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Overlays - Polylines

Polylines are a series of points that trace out a line. They can be used to outline areas or to indicate paths.

A polyine is represented by the Polyline class.

Adding a Polyline​

To add a polyline, create an instance of the Polyline class and pass the object to the addPolyline function.

var polyline:Polyline = new Polyline()
    .setColour( 0xFFFF00FF )
    .addPoint( new LatLng( -27.5, 150 ) )
    .addPoint( new LatLng( -27.5, 151 ) );

NativeMaps.service.addPolyline( polyline );

Z Order​

You can set the z-index of a polyline to ensure certain lines remain above other overlays. The z-index specifies the stack order of this line, relative to other overlays on the map.

A high z-index is drawn above objects with lower z-indexes. The default z-index value is 0.

To change the z-index simply set the zIndex property of the Polyline:

var polyline:Polyline = new Polyline()
    .setZIndex( 300 );

Encoded Path​

As a polyline can be made up of a large number of points conversion from AS3 to native objects can be time consuming process.

In order to speed this up we suggest investigating encoding a polyline as a string and using the encoded path instead of an Array of LatLng values. This reduces the conversions needed from many LatLng objects to a single String and will speed up the conversion considerably.

To set the encoded path of a polyline use the setEncodedPath function:

var polyline:Polyline = new Polyline()
    .setEncodedPath( encodedPath );

Setting the encoded path of a polyline will override the points on Android.

On iOS the encoded path is ignored.

Encoding​

To encode a polyline you can use the encode function in the PolyUtil. This will take a series of LatLng objects and encode the path of these points as a String. You can read the details of this process in the PolyUtil class.

var points:Vector.<LatLng> = ...;

var encodedPath:String = PolyUtil.encode(points);

Automatic encoding​

When adding a large polyline (> 100 points) the NativeMaps extension will automatically encode the points to improve performance. This means that you don't have to manually encode the path for large polylines but simply add points as normal and the extension will handle the encoding internally.