Mausereignisse verarbeiten

Plattform auswählen: Android iOS JavaScript

Sorgen Sie dafür, dass Datenfeatures auf mousemove und click Ereignisse reagieren, und verwenden Sie sie, um das Erscheinungsbild eines Features basierend auf der Nutzerinteraktion zu ändern.

Ereignisse auf Dataset-Ebene aktivieren

So aktivieren Sie Ereignisse auf Dataset-Ebene:

  1. Registrieren Sie eine Dataset-Ebene für Ereignisbenachrichtigungen, indem Sie die addListener() Funktion für jedes Ereignis auf der Dataset-Ebene aufrufen, das Sie registrieren möchten. In diesem Beispiel wird der Karte auch ein Listener hinzugefügt.

    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. Fügen Sie Event-Handler-Code hinzu, um das ausgewählte Feature basierend auf der Art der Interaktion zu gestalten.

    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. Verwenden Sie eine Stilfunktion für Elemente, um Stile anzuwenden. Die hier gezeigte Stilfunktion für Elemente wendet Stile bedingt basierend auf der Art der Interaktion an. Hier sind drei Stile definiert: einer, um den Rahmen bei mousemove fett zu machen, einer, um den Hintergrund bei click zu ändern, und ein Standardstil.

    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;
    }
    

Vollständiges Codebeispiel

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();