Edit

Pinch Zoom

Restrict pinch zooming to integer zoom levels.

By default, the ol/interaction/PinchZoom can leave the map at fractional zoom levels. If instead you want to constrain pinch zooming to integer zoom levels, set constrainResolution: true when constructing the view.

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index.html<!DOCTYPE html>
<html lang="en">
  <head>
    <title>Pinch Zoom</title>
    <!-- The line below is only needed for old environments like Internet Explorer and Android 4.x -->
    <script src="https://cdn.polyfill.io/v2/polyfill.min.js?features=requestAnimationFrame,Element.prototype.classList,URL"></script>
    <style>
      .map {
        width: 100%;
        height:400px;
      }
    </style>
  </head>
  <body>
    <div id="map" class="map"></div>
    <script src="index.js"></script>
  </body>
</html>
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index.jsimport 'ol/ol.css';
import Map from 'ol/Map';
import View from 'ol/View';
import {defaults as defaultInteractions, PinchZoom} from 'ol/interaction';
import TileLayer from 'ol/layer/Tile';
import OSM from 'ol/source/OSM';


var map = new Map({
  interactions: defaultInteractions().extend([
    new PinchZoom()
  ]),
  layers: [
    new TileLayer({
      source: new OSM()
    })
  ],
  target: 'map',
  view: new View({
    center: [0, 0],
    zoom: 2,
    constrainResolution: true
  })
});
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package.json{
  "name": "pinch-zoom",
  "dependencies": {
    "ol": "6.1.1"
  },
  "devDependencies": {
    "parcel": "1.11.0"
  },
  "scripts": {
    "start": "parcel index.html",
    "build": "parcel build --experimental-scope-hoisting --public-url . index.html"
  }
}