Gestire gli eventi del mouse

Seleziona la piattaforma: Android iOS JavaScript

Fai in modo che le funzionalità dei dati rispondano agli eventi mousemove e click e utilizzali per modificare l'aspetto di una funzionalità in base all'interazione dell'utente.

Abilita gli eventi del livello del set di dati

Per abilitare gli eventi su un livello di set di dati, procedere come segue:

1. Registra un livello di set di dati per le notifiche degli eventi chiamando la funzione addListener() sul livello di set di dati per ogni evento che desideri registrare. In questo esempio, anche la mappa riceve un listener.

   TypeScript

   datasetLayer = map.getDatasetFeatureLayer(datasetId);
   datasetLayer.style = applyStyle;
   
   datasetLayer.addListener('click', handleClick);
   datasetLayer.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 = [];
       datasetLayer.style = applyStyle;
     }
   });
   index.ts

   Nota:leggi la guida sull'utilizzo di TypeScript e Google Maps.

   JavaScript

   datasetLayer = map.getDatasetFeatureLayer(datasetId);
   datasetLayer.style = applyStyle;
   datasetLayer.addListener("click", handleClick);
   datasetLayer.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 = [];
       datasetLayer.style = applyStyle;
     }
   });
   index.js

2. Aggiungere il codice del gestore eventi per definire lo stile della funzionalità selezionata in base al tipo di interazione.

   TypeScript

   // Note, 'globalid' is an attribute in this Dataset.
   function handleClick(/* MouseEvent */ e) {
     if (e.features) {
       lastClickedFeatureIds =
           e.features.map((f) => f.datasetAttributes['globalid']);
     }
     //@ts-ignore
     datasetLayer.style = applyStyle;
   }
   
   function handleMouseMove(/* MouseEvent */ e) {
     if (e.features) {
       lastInteractedFeatureIds =
           e.features.map((f) => f.datasetAttributes['globalid']);
     }
     //@ts-ignore
     datasetLayer.style = applyStyle;
   }
   index.ts

   Nota:leggi la guida sull'utilizzo di TypeScript e Google Maps.

   JavaScript

   // Note, 'globalid' is an attribute in this Dataset.
   function handleClick(/* MouseEvent */ e) {
     if (e.features) {
       lastClickedFeatureIds = e.features.map(
         (f) => f.datasetAttributes["globalid"],
       );
     }
   
     //@ts-ignore
     datasetLayer.style = applyStyle;
   }
   
   function handleMouseMove(/* MouseEvent */ e) {
     if (e.features) {
       lastInteractedFeatureIds = e.features.map(
         (f) => f.datasetAttributes["globalid"],
       );
     }
   
     //@ts-ignore
     datasetLayer.style = applyStyle;
   }
   index.js

3. Utilizza una funzione di stile delle caratteristiche per applicare gli stili. La funzione di stile della funzionalità mostrata qui applica lo stile in modo condizionale in base al tipo di interazione. Qui vengono definiti tre stili: uno per rendere il bordo in grassetto su mousemove, uno per modificare lo sfondo su click e uno stile predefinito.

   TypeScript

   const styleDefault = {
     strokeColor: 'green',
     strokeWeight: 2.0,
     strokeOpacity: 1.0,
     fillColor: 'green',
     fillOpacity: 0.3,
   };
   
   const styleClicked = {
     ...styleDefault,
     strokeColor: 'blue',
     fillColor: 'blue',
     fillOpacity: 0.5,
   };
   
   const styleMouseMove = {
      ...styleDefault,
     strokeWeight: 4.0
   };
   
   function applyStyle(/* FeatureStyleFunctionOptions */ params) {
     const datasetFeature = params.feature;
     // Note, 'globalid' is an attribute in this dataset.
     //@ts-ignore
     if (lastClickedFeatureIds.includes(datasetFeature.datasetAttributes['globalid'])) {
       return styleClicked;
     }
     //@ts-ignore
     if (lastInteractedFeatureIds.includes(datasetFeature.datasetAttributes['globalid'])) {
       return styleMouseMove;
     }
     return styleDefault;
   }
   index.ts

   Nota:leggi la guida sull'utilizzo di TypeScript e Google Maps.

   JavaScript

   const styleDefault = {
     strokeColor: "green",
     strokeWeight: 2.0,
     strokeOpacity: 1.0,
     fillColor: "green",
     fillOpacity: 0.3,
   };
   const styleClicked = {
     ...styleDefault,
     strokeColor: "blue",
     fillColor: "blue",
     fillOpacity: 0.5,
   };
   const styleMouseMove = {
     ...styleDefault,
     strokeWeight: 4.0,
   };
   
   function applyStyle(/* FeatureStyleFunctionOptions */ params) {
     const datasetFeature = params.feature;
   
     // Note, 'globalid' is an attribute in this dataset.
     //@ts-ignore
     if (
       lastClickedFeatureIds.includes(datasetFeature.datasetAttributes["globalid"])
     ) {
       return styleClicked;
     }
   
     //@ts-ignore
     if (
       lastInteractedFeatureIds.includes(
         datasetFeature.datasetAttributes["globalid"],
       )
     ) {
       return styleMouseMove;
     }
     return styleDefault;
   }
   index.js

Codice di esempio completo

TypeScript

let map: google.maps.Map;
let lastInteractedFeatureIds = [];
let lastClickedFeatureIds = [];
let datasetLayer;

// Note, 'globalid' is an attribute in this Dataset.
function handleClick(/* MouseEvent */ e) {
  if (e.features) {
    lastClickedFeatureIds =
        e.features.map((f) => f.datasetAttributes['globalid']);
  }
  //@ts-ignore
  datasetLayer.style = applyStyle;
}

function handleMouseMove(/* MouseEvent */ e) {
  if (e.features) {
    lastInteractedFeatureIds =
        e.features.map((f) => f.datasetAttributes['globalid']);
  }
  //@ts-ignore
  datasetLayer.style = applyStyle;
}

async function initMap() {
  // Request needed libraries.
  const { Map } = await google.maps.importLibrary('maps') as google.maps.MapsLibrary;

  const position = {lat: 40.780101, lng: -73.967780};
  map = new Map(document.getElementById('map') as HTMLElement, {
    zoom: 13,
    center: position,
    mapId: 'b98e588c46685dd7',
    mapTypeControl: false,
  });

  // Dataset ID for NYC park data.
  const datasetId = '6fe13aa9-b900-45e7-b636-3236672c3f4f';

  //@ts-ignore
  datasetLayer = map.getDatasetFeatureLayer(datasetId);
  datasetLayer.style = applyStyle;

  datasetLayer.addListener('click', handleClick);
  datasetLayer.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 = [];
      datasetLayer.style = applyStyle;
    }
  });
  const attributionDiv = document.createElement('div');
  const attributionControl = createAttribution(map);

  attributionDiv.appendChild(attributionControl);
  map.controls[google.maps.ControlPosition.LEFT_BOTTOM].push(attributionDiv);
}

const styleDefault = {
  strokeColor: 'green',
  strokeWeight: 2.0,
  strokeOpacity: 1.0,
  fillColor: 'green',
  fillOpacity: 0.3,
};

const styleClicked = {
  ...styleDefault,
  strokeColor: 'blue',
  fillColor: 'blue',
  fillOpacity: 0.5,
};

const styleMouseMove = {
   ...styleDefault,
  strokeWeight: 4.0
};

function applyStyle(/* FeatureStyleFunctionOptions */ params) {
  const datasetFeature = params.feature;
  // Note, 'globalid' is an attribute in this dataset.
  //@ts-ignore
  if (lastClickedFeatureIds.includes(datasetFeature.datasetAttributes['globalid'])) {
    return styleClicked;
  }
  //@ts-ignore
  if (lastInteractedFeatureIds.includes(datasetFeature.datasetAttributes['globalid'])) {
    return styleMouseMove;
  }
  return styleDefault;
}

function createAttribution(map) {
  const attributionLabel = document.createElement('div');

  // Define CSS styles.
  attributionLabel.style.backgroundColor = '#fff';
  attributionLabel.style.opacity = '0.7';
  attributionLabel.style.fontFamily = 'Roboto,Arial,sans-serif';
  attributionLabel.style.fontSize = '10px';
  attributionLabel.style.padding = '2px';
  attributionLabel.style.margin = '2px';
  attributionLabel.textContent = 'Data source: NYC Open Data';
  return attributionLabel;
}

initMap();
index.ts

Nota:leggi la guida sull'utilizzo di TypeScript e Google Maps.

JavaScript

let map;
let lastInteractedFeatureIds = [];
let lastClickedFeatureIds = [];
let datasetLayer;

// Note, 'globalid' is an attribute in this Dataset.
function handleClick(/* MouseEvent */ e) {
  if (e.features) {
    lastClickedFeatureIds = e.features.map(
      (f) => f.datasetAttributes["globalid"],
    );
  }

  //@ts-ignore
  datasetLayer.style = applyStyle;
}

function handleMouseMove(/* MouseEvent */ e) {
  if (e.features) {
    lastInteractedFeatureIds = e.features.map(
      (f) => f.datasetAttributes["globalid"],
    );
  }

  //@ts-ignore
  datasetLayer.style = applyStyle;
}

async function initMap() {
  // Request needed libraries.
  const { Map } = await google.maps.importLibrary("maps");
  const position = { lat: 40.780101, lng: -73.96778 };

  map = new Map(document.getElementById("map"), {
    zoom: 13,
    center: position,
    mapId: "b98e588c46685dd7",
    mapTypeControl: false,
  });

  // Dataset ID for NYC park data.
  const datasetId = "6fe13aa9-b900-45e7-b636-3236672c3f4f";

  //@ts-ignore
  datasetLayer = map.getDatasetFeatureLayer(datasetId);
  datasetLayer.style = applyStyle;
  datasetLayer.addListener("click", handleClick);
  datasetLayer.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 = [];
      datasetLayer.style = applyStyle;
    }
  });

  const attributionDiv = document.createElement("div");
  const attributionControl = createAttribution(map);

  attributionDiv.appendChild(attributionControl);
  map.controls[google.maps.ControlPosition.LEFT_BOTTOM].push(attributionDiv);
}

const styleDefault = {
  strokeColor: "green",
  strokeWeight: 2.0,
  strokeOpacity: 1.0,
  fillColor: "green",
  fillOpacity: 0.3,
};
const styleClicked = {
  ...styleDefault,
  strokeColor: "blue",
  fillColor: "blue",
  fillOpacity: 0.5,
};
const styleMouseMove = {
  ...styleDefault,
  strokeWeight: 4.0,
};

function applyStyle(/* FeatureStyleFunctionOptions */ params) {
  const datasetFeature = params.feature;

  // Note, 'globalid' is an attribute in this dataset.
  //@ts-ignore
  if (
    lastClickedFeatureIds.includes(datasetFeature.datasetAttributes["globalid"])
  ) {
    return styleClicked;
  }

  //@ts-ignore
  if (
    lastInteractedFeatureIds.includes(
      datasetFeature.datasetAttributes["globalid"],
    )
  ) {
    return styleMouseMove;
  }
  return styleDefault;
}

function createAttribution(map) {
  const attributionLabel = document.createElement("div");

  // Define CSS styles.
  attributionLabel.style.backgroundColor = "#fff";
  attributionLabel.style.opacity = "0.7";
  attributionLabel.style.fontFamily = "Roboto,Arial,sans-serif";
  attributionLabel.style.fontSize = "10px";
  attributionLabel.style.padding = "2px";
  attributionLabel.style.margin = "2px";
  attributionLabel.textContent = "Data source: NYC Open Data";
  return attributionLabel;
}

initMap();
index.js