您可以啟用點擊事件處理功能、為螢幕閱讀器新增描述性文字,並調整標記比例,讓標記更容易存取。
- 如果標記可點選 (或拖曳),就能回應鍵盤和滑鼠的輸入動作。
- 螢幕閱讀器可閱讀
title
選項中指定的文字,並在使用者將滑鼠游標懸停在標記上時顯示。 - 放大標記會降低在所有裝置上 (特別是觸控螢幕裝置) 與標記互動所需的精準度,使用上更為方便。預設標記符合 WCAG AA 最小尺寸標準,但如果開發人員想要遵循 WCAG AAA 目標尺寸標準,就需要放大標記。
請參閱「自訂基本標記」,瞭解如何變更標記比例、新增標題文字等。
以下地圖範例含有五個可點選且可聚焦的標記,這些標記包含標題文字,且已設為 1.5 倍縮放比例:
如要使用鍵盤瀏覽標記:
- 使用 Tab 鍵可將焦點移至第一個標記,如果一張地圖上有多個標記,使用方向鍵即可輪轉切換標記。
- 如果標記可點選,按下 Enter 鍵即可執行「點選」動作。如要開啟標記內含的資訊視窗,您可以點選標記,或是按下 Enter 鍵或空格鍵。資訊視窗關閉後,焦點就會回到相關標記。
- 再次按下 Tab 鍵,即可繼續在其他地圖控制項之間移動。
將標記設計為可點擊
本節將說明如何讓標記回應點擊事件。如要將標記設計為可點擊,請按照以下步驟操作:
- 將
gmpClickable
屬性設為true
。
TypeScript
const marker = new AdvancedMarkerElement({ position, map, title: `${i + 1}. ${title}`, content: pin.element, gmpClickable: true, });
JavaScript
const marker = new AdvancedMarkerElement({ position, map, title: `${i + 1}. ${title}`, content: pin.element, gmpClickable: true, });
- 新增點擊事件監聽器,回應使用者輸入內容。
TypeScript
// Add a click listener for each marker, and set up the info window. marker.addListener('click', ({ domEvent, latLng }) => { const { target } = domEvent; infoWindow.close(); infoWindow.setContent(marker.title); infoWindow.open(marker.map, marker); });
JavaScript
// Add a click listener for each marker, and set up the info window. marker.addListener("click", ({ domEvent, latLng }) => { const { target } = domEvent; infoWindow.close(); infoWindow.setContent(marker.title); infoWindow.open(marker.map, marker); });
如要將標記復原為不可點選,請呼叫
removeListener
以移除點擊事件監聽器:// Remove the listener. google.maps.event.removeListener(clickListener);
如要進一步改善無障礙功能,請採取下列做法:
- 使用
AdvancedMarkerElement.title
選項設定標記的說明文字。 - 使用
PinElement
的scale
屬性增加標記比例。
完整程式碼範例
查看完整原始碼範例
TypeScript
async function initMap() { // Request needed libraries. const { Map, InfoWindow } = await google.maps.importLibrary("maps") as google.maps.MapsLibrary; const { AdvancedMarkerElement, PinElement } = await google.maps.importLibrary("marker") as google.maps.MarkerLibrary; const map = new Map(document.getElementById("map") as HTMLElement, { zoom: 12, center: { lat: 34.84555, lng: -111.8035 }, mapId: '4504f8b37365c3d0', }); // Set LatLng and title text for the markers. The first marker (Boynton Pass) // receives the initial focus when tab is pressed. Use arrow keys to move // between markers; press tab again to cycle through the map controls. const tourStops = [ { position: { lat: 34.8791806, lng: -111.8265049 }, title: "Boynton Pass" }, { position: { lat: 34.8559195, lng: -111.7988186 }, title: "Airport Mesa" }, { position: { lat: 34.832149, lng: -111.7695277 }, title: "Chapel of the Holy Cross" }, { position: { lat: 34.823736, lng: -111.8001857 }, title: "Red Rock Crossing" }, { position: { lat: 34.800326, lng: -111.7665047 }, title: "Bell Rock" }, ]; // Create an info window to share between markers. const infoWindow = new InfoWindow(); // Create the markers. tourStops.forEach(({position, title}, i) => { const pin = new PinElement({ glyph: `${i + 1}`, scale: 1.5, }); const marker = new AdvancedMarkerElement({ position, map, title: `${i + 1}. ${title}`, content: pin.element, gmpClickable: true, }); // Add a click listener for each marker, and set up the info window. marker.addListener('click', ({ domEvent, latLng }) => { const { target } = domEvent; infoWindow.close(); infoWindow.setContent(marker.title); infoWindow.open(marker.map, marker); }); }); } initMap();
JavaScript
async function initMap() { // Request needed libraries. const { Map, InfoWindow } = await google.maps.importLibrary("maps"); const { AdvancedMarkerElement, PinElement } = await google.maps.importLibrary( "marker", ); const map = new Map(document.getElementById("map"), { zoom: 12, center: { lat: 34.84555, lng: -111.8035 }, mapId: "4504f8b37365c3d0", }); // Set LatLng and title text for the markers. The first marker (Boynton Pass) // receives the initial focus when tab is pressed. Use arrow keys to move // between markers; press tab again to cycle through the map controls. const tourStops = [ { position: { lat: 34.8791806, lng: -111.8265049 }, title: "Boynton Pass", }, { position: { lat: 34.8559195, lng: -111.7988186 }, title: "Airport Mesa", }, { position: { lat: 34.832149, lng: -111.7695277 }, title: "Chapel of the Holy Cross", }, { position: { lat: 34.823736, lng: -111.8001857 }, title: "Red Rock Crossing", }, { position: { lat: 34.800326, lng: -111.7665047 }, title: "Bell Rock", }, ]; // Create an info window to share between markers. const infoWindow = new InfoWindow(); // Create the markers. tourStops.forEach(({ position, title }, i) => { const pin = new PinElement({ glyph: `${i + 1}`, scale: 1.5, }); const marker = new AdvancedMarkerElement({ position, map, title: `${i + 1}. ${title}`, content: pin.element, gmpClickable: true, }); // Add a click listener for each marker, and set up the info window. marker.addListener("click", ({ domEvent, latLng }) => { const { target } = domEvent; infoWindow.close(); infoWindow.setContent(marker.title); infoWindow.open(marker.map, marker); }); }); } initMap();
CSS
/* * Always set the map height explicitly to define the size of the div element * that contains the map. */ #map { height: 100%; } /* * Optional: Makes the sample page fill the window. */ html, body { height: 100%; margin: 0; padding: 0; }
HTML
<html> <head> <title>Advanced Marker Accessibility</title> <link rel="stylesheet" type="text/css" href="./style.css" /> <script type="module" src="./index.js"></script> </head> <body> <div id="map"></div> <!-- prettier-ignore --> <script>(g=>{var h,a,k,p="The Google Maps JavaScript API",c="google",l="importLibrary",q="__ib__",m=document,b=window;b=b[c]||(b[c]={});var d=b.maps||(b.maps={}),r=new Set,e=new URLSearchParams,u=()=>h||(h=new Promise(async(f,n)=>{await (a=m.createElement("script"));e.set("libraries",[...r]+"");for(k in g)e.set(k.replace(/[A-Z]/g,t=>"_"+t[0].toLowerCase()),g[k]);e.set("callback",c+".maps."+q);a.src=`https://maps.${c}apis.com/maps/api/js?`+e;d[q]=f;a.onerror=()=>h=n(Error(p+" could not load."));a.nonce=m.querySelector("script[nonce]")?.nonce||"";m.head.append(a)}));d[l]?console.warn(p+" only loads once. Ignoring:",g):d[l]=(f,...n)=>r.add(f)&&u().then(()=>d[l](f,...n))}) ({key: "AIzaSyB41DRUbKWJHPxaFjMAwdrzWzbVKartNGg", v: "beta"});</script> </body> </html>