CODEWITHSUNDEEP
androidgoogle-mapsgoogle-polyline
Zar E Ahmer
Zar E Ahmer

Reputation: 34390

Remove a line from PolyLine map in Google Map android V2?

I have searched in google and find this answer where i can remove all polyLine of a Map. But I want to remove only a particular line from the poly Line. For Example I want to remove the line from 2nd to 3rd LatLng in the given code. I want to change color of a particular line of a polyLine or make it transparent. And I also want to add a clickListener to PolyLine 

   PolylineOptions rectOptions = new PolylineOptions()
            .add(new LatLng(37.35, -122.0))
            .add(new LatLng(37.45, -122.0))  // North of the previous point, but at the same longitude
            .add(new LatLng(37.45, -122.2))  // Same latitude, and 30km to the west
            .add(new LatLng(37.35, -122.2))  // Same longitude, and 16km to the south
            .add(new LatLng(37.35, -122.0)).width(5).color(Color.RED);; // Closes the polyline.

Polyline polyline = myMap.addPolyline(rectOptions);

Main goal is to remove/make it transparent a particular line of a PolyLine on click or tap.

PolylineOptions line= new PolylineOptions().add(HAMBURG,// these are latlong
                                                            KIEL,
                                                            KIEL2,
                                                            KIEL3
                                                        new LatLng(40.748963847316034,
                                                                   -73.96807193756104)
                                                            )
                                                   .width(5).color(Color.RED);



                    Polyline polyline=  googleMap.addPolyline(line);

And i want to remov line between KIEL1 and KIEL2

Upvotes: 0

Views: 1597

Answers (1)

Simas
Simas

Reputation: 44188

You'll have to manually remove points from the polyline.

EDIT:

Step by step:

Create a List of polylines:

List<Polyline> mPolylines = new ArrayList<Polyline>();

Add PolylineOptions to the map:

Polyline polyline1 = myMap.addPolyline(rectOptions1);
Polyline polyline2 = myMap.addPolyline(rectOptions2);
Polyline polyline3 = myMap.addPolyline(rectOptions3);

Then save the added polylines to your array

mPolylines.add(polyline1);
mPolylines.add(polyline2);
mPolylines.add(polyline3);

Now at any time you can trim the polyline like so:

// Get polyline1
List<LatLng> points = mPolylines.get(0).getPoints();
// Set the bounds of points to remove (inclusive)
int startPoint = 1, endPoint = 2; // will remove kiel1 and kiel2
// Remove the points
for (int i=startPoint; i<=endPoint; i++) {
    points.remove(i);
}
// Added this line as getPoints returns a copy
mPolylines.get(0).setPoints(points);

Now in theory this should work fine. I found that the points don't actually change after setPoints.

I even tried:

Polyline polyline = mPolylines.get(0);
// Get copy of the points
List<LatLng> points = polyline.getPoints();
mPolylines.get(0).remove();
mPolylines.remove(0);
for (int i=3000; i<7000; i++) {
    points.remove(i);
}
// Create a PolylineOptions object with the new points
PolylineOptions polylineOptions = new  PolylineOptions().addAll(points);
mPolylines.add(0, mMap.addPolyline(polylineOptions));

And to my surprise a new Polyline was added (I can tell by the changed stroke width and color), but it still used the old points, even though points.size() returned the correct (trimmed) count.

I'm not sure why this is so, perhaps some error in my code. You can try these methods yourself and see if you are any luckier.

Upvotes: 1

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