Google map api V2 resize screen to match a circle drawn

Question

I am drawing a circle in a map (on the current location of the user) and I want the screen to zoom to have the circle in full screen with some margin. What I'm doing for now:

drawCercleAroundPin(_googleMap, DataManager.RADIUS_SEARCH_CERCLE, _location);

moveCamera(_googleMap, (10 / ((DataManager.RADIUS_SEARCH_CERCLE / 900) + 1))+10, 2000, _location, null);

Well I tried some idiotic calculus since i wasn't able to find a proper solution...

Does anyone have an idea?

score 6 · Accepted Answer · edited May 23 '17 at 12:08

If I understand correctly,you want your map to fit circle bounds ? If so

add a circle like this

mMap.addCircle(new CircleOptions()
        .center(new LatLng(location.getLatitude(), location.getLongitude()))
        .radius(100)
        .strokeColor(Color.RED)
        .fillColor(Color.BLUE));

**then you need bounding box of your circle,read this **

LatLngBounds bounds = boundsWithCenterAndLatLngDistance(new LatLng(location.getLatitude(), location.getLongitude()),200,200);

**and try **

private static final double ASSUMED_INIT_LATLNG_DIFF = 1.0;
private static final float ACCURACY = 0.01f;

public static LatLngBounds boundsWithCenterAndLatLngDistance(LatLng center, float latDistanceInMeters, float lngDistanceInMeters) {
    latDistanceInMeters /= 2;
    lngDistanceInMeters /= 2;
    LatLngBounds.Builder builder = LatLngBounds.builder();
    float[] distance = new float[1];
    {
        boolean foundMax = false;
        double foundMinLngDiff = 0;
        double assumedLngDiff = ASSUMED_INIT_LATLNG_DIFF;
        do {
            Location.distanceBetween(center.latitude, center.longitude, center.latitude, center.longitude + assumedLngDiff, distance);
            float distanceDiff = distance[0] - lngDistanceInMeters;
            if (distanceDiff < 0) {
                if (!foundMax) {
                    foundMinLngDiff = assumedLngDiff;
                    assumedLngDiff *= 2;
                } else {
                    double tmp = assumedLngDiff;
                    assumedLngDiff += (assumedLngDiff - foundMinLngDiff) / 2;
                    foundMinLngDiff = tmp;
                }
            } else {
                assumedLngDiff -= (assumedLngDiff - foundMinLngDiff) / 2;
                foundMax = true;
            }
        } while (Math.abs(distance[0] - lngDistanceInMeters) > lngDistanceInMeters * ACCURACY);
        LatLng east = new LatLng(center.latitude, center.longitude + assumedLngDiff);
        builder.include(east);
        LatLng west = new LatLng(center.latitude, center.longitude - assumedLngDiff);
        builder.include(west);
    }
    {
        boolean foundMax = false;
        double foundMinLatDiff = 0;
        double assumedLatDiffNorth = ASSUMED_INIT_LATLNG_DIFF;
        do {
            Location.distanceBetween(center.latitude, center.longitude, center.latitude + assumedLatDiffNorth, center.longitude, distance);
            float distanceDiff = distance[0] - latDistanceInMeters;
            if (distanceDiff < 0) {
                if (!foundMax) {
                    foundMinLatDiff = assumedLatDiffNorth;
                    assumedLatDiffNorth *= 2;
                } else {
                    double tmp = assumedLatDiffNorth;
                    assumedLatDiffNorth += (assumedLatDiffNorth - foundMinLatDiff) / 2;
                    foundMinLatDiff = tmp;
                }
            } else {
                assumedLatDiffNorth -= (assumedLatDiffNorth - foundMinLatDiff) / 2;
                foundMax = true;
            }
        } while (Math.abs(distance[0] - latDistanceInMeters) > latDistanceInMeters * ACCURACY);
        LatLng north = new LatLng(center.latitude + assumedLatDiffNorth, center.longitude);
        builder.include(north);
    }
    {
        boolean foundMax = false;
        double foundMinLatDiff = 0;
        double assumedLatDiffSouth = ASSUMED_INIT_LATLNG_DIFF;
        do {
            Location.distanceBetween(center.latitude, center.longitude, center.latitude - assumedLatDiffSouth, center.longitude, distance);
            float distanceDiff = distance[0] - latDistanceInMeters;
            if (distanceDiff < 0) {
                if (!foundMax) {
                    foundMinLatDiff = assumedLatDiffSouth;
                    assumedLatDiffSouth *= 2;
                } else {
                    double tmp = assumedLatDiffSouth;
                    assumedLatDiffSouth += (assumedLatDiffSouth - foundMinLatDiff) / 2;
                    foundMinLatDiff = tmp;
                }
            } else {
                assumedLatDiffSouth -= (assumedLatDiffSouth - foundMinLatDiff) / 2;
                foundMax = true;
            }
        } while (Math.abs(distance[0] - latDistanceInMeters) > latDistanceInMeters * ACCURACY);
        LatLng south = new LatLng(center.latitude - assumedLatDiffSouth, center.longitude);
        builder.include(south);
    }
    return builder.build();
}

finally call

CameraUpdateFactory#newLatLngBounds(bounds, padding);

I feel it's bad to copy code from other answers and it's much better to link to the original post. I plan to refactor this code as it is suboptimal and would also need to refactor it here. Anyway I also fixed code usage where you were sending radius (100 meters) instead of diameter (200 meters). The original question was about showing region defined by center, width and height. For circle width and height are equal to 2 * radius. For anyone interested this is original answer: http://stackoverflow.com/questions/6224671/mkcoordinateregionmakewithdistance-equvivalent-in-android/16417396#16417396 — MaciejGórski, Jun 24 '13 at 16:19
Thanks you are right, linking to the original answer is always best to avoid multi post... anyway I'll take a look into it — An-droid, Jun 25 '13 at 07:31
ok i've found another answer that fit my needs best. But i marked your answer since you provided some solution http://stackoverflow.com/questions/15220404/adjusting-google-map-api-v2-zoom-level-in-android — An-droid, Jun 25 '13 at 08:02

Google map api V2 resize screen to match a circle drawn

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