Gestire gli eventi del mouse

Seleziona la piattaforma: Android iOS JavaScript

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

Attiva gli eventi del livello del set di dati

Per attivare gli eventi in un livello del set di dati:

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

    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;
      }
    });

    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;
      }
    });
    

  2. Aggiungi il codice del gestore di eventi per definire lo stile della caratteristica 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;
    }

    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;
    }
    

  3. Utilizza una funzione di stile delle caratteristiche per applicare gli stili. La funzione di stile della funzionalità riportata qui applica lo stile in base al tipo di interazione. Qui sono definiti tre stili: uno per applicare il grassetto al bordo su mousemove, uno per cambiare lo sfondo su mousemove e uno 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;
    }

    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;
    }
    

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();

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();