I only want to display a google map of a specific area on the mobile screen. The map should not move beyond that area when there is user interaction such as zoom or moving the map.
For example:
These are latitude and longitude bound:
LatLng one = new LatLng(42.0140555,-88.2131937);
LatLng two = new LatLng(40.993729,-87.6622417);
I have found the solution this way. Do this on onMapReady() function.
#Override
public void onMapReady(GoogleMap googleMap) {
mMap = googleMap;
//get latlong for corners for a specified area of map
LatLng one = new LatLng(42.0140555,-88.2131937);
LatLng two = new LatLng(40.993729,-87.6622417);
LatLngBounds.Builder builder = new LatLngBounds.Builder();
//add them to builder
builder.include(one);
builder.include(two);
LatLngBounds bounds = builder.build();
//get width and height to current display screen
int width = getResources().getDisplayMetrics().widthPixels;
int height = getResources().getDisplayMetrics().heightPixels;
// 20% padding
int padding = (int) (width * 0.20);
//set latlong bounds
mMap.setLatLngBoundsForCameraTarget(bounds);
//move camera to fill the bound to screen
mMap.moveCamera(CameraUpdateFactory.newLatLngBounds(bounds, width, height, padding));
//set zoom to level to current so that you won't be able to zoom out viz. move outside bounds
mMap.setMinZoomPreference(mMap.getCameraPosition().zoom);
}
I am working on an Android app and I have two markers i want to place on a google map. The idea is that the user can see the two locations at a glance without having to interact with the map.
LatLngBounds.Builder b = new LatLngBounds.Builder();
b.include(userPos);
b.include(cardPos);
LatLngBounds bounds = b.build();
int width = (int) (0.7 * infoView.getWidth());
int height = (int) (0.7 * mapView.getHeight());
CameraUpdate cu = CameraUpdateFactory.newLatLngBounds(bounds, width, height, 5);
googleMap.animateCamera(cu);
The code works fine when the two locations are not very far apart. But when the locations are, for example, Singapore and USA, the two markers cannot be seen together.
I have tried to manually set the zoom level to 0 with the same result.
Is there any way that I can show the entire world map on the android device at once (i.e without the need for scrolling on the user's part)?
Update:
I have tried setting the map to zoom level 0 explicitly. The map does not fit the View I have created. Is it not possible to have the full world view of the map on the screen?
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 :)
Currently I work with Google-Map-v2 and I want to show Direction between two Markers. Everything is ok and direction between two Markers calculate and draw fine.But only one problem is remain.
The problem is Zoom level between these two markers in Google-Map is too much. I Search in SO and find a solution for changing Zoom Level by Following code :
LatLngBounds.Builder builder = new LatLngBounds.Builder();
builder.include(origin);
builder.include(dest);
LatLngBounds bounds = builder.build();
CameraUpdate cu = CameraUpdateFactory.newLatLngBounds(bounds, 50);
mMap.animateCamera(cu);
Now it's better But still zoom level is not good. Is it possible to do some fixes on Code ? ( if I can some padding to view is fixed )
I Also change 50 to 6,12,... But nothing changed.
You are using the correct code, and the value (50) needs to be increased if you want to zoom less (be outer) or decreased to 0 if you want to be in the smallest area containing the two markers (you can skip the value in case).
If you set a value of 150 or more, and the level is too much you can use the animation callback to zoom out after the LatLng zoom:
Google API
com.google.android.gms.maps.GoogleMap.CancelableCallback)
LatLngBounds.Builder builder = new LatLngBounds.Builder();
builder.include(origin);
builder.include(dest);
LatLngBounds bounds = builder.build();
CameraUpdate cu = CameraUpdateFactory.newLatLngBounds(bounds, 50);
mMap.animateCamera(cu, new GoogleMap.CancelableCallback(){
void onCancel(){}
void onFinish(){
CameraUpdate zout = CameraUpdateFactory.zoomBy(-3.0);
mMap.animateCamera(zout);
}
});
This should zoom to the LatLng and when finished, zoom back of 3 levels.
try this:
CameraPosition cameraPosition =
new CameraPosition.Builder()
.target(yourlatlng)
// .bearing(targetBearing)// you can ignore it
.zoom(12)// your zoom value
// .tilt(40) // angle of view
.build();
mMap.animateCamera(
CameraUpdateFactory.newCameraPosition(cameraPosition),
500,
null);
I have 2 LatLng, usually a few kilometers apart, and I want to zoom map such that both points are visible. My code below sometimes works, sometimes not (map is zoomed to level 3 then). I think the reason is that the loop is too fast for the map to make the necessary adjustments in time.
Is there a way to wait for the map to update before making the test again? To note that process runs on UI thread
double x1=from.latitude;
double x2= to.latitude;
double x1half=(x1+x2)/2;
x1=from.longitude;
x2= to.longitude;
double x2half=(x1+x2)/2;
LatLng pp=new LatLng(x1half, x2half);
map.moveCamera(CameraUpdateFactory.newLatLng(pp));//3.0
//now zoom map so that both points are in
double zoom=21;//V3.3
while(zoom>2){//
map.animateCamera( CameraUpdateFactory.zoomTo( (float) zoom ) );
if(isCurrentLocationVisible(from,map)&&isCurrentLocationVisible(to,map)) return;
/now we know map is still not visible. give it a bit more room
zoom--;
}
I'd advice you to use the newLatLngBounds() instead..You can create your bounds from your two geo points with the LatLngBounds.builder().
To the second part of your question..You could do somethink like map.post(new Runnable..) which could solve the concurrency issue.
You can use LatLngBounds like the following:
LatLngBounds.Builder builder = new LatLngBounds.Builder();
builder.include(locationOne);
builder.include(locationTwo);
LatLngBounds bounds = builder.build();
int padding = 0; // offset from edges of the map in pixels
CameraUpdate cu = CameraUpdateFactory.newLatLngBounds(bounds,screen width, screen height, padding);
map.moveCamera(cu);
When a marker is clicked, the default behavior for the camera is to center it on screen, but because I usually have long text description in the info window, it's more convenient to actually change the camera position so that the marker is on the bottom of screen(making the info window in the center of screen). I think I should be able to do that by overriding onMarkerClick function like below (the default behavior is cancelled when this function return true)
#Override
public boolean onMarkerClick(final Marker marker) {
// Google sample code comment : We return false to indicate that we have not
// consumed the event and that we wish
// for the default behavior to occur (which is for the camera to move
// such that the
// marker is centered and for the marker's info window to open, if it
// has one).
marker.showInfoWindow();
CameraUpdate center=
CameraUpdateFactory.newLatLng(new LatLng(XXXX,
XXXX));
mMap.moveCamera(center);//my question is how to get this center
// return false;
return true;
}
Edit:
Problem solved using accepted answer's steps, codes below:
#Override
public boolean onMarkerClick(final Marker marker) {
//get the map container height
LinearLayout mapContainer = (LinearLayout) findViewById(R.id.map_container);
container_height = mapContainer.getHeight();
Projection projection = mMap.getProjection();
LatLng markerLatLng = new LatLng(marker.getPosition().latitude,
marker.getPosition().longitude);
Point markerScreenPosition = projection.toScreenLocation(markerLatLng);
Point pointHalfScreenAbove = new Point(markerScreenPosition.x,
markerScreenPosition.y - (container_height / 2));
LatLng aboveMarkerLatLng = projection
.fromScreenLocation(pointHalfScreenAbove);
marker.showInfoWindow();
CameraUpdate center = CameraUpdateFactory.newLatLng(aboveMarkerLatLng);
mMap.moveCamera(center);
return true;
}
Thanks for helping ^ ^
I might edit this answer later to provide some code, but what I think could work is this:
Get LatLng (LatLng M) of the clicked marker.
Convert LatLng M to a Point (Point M) using the Projection.toScreenLocation(LatLng) method. This gives you the location of the marker on the device's display (in pixels).
Compute the location of a point (New Point) that's above Point M by half of the map's height.
Convert the New Point back to LatLng and center the map on it.
Look here for my answer on how to get the map's height.
// googleMap is a GoogleMap object
// view is a View object containing the inflated map
// marker is a Marker object
Projection projection = googleMap.getProjection();
LatLng markerPosition = marker.getPosition();
Point markerPoint = projection.toScreenLocation(markerPosition);
Point targetPoint = new Point(markerPoint.x, markerPoint.y - view.getHeight() / 2);
LatLng targetPosition = projection.fromScreenLocation(targetPoint);
googleMap.animateCamera(CameraUpdateFactory.newLatLng(targetPosition), 1000, null);
I prefer Larry McKenzie's answer which it doesn't depend on screen projection (i.e. mProjection.toScreenLocation()), my guess is the projection resolution will go poor when the map zoom level is low, it made me sometimes couldn't get an accurate position. So, calculation based on google map spec will definitely solve the problem.
Below is an example code of moving the marker to 30% of the screen size from bottom.
zoom_lvl = mMap.getCameraPosition().zoom;
double dpPerdegree = 256.0*Math.pow(2, zoom_lvl)/170.0;
double screen_height = (double) mapContainer.getHeight();
double screen_height_30p = 30.0*screen_height/100.0;
double degree_30p = screen_height_30p/dpPerdegree;
LatLng centerlatlng = new LatLng( latlng.latitude + degree_30p, latlng.longitude );
mMap.animateCamera( CameraUpdateFactory.newLatLngZoom( centerlatlng, 15 ), 1000, null);
If you don't care about the map zooming in and just want the marker to be at the bottom see below, I think it's a simpler solution
double center = mMap.getCameraPosition().target.latitude;
double southMap = mMap.getProjection().getVisibleRegion().latLngBounds.southwest.latitude;
double diff = (center - southMap);
double newLat = marker.getPosition().latitude + diff;
CameraUpdate centerCam = CameraUpdateFactory.newLatLng(new LatLng(newLat, marker.getPosition().longitude));
mMap.animateCamera(centerCam);
I had the same issue, I tried the following perfectly working solution
mMap.setOnMarkerClickListener(new OnMarkerClickListener()
{
#Override
public boolean onMarkerClick(Marker marker)
{
int yMatrix = 200, xMatrix =40;
DisplayMetrics metrics1 = new DisplayMetrics();
getWindowManager().getDefaultDisplay().getMetrics(metrics1);
switch(metrics1.densityDpi)
{
case DisplayMetrics.DENSITY_LOW:
yMatrix = 80;
xMatrix = 20;
break;
case DisplayMetrics.DENSITY_MEDIUM:
yMatrix = 100;
xMatrix = 25;
break;
case DisplayMetrics.DENSITY_HIGH:
yMatrix = 150;
xMatrix = 30;
break;
case DisplayMetrics.DENSITY_XHIGH:
yMatrix = 200;
xMatrix = 40;
break;
case DisplayMetrics.DENSITY_XXHIGH:
yMatrix = 200;
xMatrix = 50;
break;
}
Projection projection = mMap.getProjection();
LatLng latLng = marker.getPosition();
Point point = projection.toScreenLocation(latLng);
Point point2 = new Point(point.x+xMatrix,point.y-yMatrix);
LatLng point3 = projection.fromScreenLocation(point2);
CameraUpdate zoom1 = CameraUpdateFactory.newLatLng(point3);
mMap.animateCamera(zoom1);
marker.showInfoWindow();
return true;
}
});
I also faced this problem and fixed it in a hacky way. Let's declare a double field first. You need to adjust the value of it based on your requirement but I recommend you keep it between 0.001~0.009 otherwise you can miss your marker after the zoom animation.
double offset = 0.009
/*You can change it based on your requirement.
For left-right alignment please kindly keep it between 0.001~0.005 */
For bottom-centered:
LatLng camera = new LatLng(marker.getPosition().latitude+offset , marker.getPosition().longitude);
//Here "marker" is your target market on which you want to focus
For top-centered:
LatLng camera = new LatLng(marker.getPosition().latitude-offset , marker.getPosition().longitude);
For left-centered:
LatLng camera = new LatLng(marker.getPosition().latitude, marker.getPosition().longitude+offset);
For right-centered:
LatLng camera = new LatLng(marker.getPosition().latitude-offset , marker.getPosition().longitude-offset);
Then finally call the -
mMap.animateCamera(CameraUpdateFactory.newLatLngZoom(camera, yourZoom));
I did a little research and according to the documentation the map is square and at zero zoom level the width and height is 256dp and +/- 85 degrees N/S. The map width increases with zoom level so that width and height = 256 * 2N dp. Where N is the zoom level. So in theory you can determine the new location by getting the map height and dividing it by 170 total degrees to get dp per degree. Then get the screen height (or mapview height) in dp divided it by two and convert half view size to degrees of latitude. Then set your new Camera point that many degrees of latitude south. I can add code if you need it but I'm on a phone at the moment.
I have been trying out all the solutions proposed here, and came with a combined implementation of them. Considering, map projection, tilt, zoom and info window height.
It doesn't really place the marker at the bottom of the "camera view", but I think it accommodates the info window and the marker centre pretty well in most cases.
#Override
public boolean onMarkerClick(Marker marker) {
mIsMarkerClick = true;
mHandler.removeCallbacks(mUpdateTimeTask);
mLoadTask.cancel(true);
getActivity().setProgressBarIndeterminateVisibility(false);
marker.showInfoWindow();
Projection projection = getMap().getProjection();
Point marketCenter = projection.toScreenLocation(marker.getPosition());
float tiltFactor = (90 - getMap().getCameraPosition().tilt) / 90;
marketCenter.y -= mInfoWindowAdapter.getInfoWindowHeight() / 2 * tiltFactor;
LatLng fixLatLng = projection.fromScreenLocation(marketCenter);
mMap.animateCamera(CameraUpdateFactory.newLatLng(fixLatLng), null);
return true;
}
And then, your custom adapter would have to keep an instance of the info window inflated view, to be able to fetch its height.
public int getInfoWindowHeight(){
if (mLastInfoWindoView != null){
return mLastInfoWindoView.getMeasuredHeight();
}
return 0;
}
Anyone who's still looking to center the camera according to location coordinates
CameraPosition cameraPosition = new CameraPosition.Builder().target(new LatLng(Lat, Lon))
.zoom(15)
.bearing(0)
.tilt(45)
.build();
map.animateCamera(CameraUpdateFactory.newCameraPosition(cameraPosition));
Credits
After some experiences i've implemented the solution that fine for me.
DisplayMetrics metrics = new DisplayMetrics();
context.getWindowManager().getDefaultDisplay().getMetrics(metrics);
Point targetPoint = new Point(metrics.widthPixels / 2, metrics.heightPixels - metrics.heightPixels / 9);
LatLng targetLatlng = map.getProjection().fromScreenLocation(targetPoint);
double fromCenterToTarget = SphericalUtil.computeDistanceBetween(map.getCameraPosition().target, targetLatlng);
LatLng center = SphericalUtil.computeOffset(new LatLng(location.latitude, location.longitude), fromCenterToTarget/1.2, location.bearing);
CameraUpdate camera = CameraUpdateFactory.newLatLng(center);
map.animateCamera(camera, 1000, null);
Here. First, we pick the physical point on the screen where the marker should be moved. Then, convert it to LatLng. Next step - calculate distance from current marker position (in center) to target. Finally, we move the center of map straight from the marker to calculated distance.
I needed something similar, but with also zoom, tilt and bearing in the equation.
My problem is more complex, but the solution is a sort of generalization so it could be applied also to the problem in the question.
In my case, I update programmatically the position of a marker; the camera can be rotated, zoomed and tilted, but I want the marker always visible at a specific percentage of the View height from the bottom. (similar to the car marker position in the Maps navigation)
The solution:
I first pick the map location on the center of the screen and the location of a point that would be visible at a percentage of the View from the bottom (using map projection); I get the distance between these two points in meters, then I calculate a position, starting from the marker position, moving for the calculated distance towards the bearing direction; this new position is my new Camera target.
The code (Kotlin):
val movePointBearing =
if (PERCENTAGE_FROM_BOTTOM > 50) {
(newBearing + 180) % 360
} else newBearing
val newCameraTarget = movePoint(
markerPosition,
distanceFromMapCenter(PERCENTAGE_FROM_BOTTOM),
markerBearing)
with the movePoint method copied from here:
https://stackoverflow.com/a/43225262/2478422
and the distanceFromMapCenter method defined as:
fun distanceFromMapCenter(screenPercentage: Int): Float {
val screenHeight = mapFragment.requireView().height
val screenWith = mapFragment.requireView().width
val projection = mMap.projection
val center = mMap.cameraPosition.target
val offsetPointY = screenHeight - (screenHeight * screenPercentage / 100)
val offsetPointLocation = projection.fromScreenLocation(Point(screenWith / 2, offsetPointY))
return distanceInMeters(center, offsetPointLocation)
}
then just define a distanceInMeters method (for example using android Location class)
I hope the idea is clear without any further explanations.
One obvious limitation: it applies the logic using the current zoom and tilt, so it would not work if the new camera position requires also a different zoom_level and tilt.