I have 10 markers in the GoogleMap. I want to zoom in as much as possible and keep all markers in view? In the earlier version this can be achieved from zoomToSpan() but in v2 I have no idea how about doing that. Further, I know the radius of the circle that needs to be visible.
You should use the CameraUpdate class to do (probably) all programmatic map movements.
To do this, first calculate the bounds of all the markers like so:
LatLngBounds.Builder builder = new LatLngBounds.Builder();
for (Marker marker : markers) {
builder.include(marker.getPosition());
}
LatLngBounds bounds = builder.build();
Then obtain a movement description object by using the factory: CameraUpdateFactory:
int padding = 0; // offset from edges of the map in pixels
CameraUpdate cu = CameraUpdateFactory.newLatLngBounds(bounds, padding);
Finally move the map:
googleMap.moveCamera(cu);
Or if you want an animation:
googleMap.animateCamera(cu);
That's all :)
Clarification 1
Almost all movement methods require the Map object to have passed the layout process. You can wait for this to happen using the addOnGlobalLayoutListener construct. Details can be found in comments to this answer and remaining answers. You can also find a complete code for setting map extent using addOnGlobalLayoutListener here.
Clarification 2
One comment notes that using this method for only one marker results in map zoom set to a "bizarre" zoom level (which I believe to be maximum zoom level available for given location). I think this is expected because:
- The
LatLngBounds boundsinstance will havenortheastproperty equal tosouthwest, meaning that the portion of area of the earth covered by thisboundsis exactly zero. (This is logical since a single marker has no area.) - By passing
boundstoCameraUpdateFactory.newLatLngBoundsyou essentially request a calculation of such a zoom level thatbounds(having zero area) will cover the whole map view. - You can actually perform this calculation on a piece of paper. The theoretical zoom level that is the answer is +∞ (positive infinity). In practice the
Mapobject doesn't support this value so it is clamped to a more reasonable maximum level allowed for given location.
Another way to put it: how can Map object know what zoom level should it choose for a single location? Maybe the optimal value should be 20 (if it represents a specific address). Or maybe 11 (if it represents a town). Or maybe 6 (if it represents a country). API isn't that smart and the decision is up to you.
So, you should simply check if markers has only one location and if so, use one of:
CameraUpdate cu = CameraUpdateFactory.newLatLng(marker.getPosition())- go to marker position, leave current zoom level intact.CameraUpdate cu = CameraUpdateFactory.newLatLngZoom(marker.getPosition(), 12F)- go to marker position, set zoom level to arbitrarily chosen value 12.
Google Map V2
The following solution works for Android Marshmallow 6 (API 23, API 24, API 25, API 26, API 27, API 28). It also works in Xamarin.
LatLngBounds.Builder builder = new LatLngBounds.Builder();
//the include method will calculate the min and max bound.
builder.include(marker1.getPosition());
builder.include(marker2.getPosition());
builder.include(marker3.getPosition());
builder.include(marker4.getPosition());
LatLngBounds bounds = builder.build();
int width = getResources().getDisplayMetrics().widthPixels;
int height = getResources().getDisplayMetrics().heightPixels;
int padding = (int) (width * 0.10); // offset from edges of the map 10% of screen
CameraUpdate cu = CameraUpdateFactory.newLatLngBounds(bounds, width, height, padding);
mMap.animateCamera(cu);
So
I needed to use addOnGlobalLayoutListener to get the appropriate sample
for example, your Google Map is inside RelativeLayout:
RelativeLayout mapLayout = (RelativeLayout)findViewById(R.id.map_layout);
mapLayout.getViewTreeObserver().addOnGlobalLayoutListener(new OnGlobalLayoutListener() {
@Override
public void onGlobalLayout() {
//and write code, which you can see in answer above
}
});
I couldnt use the onGlobalLayoutlistener, so here is another solution to prevent the
"Map size can't be 0. Most likely, layout has not yet occured for the map view. Either wait until layout has occurred or use newLatLngBounds(LatLngBounds, int, int, int) which allows you to specify the map's dimensions." error:
mMap.setOnMapLoadedCallback(new GoogleMap.OnMapLoadedCallback() {
@Override
public void onMapLoaded() {
mMap.moveCamera(CameraUpdateFactory.newLatLngBounds(builder.build(), 15));
}
});
Working fine for me.
From this code, I am displaying multiple markers with particular zoom on map screen.
// Declared variables
private LatLngBounds bounds;
private LatLngBounds.Builder builder;
// Method for adding multiple marker points with drawable icon
private void drawMarker(LatLng point, String text) {
MarkerOptions markerOptions = new MarkerOptions();
markerOptions.position(point).title(text).icon(BitmapDescriptorFactory.fromResource(R.drawable.icon));
mMap.addMarker(markerOptions);
builder.include(markerOptions.getPosition());
}
// For adding multiple markers visible on map
@Override
public void onMapReady(GoogleMap googleMap) {
mMap = googleMap;
builder = new LatLngBounds.Builder();
for (int i = 0; i < locationList.size(); i++) {
drawMarker(new LatLng(Double.parseDouble(locationList.get(i).getLatitude()), Double.parseDouble(locationList.get(i).getLongitude())), locationList.get(i).getNo());
}
bounds = builder.build();
CameraUpdate cu = CameraUpdateFactory.newLatLngBounds(bounds, 0);
mMap.animateCamera(cu);
Note - This is not a solution to the original question. This is a solution to one of the subproblems discussed above.
Solution to @andr Clarification 2 -
Its really problematic when there's only one marker in the bounds and due to it the zoom level is set to a very high level (level 21). And Google does not provide any way to set the max zoom level at this point. This can also happen when there are more than 1 marker but they are all pretty close to each other. Then also the same problem will occur.
Solution - Suppose you want your Map to never go beyond 16 zoom level. Then after doing -
CameraUpdate cu = CameraUpdateFactory.newLatLngBounds(bounds, padding);
mMap.moveCamera(cu);
Check if your zoom level has crossed level 16(or whatever you want) -
float currentZoom = mMap.getCameraPosition().zoom;
And if this level is greater than 16, which it will only be if there are very less markers or all the markers are very close to each other, then simply zoom out your map at that particular position only by seting the zoom level to 16.
mMap.moveCamera(CameraUpdateFactory.zoomTo(16));
This way you'll never have the problem of "bizarre" zoom level explained very well by @andr too.
this would help.. from google apis demos
private List<Marker> markerList = new ArrayList<>();
Marker marker = mGoogleMap.addMarker(new MarkerOptions().position(geoLatLng)
.title(title));
markerList.add(marker);
// Pan to see all markers in view.
// Cannot zoom to bounds until the map has a size.
final View mapView = getSupportFragmentManager().findFragmentById(R.id.map).getView();
if (mapView!=null) {
if (mapView.getViewTreeObserver().isAlive()) {
mapView.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
@SuppressWarnings("deprecation") // We use the new method when supported
@SuppressLint("NewApi") // We check which build version we are using.
@Override
public void onGlobalLayout() {
//Calculate the markers to get their position
LatLngBounds.Builder b = new LatLngBounds.Builder();
for (Marker m : markerList) {
b.include(m.getPosition());
}
// also include current location to include in the view
b.include(new LatLng(mLocation.getLatitude(),mLocation.getLongitude()));
LatLngBounds bounds = b.build();
if (Build.VERSION.SDK_INT < Build.VERSION_CODES.JELLY_BEAN) {
mapView.getViewTreeObserver().removeGlobalOnLayoutListener(this);
} else {
mapView.getViewTreeObserver().removeOnGlobalLayoutListener(this);
}
mGoogleMap.moveCamera(CameraUpdateFactory.newLatLngBounds(bounds, 50));
}
});
}
}
for clear info look at this url. https://github.com/googlemaps/android-samples/blob/master/ApiDemos/app/src/main/java/com/example/mapdemo/MarkerDemoActivity.java
I had similar problem, using following code solved the issue:
CameraUpdateFactory.newLatLngBounds(bounds, 200, 200, 5) generally the location differences in my case are no more than two neighbour cities.
Use the method "getCenterCoordinate" to obtain the center coordinate and use in CameraPosition.
private void setUpMap() {
mMap.setMyLocationEnabled(true);
mMap.getUiSettings().setScrollGesturesEnabled(true);
mMap.getUiSettings().setTiltGesturesEnabled(true);
mMap.getUiSettings().setRotateGesturesEnabled(true);
clientMarker = mMap.addMarker(new MarkerOptions()
.position(new LatLng(Double.valueOf(-12.1024174), Double.valueOf(-77.0262274)))
.icon(BitmapDescriptorFactory.fromResource(R.mipmap.ic_taxi))
);
clientMarker = mMap.addMarker(new MarkerOptions()
.position(new LatLng(Double.valueOf(-12.1024637), Double.valueOf(-77.0242617)))
.icon(BitmapDescriptorFactory.fromResource(R.mipmap.ic_location))
);
camPos = new CameraPosition.Builder()
.target(getCenterCoordinate())
.zoom(17)
.build();
camUpd3 = CameraUpdateFactory.newCameraPosition(camPos);
mMap.animateCamera(camUpd3);
}
public LatLng getCenterCoordinate(){
LatLngBounds.Builder builder = new LatLngBounds.Builder();
builder.include(new LatLng(Double.valueOf(-12.1024174), Double.valueOf(-77.0262274)));
builder.include(new LatLng(Double.valueOf(-12.1024637), Double.valueOf(-77.0242617)));
LatLngBounds bounds = builder.build();
return bounds.getCenter();
}
I have one other way to do this same thing works perfectly. so the idea behind to show all markers on the screen we need a center lat long and zoom level. here is the function which will give you both and need all marker's Latlng objects as input.
public Pair<LatLng, Integer> getCenterWithZoomLevel(LatLng... l) {
float max = 0;
if (l == null || l.length == 0) {
return null;
}
LatLngBounds.Builder b = new LatLngBounds.Builder();
for (int count = 0; count < l.length; count++) {
if (l[count] == null) {
continue;
}
b.include(l[count]);
}
LatLng center = b.build().getCenter();
float distance = 0;
for (int count = 0; count < l.length; count++) {
if (l[count] == null) {
continue;
}
distance = distance(center, l[count]);
if (distance > max) {
max = distance;
}
}
double scale = max / 1000;
int zoom = ((int) (16 - Math.log(scale) / Math.log(2)));
return new Pair<LatLng, Integer>(center, zoom);
}
This function return Pair object which you can use like
Pair pair = getCenterWithZoomLevel(l1,l2,l3..); mGoogleMap.moveCamera(CameraUpdateFactory.newLatLngZoom(pair.first, pair.second));
you can instead of using padding to keep away your markers from screen boundaries, you can adjust zoom by -1.
Show All Markers with Google map
In these Methods store all Markers and automatically zoom to show all markers in google map.
// Declare the Markers List.
List<MarkerOptions> markerList;
private BitmapDescriptor vnrPoint,banPoint;
public void storeAllMarkers()
{
markerList=new ArrayList<>();
markerList.removeAll(markerList);
// latitude and longitude of Virudhunagar
double latitude1=9.587209;
double longitude1=77.951431;
vnrPoint=BitmapDescriptorFactory.fromResource(R.drawable.location_icon_1);
LatLng vnr = new LatLng(latitude1, longitude1);
MarkerOptions vnrMarker = new MarkerOptions();
vnrMarker.position(vnr);
vnrMarker.icon(vnrPoint);
markerList.add(vnrMarker);
// latitude and longitude of Bengaluru
double latitude2=12.972442;
double longitude2=77.580643;
banPoint=BitmapDescriptorFactory.fromResource(R.drawable.location_icon_2);
LatLng ban = new LatLng(latitude2, longitude2);
MarkerOptions bengalureMarker = new MarkerOptions();
bengalureMarker.position(ban);
bengalureMarker.icon(banPoint);
markerList.add(bengalureMarker);
// You can add any numbers of MarkerOptions like this.
showAllMarkers();
}
public void showAllMarkers()
{
LatLngBounds.Builder builder = new LatLngBounds.Builder();
for (MarkerOptions m : markerList) {
builder.include(m.getPosition());
}
LatLngBounds bounds = builder.build();
int width = getResources().getDisplayMetrics().widthPixels;
int height = getResources().getDisplayMetrics().heightPixels;
int padding = (int) (width * 0.30);
// Zoom and animate the google map to show all markers
CameraUpdate cu = CameraUpdateFactory.newLatLngBounds(bounds, width, height, padding);
googleMap.animateCamera(cu);
}
//For adding a marker in Google map
MarkerOptions mp = new MarkerOptions();
mp.position(new LatLng(Double.parseDouble(latitude), Double.parseDouble(longitude)));
mp.snippet(strAddress);
map.addMarker(mp);
try {
b = new LatLngBounds.Builder();
if (MapDetailsList.list != null && MapDetailsList.list.size() > 0) {
for (int i = 0; i < MapDetailsList.list.size(); i++) {
b.include(new LatLng(Double.parseDouble(MapDetailsList.list.get(i).getLatitude()),
Double.parseDouble(MapDetailsList.list.get(i).getLongitude())));
}
LatLngBounds bounds = b.build();
DisplayMetrics displayMetrics = getResources().getDisplayMetrics();
int width = displayMetrics.widthPixels;
int height = displayMetrics.heightPixels;
// Change the padding as per needed
CameraUpdate cu = CameraUpdateFactory.newLatLngBounds(bounds, width-200, height-200, 5);
// map.setCenter(bounds.getCenter());
map.animateCamera(cu);
}
} catch (Exception e) {
}
http://i64.tinypic.com/2qjybh4.png
来源：https://stackoverflow.com/questions/14828217/android-map-v2-zoom-to-show-all-the-markers