React Map GL Draw

react-map-gl-draw is a react based drawing library tailored for react-map-gl.

Options

• mode (Object, Optional) - A mode instance. default to null.

Support the following modes from @nebula.gl/edit-modes. Note: Currently react-map-gl-draw does not support modeConfig in @nebula.gl/edit-modes.

• DrawCircleByDiameterMode: Lets you draw a GeoJson Circle feature.
• DrawCircleFromCenterMode: Lets you draw a GeoJson Circle feature.
• DrawPointMode: Lets you draw a GeoJson Point feature.
• DrawLineStringMode: Lets you draw a GeoJson LineString feature.
• DrawPolygonMode: Lets you draw a GeoJson Polygon feature.
• DrawRectangleMode: Lets you draw a Rectangle (represented as GeoJson Polygon feature) with two clicks - start drawing on first click, and finish drawing on second click.
  • If you'd like to starting drawing by mouse down and end drawing by mouse up, you can use modeConfig: {dragToDraw: true}. See modeConfig for more details.
• MeasureDistanceMode: Lets you measure distance over multiple points.
• MeasureAreaMode: Lets you measure the area of a polygon.
• MeasureAngleMode: Lets you measure an angle.

And an advanced

• EditingMode: Lets you select and drag vertices; and drag features.

• modeConfig (Object, Optional) - Additional configuration for the provided mode. Check nebula.gl doc to see mode details.

• features (Feature[], Optional) - List of features in GeoJson format. If features are provided from users, then react-map-gl-draw respect the users' input, and therefore ignore any internal features. But if features are not provided, then react-map-gl-draw manages features internally, and users can access and manipulate the features by calling getFeatures, addFeatures, and deleteFeatures.

• selectedFeatureIndex (String, Optional) - Index of the selected feature.

• clickRadius (Number, Optional) - Radius to detect features around a hovered or clicked point. Default value is 0

• onSelect (Function, Optional) - callback when clicking a position when selectable set to true. Receives an object containing the following parameters

  • selectedFeature: selected feature. null if clicked an empty space.
  • selectedFeatureIndex: selected feature index.null if clicked an empty space.
  • editHandleIndex: selected editHandle index. null if clicked an empty space.
  • selectedEditHandleIndexes: current selected editHandle indexes, empty array if no selection.
  • screenCoords: screen coordinates of the clicked position.
  • mapCoords: map coordinates of the clicked position.

• onUpdate (Function, Optional) - callback when any feature is updated. Receives an object containing the following parameters

  • data (Feature[]) - the updated list of GeoJSON features.
  • editType (String) - addFeature, addPosition, finishMovePosition
  • editContext (Array) - list of edit objects, depend on editType, each object may contain featureIndexes, editHandleIndexes, screenCoords, mapCoords.

Feature object structure:

{
  id, // an unique identified generated inside react-map-gl-draw library
  geometry: {
    coordinates, // latitude longitude pairs of the geometry points
    type // geojson type, one of `Point`, `LineString`, or `Polygon`
  },
  properties: {
    renderType, // Mainly used for styling, one of `Point`, `LineString`, `Polygon`, or `Rectangle`. Different from `geometry.type`. i.e. a rectangle's renderType is `Rectangle`, and `geometry.type` is `Polygon`. An incomplete (not closed) Polygon's renderType is `Polygon`, `geometry.type` is `LineString`
    ...otherProps // other properties user passed in
  }
}

Styling related options

• featureStyle (Object|Function, Optional) : Object - Either a style objects or a function to style a feature, function parameters are
  • feature: feature to style.
  • index: index of the feature.
  • state: one of SELECTED, HOVERED, INACTIVE, UNCOMMITTED, CLOSING.

Returns is a map of style objects passed to SVG path elements.

• featureShape (String|Function, Optional): if is a string, should be one of rect or circle. If is a function, will receive the following parameters

  • feature: feature to style.
  • index: index of the feature.
  • state: one of SELECTED, HOVERED, INACTIVE, UNCOMMITTED, CLOSING.

• editHandleStyle (Object|Function, Optional) : Object - Either a style objects or a function to style an editHandle, function parameters are

  • feature: feature to style.
  • index: index of the editHandle vertex in the feature.
  • state: one of SELECTED, HOVERED, INACTIVE, UNCOMMITTED, CLOSING.
  • shape: shape resolved from editHandleShape.

Returns is a map of style objects passed to SVG circle or rect elements.

• editHandleShape (String|Function, Optional): if is a string, should be one of rect or circle. If is a function, will receive the following parameters
  • feature: feature to style.
  • index: index of the editHandle vertex in the feature.
  • state: one of SELECTED, HOVERED, INACTIVE, UNCOMMITTED, CLOSING.

Explanations

• Feature: any drawn shape, one of point, line, polygon or rectangle.
• EditHandle: vertex of the feature being edited.

State related concepts:

• INACTIVE: neither selected nor hovered, default state of a complete feature or editHandle.
• SELECTED: being clicked or dragged.
• HOVERED: hovered over by the mouse pointer.
• UNCOMMITTED: in the middle of drawing, not yet added to the feature being edited.
• CLOSING: closing a polygon.

Styling based on state:

As shown in the above image, for the feature currently being edited,

• featureStyle({feature, state: SELECTED}) will be applied to the committed parts of the feature. (Green strokes)
• editHandleStyle({state: SELECTED}) will be applied to the committed editHandle vertices. (Vertices with black stroke)
• featureStyle({feature, state: UNCOMMITTED}) will be applied to the uncommitted parts of the feature. (Gray stroke)
• editHandleStyle({state: UNCOMMITTED}) will be applied to the uncommitted editHandle vertex. (Gray vertex)

Methods

getFeatures

• Return a list of finished GeoJson features.

addFeatures (Feature | Feature[])

• Add a single or multiple GeoJson features to editor.

deleteFeatures (Feature | Feature[])

• Delete a single or multiple GeoJson features to editor.

deleteHandlers (featureIndex: number | undefined, handleIndexes: number[] | undefined)

• Delete the passed handleIndexes from a feature index, if both parameters are ignored, current selection respectively will be used.

• Returns a feature collection with the modified features. See the example for more details.

Know Issues

• @turf/difference: If you are seeing the below error, you can force @turf/difference's version in your project package.json file and redo yarn install.

./node_modules/@turf/difference/index.mjs Can't import the named export 'diff' from non EcmaScript module (only default export is available)

{
  ...,
  "dependencies": {
    ...
  },
  "resolutions": {
    "@turf/difference": "6.0.1"
  }
}

references:

• yarn
• @turf/difference issue
• related issues: issues/335 issues/333

Code Example

Basic example: Draw polygon

import React, { Component } from 'react';
import MapGL from 'react-map-gl';
import { Editor, DrawPolygonMode } from 'react-map-gl-draw';

const DEFAULT_VIEWPORT = {
  width: 800,
  height: 600,
  longitude: -122.45,
  latitude: 37.78,
  zoom: 14,
};

class App extends Component {
  constructor(props) {
    super(props);
    this.state = {
      viewport: DEFAULT_VIEWPORT,
      modeHandler: null,
    };
  }

  _updateViewport = (viewport) => {
    this.setState({ viewport });
  };

  render() {
    const { viewport } = this.state;
    const mode = React.useState(new DrawPolygonMode());
    return (
      <MapGL
        {...viewport}
        width="100%"
        height="100%"
        mapStyle={'mapbox://styles/mapbox/light-v9'}
        onViewportChange={this._updateViewport}
      >
        <Editor
          // to make the lines/vertices easier to interact with
          clickRadius={12}
          mode={mode}
        />
        {this._renderToolbar()}
      </MapGL>
    );
  }
}

Add customized styles

This is continuous example extends from the Basic Example. Check default style used in editor for more details.

const mode = React.useState(new DrawPolygonMode());

<Editor
  // to make the lines/vertices easier to interact with
  clickRadius={12}
  mode={mode}
  featureStyle={({ feature, state }) => {
    if (state === RENDER_STATE.SELECTED) {
      return {
        stroke: 'rgb(38, 181, 242)',
        fill: 'rgb(189,189,189)',
      };
    }
    return {
      stroke: 'rgb(189,189,189)',
      strokeDasharray: '4,2',
    };
  }}
  editHandleStyle={({ feature, shape, state }) => {
    if (state === RENDER_STATE.SELECTED) {
      return {
        stroke: 'rgb(38, 181, 242)',
        fill: 'rgb(189,189,189)',
      };
    }
    return {
      stroke: 'rgb(189,189,189)',
      strokeDasharray: '4,2',
    };
  }}
  editHandleShape={'circle'}
/>;

Advanced example: multiple draw modes and editing drawn features

codesandbox

import * as React from 'react';
import MapGL from 'react-map-gl';
import { Editor, EditingMode, DrawLineStringMode, DrawPolygonMode } from 'react-map-gl-draw';

const MODES = [
  { id: 'drawPolyline', text: 'Draw Polyline', handler: DrawLineStringMode },
  { id: 'drawPolygon', text: 'Draw Polygon', handler: DrawPolygonMode },
  { id: 'editing', text: 'Edit Feature', handler: EditingMode },
];

const DEFAULT_VIEWPORT = {
  width: 800,
  height: 600,
  longitude: -122.45,
  latitude: 37.78,
  zoom: 14,
};

class App extends React.Component {
  constructor(props) {
    super(props);
    this.state = {
      viewport: DEFAULT_VIEWPORT,
      modeId: null,
      modeHandler: null,
    };
  }

  _switchMode = (evt) => {
    const modeId = evt.target.value === this.state.modeId ? null : evt.target.value;
    const mode = MODES.find((m) => m.id === modeId);
    const modeHandler = mode ? new mode.handler() : null;
    this.setState({ modeId, modeHandler });
  };

  _renderToolbar = () => {
    return (
      <div style={{ position: 'absolute', top: 0, right: 0, maxWidth: '320px' }}>
        <select onChange={this._switchMode}>
          <option value="">--Please choose a draw mode--</option>
          {MODES.map((mode) => (
            <option key={mode.id} value={mode.id}>
              {mode.text}
            </option>
          ))}
        </select>
      </div>
    );
  };

  _updateViewport = (viewport) => {
    this.setState({ viewport });
  };

  render() {
    const { viewport, modeHandler } = this.state;
    return (
      <MapGL
        {...viewport}
        width="100%"
        height="100%"
        mapStyle={'mapbox://styles/mapbox/light-v9'}
        onViewportChange={this._updateViewport}
      >
        <Editor
          // to make the lines/vertices easier to interact with
          clickRadius={12}
          mode={modeHandler}
        />
        {this._renderToolbar()}
      </MapGL>
    );
  }
}