View Min-Zoom

Demonstrates how the view's minimum zoom level can be changed.

The minZoom option for a view limits how far out you can zoom. This property can be updated by calling view.setMinZoom(newMinZoom). In this example, the minimum zoom level is set so that you only see one world at a time. Resize your browser window to change the threshold.

main.js

import Map from 'ol/Map.js';
import OSM from 'ol/source/OSM.js';
import TileLayer from 'ol/layer/Tile.js';
import View from 'ol/View.js';

const viewport = document.getElementById('map');

function getMinZoom() {
  const width = viewport.clientWidth;
  return Math.ceil(Math.LOG2E * Math.log(width / 256));
}

const initialZoom = getMinZoom();

const view = new View({
  center: [0, 0],
  minZoom: initialZoom,
  zoom: initialZoom,
});

const map = new Map({
  layers: [
    new TileLayer({
      source: new OSM(),
    }),
  ],
  target: 'map',
  view: view,
});

window.addEventListener('resize', function () {
  const minZoom = getMinZoom();
  if (minZoom !== view.getMinZoom()) {
    view.setMinZoom(minZoom);
  }
});

index.html

<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8">
    <title>View Min-Zoom</title>
    <link rel="stylesheet" href="node_modules/ol/ol.css">
    <style>
      .map {
        width: 100%;
        height: 400px;
      }
    </style>
  </head>
  <body>
    <div id="map" class="map"></div>

    <script type="module" src="main.js"></script>
  </body>
</html>

package.json

{
  "name": "min-zoom",
  "dependencies": {
    "ol": "9.1.0"
  },
  "devDependencies": {
    "vite": "^3.2.3"
  },
  "scripts": {
    "start": "vite",
    "build": "vite build"
  }
}