نظرة عامة
اجعل طبقة المعالم تستجيب للحدثين mousemove
وclick
، واستخدِمها لعرض معلومات حول الحدود التي تم النقر عليها. تتضمّن هذه المعلومات رقم التعريف والاسم المعروض ونوع الميزة. تعرض خريطة المثال التالية حدود "المنطقة الإدارية، المستوى 2"، وتتضمّن رمز معالجة الأحداث الذي يضبط أنماط المضلّعات استنادًا إلى تفاعل المستخدم (mousemove
يغيّر سمك الحدود، وclick
يظلّل لون الخلفية ويؤدي إلى عرض نافذة معلومات).
تفعيل أحداث طبقة المعالم
اتّبِع الخطوات التالية لتفعيل الأحداث على طبقة معالم:
يمكنك تسجيل طبقة معالم لتلقّي إشعارات الأحداث من خلال استدعاء الدالة
addListener()
في طبقة المعالم لكل حدث تريد تسجيله. في هذا المثال، تحصل الخريطة أيضًا على مستمع.TypeScript
// Add the feature layer. //@ts-ignore featureLayer = map.getFeatureLayer('ADMINISTRATIVE_AREA_LEVEL_2'); // Add the event listeners for the feature layer. featureLayer.addListener('click', handleClick); featureLayer.addListener('mousemove', handleMouseMove); // Map event listener. map.addListener('mousemove', () => { // If the map gets a mousemove, that means there are no feature layers // with listeners registered under the mouse, so we clear the last // interacted feature ids. if (lastInteractedFeatureIds?.length) { lastInteractedFeatureIds = []; featureLayer.style = applyStyle; } });
JavaScript
// Add the feature layer. //@ts-ignore featureLayer = map.getFeatureLayer("ADMINISTRATIVE_AREA_LEVEL_2"); // Add the event listeners for the feature layer. featureLayer.addListener("click", handleClick); featureLayer.addListener("mousemove", handleMouseMove); // Map event listener. map.addListener("mousemove", () => { // If the map gets a mousemove, that means there are no feature layers // with listeners registered under the mouse, so we clear the last // interacted feature ids. if (lastInteractedFeatureIds?.length) { lastInteractedFeatureIds = []; featureLayer.style = applyStyle; } });
أضِف رمز معالج الأحداث لتصميم المضلّع المحدّد استنادًا إلى نوع التفاعل.
TypeScript
function handleClick(/* MouseEvent */ e) { lastClickedFeatureIds = e.features.map(f => f.placeId); lastInteractedFeatureIds = []; featureLayer.style = applyStyle; createInfoWindow(e); } function handleMouseMove(/* MouseEvent */ e) { lastInteractedFeatureIds = e.features.map(f => f.placeId); featureLayer.style = applyStyle; }
JavaScript
function handleClick(/* MouseEvent */ e) { lastClickedFeatureIds = e.features.map((f) => f.placeId); lastInteractedFeatureIds = []; featureLayer.style = applyStyle; createInfoWindow(e); } function handleMouseMove(/* MouseEvent */ e) { lastInteractedFeatureIds = e.features.map((f) => f.placeId); featureLayer.style = applyStyle; }
استخدِم دالة نمط عنصر لتطبيق الأنماط. تطبّق دالة نمط العنصر هنا النمط بشكل مشروط استنادًا إلى نوع التفاعل. يتم تحديد ثلاثة أنماط هنا: نمط لجعل الحدود غليظة عند
mousemove
، ونمط لتغيير الخلفية وعرض نافذة معلومات عندclick
، ونمط تلقائي.TypeScript
// Define styles. // Stroke and fill with minimum opacity value. const styleDefault = { strokeColor: '#810FCB', strokeOpacity: 1.0, strokeWeight: 2.0, fillColor: 'white', fillOpacity: 0.1, // Polygons must be visible to receive events. }; // Style for the clicked polygon. const styleClicked = { ...styleDefault, fillColor: '#810FCB', fillOpacity: 0.5, }; // Style for polygon on mouse move. const styleMouseMove = { ...styleDefault, strokeWeight: 4.0, }; // Apply styles using a feature style function. function applyStyle(/* FeatureStyleFunctionOptions */ params) { const placeId = params.feature.placeId; //@ts-ignore if (lastClickedFeatureIds.includes(placeId)) { return styleClicked; } //@ts-ignore if (lastInteractedFeatureIds.includes(placeId)) { return styleMouseMove; } return styleDefault; }
JavaScript
// Define styles. // Stroke and fill with minimum opacity value. const styleDefault = { strokeColor: "#810FCB", strokeOpacity: 1.0, strokeWeight: 2.0, fillColor: "white", fillOpacity: 0.1, // Polygons must be visible to receive events. }; // Style for the clicked polygon. const styleClicked = { ...styleDefault, fillColor: "#810FCB", fillOpacity: 0.5, }; // Style for polygon on mouse move. const styleMouseMove = { ...styleDefault, strokeWeight: 4.0, }; // Apply styles using a feature style function. function applyStyle(/* FeatureStyleFunctionOptions */ params) { const placeId = params.feature.placeId; //@ts-ignore if (lastClickedFeatureIds.includes(placeId)) { return styleClicked; } //@ts-ignore if (lastInteractedFeatureIds.includes(placeId)) { return styleMouseMove; } return styleDefault; }
مثال كامل على الرمز البرمجي
TypeScript
let map: google.maps.Map; let featureLayer; let infoWindow; let lastInteractedFeatureIds = []; let lastClickedFeatureIds = []; function handleClick(/* MouseEvent */ e) { lastClickedFeatureIds = e.features.map(f => f.placeId); lastInteractedFeatureIds = []; featureLayer.style = applyStyle; createInfoWindow(e); } function handleMouseMove(/* MouseEvent */ e) { lastInteractedFeatureIds = e.features.map(f => f.placeId); featureLayer.style = applyStyle; } async function initMap() { // Request needed libraries. const { Map, InfoWindow } = await google.maps.importLibrary('maps') as google.maps.MapsLibrary; map = new Map(document.getElementById('map') as HTMLElement, { center: {lat: 39.23, lng: -105.73}, zoom: 8, // In the cloud console, configure your Map ID with a style that enables the // 'Administrative Area Level 2' Data Driven Styling type. mapId: 'a3efe1c035bad51b', // Substitute your own map ID. mapTypeControl: false, }); // Add the feature layer. //@ts-ignore featureLayer = map.getFeatureLayer('ADMINISTRATIVE_AREA_LEVEL_2'); // Add the event listeners for the feature layer. featureLayer.addListener('click', handleClick); featureLayer.addListener('mousemove', handleMouseMove); // Map event listener. map.addListener('mousemove', () => { // If the map gets a mousemove, that means there are no feature layers // with listeners registered under the mouse, so we clear the last // interacted feature ids. if (lastInteractedFeatureIds?.length) { lastInteractedFeatureIds = []; featureLayer.style = applyStyle; } }); // Create the infowindow. infoWindow = new InfoWindow({}); // Apply style on load, to enable clicking. featureLayer.style = applyStyle; } // Helper function for the infowindow. async function createInfoWindow(event) { let feature = event.features[0]; if (!feature.placeId) return; // Update the infowindow. const place = await feature.fetchPlace(); let content = '<span style="font-size:small">Display name: ' + place.displayName + '<br/> Place ID: ' + feature.placeId + '<br/> Feature type: ' + feature.featureType + '</span>'; updateInfoWindow(content, event.latLng); } // Define styles. // Stroke and fill with minimum opacity value. const styleDefault = { strokeColor: '#810FCB', strokeOpacity: 1.0, strokeWeight: 2.0, fillColor: 'white', fillOpacity: 0.1, // Polygons must be visible to receive events. }; // Style for the clicked polygon. const styleClicked = { ...styleDefault, fillColor: '#810FCB', fillOpacity: 0.5, }; // Style for polygon on mouse move. const styleMouseMove = { ...styleDefault, strokeWeight: 4.0, }; // Apply styles using a feature style function. function applyStyle(/* FeatureStyleFunctionOptions */ params) { const placeId = params.feature.placeId; //@ts-ignore if (lastClickedFeatureIds.includes(placeId)) { return styleClicked; } //@ts-ignore if (lastInteractedFeatureIds.includes(placeId)) { return styleMouseMove; } return styleDefault; } // Helper function to create an info window. function updateInfoWindow(content, center) { infoWindow.setContent(content); infoWindow.setPosition(center); infoWindow.open({ map, shouldFocus: false, }); } initMap();
JavaScript
let map; let featureLayer; let infoWindow; let lastInteractedFeatureIds = []; let lastClickedFeatureIds = []; function handleClick(/* MouseEvent */ e) { lastClickedFeatureIds = e.features.map((f) => f.placeId); lastInteractedFeatureIds = []; featureLayer.style = applyStyle; createInfoWindow(e); } function handleMouseMove(/* MouseEvent */ e) { lastInteractedFeatureIds = e.features.map((f) => f.placeId); featureLayer.style = applyStyle; } async function initMap() { // Request needed libraries. const { Map, InfoWindow } = await google.maps.importLibrary("maps"); map = new Map(document.getElementById("map"), { center: { lat: 39.23, lng: -105.73 }, zoom: 8, // In the cloud console, configure your Map ID with a style that enables the // 'Administrative Area Level 2' Data Driven Styling type. mapId: "a3efe1c035bad51b", // Substitute your own map ID. mapTypeControl: false, }); // Add the feature layer. //@ts-ignore featureLayer = map.getFeatureLayer("ADMINISTRATIVE_AREA_LEVEL_2"); // Add the event listeners for the feature layer. featureLayer.addListener("click", handleClick); featureLayer.addListener("mousemove", handleMouseMove); // Map event listener. map.addListener("mousemove", () => { // If the map gets a mousemove, that means there are no feature layers // with listeners registered under the mouse, so we clear the last // interacted feature ids. if (lastInteractedFeatureIds?.length) { lastInteractedFeatureIds = []; featureLayer.style = applyStyle; } }); // Create the infowindow. infoWindow = new InfoWindow({}); // Apply style on load, to enable clicking. featureLayer.style = applyStyle; } // Helper function for the infowindow. async function createInfoWindow(event) { let feature = event.features[0]; if (!feature.placeId) return; // Update the infowindow. const place = await feature.fetchPlace(); let content = '<span style="font-size:small">Display name: ' + place.displayName + "<br/> Place ID: " + feature.placeId + "<br/> Feature type: " + feature.featureType + "</span>"; updateInfoWindow(content, event.latLng); } // Define styles. // Stroke and fill with minimum opacity value. const styleDefault = { strokeColor: "#810FCB", strokeOpacity: 1.0, strokeWeight: 2.0, fillColor: "white", fillOpacity: 0.1, // Polygons must be visible to receive events. }; // Style for the clicked polygon. const styleClicked = { ...styleDefault, fillColor: "#810FCB", fillOpacity: 0.5, }; // Style for polygon on mouse move. const styleMouseMove = { ...styleDefault, strokeWeight: 4.0, }; // Apply styles using a feature style function. function applyStyle(/* FeatureStyleFunctionOptions */ params) { const placeId = params.feature.placeId; //@ts-ignore if (lastClickedFeatureIds.includes(placeId)) { return styleClicked; } //@ts-ignore if (lastInteractedFeatureIds.includes(placeId)) { return styleMouseMove; } return styleDefault; } // Helper function to create an info window. function updateInfoWindow(content, center) { infoWindow.setContent(content); infoWindow.setPosition(center); infoWindow.open({ map, shouldFocus: false, }); } 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>Handle Region Boundary Click Event</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: "weekly"});</script> </body> </html>
تجربة عيّنة
اطّلِع على مزيد من المعلومات عن الأحداث.