How to style editable circle controls in Google Maps

Question

Does anyone know of an easy way to style the user controls (white dots on the bouns of the radius) for the editable circles in Google Maps? I cant find any way of doing this in the API documentation. At the very least it would be great to have the dots on a lower zindex than my pin but modify the zindex options of both has no results.

Answer 1

One option would be to do something like this example from the "article": Fun with MVC in the Google Maps Javascript API v3 documentation/ The handles there are just markers, the distance from the center is bound to the raduis, the center marker is bound to the center of the circle.

example fiddle

function init() { 
  var mapDiv = document.getElementById('map-canvas'); 
  var map = new google.maps.Map(mapDiv, { 
        center: new google.maps.LatLng(37.790234970864, -122.39031314844), 
        zoom: 8, 
        mapTypeId: google.maps.MapTypeId.ROADMAP 
      }); 
  var distanceWidget = new DistanceWidget(map);
  google.maps.event.addListener(distanceWidget, 'distance_changed', function() { 
   displayInfo(distanceWidget); 
  }); 

  google.maps.event.addListener(distanceWidget, 'position_changed', function() { 
    displayInfo(distanceWidget); 
  });
} 

google.maps.event.addDomListener(window, 'load', init); 

Modified DistanceWidget code (changed the marker icons):

  /** 
   * A distance widget that will display a circle that can be resized and will 
   * provide the radius in km. 
   * 
   * @param {google.maps.Map} map The map on which to attach the distance widget. 
   * 
   * @constructor 
   */
  function DistanceWidget(map) {
      this.set('map', map);
      this.set('position', map.getCenter());

      var marker = new google.maps.Marker({
          draggable: true,
          icon: {
              url: "https://maps.gstatic.com/intl/en_us/mapfiles/markers2/measle_blue.png",
              size: new google.maps.Size(7, 7),
              anchor: new google.maps.Point(4, 4)
          },
          title: 'Move me!'
      });

      // Bind the marker map property to the DistanceWidget map property 
      marker.bindTo('map', this);

      // Bind the marker position property to the DistanceWidget position 
      // property 
      marker.bindTo('position', this);

      // Create a new radius widget 
      var radiusWidget = new RadiusWidget();

      // Bind the radiusWidget map to the DistanceWidget map 
      radiusWidget.bindTo('map', this);

      // Bind the radiusWidget center to the DistanceWidget position 
      radiusWidget.bindTo('center', this, 'position');

      // Bind to the radiusWidgets' distance property 
      this.bindTo('distance', radiusWidget);

      // Bind to the radiusWidgets' bounds property 
      this.bindTo('bounds', radiusWidget);
  }
  DistanceWidget.prototype = new google.maps.MVCObject();

  /** 
   * A radius widget that add a circle to a map and centers on a marker. 
   * 
   * @constructor 
   */
  function RadiusWidget() {
      var circle = new google.maps.Circle({
          strokeWeight: 2
      });

      // Set the distance property value, default to 50km. 
      this.set('distance', 50);

      // Bind the RadiusWidget bounds property to the circle bounds property. 
      this.bindTo('bounds', circle);

      // Bind the circle center to the RadiusWidget center property 
      circle.bindTo('center', this);

      // Bind the circle map to the RadiusWidget map 
      circle.bindTo('map', this);

      // Bind the circle radius property to the RadiusWidget radius property 
      circle.bindTo('radius', this);

      this.addSizer_();
  }
  RadiusWidget.prototype = new google.maps.MVCObject();


  /** 
   * Update the radius when the distance has changed. 
   */
  RadiusWidget.prototype.distance_changed = function () {
      this.set('radius', this.get('distance') * 1000);
  };
  /** 
   * Add the sizer marker to the map. 
   * 
   * @private 
   */
  RadiusWidget.prototype.addSizer_ = function () {
      var sizer = new google.maps.Marker({
          draggable: true,
          icon: {
              url: "https://maps.gstatic.com/intl/en_us/mapfiles/markers2/measle_blue.png",
              size: new google.maps.Size(7, 7),
              anchor: new google.maps.Point(4, 4)
          },
          title: 'Drag me!'
      });

      sizer.bindTo('map', this);
      sizer.bindTo('position', this, 'sizer_position');

      var me = this;
      google.maps.event.addListener(sizer, 'drag', function () {
          // Set the circle distance (radius) 
          me.setDistance();
      });
  };

  /** 
   * Update the center of the circle and position the sizer back on the line. 
   * 
   * Position is bound to the DistanceWidget so this is expected to change when 
   * the position of the distance widget is changed. 
   */
  RadiusWidget.prototype.center_changed = function () {
      var bounds = this.get('bounds');

      // Bounds might not always be set so check that it exists first. 
      if (bounds) {
          var lng = bounds.getNorthEast().lng();

          // Put the sizer at center, right on the circle. 
          var position = new google.maps.LatLng(this.get('center').lat(), lng);
          this.set('sizer_position', position);
      }
  };

  /** 
   * Calculates the distance between two latlng locations in km. 
   * @see http://www.movable-type.co.uk/scripts/latlong.html 
   * 
   * @param {google.maps.LatLng} p1 The first lat lng point. 
   * @param {google.maps.LatLng} p2 The second lat lng point. 
   * @return {number} The distance between the two points in km. 
   * @private 
   */
  RadiusWidget.prototype.distanceBetweenPoints_ = function (p1, p2) {
      if (!p1 || !p2) {
          return 0;
      }

      var R = 6371; // Radius of the Earth in km 
      var dLat = (p2.lat() - p1.lat()) * Math.PI / 180;
      var dLon = (p2.lng() - p1.lng()) * Math.PI / 180;
      var a = Math.sin(dLat / 2) * Math.sin(dLat / 2) + Math.cos(p1.lat() * Math.PI / 180) * Math.cos(p2.lat() * Math.PI / 180) * Math.sin(dLon / 2) * Math.sin(dLon / 2);
      var c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1 - a));
      var d = R * c;
      return d;
  };


  /** 
   * Set the distance of the circle based on the position of the sizer. 
   */
  RadiusWidget.prototype.setDistance = function () {
      // As the sizer is being dragged, its position changes.  Because the 
      // RadiusWidget's sizer_position is bound to the sizer's position, it will 
      // change as well. 
      var pos = this.get('sizer_position');
      var center = this.get('center');
      var distance = this.distanceBetweenPoints_(center, pos);

      // Set the distance property for any objects that are bound to it 
      this.set('distance', distance);
  };

  function displayInfo(widget) {
      var info = document.getElementById('info');
      info.innerHTML = 'Position: ' + widget.get('position').toUrlValue(3) + ', distance: ' + widget.get('distance').toFixed(3);
  }

code snippet:

function init() {
  var mapDiv = document.getElementById('map-canvas');
  var map = new google.maps.Map(mapDiv, {
    center: new google.maps.LatLng(37.790234970864, -122.39031314844),
    zoom: 8,
    mapTypeId: google.maps.MapTypeId.ROADMAP
  });
  var distanceWidget = new DistanceWidget(map);
  google.maps.event.addListener(distanceWidget, 'distance_changed', function() {
    displayInfo(distanceWidget);
  });

  google.maps.event.addListener(distanceWidget, 'position_changed', function() {
    displayInfo(distanceWidget);
  });
}

google.maps.event.addDomListener(window, 'load', init);

/** 
 * A distance widget that will display a circle that can be resized and will
 * provide the radius in km.
 *
 * @param {google.maps.Map} map The map on which to attach the distance widget.
 *
 * @constructor
 */
function DistanceWidget(map) {
  this.set('map', map);
  this.set('position', map.getCenter());

  var marker = new google.maps.Marker({
    draggable: true,
    icon: {
      url: "https://maps.gstatic.com/intl/en_us/mapfiles/markers2/measle_blue.png",
      size: new google.maps.Size(7, 7),
      anchor: new google.maps.Point(4, 4)
    },
    title: 'Move me!'
  });

  // Bind the marker map property to the DistanceWidget map property 
  marker.bindTo('map', this);

  // Bind the marker position property to the DistanceWidget position 
  // property 
  marker.bindTo('position', this);

  // Create a new radius widget 
  var radiusWidget = new RadiusWidget();

  // Bind the radiusWidget map to the DistanceWidget map 
  radiusWidget.bindTo('map', this);

  // Bind the radiusWidget center to the DistanceWidget position 
  radiusWidget.bindTo('center', this, 'position');

  // Bind to the radiusWidgets' distance property 
  this.bindTo('distance', radiusWidget);

  // Bind to the radiusWidgets' bounds property 
  this.bindTo('bounds', radiusWidget);
}
DistanceWidget.prototype = new google.maps.MVCObject();

/** 
 * A radius widget that add a circle to a map and centers on a marker.
 *
 * @constructor
 */
function RadiusWidget() {
  var circle = new google.maps.Circle({
    strokeWeight: 2
  });

  // Set the distance property value, default to 50km. 
  this.set('distance', 50);

  // Bind the RadiusWidget bounds property to the circle bounds property. 
  this.bindTo('bounds', circle);

  // Bind the circle center to the RadiusWidget center property 
  circle.bindTo('center', this);

  // Bind the circle map to the RadiusWidget map 
  circle.bindTo('map', this);

  // Bind the circle radius property to the RadiusWidget radius property 
  circle.bindTo('radius', this);

  this.addSizer_();
}
RadiusWidget.prototype = new google.maps.MVCObject();


/** 
 * Update the radius when the distance has changed.
 */
RadiusWidget.prototype.distance_changed = function() {
  this.set('radius', this.get('distance') * 1000);
};
/** 
 * Add the sizer marker to the map.
 *
 * @private
 */
RadiusWidget.prototype.addSizer_ = function() {
  var sizer = new google.maps.Marker({
    draggable: true,
    icon: {
      url: "https://maps.gstatic.com/intl/en_us/mapfiles/markers2/measle_blue.png",
      size: new google.maps.Size(7, 7),
      anchor: new google.maps.Point(4, 4)
    },
    title: 'Drag me!'
  });

  sizer.bindTo('map', this);
  sizer.bindTo('position', this, 'sizer_position');

  var me = this;
  google.maps.event.addListener(sizer, 'drag', function() {
    // Set the circle distance (radius) 
    me.setDistance();
  });
};

/** 
 * Update the center of the circle and position the sizer back on the line.
 *
 * Position is bound to the DistanceWidget so this is expected to change when
 * the position of the distance widget is changed.
 */
RadiusWidget.prototype.center_changed = function() {
  var bounds = this.get('bounds');

  // Bounds might not always be set so check that it exists first. 
  if (bounds) {
    var lng = bounds.getNorthEast().lng();

    // Put the sizer at center, right on the circle. 
    var position = new google.maps.LatLng(this.get('center').lat(), lng);
    this.set('sizer_position', position);
  }
};

/** 
 * Calculates the distance between two latlng locations in km.
 * @see http://www.movable-type.co.uk/scripts/latlong.html
 *
 * @param {google.maps.LatLng} p1 The first lat lng point.
 * @param {google.maps.LatLng} p2 The second lat lng point.
 * @return {number} The distance between the two points in km.
 * @private
 */
RadiusWidget.prototype.distanceBetweenPoints_ = function(p1, p2) {
  if (!p1 || !p2) {
    return 0;
  }

  var R = 6371; // Radius of the Earth in km 
  var dLat = (p2.lat() - p1.lat()) * Math.PI / 180;
  var dLon = (p2.lng() - p1.lng()) * Math.PI / 180;
  var a = Math.sin(dLat / 2) * Math.sin(dLat / 2) + Math.cos(p1.lat() * Math.PI / 180) * Math.cos(p2.lat() * Math.PI / 180) * Math.sin(dLon / 2) * Math.sin(dLon / 2);
  var c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1 - a));
  var d = R * c;
  return d;
};


/** 
 * Set the distance of the circle based on the position of the sizer.
 */
RadiusWidget.prototype.setDistance = function() {
  // As the sizer is being dragged, its position changes.  Because the 
  // RadiusWidget's sizer_position is bound to the sizer's position, it will 
  // change as well. 
  var pos = this.get('sizer_position');
  var center = this.get('center');
  var distance = this.distanceBetweenPoints_(center, pos);

  // Set the distance property for any objects that are bound to it 
  this.set('distance', distance);
};

function displayInfo(widget) {
  var info = document.getElementById('info');
  info.innerHTML = 'Position: ' + widget.get('position').toUrlValue(3) + ', distance: ' + widget.get('distance').toFixed(3);
}

html,
body,
#map-canvas {
  height: 100%;
  margin: 0px;
  padding: 0px
}

<script src="https://maps.googleapis.com/maps/api/js?v=3&libraries=geometry"></script>
<div id="info"></div>
<div id="map-canvas"></div>

Answer 2

I'm afraid you can't. The API provides no control over those handles, and since the circles live inside a canvas, there's no easy way to identify the element in order to style it.

Edit:

You can declare your circle as non-editable and allow edits only on mouseover.

var circle=new google.maps.Circle({ 
    center: map.getCenter(),
    map: map,
    editable: false
});

google.maps.event.addListener(circle, 'mouseover', function () {
    circle.set('editable',true);
});

google.maps.event.addListener(circle, 'mouseout', function () {
    circle.set('editable',false);
});