Layer Visibility

<!--
  示例：图层显隐
  核心逻辑：setLayoutProperty 切换 visibility，分别控制面、线、标注三个图层
  依赖：MapLibre GL JS 4 · jsDelivr CDN · demotiles 样式
-->
<!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>图层显隐</title>
<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/maplibre-gl@4/dist/maplibre-gl.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;color:#16181d}
  .bar{flex:0 0 auto;display:flex;gap:14px;align-items:center;padding:8px 12px;
       background:#f6f7f9;border-bottom:1px solid #e3e6ea;font-size:12px;color:#58606e;flex-wrap:wrap}
  .bar b{color:#16181d;font-weight:600}
  .bar label{display:flex;gap:5px;align-items:center;cursor:pointer}
  .btn{border:1px solid #cdd3db;background:#fff;border-radius:4px;padding:3px 9px;
       font:12px/1.5 inherit;color:#16181d;cursor:pointer}
  #map{flex:1 1 auto;min-height:0}
</style>
</head>
<body>
<div class="bar">
  <label><input type="checkbox" data-layer="zone-fill" checked> 面</label>
  <label><input type="checkbox" data-layer="zone-line" checked> 线</label>
  <label><input type="checkbox" data-layer="zone-label" checked> 标注</label>
  <button class="btn" id="all">全部切换</button>
  <span>状态 <b id="state">三层可见</b></span>
</div>
<div id="map"></div>
<script src="https://cdn.jsdelivr.net/npm/maplibre-gl@4/dist/maplibre-gl.js"></script>
<script>
(function () {
  'use strict';

  if (typeof maplibregl === 'undefined') {
    document.body.innerHTML =
      '<div style="padding:24px;color:#b42318">MapLibre 加载失败，请检查能否访问 cdn.jsdelivr.net</div>';
    return;
  }

  var zones = {
    type: 'FeatureCollection',
    features: [
      { type: 'Feature', properties: { name: 'NORTH' },
        geometry: { type: 'Polygon', coordinates: [[[98, 38], [108, 39], [107, 43], [97, 42], [98, 38]]] } },
      { type: 'Feature', properties: { name: 'EAST' },
        geometry: { type: 'Polygon', coordinates: [[[112, 31], [121, 31], [122, 37], [112, 37], [112, 31]]] } },
      { type: 'Feature', properties: { name: 'SOUTH' },
        geometry: { type: 'Polygon', coordinates: [[[104, 23], [114, 23], [115, 28], [104, 29], [104, 23]]] } },
      { type: 'Feature', properties: { name: 'NORTH' },
        geometry: { type: 'Point', coordinates: [102.5, 40.5] } },
      { type: 'Feature', properties: { name: 'EAST' },
        geometry: { type: 'Point', coordinates: [117.0, 34.0] } },
      { type: 'Feature', properties: { name: 'SOUTH' },
        geometry: { type: 'Point', coordinates: [109.5, 25.5] } }
    ]
  };

  var map = new maplibregl.Map({
    container: 'map',
    style: 'https://demotiles.maplibre.org/style.json',
    center: [109.5, 33.0],
    zoom: 3.4,
    attributionControl: { compact: true, customAttribution: 'MapLibre demo tiles' }
  });

  map.addControl(new maplibregl.NavigationControl(), 'top-right');

  map.on('load', function () {
    map.addSource('zones', { type: 'geojson', data: zones });

    map.addLayer({
      id: 'zone-fill',
      type: 'fill',
      source: 'zones',
      filter: ['==', ['geometry-type'], 'Polygon'],
      paint: { 'fill-color': '#8ab4e8', 'fill-opacity': 0.35 }
    });

    map.addLayer({
      id: 'zone-line',
      type: 'line',
      source: 'zones',
      filter: ['==', ['geometry-type'], 'Polygon'],
      paint: { 'line-color': '#2f6fbd', 'line-width': 2 }
    });

    map.addLayer({
      id: 'zone-label',
      type: 'symbol',
      source: 'zones',
      filter: ['==', ['geometry-type'], 'Point'],
      layout: {
        'text-field': ['get', 'name'],
        'text-font': ['Noto Sans Regular'],
        'text-size': 14
      },
      paint: {
        'text-color': '#15304a',
        'text-halo-color': '#ffffff',
        'text-halo-width': 1.5
      }
    });
  });

  function setVisible(layerId, visible) {
    if (!map.getLayer(layerId)) return;
    map.setLayoutProperty(layerId, 'visibility', visible ? 'visible' : 'none');
  }

  function report() {
    var on = [];
    document.querySelectorAll('[data-layer]').forEach(function (box) {
      if (box.checked) on.push(box.parentNode.textContent.trim());
    });
    document.getElementById('state').textContent =
      on.length === 0 ? '全部隐藏' : on.join('、') + ' 可见';
  }

  document.querySelectorAll('[data-layer]').forEach(function (box) {
    box.addEventListener('change', function () {
      setVisible(this.getAttribute('data-layer'), this.checked);
      report();
    });
  });

  document.getElementById('all').addEventListener('click', function () {
    var boxes = document.querySelectorAll('[data-layer]');
    var anyOn = Array.prototype.some.call(boxes, function (b) { return b.checked; });
    Array.prototype.forEach.call(boxes, function (b) {
      b.checked = !anyOn;
      setVisible(b.getAttribute('data-layer'), !anyOn);
    });
    report();
  });

  map.on('error', function (e) {
    if (e.error) console.warn('地图错误：' + e.error.message);
  });
})();
</script>
</body>
</html>