getBoundingBox(0) giving weird results

[moving-bits]

To my understanding (but I may be wrong), getBoundingBox(0) returns the minimum box of the map's current viewport in lat/lon format.

This sometimes works, at other times I get seemingly weird results like a small area around 0/0 or some other coordinates unrelated to the viewport currently being displayed on the map.

Observation is with Mapsforge offline maps, with either a single offline map or in "combined" mode. (Haven't tried online maps yet.)

What is the correct way to get the actual coordinates of top/left and bottom/right corner for the map?

[moving-bits]

Example: I used mMap.animator().animateTo(bounds) to set the viewport to [N 53° 32.754' · E 013° 14.274',N 53° 34.860' · E 013° 17.567'].

A second later (to allow for animation) I checked the value of getBoundingBox(), and it returned S 00° 01.749' · W 000° 01.011',N 00° 01.749' · E 000° 01.011' (although displaying a viewport related to the one I requested, though not including it fully, but that's a different issue).

I a different test with the same target bounds I got this: N 20° 05.481' · E 004° 15.925',N 20° 08.371' · E 004° 17.704' - both is completely unrelated to the bounds I requested the map to zoom to.

[devemux86]

Map.getBoundingBox(0) should be the method,
although we haven't seen anything strange so far.

[devemux86]

Are you sure there isn't a thread issue?

[moving-bits]

this is the code part from the fragment:

public void zoomToBounds(final BoundingBox bounds) {
  if (bounds.getLatitudeSpan() == 0 && bounds.getLongitudeSpan() == 0) {
      mMap.animator().animateTo(new GeoPoint(bounds.getMaxLatitude(), bounds.getMaxLongitude()));
  } else {
      if (mMap.getWidth() == 0 || mMap.getHeight() == 0) {
          //See Bug #14948: w/o map width/height the bounds can't be calculated
          // -> postphone animation to later on UI thread (where map width/height will be set)
          mMap.post(() -> mMap.animator().animateTo(bounds));
      } else {
          mMap.animator().animateTo(bounds);
      }
  }
  ActivityMixin.postDelayed(() -> {
      BoundingBox bb = getBoundingBox();
      Log.e("bounds: " + GeopointFormatter.format(GeopointFormatter.Format.LAT_LON_DECMINUTE, Geopoint.forE6(bb.minLatitudeE6, bb.minLongitudeE6))
          + "," + GeopointFormatter.format(GeopointFormatter.Format.LAT_LON_DECMINUTE, Geopoint.forE6(bb.maxLatitudeE6, bb.maxLongitudeE6)));
  }, 1000);
}

(the last block only does some formatting to the results of `getBoundingBox()`)

[devemux86]

Can you create a small code example showing the report?
Then we can test it with VTM samples.

If it is reproducible, it would be easier to check what is going on.

When using setMapPosition instead of animation, does it work better?

[moving-bits]

I've changed the code to use setMapPosition(), but that does not seem to have any different result:

public void zoomToBounds(final BoundingBox bounds) {
    logBounds("requested: ", bounds);
    if (bounds.getLatitudeSpan() == 0 && bounds.getLongitudeSpan() == 0) {
        mMap.animator().animateTo(new GeoPoint(bounds.getMaxLatitude(), bounds.getMaxLongitude()));
    } else {
        if (mMap.getWidth() == 0 || mMap.getHeight() == 0) {
            //See Bug #14948: w/o map width/height the bounds can't be calculated
            // -> postphone animation to later on UI thread (where map width/height will be set)
            mMap.post(() -> {
                // mMap.animator().animateTo(bounds);
                MapPosition mp = mMap.getMapPosition();
                mp.setByBoundingBox(bounds, mMap.getWidth(), mMap.getHeight());
                mMap.setMapPosition(mp);
            });
        } else {
            // mMap.animator().animateTo(bounds);
            MapPosition mp = mMap.getMapPosition();
            mp.setByBoundingBox(bounds, mMap.getWidth(), mMap.getHeight());
            mMap.setMapPosition(mp);
        }
    }
    ActivityMixin.postDelayed(() -> logBounds("result: ", getBoundingBox()), 1000);
}

private void logBounds(final String info, final BoundingBox bb) {
    Log.e(info + GeopointFormatter.format(GeopointFormatter.Format.LAT_LON_DECMINUTE, Geopoint.forE6(bb.minLatitudeE6, bb.minLongitudeE6))
            + "," + GeopointFormatter.format(GeopointFormatter.Format.LAT_LON_DECMINUTE, Geopoint.forE6(bb.maxLatitudeE6, bb.maxLongitudeE6)));
}

Logcat output is:

[main] requested: N 53° 32.894' · E 013° 15.233',N 53° 33.818' · E 013° 16.501'
[main] result: S 00° 01.749' · W 000° 01.011',N 00° 01.749' · E 000° 01.011'

(but I do get useful results sometimes, so it may be a timing issue. Will retest with a longer delay for the second logging call)

[devemux86]

Maybe a conversion issue between degrees vs microdegrees?