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Overlay Map Types

This example uses a tile overlay MapType to overlay the map's tile coordinates on top of the default map tiles.

Read the documentation.

TypeScript

/*
 * This demo illustrates the coordinate system used to display map tiles in the
 * API.
 *
 * Tiles in Google Maps are numbered from the same origin as that for
 * pixels. For Google's implementation of the Mercator projection, the origin
 * tile is always at the northwest corner of the map, with x values increasing
 * from west to east and y values increasing from north to south.
 *
 * Try panning and zooming the map to see how the coordinates change.
 */

class CoordMapType {
  tileSize: google.maps.Size;

  constructor(tileSize: google.maps.Size) {
    this.tileSize = tileSize;
  }
  getTile(
    coord: google.maps.Point,
    zoom: number,
    ownerDocument: Document
  ): HTMLElement {
    const div = ownerDocument.createElement("div");
    div.innerHTML = String(coord);
    div.style.width = this.tileSize.width + "px";
    div.style.height = this.tileSize.height + "px";
    div.style.fontSize = "10";
    div.style.borderStyle = "solid";
    div.style.borderWidth = "1px";
    div.style.borderColor = "#AAAAAA";
    return div;
  }
  releaseTile(tile: Element): void {}
}

function initMap(): void {
  const map = new google.maps.Map(
    document.getElementById("map") as HTMLElement,
    {
      zoom: 10,
      center: { lat: 41.85, lng: -87.65 }
    }
  );

  // Insert this overlay map type as the first overlay map type at
  // position 0. Note that all overlay map types appear on top of
  // their parent base map.
  map.overlayMapTypes.insertAt(
    0,
    new CoordMapType(new google.maps.Size(256, 256))
  );
}

JavaScript

/*
 * This demo illustrates the coordinate system used to display map tiles in the
 * API.
 *
 * Tiles in Google Maps are numbered from the same origin as that for
 * pixels. For Google's implementation of the Mercator projection, the origin
 * tile is always at the northwest corner of the map, with x values increasing
 * from west to east and y values increasing from north to south.
 *
 * Try panning and zooming the map to see how the coordinates change.
 */
class CoordMapType {
  constructor(tileSize) {
    this.tileSize = tileSize;
  }
  getTile(coord, zoom, ownerDocument) {
    const div = ownerDocument.createElement("div");
    div.innerHTML = String(coord);
    div.style.width = this.tileSize.width + "px";
    div.style.height = this.tileSize.height + "px";
    div.style.fontSize = "10";
    div.style.borderStyle = "solid";
    div.style.borderWidth = "1px";
    div.style.borderColor = "#AAAAAA";
    return div;
  }
  releaseTile(tile) {}
}

function initMap() {
  const map = new google.maps.Map(document.getElementById("map"), {
    zoom: 10,
    center: { lat: 41.85, lng: -87.65 }
  });
  // Insert this overlay map type as the first overlay map type at
  // position 0. Note that all overlay map types appear on top of
  // their parent base map.
  map.overlayMapTypes.insertAt(
    0,
    new CoordMapType(new google.maps.Size(256, 256))
  );
}

CSS


      

HTML

<!DOCTYPE html>
<html>
  <head>
    <title>Overlay Map Types</title>
    <script src="https://polyfill.io/v3/polyfill.min.js?features=default"></script>
    <script
      src="https://maps.googleapis.com/maps/api/js?key=YOUR_API_KEY&callback=initMap&libraries=&v=weekly"
      defer
    ></script>
    <link rel="stylesheet" type="text/css" href="./style.css" />
    <script src="./app.js"></script>
  </head>
  <body>
    <div id="map"></div>
  </body>
</html>

All

<!DOCTYPE html>
<html>
  <head>
    <title>Overlay Map Types</title>
    <script src="https://polyfill.io/v3/polyfill.min.js?features=default"></script>
    <script
      src="https://maps.googleapis.com/maps/api/js?key=YOUR_API_KEY&callback=initMap&libraries=&v=weekly"
      defer
    ></script>
    <style type="text/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>
    <script>
      "use strict";

      /*
       * This demo illustrates the coordinate system used to display map tiles in the
       * API.
       *
       * Tiles in Google Maps are numbered from the same origin as that for
       * pixels. For Google's implementation of the Mercator projection, the origin
       * tile is always at the northwest corner of the map, with x values increasing
       * from west to east and y values increasing from north to south.
       *
       * Try panning and zooming the map to see how the coordinates change.
       */
      class CoordMapType {
        constructor(tileSize) {
          this.tileSize = tileSize;
        }

        getTile(coord, zoom, ownerDocument) {
          const div = ownerDocument.createElement("div");
          div.innerHTML = String(coord);
          div.style.width = this.tileSize.width + "px";
          div.style.height = this.tileSize.height + "px";
          div.style.fontSize = "10";
          div.style.borderStyle = "solid";
          div.style.borderWidth = "1px";
          div.style.borderColor = "#AAAAAA";
          return div;
        }

        releaseTile(tile) {}
      }

      function initMap() {
        const map = new google.maps.Map(document.getElementById("map"), {
          zoom: 10,
          center: {
            lat: 41.85,
            lng: -87.65
          }
        }); // Insert this overlay map type as the first overlay map type at
        // position 0. Note that all overlay map types appear on top of
        // their parent base map.

        map.overlayMapTypes.insertAt(
          0,
          new CoordMapType(new google.maps.Size(256, 256))
        );
      }
    </script>
  </head>
  <body>
    <div id="map"></div>
  </body>
</html>
"use strict"; /* * This demo illustrates the coordinate system used to display map tiles in the * API. * * Tiles in Google Maps are numbered from the same origin as that for * pixels. For Google's implementation of the Mercator projection, the origin * tile is always at the northwest corner of the map, with x values increasing * from west to east and y values increasing from north to south. * * Try panning and zooming the map to see how the coordinates change. */ class CoordMapType { constructor(tileSize) { this.tileSize = tileSize; } getTile(coord, zoom, ownerDocument) { const div = ownerDocument.createElement("div"); div.innerHTML = String(coord); div.style.width = this.tileSize.width + "px"; div.style.height = this.tileSize.height + "px"; div.style.fontSize = "10"; div.style.borderStyle = "solid"; div.style.borderWidth = "1px"; div.style.borderColor = "#AAAAAA"; return div; } releaseTile(tile) {} } function initMap() { const map = new google.maps.Map(document.getElementById("map"), { zoom: 10, center: { lat: 41.85, lng: -87.65 } }); // Insert this overlay map type as the first overlay map type at // position 0. Note that all overlay map types appear on top of // their parent base map. map.overlayMapTypes.insertAt( 0, new CoordMapType(new google.maps.Size(256, 256)) ); }
/* 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; }
<!DOCTYPE html> <html> <head> <title>Overlay Map Types</title> <script src="https://polyfill.io/v3/polyfill.min.js?features=default"></script> <script src="https://maps.googleapis.com/maps/api/js?key=AIzaSyCb1xprYSpXd0q_yDsJ1W2UGhfl9_YGKU0&callback=initMap&libraries=&v=weekly" defer ></script> <!-- jsFiddle will insert css and js --> </head> <body> <div id="map"></div> </body> </html>