Get the lat lng when plotting the polygon points - google-maps

Question

I am trying to get the lat lng of the polygon while drawing the polygon on google map. Does anyone know what event is triggered when we plot the points of polygon.
Basically what I am trying to do is undo/redo function for the polygon. So when a user plots 2 points one then clicks undo then it should be able to delete 1 point on one click.
As the map click event is disabled while drawing a polygon how to get the lat lng points? Is it possible what I am trying to do? Can anyone please help me with this? Any links or examples that I could refer to?
Below is my code to draw polygon:
drawingManager = new google.maps.drawing.DrawingManager({
drawingMode: google.maps.drawing.OverlayType.POLYGON,
drawingControl: false,
polygonOptions: {
strokeWeight: 2,
fillOpacity: 0.2,
editable: true,
fillColor: '#FFF000',
strokeColor: '#FFF000',
geodesic: true,
suppressUndo: true
},
polylineOptions: {
editable: false,
suppressUndo: true
}
});
drawingManager.setMap(map);

Answer 1

Try this
var myPoly;
google.maps.event.addListener(drawingManager, 'polygoncomplete', function(polygon) {
myPoly = polygon;
get_coordinates(polygon);//call to get coordinates
//editing polygon function
google.maps.event.addListener(polygon.getPath(), 'set_at', function() {
get_coordinates(polygon);//call to get coordinates
});
var newShape = polygon.overlay;
//newShape.type = polygon.type;
google.maps.event.addListener(newShape, 'click', function() {
setSelection(newShape);
});
setSelection(newShape);
});
and the get coordinate function
//function to get coordinates of polygon
function get_coordinates(polygon){
var full_path = [];//initialize array for set coordinates.
polygon.getPath().forEach(function(elem, index){
full_path.push(elem.toUrlValue());
});
return full_path;
}

Answer 2

ok. I can give you all the functions you need. You can integrate last code with the following. And you cannot delete any point but replace it.
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);
}
}
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,
markerOptions: {
draggable: true
},
polylineOptions: {
editable: true
},
rectangleOptions: polyOptions,
circleOptions: polyOptions,
polygonOptions: polyOptions,
map: map
});
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);
// 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);