Google Maps Drawing Manager limit to 1 polygon

I am creating a map with the google maps v3 API. Using the drawing manager to draw shapes. Is there a way to disable the polygon button after 1 polygon has been drawn? I been reading thru the API but can't find any events for polygon start, only for polygoncomplete.

Maybe a way to detect drawingmode change? or remove google.maps.drawing.OverlayType.POLYGON but put it back if the current polygon was deleted?

Answers


documentation.

  1. Start from this sample.

  2. hide the drawing control in the polygoncomplete event

        drawingManager.setOptions({
          drawingControl: false
        });
    
  3. add the drawing control in the deleteSelectedShape function

      drawingManager.setOptions({
       drawingControl: true
     });
    
  4. configure the drawingManager to only add polygons

      drawingControlOptions: {
        drawingModes: [
          google.maps.drawing.OverlayType.POLYGON
        ]
      },
    

working example

code snippet:

var drawingManager;
var selectedShape;
var colors = ['#1E90FF', '#FF1493', '#32CD32', '#FF8C00', '#4B0082'];
var selectedColor;
var colorButtons = {};

function clearSelection() {
  if (selectedShape) {
    selectedShape.setEditable(false);
    selectedShape = null;
  }
}

function setSelection(shape) {
  clearSelection();
  selectedShape = shape;
  shape.setEditable(true);
  selectColor(shape.get('fillColor') || shape.get('strokeColor'));
}

function deleteSelectedShape() {
  if (selectedShape) {
    selectedShape.setMap(null);
    // To show:
    drawingManager.setOptions({
      drawingControl: true
    });
  }
}

function selectColor(color) {
  selectedColor = color;
  for (var i = 0; i < colors.length; ++i) {
    var currColor = colors[i];
    colorButtons[currColor].style.border = currColor == color ? '2px solid #789' : '2px solid #fff';
  }

  // Retrieves the current options from the drawing manager and replaces the
  // stroke or fill color as appropriate.
  var polylineOptions = drawingManager.get('polylineOptions');
  polylineOptions.strokeColor = color;
  drawingManager.set('polylineOptions', polylineOptions);

  var rectangleOptions = drawingManager.get('rectangleOptions');
  rectangleOptions.fillColor = color;
  drawingManager.set('rectangleOptions', rectangleOptions);

  var circleOptions = drawingManager.get('circleOptions');
  circleOptions.fillColor = color;
  drawingManager.set('circleOptions', circleOptions);

  var polygonOptions = drawingManager.get('polygonOptions');
  polygonOptions.fillColor = color;
  drawingManager.set('polygonOptions', polygonOptions);
}

function setSelectedShapeColor(color) {
  if (selectedShape) {
    if (selectedShape.type == google.maps.drawing.OverlayType.POLYLINE) {
      selectedShape.set('strokeColor', color);
    } else {
      selectedShape.set('fillColor', color);
    }
  }
}

function makeColorButton(color) {
  var button = document.createElement('span');
  button.className = 'color-button';
  button.style.backgroundColor = color;
  google.maps.event.addDomListener(button, 'click', function() {
    selectColor(color);
    setSelectedShapeColor(color);
  });

  return button;
}

function buildColorPalette() {
  var colorPalette = document.getElementById('color-palette');
  for (var i = 0; i < colors.length; ++i) {
    var currColor = colors[i];
    var colorButton = makeColorButton(currColor);
    colorPalette.appendChild(colorButton);
    colorButtons[currColor] = colorButton;
  }
  selectColor(colors[0]);
}

function initialize() {
  var map = new google.maps.Map(document.getElementById('map'), {
    zoom: 10,
    center: new google.maps.LatLng(22.344, 114.048),
    mapTypeId: google.maps.MapTypeId.ROADMAP,
    disableDefaultUI: true,
    zoomControl: true
  });

  var polyOptions = {
    strokeWeight: 0,
    fillOpacity: 0.45,
    editable: true
  };
  // Creates a drawing manager attached to the map that allows the user to draw
  // markers, lines, and shapes.
  drawingManager = new google.maps.drawing.DrawingManager({
    drawingMode: google.maps.drawing.OverlayType.POLYGON,
    drawingControlOptions: {
      drawingModes: [
        google.maps.drawing.OverlayType.POLYGON
      ]
    },
    markerOptions: {
      draggable: true
    },
    polylineOptions: {
      editable: true
    },
    rectangleOptions: polyOptions,
    circleOptions: polyOptions,
    polygonOptions: polyOptions,
    map: map
  });

  google.maps.event.addListener(drawingManager, 'overlaycomplete', function(event) {
    if (event.type == google.maps.drawing.OverlayType.CIRCLE) {
      var radius = event.overlay.getRadius();
    }
  });
  google.maps.event.addListener(drawingManager, 'overlaycomplete', function(e) {
    if (e.type != google.maps.drawing.OverlayType.MARKER) {
      // Switch back to non-drawing mode after drawing a shape.
      drawingManager.setDrawingMode(null);
      // To hide:
      drawingManager.setOptions({
        drawingControl: false
      });

      // Add an event listener that selects the newly-drawn shape when the user
      // mouses down on it.
      var newShape = e.overlay;
      newShape.type = e.type;
      google.maps.event.addListener(newShape, 'click', function() {
        setSelection(newShape);
      });
      setSelection(newShape);
    }
  });

  // Clear the current selection when the drawing mode is changed, or when the
  // map is clicked.
  google.maps.event.addListener(drawingManager, 'drawingmode_changed', clearSelection);
  google.maps.event.addListener(map, 'click', clearSelection);
  google.maps.event.addDomListener(document.getElementById('delete-button'), 'click', deleteSelectedShape);

  buildColorPalette();
}
google.maps.event.addDomListener(window, 'load', initialize);
#map,
html,
body {
  padding: 0;
  margin: 0;
  height: 100%;
}

#panel {
  width: 200px;
  font-family: Arial, sans-serif;
  font-size: 13px;
  float: right;
  margin: 10px;
}

#color-palette {
  clear: both;
}

.color-button {
  width: 14px;
  height: 14px;
  font-size: 0;
  margin: 2px;
  float: left;
  cursor: pointer;
}

#delete-button {
  margin-top: 5px;
}
<script src="http://maps.google.com/maps/api/js?key=AIzaSyCkUOdZ5y7hMm0yrcCQoCvLwzdM6M8s5qk&libraries=drawing"></script>
<div id="panel">
  <div id="color-palette"></div>
  <div>
    <button id="delete-button">Delete Selected Shape</button>
  </div>
</div>
<div id="map"></div>

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