Edit

Draw Features

draw12 edit13 freehand3 vector71

Example of using the ol/interaction/Draw interaction.

Example of using the Draw interaction. Select a geometry type from the dropdown above to start drawing. To finish drawing, click the last point. To activate freehand drawing for lines, polygons, and circles, hold the Shift key. To remove the last point of a line or polygon, press "Undo".

main.js
import Draw from 'ol/interaction/Draw';
import Map from 'ol/Map';
import View from 'ol/View';
import {OSM, Vector as VectorSource} from 'ol/source';
import {Tile as TileLayer, Vector as VectorLayer} from 'ol/layer';

const raster = new TileLayer({
  source: new OSM(),
});

const source = new VectorSource({wrapX: false});

const vector = new VectorLayer({
  source: source,
});

const map = new Map({
  layers: [raster, vector],
  target: 'map',
  view: new View({
    center: [-11000000, 4600000],
    zoom: 4,
  }),
});

const typeSelect = document.getElementById('type');

let draw; // global so we can remove it later
function addInteraction() {
  const value = typeSelect.value;
  if (value !== 'None') {
    draw = new Draw({
      source: source,
      type: typeSelect.value,
    });
    map.addInteraction(draw);
  }
}

/**
 * Handle change event.
 */
typeSelect.onchange = function () {
  map.removeInteraction(draw);
  addInteraction();
};

document.getElementById('undo').addEventListener('click', function () {
  draw.removeLastPoint();
});

addInteraction();
index.html
<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8">
    <title>Draw Features</title>
    <link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/[email protected]/dist/css/bootstrap.min.css">
    <link rel="stylesheet" href="node_modules/ol/ol.css">
    <style>
      .map {
        width: 100%;
        height: 400px;
      }
    </style>
  </head>
  <body>
    <div id="map" class="map"></div>
    <div class="row">
      <div class="col-auto">
        <span class="input-group">
          <label class="input-group-text" for="type">Geometry type:</label>
          <select class="form-select" id="type">
            <option value="Point">Point</option>
            <option value="LineString">LineString</option>
            <option value="Polygon">Polygon</option>
            <option value="Circle">Circle</option>
            <option value="None">None</option>
          </select>
          <input class="form-control" type="button" value="Undo" id="undo">
        </span>
      </div>
    </div>
    <!-- Pointer events polyfill for old browsers, see https://caniuse.com/#feat=pointer -->
    <script src="https://unpkg.com/[email protected]/dist/elm-pep.js"></script>
    <script type="module" src="main.js"></script>
  </body>
</html>
package.json
{
  "name": "draw-features",
  "dependencies": {
    "ol": "7.1.0"
  },
  "devDependencies": {
    "vite": "^3.0.3",
    "@babel/core": "latest"
  },
  "scripts": {
    "start": "vite",
    "build": "vite build"
  }
}