${propName[0].toUpperCase()}${propName.slice(1)}`];
        setter?.call(map, nextValue);
      }
    }
    return changed;
  }

  /* Update map style to match props
     @param {object} nextProps
     @param {object} currProps
     @returns {bool} true if style is changed
   */
  _updateStyle(nextProps: MapboxProps, currProps: MapboxProps): boolean {
    if (nextProps.cursor !== currProps.cursor) {
      this._map.getCanvas().style.cursor = nextProps.cursor || '';
    }
    if (nextProps.mapStyle !== currProps.mapStyle) {
      const {mapStyle = DEFAULT_STYLE, styleDiffing = true} = nextProps;
      const options: any = {
        diff: styleDiffing
      };
      if ('localIdeographFontFamily' in nextProps) {
        // @ts-ignore Mapbox specific prop
        options.localIdeographFontFamily = nextProps.localIdeographFontFamily;
      }
      this._map.setStyle(normalizeStyle(mapStyle), options);
      return true;
    }
    return false;
  }

  /* Update fog, light and terrain to match props
     @param {object} nextProps
     @param {object} currProps
     @returns {bool} true if anything is changed
   */
  _updateStyleComponents(nextProps: MapboxProps, currProps: MapboxProps): boolean {
    const map = this._map;
    let changed = false;
    if (map.isStyleLoaded()) {
      if ('light' in nextProps && map.setLight && !deepEqual(nextProps.light, currProps.light)) {
        changed = true;
        map.setLight(nextProps.light);
      }
      if ('fog' in nextProps && map.setFog && !deepEqual(nextProps.fog, currProps.fog)) {
        changed = true;
        map.setFog(nextProps.fog);
      }
      if (
        'terrain' in nextProps &&
        map.setTerrain &&
        !deepEqual(nextProps.terrain, currProps.terrain)
      ) {
        if (!nextProps.terrain || map.getSource(nextProps.terrain.source)) {
          changed = true;
          map.setTerrain(nextProps.terrain);
        }
      }
    }
    return changed;
  }

  /* Update interaction handlers to match props
     @param {object} nextProps
     @param {object} currProps
     @returns {bool} true if anything is changed
   */
  _updateHandlers(nextProps: MapboxProps, currProps: MapboxProps): boolean {
    const map = this._map;
    let changed = false;
    for (const propName of handlerNames) {
      const newValue = nextProps[propName] ?? true;
      const oldValue = currProps[propName] ?? true;
      if (!deepEqual(newValue, oldValue)) {
        changed = true;
        if (newValue) {
          map[propName].enable(newValue);
        } else {
          map[propName].disable();
        }
      }
    }
    return changed;
  }

  _onEvent = (e: MapEvent) => {
    // @ts-ignore
    const cb = this.props[otherEvents[e.type]];
    if (cb) {
      cb(e);
    } else if (e.type === 'error') {
      console.error((e as ErrorEvent).error); // eslint-disable-line
    }
  };

  private _queryRenderedFeatures(point: Point) {
    const map = this._map;
    const {interactiveLayerIds = []} = this.props;
    try {
      return map.queryRenderedFeatures(point, {
        layers: interactiveLayerIds.filter(map.getLayer.bind(map))
      });
    } catch {
      // May fail if style is not loaded
      return [];
    }
  }

  _updateHover(e: MapMouseEvent) {
    const {props} = this;
    const shouldTrackHoveredFeatures =
      props.interactiveLayerIds && (props.onMouseMove || props.onMouseEnter || props.onMouseLeave);

    if (shouldTrackHoveredFeatures) {
      const eventType = e.type;
      const wasHovering = this._hoveredFeatures?.length > 0;
      const features = this._queryRenderedFeatures(e.point);
      const isHovering = features.length > 0;

      if (!isHovering && wasHovering) {
        e.type = 'mouseleave';
        this._onPointerEvent(e);
      }
      this._hoveredFeatures = features;
      if (isHovering && !wasHovering) {
        e.type = 'mouseenter';
        this._onPointerEvent(e);
      }
      e.type = eventType;
    } else {
      this._hoveredFeatures = null;
    }
  }

  _onPointerEvent = (e: MapMouseEvent) => {
    if (e.type === 'mousemove' || e.type === 'mouseout') {
      this._updateHover(e);
    }

    // @ts-ignore
    const cb = this.props[pointerEvents[e.type]];
    if (cb) {
      if (this.props.interactiveLayerIds && e.type !== 'mouseover' && e.type !== 'mouseout') {
        e.features = this._hoveredFeatures || this._queryRenderedFeatures(e.point);
      }
      cb(e);
      delete e.features;
    }
  };

  _onCameraEvent = (e: ViewStateChangeEvent) => {
    if (!this._internalUpdate) {
      // @ts-ignore
      const cb = this.props[cameraEvents[e.type]];
      const tr = this._proxyTransform;
      if (cb) {
        e.viewState = transformToViewState(tr.$proposedTransform ?? tr);
        cb(e);
      }
      if (e.type === 'moveend') {
        tr.$proposedTransform = null;
      }
    }
    if (e.type in this._deferredEvents) {
      this._deferredEvents[e.type] = false;
    }
  };

  _fireEvent(baseFire: Function, event: string | MapEvent, properties?: object) {
    const map = this._map;
    const tr = this._proxyTransform;

    // Always expose the controlled transform to controls/end user
    const internal = tr.$internalUpdate;
    try {
      tr.$internalUpdate = false;
      baseFire.call(map, event, properties);
    } finally {
      tr.$internalUpdate = internal;
    }

    return map;
  }

  // If there are camera changes driven by props, invoke camera events so that DOM controls are synced
  _fireDefferedEvents() {
    const map = this._map;
    this._internalUpdate = true;
    for (const eventType in this._deferredEvents) {
      if (this._deferredEvents[eventType]) {
        map.fire(eventType);
      }
    }
    this._internalUpdate = false;
  }
}

/**
 * Access token can be provided via one of:
 *   mapboxAccessToken prop
 *   access_token query parameter
 *   MapboxAccessToken environment variable
 *   REACT_APP_MAPBOX_ACCESS_TOKEN environment variable
 * @returns access token
 */
function getAccessTokenFromEnv(): string {
  let accessToken = null;

  /* global location, process */
  if (typeof location !== 'undefined') {
    const match = /access_token=([^&\/]*)/.exec(location.search);
    accessToken = match && match[1];
  }

  // Note: This depends on bundler plugins (e.g. webpack) importing environment correctly
  try {
    // eslint-disable-next-line no-process-env
    accessToken = accessToken || process.env.MapboxAccessToken;
  } catch {
    // ignore
  }

  try {
    // eslint-disable-next-line no-process-env
    accessToken = accessToken || process.env.REACT_APP_MAPBOX_ACCESS_TOKEN;
  } catch {
    // ignore
  }

  return accessToken;
}