Accessible

<!--
  说明：无障碍地图的中文示例，数据在页面内生成，可独立运行。
  核心逻辑：tabindex 焦点 + keydown 控制 View + aria-live 播报中心坐标
  依赖：OpenLayers 10.3.1 · jsDelivr CDN
-->
<!DOCTYPE html>
<html lang="zh-CN">
<head>
<meta name="robots" content="noindex,follow">
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>无障碍地图</title>
<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/ol@10.3.1/ol.css">
<style>
  html,body{height:100%;margin:0}
  body{display:flex;flex-direction:column;overflow:hidden;
       font:13px/1.6 -apple-system,"Segoe UI","PingFang SC",sans-serif}
  .bar{flex:0 0 auto;padding:8px 12px;background:#f6f7f9;border-bottom:1px solid #e3e6ea;
       display:flex;gap:10px;align-items:center;flex-wrap:wrap;font-size:12px;color:#58606e}
  .bar label{display:flex;gap:5px;align-items:center;cursor:pointer}
  .bar button{font:inherit;padding:3px 9px;border:1px solid #c9ced6;background:#fff;
       border-radius:5px;cursor:pointer;color:#333}
  .bar button:hover{background:#eef2f8}
  .bar input[type=range]{width:110px;vertical-align:middle}
  .bar input[type=text]{font:inherit;padding:2px 6px;border:1px solid #c9ced6;border-radius:4px}
  #map{flex:1 1 auto;min-height:0;background:#eef0f3;position:relative}
  .panel{flex:0 0 auto;max-height:34%;overflow:auto;padding:8px 12px;font-size:12px;
       background:#fff;border-top:1px solid #e3e6ea;color:#3d4451}
  .panel pre{margin:0;font-family:Consolas,"Courier New",monospace;font-size:11px;
       white-space:pre-wrap;word-break:break-all;line-height:1.5}
  .ol-attribution{font-size:11px}

</style>
</head>
<body>
<div class="bar">
<button id="zin" type="button">放大 +</button>
<button id="zout" type="button">缩小 −</button>
<button id="reset" type="button">回到北京</button>
<span id="live" role="status" aria-live="polite">中心 116.3970, 39.9090 · 缩放 11.0</span>
</div>
<div id="map" tabindex="0" aria-label="地图区域：方向键平移，加号减号缩放"></div>

<script src="https://cdn.jsdelivr.net/npm/ol@10.3.1/dist/ol.js"></script>
<script>
(function () {
  'use strict';

  if (typeof ol === 'undefined') {
    var errBox = document.getElementById('map');
    if (errBox) {
      errBox.innerHTML = '<div style="padding:20px;color:#b42318">OpenLayers 加载失败，请检查能否访问 cdn.jsdelivr.net</div>';
    }
    return;
  }

  var fromLonLat = ol.proj.fromLonLat;
  var home = fromLonLat([116.397, 39.909]);
  var view = new ol.View({center: home, zoom: 11, minZoom: 3, maxZoom: 18});
  var map = new ol.Map({
    target: 'map',
    layers: [new ol.layer.Tile({source: new ol.source.XYZ({url: 'https://server.arcgisonline.com/ArcGIS/rest/services/World_Street_Map/MapServer/tile/{z}/{y}/{x}', attributions: 'Tiles © Esri'})})],
    view: view,
    controls: ol.control.defaults.defaults({attribution: false, zoom: true, rotate: false})
  });

  var mapEl = document.getElementById('map');
  var live = document.getElementById('live');

  function describe() {
    var c = ol.proj.toLonLat(view.getCenter());
    live.textContent = '中心 ' + c[0].toFixed(4) + ', ' + c[1].toFixed(4) +
      ' · 缩放 ' + view.getZoom().toFixed(1);
  }

  function pan(dx, dy) {
    var c = view.getCenter();
    var r = view.getResolution();
    view.animate({center: [c[0] + dx * r * 60, c[1] + dy * r * 60], duration: 180});
  }

  function zoomBy(delta) {
    view.animate({zoom: view.getZoom() + delta, duration: 180});
  }

  view.on(['change:center', 'change:resolution'], describe);

  /* 鼠标点击地图后把焦点交给地图容器，键盘操作才有落点 */
  mapEl.addEventListener('click', function () { mapEl.focus(); });

  mapEl.addEventListener('keydown', function (evt) {
    var key = evt.key;
    if (key === 'ArrowLeft') { pan(-1, 0); }
    else if (key === 'ArrowRight') { pan(1, 0); }
    else if (key === 'ArrowUp') { pan(0, 1); }
    else if (key === 'ArrowDown') { pan(0, -1); }
    else if (key === '+' || key === '=') { zoomBy(1); }
    else if (key === '-' || key === '_') { zoomBy(-1); }
    else { return; }
    evt.preventDefault();
  });

  document.getElementById('zin').addEventListener('click', function () { zoomBy(1); });
  document.getElementById('zout').addEventListener('click', function () { zoomBy(-1); });
  document.getElementById('reset').addEventListener('click', function () {
    view.animate({center: home, zoom: 11, duration: 250});
  });

  describe();
})();
</script>
</body>
</html>