Develop Reference

Direction of target annotation when outside of visible area in android

I would like to show the direction images on all sides of the screen. E.g. if the target's location is the right side of user's location and is outside of the visible map area, then I want to add a direction image as shown on the picture below (The Green annotation is user's location, red one is the direction for the target, which is out of bounds of the screen):
I found a solution for IOS here:
Direction of target annotation when outside of visible area
But unable to find solution in android yet.

Finally i found the solution:
//Add at class level
private static final int NORTH = 1;
private static final int SOUTH = 2;
private static final int EAST = 3;
private static final int WEST = 4;
private ImageView imgEast;
private ImageView imgWest;
private ImageView imgNorth;
private ImageView imgSouth;
private LatLng source;
private LatLng target;
//In onCreate or somewhere else
imgEast = (ImageView) findViewById(R.id.east);
imgWest = (ImageView) findViewById(R.id.west);
imgNorth = (ImageView) findViewById(R.id.north);
imgSouth = (ImageView) findViewById(R.id.south);
source = new LatLng(31.499851, 74.317489);
target = new LatLng(33.736189, 73.096848);
//Add after populating map
googleMap.setOnCameraChangeListener(new OnCameraChangeListener() {
#Override
public void onCameraChange(CameraPosition position) {
if(isLocationVisible(source) && !isLocationVisible(target)){
double bearing = calculateBearing(source, target);
showCardinalPointDirection(bearing);
}else{
hideCardinalPointers();
}
}
});
public boolean isLocationVisible(LatLng latLng){
LatLngBounds curScreen = googleMap.getProjection()
.getVisibleRegion().latLngBounds;
if(curScreen.contains(latLng)){
return true;
}else{
return false;
}
}
private double calculateBearing(LatLng source, LatLng target){
double lat1 = DegreesToRadians(source.latitude);
double lon1 = DegreesToRadians(source.longitude);
double lat2 = DegreesToRadians(target.latitude);
double lon2 = DegreesToRadians(target.longitude);
double dLon = lon2 - lon1;
double y = Math.sin(dLon) * Math.cos(lat2);
double x = Math.cos(lat1) * Math.sin(lat2) - Math.sin(lat1) * Math.cos(lat2) * Math.cos(dLon);
double radiansBearing = Math.atan2(y, x);
if(radiansBearing < 0.0)
radiansBearing += 2*Math.PI;
return RadiansToDegrees(radiansBearing);
}
private void showCardinalPointDirection(double bearing){
int direction = cardinalPointWithBearing(bearing);
View activeDirection = null;
switch(direction){
case EAST:
activeDirection = this.imgEast;
break;
case WEST:
activeDirection = this.imgWest;
break;
case SOUTH:
activeDirection = this.imgSouth;
break;
case NORTH:
activeDirection = this.imgNorth;
break;
}
//Hide all pointers
hideCardinalPointers();
//Visible only active direction pointer
activeDirection.setVisibility(View.VISIBLE);
//Set rotation to show direction
activeDirection.setRotation((float)bearing);
}
private int cardinalPointWithBearing(double bearing){
if (bearing > 45.0 && bearing <= 135.0) {
return EAST;
} else if (bearing > 135.0 && bearing <= 225.0) {
return SOUTH;
} else if (bearing > 225.0 && bearing <= 315.0) {
return WEST;
} else {
return NORTH;
}
}
double DegreesToRadians(double degrees) {
return degrees * Math.PI / 180.0;
};
double RadiansToDegrees(double radians) {
return radians * 180.0/Math.PI;
};
private void hideCardinalPointers(){
imgEast.setVisibility(View.INVISIBLE);
imgWest.setVisibility(View.INVISIBLE);
imgSouth.setVisibility(View.INVISIBLE);
imgNorth.setVisibility(View.INVISIBLE);
}

Animate the rotation of the Marker in google map v2

i am using google maps v2.
i have a marker on map, this marker changes rotation every while.
I want to animate the rotation of my maker to rotate smoothly.
Can anyone help please

That's mine implementation of smooth marker movement with maker image rotation (when it's set to FLAT [important]). The marker is moved to the requested location smoothly plus it's rotated to the requested degree with a proper direction. For example, when moving from 5deg to 355deg it moves anticlockwise, when 355deg to 5deg it moves clockwise.
public void animateMarker(final Location location)
{
if (myMarkerLOC != null) {
final LatLngInterpolator latLngInterpolator = new LatLngInterpolator.LinearFixed();
ValueAnimator valueAnimator = new ValueAnimator();
final LatLng startPosition = myMarkerLOC.getPosition();
final float startRotation = myMarkerLOC.getRotation();
final float angle = 180 - Math.abs(Math.abs(startRotation - location.getBearing()) - 180);
final float right = WhichWayToTurn(startRotation, location.getBearing());
valueAnimator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener()
{
#Override
public void onAnimationUpdate(ValueAnimator animation)
{
try {
if (myMarkerLOC == null) // oops... destroying map during animation...
{
return;
}
float v = animation.getAnimatedFraction();
LatLng newPosition = latLngInterpolator.interpolate(v, startPosition, PositionUtil.toLatLng(location));
float rotation = startRotation + right * v * angle;
myMarkerLOC.setRotation((float) rotation);
myMarkerLOC.setPosition(newPosition);
} catch (Exception ex) {
// I don't care atm..
}
}
});
valueAnimator.setFloatValues(0, 1);
valueAnimator.setDuration(300);
valueAnimator.start();
}
}
private float WhichWayToTurn(float currentDirection, float targetDirection)
{
float diff = targetDirection - currentDirection;
if (Math.abs(diff) == 0)
{
return 0;
}
if(diff > 180)
{
return -1;
}
else
{
return 1;
}
}
public interface LatLngInterpolator
{
public LatLng interpolate(float fraction, LatLng a, LatLng b);
public class Linear implements LatLngInterpolator
{
#Override
public LatLng interpolate(float fraction, LatLng a, LatLng b)
{
double lat = (b.latitude - a.latitude) * fraction + a.latitude;
double lng = (b.longitude - a.longitude) * fraction + a.longitude;
return new LatLng(lat, lng);
}
}
public class LinearFixed implements LatLngInterpolator
{
#Override
public LatLng interpolate(float fraction, LatLng a, LatLng b) {
double lat = (b.latitude - a.latitude) * fraction + a.latitude;
double lngDelta = b.longitude - a.longitude;
// Take the shortest path across the 180th meridian.
if (Math.abs(lngDelta) > 180) {
lngDelta -= Math.signum(lngDelta) * 360;
}
double lng = lngDelta * fraction + a.longitude;
return new LatLng(lat, lng);
}
}
}
Missing implementation of "toLatLong" method:
public static LatLng toLatLng(final Location location)
{
return new LatLng(location.getLatitude(), location.getLongitude());
}
I hope that helps.

boolean isRotating = false;
public void rotateMarker(final Marker marker, final float toRotation) {
if(!isRotating) {
isRotating = true;
final Handler handler = new Handler();
final long start = SystemClock.uptimeMillis();
final float startRotation = marker.getRotation();
final long duration = 1000;
float deltaRotation = Math.abs(toRotation - startRotation) % 360;
final float rotation = (deltaRotation > 180 ? 360 - deltaRotation : deltaRotation) *
((toRotation - startRotation >= 0 && toRotation - startRotation <= 180) || (toRotation - startRotation <= -180 && toRotation - startRotation >= -360) ? 1 : -1);
final LinearInterpolator interpolator = new LinearInterpolator();
handler.post(new Runnable() {
#Override
public void run() {
long elapsed = SystemClock.uptimeMillis() - start;
float t = interpolator.getInterpolation((float) elapsed / duration);
marker.setRotation((startRotation + t * rotation) % 360);
if (t < 1.0) {
// Post again 16ms later.
handler.postDelayed(this, 16);
} else {
isRotating = false;
}
}
});
}
}
This is how I rotate the marker, I don't know this is the best code or not.
But I think it will prevent wrong rotation. EDIT: Add var isRotating (Thanks #Trần Văn Huy)
Update Explanation:

static public void rotateMarker(final Marker marker, final float toRotation, GoogleMap map) {
final Handler handler = new Handler();
final long start = SystemClock.uptimeMillis();
final float startRotation = marker.getRotation();
final long duration = 1555;
final Interpolator interpolator = new LinearInterpolator();
handler.post(new Runnable() {
#Override
public void run() {
long elapsed = SystemClock.uptimeMillis() - start;
float t = interpolator.getInterpolation((float) elapsed / duration);
float rot = t * toRotation + (1 -t) * startRotation;
marker.setRotation(-rot > 180 ? rot/2 : rot);
if (t < 1.0) {
// Post again 16ms later.
handler.postDelayed(this, 16);
}
}
});
}
i have managed to do it :)

With #Bhagaskara Liancer answer.Add var isMarkerRotating with help marker rotate smoothly.
private boolean isMarkerRotating = false;
public void rotateMarker(final Marker marker, final float toRotation) {
if(!isMarkerRotating){
final Handler handler = new Handler();
final long start = SystemClock.uptimeMillis();
final float startRotation = marker.getRotation();
final long duration = 1000;
float deltaRotation = Math.abs(toRotation - startRotation) % 360;
final float rotation = (deltaRotation > 180 ? 360 - deltaRotation : deltaRotation) * ((toRotation - startRotation >= 0 && toRotation - startRotation <= 180)
|| (toRotation - startRotation <=-180 && toRotation- startRotation>= -360) ? 1 : -1);
final LinearInterpolator interpolator = new LinearInterpolator();
handler.post(new Runnable() {
#Override
public void run() {
isMarkerRotating = true;
long elapsed = SystemClock.uptimeMillis() - start;
float t = interpolator.getInterpolation((float) elapsed / duration);
marker.setRotation((startRotation + t* rotation)%360);
if (t < 1.0) {
// Post again 16ms later.
handler.postDelayed(this, 16);
}else {
isMarkerRotating = false;
}
}
});
}
}

Here is the simple example
You can use the following MarkerAnimation class for animating marker with rotation.
import android.graphics.Point;
import android.location.Location;
import android.os.Handler;
import android.os.SystemClock;
import android.view.animation.Interpolator;
import android.view.animation.LinearInterpolator;
import com.gogrocerycart.settings.Constants;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.Projection;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.Marker;
/**
* Created by Vinil Chandran on 7/6/18.
*/
public class MarkerAnimation {
private static Location fromPosition;
private static float angle = 0;
public static void move(GoogleMap mMap, final Marker marker, final Location toPosition) {
if (fromPosition != null && marker != null && toPosition != null) {
final Handler handlerRotation = new Handler();
final long startAngle = SystemClock.uptimeMillis();
final float startRotation = marker.getRotation();
final long durationRotation = 300;
final Interpolator interpolatorRotation = new LinearInterpolator();
float bearing = fromPosition.bearingTo(toPosition);
Print.e("Bearing:" + bearing);
angle = bearing<0?(360+bearing):bearing;
angle = angle%360f;
Print.e("Angle:" + angle);
handlerRotation.post(new Runnable() {
#Override
public void run() {
long elapsed = SystemClock.uptimeMillis() - startAngle;
float t = interpolatorRotation.getInterpolation((float) elapsed / durationRotation);
float rot = t * angle + (1 - t) * startRotation;
float mAngle = -rot > 180 ? rot / 2 : rot;
marker.setRotation(mAngle);
if (t < 1.0) {
handlerRotation.postDelayed(this, 16);
} else {
final Handler handler = new Handler();
final long start = SystemClock.uptimeMillis();
Projection projection = mMap.getProjection();
Point startPoint = projection.toScreenLocation(marker.getPosition());
final LatLng startLatLng = projection.fromScreenLocation(startPoint);
final long duration = Constants.LOCATION_REQUEST_INTERVAL;
final Interpolator interpolator = new LinearInterpolator();
handler.post(new Runnable() {
#Override
public void run() {
long elapsed = SystemClock.uptimeMillis() - start;
float t = interpolator.getInterpolation((float) elapsed
/ duration);
double lng = t * toPosition.getLongitude() + (1 - t)
* startLatLng.longitude;
double lat = t * toPosition.getLatitude() + (1 - t)
* startLatLng.latitude;
marker.setPosition(new LatLng(lat, lng));
if (t < 1.0) {
// Post again 16ms later.
handler.postDelayed(this, 16);
}
}
});
}
}
});
}
fromPosition = toPosition;
}
}
Just call the following code for moving the marker when the location is changed.
if (carMarker != null) {
MarkerAnimation.move(mMap,carMarker, location);
}

Had the same problem, in my case I used ValueAnimator
static public void rotateMarker(final Marker marker, final float toRotation) {
ValueAnimator animator = ValueAnimator.ofFloat(marker.getRotation(), toRotation);
animator.setDuration(duration);
animator.setInterpolator(new AccelerateDecelerateInterpolator());
animator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
#Override
public void onAnimationUpdate(ValueAnimator animation) {
float rotate = Float.parseFloat(animation.getAnimatedValue().toString());
marker.setRotation(rotate);
}
});
animator.start();
}

The answer from Alexandr Kolesnik seems to be the most simple.
Here's a Kotlin extension version of it.
You can pass in an interpolator to avoid a little thrash.
fun Marker.animateRotation(toRotation: Float, interpolator: TimeInterpolator? = AccelerateDecelerateInterpolator()) {
val animator = ValueAnimator.ofFloat(rotation, toRotation)
animator.duration = 500
animator.interpolator = interpolator
animator.addUpdateListener {
rotation = it.animatedValue as? Float ?: return#addUpdateListener
}
animator.start()
}

You would want to use MarkerOption rotation method
public MarkerOptions rotation (float rotation)
Sets the rotation of the marker in degrees clockwise about the
marker's anchor point. The axis of rotation is perpendicular to the
marker. A rotation of 0 corresponds to the default position of the
marker. When the marker is flat on the map, the default position is
North aligned and the rotation is such that the marker always remains
flat on the map. When the marker is a billboard, the default position
is pointing up and the rotation is such that the marker is always
facing the camera. The default value is 0.
Returns the object for which the method was called, with the new
rotation set.

Google Maps Android API v2 limit panning [duplicate]

I've added GroundOverlay to map and want to limit scrolling and zooming within this area.
How to limit scrolling within some bounds on android google maps?
Is it possible to get instantly motion points from MapFragment?
Please, help me.

Constraining the camera has (finally!) been added as a feature as part of the release of Google Play Services 9.4 -- you can call setLatLngBoundsForCameraTarget(LatLngBounds bounds) to set the allowed panning area.
// Create a LatLngBounds that includes the city of Adelaide in Australia.
final LatLngBounds ADELAIDE = new LatLngBounds(
new LatLng(-35.0, 138.58), new LatLng(-34.9, 138.61));
// Constrain the camera target to the Adelaide bounds.
mMap.setLatLngBoundsForCameraTarget(ADELAIDE);
You can find a thorough explanation in the documentation: Restricting the user's panning to a given area and a sample activity in GitHub.

May be it is too late, but here is my solution:
Disabled built-in GoogleMap's gestures.
Added custom gestures (for scrolling, fling and scaling).
Checking for allowed area when processing events.
Set bounds/zoom manually with standard Map's functions.
And here is my example:
[UPDATED]
There was a problem - when touch events were recieved before map was initialized.
check null values in onInterceptTouchEvent
Also I have discovered that my solution is slightly slowly than build-in function.
import android.content.Context;
import android.graphics.Point;
import android.os.Handler;
import android.util.AttributeSet;
import android.view.GestureDetector;
import android.view.MotionEvent;
import android.view.ScaleGestureDetector;
import com.google.android.gms.common.GooglePlayServicesNotAvailableException;
import com.google.android.gms.maps.CameraUpdate;
import com.google.android.gms.maps.CameraUpdateFactory;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.GoogleMapOptions;
import com.google.android.gms.maps.MapView;
import com.google.android.gms.maps.MapsInitializer;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.VisibleRegion;
public class RestrictedMapView extends MapView {
public static float MAX_ZOOM = 20;
public static float MIN_ZOOM = 5;
public static float MIN_ZOOM_FOR_FLING = 7;
public static double MAX_LONGITUDE = 183.61;
public static double MIN_LONGITUDE = 159.31;
public static double MAX_LATITUDE = -32.98;
public static double MIN_LATITUDE = -53.82;
public static double DEF_LATITUDE = -41.78;
public static double DEF_LONGITUDE = 173.02;
public static float DEF_ZOOM = 7;
private Handler mHandler = new Handler();
private Context mContext;
private VisibleRegion mLastCorrectRegion = null;
private boolean mIsInAnimation = false;
public RestrictedMapView(Context c, AttributeSet a, int o) {
super(c, a, o);
init(c);
}
public RestrictedMapView(Context c, AttributeSet a) {
super(c, a);
init(c);
}
public RestrictedMapView(Context c) {
super(c);
init(c);
}
public RestrictedMapView(Context c, GoogleMapOptions o) {
super(c, o);
init(c);
}
private GestureDetector mGestureDetector = null;
private GestureDetector.SimpleOnGestureListener mGestudeListener =
new GestureDetector.SimpleOnGestureListener() {
#Override
public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) {
if (mIsInAnimation) return false;
GoogleMap map = getMap();
LatLng target = map.getCameraPosition().target;
Point screenPoint = map.getProjection().toScreenLocation(target);
Point newPoint = new Point(screenPoint.x + (int)distanceX, screenPoint.y + (int)distanceY);
LatLng mapNewTarget = map.getProjection().fromScreenLocation(newPoint);
CameraUpdate update = CameraUpdateFactory.newLatLngZoom(
mapNewTarget,map.getCameraPosition().zoom);
tryUpdateCamera(update, 0);
return true;
}
#Override
public boolean onFling (MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
if (mIsInAnimation) return false;
GoogleMap map = getMap();
double zoom = map.getCameraPosition().zoom;
if (zoom < MIN_ZOOM_FOR_FLING)
return false;
int velocity = (int) Math.sqrt(velocityX * velocityX + velocityY * velocityY);
if (velocity < 500) return false;
double k1 = 0.002d; /*exipemental*/
double k2 = 0.002d;/*exipemental*/
LatLng target = map.getCameraPosition().target;
Point screenPoint = map.getProjection().toScreenLocation(target);
Point newPoint = new Point(screenPoint.x - (int)(velocityX * k1 * zoom * zoom/*exipemental*/),
screenPoint.y - (int)(velocityY * k1 * zoom * zoom/*exipemental*/));
LatLng mapNewTarget = map.getProjection().fromScreenLocation(newPoint);
CameraUpdate update = CameraUpdateFactory.newLatLngZoom(
mapNewTarget,map.getCameraPosition().zoom);
tryUpdateCamera(update, (int)(velocity * k2 * zoom * zoom) /*exipemental*/);
return true;
}
};
private ScaleGestureDetector mScaleGestureDetector = null;
private ScaleGestureDetector.SimpleOnScaleGestureListener mScaleGestudeListener =
new ScaleGestureDetector.SimpleOnScaleGestureListener() {
#Override
public boolean onScale (ScaleGestureDetector detector) {
if (mIsInAnimation) return false;
GoogleMap map = getMap();
double zoom = map.getCameraPosition().zoom;
double k = 1d / detector.getScaleFactor();
int x = (int) detector.getFocusX();
int y = (int) detector.getFocusY();
LatLng mapFocus = map.getProjection().
fromScreenLocation(new Point(x, y));
LatLng target = map.getCameraPosition().target;
zoom = zoom + Math.log(detector.getScaleFactor()) / Math.log(2d);
if (zoom < MIN_ZOOM)
if (zoom == MIN_ZOOM) return false;
else zoom = MIN_ZOOM;
if (zoom > MAX_ZOOM)
if (zoom == MAX_ZOOM) return false;
else zoom = MAX_ZOOM;
double dx = norm(mapFocus.longitude) - norm(target.longitude);
double dy = mapFocus.latitude - target.latitude;
double dk = 1d - 1d / k;
LatLng newTarget = new LatLng(target.latitude - dy * dk,
norm(target.longitude) - dx * dk);
CameraUpdate update = CameraUpdateFactory.newLatLngZoom(newTarget, (float) zoom);
tryUpdateCamera(update, 0);
return true;
}
};
private void tryUpdateCamera(CameraUpdate update, int animateTime) {
GoogleMap map = getMap();
final VisibleRegion reg = map.getProjection().getVisibleRegion();
if (animateTime <= 0) {
map.moveCamera(update);
checkCurrentRegion(reg);
} else {
mIsInAnimation = true;
map.animateCamera(update, animateTime, new GoogleMap.CancelableCallback() {
#Override
public void onFinish() {
mIsInAnimation = false;
checkCurrentRegion(reg);
}
#Override
public void onCancel() {
mIsInAnimation = false;
checkCurrentRegion(reg);
}
});
}
}
private void checkCurrentRegion(VisibleRegion oldReg) {
GoogleMap map = getMap();
VisibleRegion regNew = map.getProjection().getVisibleRegion();
if (checkBounds(regNew)) {
mLastCorrectRegion = regNew;
} else {
if (mLastCorrectRegion != null)
oldReg = mLastCorrectRegion;
mIsInAnimation = true;
map.animateCamera(CameraUpdateFactory.newLatLngBounds(
oldReg.latLngBounds, 0),
200, new GoogleMap.CancelableCallback() {
#Override
public void onFinish() {
mIsInAnimation = false;
}
#Override
public void onCancel() {
mIsInAnimation = false;
}
});
}
}
/**
*
*
* #param lonVal
* #return
*/
private double norm(double lonVal) {
while (lonVal > 360d) lonVal -= 360d;
while (lonVal < -360d) lonVal += 360d;
if (lonVal < 0) lonVal = 360d + lonVal;
return lonVal;
}
private double denorm(double lonVal) {
if (lonVal > 180d) lonVal = -360d + lonVal;
return lonVal;
}
private boolean checkBounds(VisibleRegion reg) {
double left = Math.min(
Math.min(norm(reg.farLeft.longitude), norm(reg.nearLeft.longitude)),
Math.min(norm(reg.farRight.longitude), norm(reg.nearRight.longitude)));
double right = Math.max(
Math.max(norm(reg.farLeft.longitude), norm(reg.nearLeft.longitude)),
Math.max(norm(reg.farRight.longitude), norm(reg.nearRight.longitude)));
double top = Math.max(
Math.max(reg.farLeft.latitude, reg.nearLeft.latitude),
Math.max(reg.farRight.latitude, reg.nearRight.latitude));
double bottom = Math.min(
Math.min(reg.farLeft.latitude, reg.nearLeft.latitude),
Math.min(reg.farRight.latitude, reg.nearRight.latitude));
boolean limitBounds = left < MIN_LONGITUDE || right > MAX_LONGITUDE ||
bottom < MIN_LATITUDE || top > MAX_LATITUDE;
return !limitBounds;
}
private void init(Context c) {
try {
MapsInitializer.initialize(c);
} catch (GooglePlayServicesNotAvailableException e) {
e.printStackTrace();
}
mContext = c;
mHandler.post(new Runnable() {
#Override
public void run() {
GoogleMap map = getMap();
if (map != null) {
getMap().getUiSettings().setZoomControlsEnabled(false);
map.getUiSettings().setAllGesturesEnabled(false);
map.moveCamera(CameraUpdateFactory.newLatLngZoom(
new LatLng(DEF_LATITUDE, DEF_LONGITUDE), DEF_ZOOM));
mLastCorrectRegion = map.getProjection().getVisibleRegion();
mGestureDetector = new GestureDetector(mContext, mGestudeListener);
mScaleGestureDetector = new ScaleGestureDetector(mContext, mScaleGestudeListener);
} else mHandler.post(this);
}
});
}
#Override
public boolean onInterceptTouchEvent(MotionEvent event) {
if (mGestureDetector != null) mGestureDetector.onTouchEvent(event);
if (mScaleGestureDetector != null) mScaleGestureDetector.onTouchEvent(event);
return super.onInterceptTouchEvent(event);
}
}
Definition within my xml-layout of fragment:
<com.package....RestrictedMapView
android:id="#+id/mapview"
android:layout_width="match_parent"
android:layout_height="match_parent" />
In xml file it is possible to define custom zoom/location buttons and set click listeners for manual manipulating camera (in this case you have to check MAX_ZOOM and MIN_ZOOM, and check if the current location is within the allowed bounds).

Too bad that google doesn't let us intercept and block the user, i found that MaciejGórski's answer is the one that suits best to my needs.
I wanted to share my solution (Based on his answer) with you.
First i defined the bounds and max/min zoom:
private final LatLngBounds BOUNDS = new LatLngBounds(new LatLng(41.8138,12.3891), new LatLng(41.9667, 12.5938));
private final int MAX_ZOOM = 18;
private final int MIN_ZOOM = 14;
Then i created this little function to test if current camera bounds are outside of max bounds and return the difference in latitude and longitude.
/**
* Returns the correction for Lat and Lng if camera is trying to get outside of visible map
* #param cameraBounds Current camera bounds
* #return Latitude and Longitude corrections to get back into bounds.
*/
private LatLng getLatLngCorrection(LatLngBounds cameraBounds) {
double latitude=0, longitude=0;
if(cameraBounds.southwest.latitude < BOUNDS.southwest.latitude) {
latitude = BOUNDS.southwest.latitude - cameraBounds.southwest.latitude;
}
if(cameraBounds.southwest.longitude < BOUNDS.southwest.longitude) {
longitude = BOUNDS.southwest.longitude - cameraBounds.southwest.longitude;
}
if(cameraBounds.northeast.latitude > BOUNDS.northeast.latitude) {
latitude = BOUNDS.northeast.latitude - cameraBounds.northeast.latitude;
}
if(cameraBounds.northeast.longitude > BOUNDS.northeast.longitude) {
longitude = BOUNDS.northeast.longitude - cameraBounds.northeast.longitude;
}
return new LatLng(latitude, longitude);
}
Then the Handler that controls the overscroll (And overzoom) limiting it every 100ms.
/**
* Bounds the user to the overlay.
*/
private class OverscrollHandler extends Handler {
#Override
public void handleMessage(Message msg) {
CameraPosition position = mMap.getCameraPosition();
VisibleRegion region = mMap.getProjection().getVisibleRegion();
float zoom = 0;
if(position.zoom < MIN_ZOOM) zoom = MIN_ZOOM;
if(position.zoom > MAX_ZOOM) zoom = MAX_ZOOM;
LatLng correction = getLatLngCorrection(region.latLngBounds);
if(zoom != 0 || correction.latitude != 0 || correction.longitude != 0) {
zoom = (zoom==0)?position.zoom:zoom;
double lat = position.target.latitude + correction.latitude;
double lon = position.target.longitude + correction.longitude;
CameraPosition newPosition = new CameraPosition(new LatLng(lat,lon), zoom, position.tilt, position.bearing);
CameraUpdate update = CameraUpdateFactory.newCameraPosition(newPosition);
mMap.moveCamera(update);
}
/* Recursively call handler every 100ms */
sendEmptyMessageDelayed(0,100);
}
}
This handler must be defined as a field inside current class (I did this in a class that extends SupportMapFragment)
private OverscrollHandler mOverscrollHandler = new OverscrollHandler();
And lastly it must be called for the first time, i did it at the end of onActivityCreated to be sure that map exists.
#Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
mContext = getActivity();
mMap = getMap();
mMap.setMapType(GoogleMap.MAP_TYPE_NONE);
mMap.addTileOverlay(new TileOverlayOptions().tileProvider(new VexLocalTileProvider(getResources().getAssets())));
CameraUpdate upd = CameraUpdateFactory.newLatLngZoom(new LatLng(41.87145, 12.52849), 14);
mMap.moveCamera(upd);
mOverscrollHandler.sendEmptyMessageDelayed(0,100);
}
Hope you will find it useful!

Instead of using new and shiny push technology which is onCameraChange, you may try to use old poll technology: map.getCameraPosition() or map.getProjection().getVisibleRegion(). You can then check if returned value is what you like and if not, map.moveCamera(...).
Basically you need a Handler, which will get the value of camera position in handleMessage and you send messages to this handler every 10ms or so. Inside handleMessage do sendEmptyMessageDelayed.
You can also use Runnable instead of Message (but that's a matter of taste).

limit zoom you can user this code
private GoogleMap mMap;
// Set a preference for minimum and maximum zoom.
mMap.setMinZoomPreference(6.0f);
mMap.setMaxZoomPreference(14.0f);

In maps API v2 there's a Min/MaxZoomLevel on the GoogleMap class, but I don't know if you can set it in any way.
Another approach would be to add a
GoogleMap.OnCameraChangeListener
to your map and by implementing
public void onCameraChange(CameraPosition cameraPosition);
To restrict the visible area, using GoogleMap.moveCamera(cameraPosition)
That is if you wish the user to be able to scroll or zoom "some".
You can also totally deactivate the scroll/zoom events via GoogleMapOptions

limit scrolling and zooming Google Maps Android API v2

I've added GroundOverlay to map and want to limit scrolling and zooming within this area.
How to limit scrolling within some bounds on android google maps?
Is it possible to get instantly motion points from MapFragment?
Please, help me.

Constraining the camera has (finally!) been added as a feature as part of the release of Google Play Services 9.4 -- you can call setLatLngBoundsForCameraTarget(LatLngBounds bounds) to set the allowed panning area.
// Create a LatLngBounds that includes the city of Adelaide in Australia.
final LatLngBounds ADELAIDE = new LatLngBounds(
new LatLng(-35.0, 138.58), new LatLng(-34.9, 138.61));
// Constrain the camera target to the Adelaide bounds.
mMap.setLatLngBoundsForCameraTarget(ADELAIDE);
You can find a thorough explanation in the documentation: Restricting the user's panning to a given area and a sample activity in GitHub.

May be it is too late, but here is my solution:
Disabled built-in GoogleMap's gestures.
Added custom gestures (for scrolling, fling and scaling).
Checking for allowed area when processing events.
Set bounds/zoom manually with standard Map's functions.
And here is my example:
[UPDATED]
There was a problem - when touch events were recieved before map was initialized.
check null values in onInterceptTouchEvent
Also I have discovered that my solution is slightly slowly than build-in function.
import android.content.Context;
import android.graphics.Point;
import android.os.Handler;
import android.util.AttributeSet;
import android.view.GestureDetector;
import android.view.MotionEvent;
import android.view.ScaleGestureDetector;
import com.google.android.gms.common.GooglePlayServicesNotAvailableException;
import com.google.android.gms.maps.CameraUpdate;
import com.google.android.gms.maps.CameraUpdateFactory;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.GoogleMapOptions;
import com.google.android.gms.maps.MapView;
import com.google.android.gms.maps.MapsInitializer;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.VisibleRegion;
public class RestrictedMapView extends MapView {
public static float MAX_ZOOM = 20;
public static float MIN_ZOOM = 5;
public static float MIN_ZOOM_FOR_FLING = 7;
public static double MAX_LONGITUDE = 183.61;
public static double MIN_LONGITUDE = 159.31;
public static double MAX_LATITUDE = -32.98;
public static double MIN_LATITUDE = -53.82;
public static double DEF_LATITUDE = -41.78;
public static double DEF_LONGITUDE = 173.02;
public static float DEF_ZOOM = 7;
private Handler mHandler = new Handler();
private Context mContext;
private VisibleRegion mLastCorrectRegion = null;
private boolean mIsInAnimation = false;
public RestrictedMapView(Context c, AttributeSet a, int o) {
super(c, a, o);
init(c);
}
public RestrictedMapView(Context c, AttributeSet a) {
super(c, a);
init(c);
}
public RestrictedMapView(Context c) {
super(c);
init(c);
}
public RestrictedMapView(Context c, GoogleMapOptions o) {
super(c, o);
init(c);
}
private GestureDetector mGestureDetector = null;
private GestureDetector.SimpleOnGestureListener mGestudeListener =
new GestureDetector.SimpleOnGestureListener() {
#Override
public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) {
if (mIsInAnimation) return false;
GoogleMap map = getMap();
LatLng target = map.getCameraPosition().target;
Point screenPoint = map.getProjection().toScreenLocation(target);
Point newPoint = new Point(screenPoint.x + (int)distanceX, screenPoint.y + (int)distanceY);
LatLng mapNewTarget = map.getProjection().fromScreenLocation(newPoint);
CameraUpdate update = CameraUpdateFactory.newLatLngZoom(
mapNewTarget,map.getCameraPosition().zoom);
tryUpdateCamera(update, 0);
return true;
}
#Override
public boolean onFling (MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
if (mIsInAnimation) return false;
GoogleMap map = getMap();
double zoom = map.getCameraPosition().zoom;
if (zoom < MIN_ZOOM_FOR_FLING)
return false;
int velocity = (int) Math.sqrt(velocityX * velocityX + velocityY * velocityY);
if (velocity < 500) return false;
double k1 = 0.002d; /*exipemental*/
double k2 = 0.002d;/*exipemental*/
LatLng target = map.getCameraPosition().target;
Point screenPoint = map.getProjection().toScreenLocation(target);
Point newPoint = new Point(screenPoint.x - (int)(velocityX * k1 * zoom * zoom/*exipemental*/),
screenPoint.y - (int)(velocityY * k1 * zoom * zoom/*exipemental*/));
LatLng mapNewTarget = map.getProjection().fromScreenLocation(newPoint);
CameraUpdate update = CameraUpdateFactory.newLatLngZoom(
mapNewTarget,map.getCameraPosition().zoom);
tryUpdateCamera(update, (int)(velocity * k2 * zoom * zoom) /*exipemental*/);
return true;
}
};
private ScaleGestureDetector mScaleGestureDetector = null;
private ScaleGestureDetector.SimpleOnScaleGestureListener mScaleGestudeListener =
new ScaleGestureDetector.SimpleOnScaleGestureListener() {
#Override
public boolean onScale (ScaleGestureDetector detector) {
if (mIsInAnimation) return false;
GoogleMap map = getMap();
double zoom = map.getCameraPosition().zoom;
double k = 1d / detector.getScaleFactor();
int x = (int) detector.getFocusX();
int y = (int) detector.getFocusY();
LatLng mapFocus = map.getProjection().
fromScreenLocation(new Point(x, y));
LatLng target = map.getCameraPosition().target;
zoom = zoom + Math.log(detector.getScaleFactor()) / Math.log(2d);
if (zoom < MIN_ZOOM)
if (zoom == MIN_ZOOM) return false;
else zoom = MIN_ZOOM;
if (zoom > MAX_ZOOM)
if (zoom == MAX_ZOOM) return false;
else zoom = MAX_ZOOM;
double dx = norm(mapFocus.longitude) - norm(target.longitude);
double dy = mapFocus.latitude - target.latitude;
double dk = 1d - 1d / k;
LatLng newTarget = new LatLng(target.latitude - dy * dk,
norm(target.longitude) - dx * dk);
CameraUpdate update = CameraUpdateFactory.newLatLngZoom(newTarget, (float) zoom);
tryUpdateCamera(update, 0);
return true;
}
};
private void tryUpdateCamera(CameraUpdate update, int animateTime) {
GoogleMap map = getMap();
final VisibleRegion reg = map.getProjection().getVisibleRegion();
if (animateTime <= 0) {
map.moveCamera(update);
checkCurrentRegion(reg);
} else {
mIsInAnimation = true;
map.animateCamera(update, animateTime, new GoogleMap.CancelableCallback() {
#Override
public void onFinish() {
mIsInAnimation = false;
checkCurrentRegion(reg);
}
#Override
public void onCancel() {
mIsInAnimation = false;
checkCurrentRegion(reg);
}
});
}
}
private void checkCurrentRegion(VisibleRegion oldReg) {
GoogleMap map = getMap();
VisibleRegion regNew = map.getProjection().getVisibleRegion();
if (checkBounds(regNew)) {
mLastCorrectRegion = regNew;
} else {
if (mLastCorrectRegion != null)
oldReg = mLastCorrectRegion;
mIsInAnimation = true;
map.animateCamera(CameraUpdateFactory.newLatLngBounds(
oldReg.latLngBounds, 0),
200, new GoogleMap.CancelableCallback() {
#Override
public void onFinish() {
mIsInAnimation = false;
}
#Override
public void onCancel() {
mIsInAnimation = false;
}
});
}
}
/**
*
*
* #param lonVal
* #return
*/
private double norm(double lonVal) {
while (lonVal > 360d) lonVal -= 360d;
while (lonVal < -360d) lonVal += 360d;
if (lonVal < 0) lonVal = 360d + lonVal;
return lonVal;
}
private double denorm(double lonVal) {
if (lonVal > 180d) lonVal = -360d + lonVal;
return lonVal;
}
private boolean checkBounds(VisibleRegion reg) {
double left = Math.min(
Math.min(norm(reg.farLeft.longitude), norm(reg.nearLeft.longitude)),
Math.min(norm(reg.farRight.longitude), norm(reg.nearRight.longitude)));
double right = Math.max(
Math.max(norm(reg.farLeft.longitude), norm(reg.nearLeft.longitude)),
Math.max(norm(reg.farRight.longitude), norm(reg.nearRight.longitude)));
double top = Math.max(
Math.max(reg.farLeft.latitude, reg.nearLeft.latitude),
Math.max(reg.farRight.latitude, reg.nearRight.latitude));
double bottom = Math.min(
Math.min(reg.farLeft.latitude, reg.nearLeft.latitude),
Math.min(reg.farRight.latitude, reg.nearRight.latitude));
boolean limitBounds = left < MIN_LONGITUDE || right > MAX_LONGITUDE ||
bottom < MIN_LATITUDE || top > MAX_LATITUDE;
return !limitBounds;
}
private void init(Context c) {
try {
MapsInitializer.initialize(c);
} catch (GooglePlayServicesNotAvailableException e) {
e.printStackTrace();
}
mContext = c;
mHandler.post(new Runnable() {
#Override
public void run() {
GoogleMap map = getMap();
if (map != null) {
getMap().getUiSettings().setZoomControlsEnabled(false);
map.getUiSettings().setAllGesturesEnabled(false);
map.moveCamera(CameraUpdateFactory.newLatLngZoom(
new LatLng(DEF_LATITUDE, DEF_LONGITUDE), DEF_ZOOM));
mLastCorrectRegion = map.getProjection().getVisibleRegion();
mGestureDetector = new GestureDetector(mContext, mGestudeListener);
mScaleGestureDetector = new ScaleGestureDetector(mContext, mScaleGestudeListener);
} else mHandler.post(this);
}
});
}
#Override
public boolean onInterceptTouchEvent(MotionEvent event) {
if (mGestureDetector != null) mGestureDetector.onTouchEvent(event);
if (mScaleGestureDetector != null) mScaleGestureDetector.onTouchEvent(event);
return super.onInterceptTouchEvent(event);
}
}
Definition within my xml-layout of fragment:
<com.package....RestrictedMapView
android:id="#+id/mapview"
android:layout_width="match_parent"
android:layout_height="match_parent" />
In xml file it is possible to define custom zoom/location buttons and set click listeners for manual manipulating camera (in this case you have to check MAX_ZOOM and MIN_ZOOM, and check if the current location is within the allowed bounds).

Too bad that google doesn't let us intercept and block the user, i found that MaciejGórski's answer is the one that suits best to my needs.
I wanted to share my solution (Based on his answer) with you.
First i defined the bounds and max/min zoom:
private final LatLngBounds BOUNDS = new LatLngBounds(new LatLng(41.8138,12.3891), new LatLng(41.9667, 12.5938));
private final int MAX_ZOOM = 18;
private final int MIN_ZOOM = 14;
Then i created this little function to test if current camera bounds are outside of max bounds and return the difference in latitude and longitude.
/**
* Returns the correction for Lat and Lng if camera is trying to get outside of visible map
* #param cameraBounds Current camera bounds
* #return Latitude and Longitude corrections to get back into bounds.
*/
private LatLng getLatLngCorrection(LatLngBounds cameraBounds) {
double latitude=0, longitude=0;
if(cameraBounds.southwest.latitude < BOUNDS.southwest.latitude) {
latitude = BOUNDS.southwest.latitude - cameraBounds.southwest.latitude;
}
if(cameraBounds.southwest.longitude < BOUNDS.southwest.longitude) {
longitude = BOUNDS.southwest.longitude - cameraBounds.southwest.longitude;
}
if(cameraBounds.northeast.latitude > BOUNDS.northeast.latitude) {
latitude = BOUNDS.northeast.latitude - cameraBounds.northeast.latitude;
}
if(cameraBounds.northeast.longitude > BOUNDS.northeast.longitude) {
longitude = BOUNDS.northeast.longitude - cameraBounds.northeast.longitude;
}
return new LatLng(latitude, longitude);
}
Then the Handler that controls the overscroll (And overzoom) limiting it every 100ms.
/**
* Bounds the user to the overlay.
*/
private class OverscrollHandler extends Handler {
#Override
public void handleMessage(Message msg) {
CameraPosition position = mMap.getCameraPosition();
VisibleRegion region = mMap.getProjection().getVisibleRegion();
float zoom = 0;
if(position.zoom < MIN_ZOOM) zoom = MIN_ZOOM;
if(position.zoom > MAX_ZOOM) zoom = MAX_ZOOM;
LatLng correction = getLatLngCorrection(region.latLngBounds);
if(zoom != 0 || correction.latitude != 0 || correction.longitude != 0) {
zoom = (zoom==0)?position.zoom:zoom;
double lat = position.target.latitude + correction.latitude;
double lon = position.target.longitude + correction.longitude;
CameraPosition newPosition = new CameraPosition(new LatLng(lat,lon), zoom, position.tilt, position.bearing);
CameraUpdate update = CameraUpdateFactory.newCameraPosition(newPosition);
mMap.moveCamera(update);
}
/* Recursively call handler every 100ms */
sendEmptyMessageDelayed(0,100);
}
}
This handler must be defined as a field inside current class (I did this in a class that extends SupportMapFragment)
private OverscrollHandler mOverscrollHandler = new OverscrollHandler();
And lastly it must be called for the first time, i did it at the end of onActivityCreated to be sure that map exists.
#Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
mContext = getActivity();
mMap = getMap();
mMap.setMapType(GoogleMap.MAP_TYPE_NONE);
mMap.addTileOverlay(new TileOverlayOptions().tileProvider(new VexLocalTileProvider(getResources().getAssets())));
CameraUpdate upd = CameraUpdateFactory.newLatLngZoom(new LatLng(41.87145, 12.52849), 14);
mMap.moveCamera(upd);
mOverscrollHandler.sendEmptyMessageDelayed(0,100);
}
Hope you will find it useful!

Instead of using new and shiny push technology which is onCameraChange, you may try to use old poll technology: map.getCameraPosition() or map.getProjection().getVisibleRegion(). You can then check if returned value is what you like and if not, map.moveCamera(...).
Basically you need a Handler, which will get the value of camera position in handleMessage and you send messages to this handler every 10ms or so. Inside handleMessage do sendEmptyMessageDelayed.
You can also use Runnable instead of Message (but that's a matter of taste).

limit zoom you can user this code
private GoogleMap mMap;
// Set a preference for minimum and maximum zoom.
mMap.setMinZoomPreference(6.0f);
mMap.setMaxZoomPreference(14.0f);

In maps API v2 there's a Min/MaxZoomLevel on the GoogleMap class, but I don't know if you can set it in any way.
Another approach would be to add a
GoogleMap.OnCameraChangeListener
to your map and by implementing
public void onCameraChange(CameraPosition cameraPosition);
To restrict the visible area, using GoogleMap.moveCamera(cameraPosition)
That is if you wish the user to be able to scroll or zoom "some".
You can also totally deactivate the scroll/zoom events via GoogleMapOptions

Get Latitude,Longtitude by a stable marker?

I have to make an application with a marker on the center of a srceen and by moving the map
and not the marker get lat,lon of the point that the marker shows. I have search the internet for something like Drag Marker but I am
not sure if this is what I need.Any Solution?

In your mapActivity wrtie this.
Location l = new Location();
// Location class will be used to calculate distance moved by map
TimerTask tm;
GeoPoint oldCenterOfMap, newCenteOfMap;
// On your on resume method of activity do oldCenterOfMap = mapView.getMapCenter();
Handler mHandler = new Handler();
int isTouched = 0;
MapView mapview = (MapView) findViewById(R.id.yourmapview_from_xml);
mapView.setOnTouchListener(new OnTouchListener() {
#Override
public boolean onTouch(View v, MotionEvent event) {
if (event.getAction() == MotionEvent.ACTION_UP) {
newCenteOfMap = mapView.getMapCenter();
if (mapchanged(oldCenterOfMap, newCenteOfMap)) {
isTouched++;
// Here is what would you do when you lift your finger fromt he map*****
newCenteOfMap =mapView.getMapCenter());
if (isTouched >= 1) {
if (isTouched > 1) {
mHandler.removeCallbacks(tm_circle);
isTouched = 1;
}
mHandler.postDelayed(tm_circle, 1200);
}
}
if (!mapchanged(oldCenterOfMap, newCenteOfMap))
mHandler.removeCallbacks(tm_circle);
}
return false;
}
});
tm_circle = new TimerTask() {
#Override
public void run() {
isTouched = 0;
// here is what you do after you touched a map moved after 1.2 seconds
oldCenterOfMap = mapView.getMapCenter();
}
};
public boolean mapchanged(GeoPoint oldCenter, GeoPoint newCenter) {
String distance = l.CalclauteDistance(oldCenter.getLongitudeE6() / 1E6,
oldCenter.getLatitudeE6() / 1E6,
newCenter.getLongitudeE6() / 1E6,
newCenter.getLatitudeE6() / 1E6);
if (Double.valueOf(distance) == 0.0)
return false;
else
return true;
}
Previous code would keep the track of the map movement.
Next code will respond in case of map movement.
In the comments present in the code above ( // here is what you do after you touched a map moved after 1.2 seconds AND // Here is what would you do when you lift your finger fromt he map*****) follow the instruction on my answer on another post.
Here Adding multiple overlays on mapview dynamically
Edit
public String CalclauteDistance(double long1, double lat1, double long2,
double lat2) {
String Result;
Point p1 = new Point(long1, lat1);
Point p2 = new Point(long2, lat2);
Result = p1.distanceTo(p2) + "";
return Result;
}
Here is the function (CalclauteDistance) from location class.