Remove itemizedOverlay during onLocationChanged

Question

What I want to achieve is to have 2 kinds of markers displayed on a map.

1)Red markers that display events drawn from a database (done that - itemizedOverlay)

2)Orange marker which will dynamically display the user's location on the map(itemizedOverlay2).

I'm using ItemizedOverlay to have the 2 different layers (one for events and one for user location) but I have an issue with the dynamic marker that shows user position.

ISSUE:

What happens is the LocationListener successfully gets the latitude/longitude and places a point on the map BUT the previous point still exists. So I have a trail of markers showing the user's location.

I have implemented a few ways I found searching the internet but none of which happen during the calling of onLocationChanged.

class myLocationListener implements LocationListener{
        OverlayItem overlayItem;


        @Override
        public void onLocationChanged(Location location) {

            if (location != null){

                mapOverlays.remove(itemizedOverlay2);
                mapView.invalidate();

                lat = location.getLatitude();
                longi = location.getLongitude();
                GeoPoint point = new GeoPoint((int) (lat * 1E6), (int) (longi * 1E6));
                mControl.animateTo(point);

                overlayItem = new OverlayItem(point, "My Location", "This is probably where you are");
                itemizedOverlay2.addOverlay(overlayItem);
                mapOverlays.add(itemizedOverlay2);

            }

        }

I know that you might need more of my code but let's just stay at this block see if someone sees where I'm getting it wrong.

Thank you.

This link might be useful to you : [Android MapView can't remove marker](http://stackoverflow.com/a/4634287/3577656). — Rajal, Aug 12 '14 at 11:56

score 1 · Accepted Answer · answered Apr 25 '12 at 15:30

1

You haven't posted the code for the class that itemizedOverlay2 belongs to, but I'm guessing it extends ItemizedOverlay. Since it has an addOverlay() method, I'm also guessing that it has a .clear() method.

If so, the you should call the clear() before you add the new location

itemizedOverlay2.clear();
itemizedOverlay2.addOverlay(overlayItem);

answered Apr 25 '12 at 15:30

NickT

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you are correct about itemizedOverlay2 extends a class called MyItemizedOverlay thing is there is not clear() method. clear() method is available for the mapOverlays mapOverlays.clear() Which I have tried and it clears BOTH itemizedOverlay and itemizedOverlay2 – bubbly Apr 25 '12 at 16:00
You should write a clear() method then. public void clear() {mOverlays.clear();} – NickT Apr 25 '12 at 16:10
Wouldn't that remove BOTH items? (itemizedOverlay and itemizedOverlay2) ? – bubbly Apr 25 '12 at 17:27
No it wouldn't, call clear to remove the item that's already on the overlay, then addOverlay to add the new one, as in the posted answer. – NickT Apr 25 '12 at 17:39
You are right, it worked. I'm new to android and even though I tried the clear() method out, I cleared both the items. Didn't think about using it the way you just mentioned :) Silly of me. Thank you. – bubbly Apr 25 '12 at 17:46

score 0 · Answer 2 · answered Apr 25 '12 at 15:32

0

Use built in class MyLocationOverlay :

position = new MyLocationOverlay(this, mapView);
position.enableMyLocation();
mapOverlays.add(position);

answered Apr 25 '12 at 15:32

vtuhtan

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7
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I have considered that, but it is an alternative way, not a solution to my problem. But with MyLocationOverlay I don't know how to change frequency of receiving the position and generally I do not know if it can do all the things what the LocationListener can. – bubbly Apr 25 '12 at 16:03

Remove itemizedOverlay during onLocationChanged

2 Answers2