التعامل مع أحداث الماوس

اختيار النظام الأساسي: Android iOS JavaScript

نظرة عامة

اجعل طبقة العناصر تستجيب للحدثَين mousemove وclick، واستخدِم الحدثَين لعرض معلومات عن الحدود التي تم النقر عليها. تشمل هذه المعلومات رقم التعريف والاسم المعروض ونوع العنصر. يعرض مثال الخريطة التاليحدود المستوى 2 من المنطقة الإدارية، ويحتوي على رمز معالجة الأحداث الذي يُعدّل تنسيق المضلّعات استنادًا إلى تفاعل المستخدِم (mousemove يغيّر سمك الحدود، وclick يُضفي درجة ظلّ على لون الخلفية ويتسبّب في عرض نافذة معلومات).

تفعيل أحداث طبقة العناصر

اتّبِع الخطوات التالية لتفعيل الأحداث على طبقة عناصر:

1. سجِّل طبقة ميزة لإشعارات الأحداث من خلال استدعاء دالة addListener() في طبقة الميزة 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;
     }
   });
   index.ts

   ملاحظة: اطّلِع على الدليل حول استخدام TypeScript و"خرائط Google".

   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;
     }
   });
   index.js

2. أضِف رمز معالِج الحدث لتنسيق المضلع 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;
   }
   index.ts

   ملاحظة: اطّلِع على الدليل حول استخدام TypeScript و"خرائط Google".

   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;
   }
   index.js

3. استخدِم دالة نمط العناصر لتطبيق الأنماط. تطبّق دالة نمط الميزة المعروضة هنا النمط بشكل مشروط استنادًا إلى نوع التفاعل. تمّ تحديد ثلاثة أنماط هنا: أحدها لجعل الحدود غامقة في mousemove، وأحدهما ل تغيير الخلفية وعرض نافذة معلومات في click، 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;
   }
   index.ts

   ملاحظة: اقرأ الدليل حول استخدام TypeScript و"خرائط Google".

   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;
   }
   index.js

ملاحظة: بما أنّه لا يمكن التفاعل إلا مع العناصر المرئية، يجب أن يكون fillOpacity لأسلوب الملء التلقائي 0.1 أو أكثر.

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();
index.ts

ملاحظة: اقرأ الدليل حول استخدام TypeScript و"خرائط Google".

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();
index.js

ملاحظة: يتم جمع JavaScript من مقتطف TypeScript.

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;
}
style.css

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>
index.html

تجربة "عيّنة"

JSFiddle.net Google Cloud Shell

اطّلِع على مزيد من المعلومات عن الأحداث.