Center android google map on group of markers? - android

I have a bunch of markers in which I load onto a google map. My problem is that, the camera is not ontop of the markers. Can I center it on top of all my markers?
I am adding my markers with this code:
for(int i = 0; i < jsonArray.length(); i++) {
String breweryName = jsonArray.getJSONObject(i).getString("brewery");
String lat = jsonArray.getJSONObject(i).getString("lat");
String lng = jsonArray.getJSONObject(i).getString("lng");
String bID = jsonArray.getJSONObject(i).getString("breweryID");
double latD = Double.parseDouble(lat);
double lngD = Double.parseDouble(lng);
m.addMarker(new MarkerOptions()
.position(new LatLng(latD, lngD))
.title(breweryName));
}
I looked on stack and found this question, which is the same as mine:
Android Google maps API V2 center markers
But there isnt much context behind it and am not sure how to implement it.

You can animate your camera within specific bounds. Let's say you have an ArrayList of markers, something like (this could also be a list of LatLngs, doubles, anything that contains the latitude/longitude for your marker)
List<MarkerOptions> markers = new ArrayList<MarkerOptions>();
You can then make sure they are all visible on your map by doing the following
LatLngBounds.Builder builder = new LatLngBounds.Builder();
LatLng position;
for(int i = 0; i < markers.size(); i++){
position = markers.get(i).getPosition();
builder.include(new LatLng(position.latitude, position.longitude));
}
LatLngBounds bounds = builder.build();
map.animateCamera(CameraUpdateFactory.newLatLngBounds(bounds, 15));

Related

I want to show distance on Polyline googlemap Android

I want to show distance of each connected node on polyline. Currently i am not getting such method to show the text over polyline. Please help is it possible to do in android google maps api.
This method (Java) adds a polyline to the map and adds the distance of each segment as text on the polyline - using the referenced method in another answer for displaying the text.
private void polylineLabels() {
LatLng pt1 = new LatLng(39.935484,-83.023490);
LatLng pt2 = new LatLng(39.098487,-84.446861);
LatLng pt3 = new LatLng(39.743435,-86.104479);
LatLng pt4 = new LatLng(38.202789,-85.739295);
LatLng pt5 = new LatLng(38.614276,-90.138124);
routePts.add(pt1);
routePts.add(pt2);
routePts.add(pt3);
routePts.add(pt4);
routePts.add(pt5);
for (int i = 1; i < routePts.size(); i++) {
Polyline line = mMap.addPolyline(
new PolylineOptions()
.add(routePts.get(i-1), routePts.get(i)).
width(5).color(Color.RED));
double d = SphericalUtil.computeDistanceBetween(routePts.get(i-1),routePts.get(i));
int dInt = (int)d;
String msg = Integer.toString(dInt)+"m";
LatLng midpt = SphericalUtil.interpolate(routePts.get(i-1),routePts.get(i), 0.5);
Marker m = addText(this, mMap, midpt, msg, 2, 18);
}
}
And the result:
You'll have to experiment with offset location to better position each label.
Here's the answer which defines the addText method: https://stackoverflow.com/a/30185289/2711811 .

Markers in android google maps json

I have a hicking app, that gets a array of markers from my database and plots them on my map, afterward it draws a polyline connecting all the markers. What i want to do is , to draw the polyline connecting the markers, but instead of showing 10 or 20 or 100 markers, to only SHOW 2, the marker that starts and the one that ends.
Would appreciate any help.
Below is the function that i use to draw the polylines.
private void createPolylinesFromLatLng(ArrayList<LatLng> polylist){
PolylineOptions options = new PolylineOptions().width(5).color(Color.BLUE).geodesic(true);
for (int z = 0; z < polylist.size(); z++) {
LatLng point = polylist.get(z);
options.add(point);
totalDistanceInMeters = SphericalUtil.computeLength(polylist);
test=String.format("%.2f",totalDistanceInMeters);
}
and this is how i retrieve my markers into a array
JSONArray array = new JSONArray(response);
for (int i = 0; i < array.length(); i++) {
JSONObject jo = array.getJSONObject(i);
Double lat = Double.parseDouble(jo.getString("lat"));
Double lng = Double.parseDouble(jo.getString("lon"));
polyline = new LatLng(Double.parseDouble(jo.getString("lat")),
Double.parseDouble(jo.getString("lon")));
polylist.add(polyline);
// location = new LatLng(lat,lng);
location=polyline;
MarkerOptions options = new MarkerOptions();
options.position(location);
mMap.addMarker(options);
thank you
One way of doing this would to just surround your code where you add the Marker with a if statement like this:
if(i == 0 || i == (array.length() - 1)){
MarkerOptions options = new MarkerOptions();
options.position(location);
mMap.addMarker(options);
}
That way only the first location and the last location are added.

How to create multiple markers with infoWindow showing google maps api

I'm using google directions and make a route between two points and setting a marker and I need to set a window with some information in both of these markers, but According to google I just can show a window one at the time! But in Uber App they did with both points.
This is what I did :
public void drawRoute(){
PolylineOptions po;
if(polyline == null){
po = new PolylineOptions();
for(int i = 0, tam = latLngs.size(); i < tam; i++){
po.add(latLngs.get(i));
}
po.color(Color.BLACK).width(10);
polyline = mMap.addPolyline(po);
LatLng myCurrentLocation = new LatLng(lat, lon);
mMap.moveCamera(CameraUpdateFactory.newLatLngZoom(myCurrentLocation, 11));
Marker mMarker;
mMarker = mMap.addMarker(new MarkerOptions().position(finalLocaltion).title(finalLocationName));
mMarker.showInfoWindow();
}
else{
polyline.setPoints(latLngs);
}
}
The window only appears when I click, and not by default!

Google map v2 Heatmap population

Would it be possible to use a heat map to represent/show the amount of people in the specific area using google map v2?
If not , would there be other library or API that I can use to know represent the amount of people in the area.
reference that I saw on the internet: http://googlemapsmania.blogspot.com/2014/02/population-mapping.html
Hey here is the example how you can use heatmap and show your max population
Add all marker in your map then use this code.
HeatmapTileProvider mProvider;
TileOverlay mOverlay;
// Add your all lat lng inside this array list and pass it to addHeatMap
List<LatLng> list = new ArrayList<LatLng>();
double puLat = 0, puLng = 0;
private void createMarker() {
double cLat, cLng;
cLat = locationCur.getLatitude();
cLng = locationCur.getLongitude();
Marker testMarker = googleMap.addMarker(new MarkerOptions()
.position(new LatLng(cLat, cLng)).draggable(true)
.title("Demanding Areas").flat(false));
testMarker.showInfoWindow();
}
private void addHeatMap() {
mProvider = new HeatmapTileProvider.Builder().data(list).build();
mOverlay = googleMap.addTileOverlay(new TileOverlayOptions()
.tileProvider(mProvider));
}
Hope this will help you

Android maps auto zooming

Hi Im having a little issue with displaying points on a map.
I use an Arraylist to store multiple lat/lng values and then do a for loop to add the point and auto zoom. Everything works fine when there are 2 or more markers. The problem is when only 1 marker is added it zooms in too close.
Anyone know how to resolve this?
public static void processMap()
{
for (int i = 0; i < lat.size(); i++)
{
MarkerOptions markerOptions = new MarkerOptions();
LatLng latLng = new LatLng(lat.get(i), lng.get(i));
markerOptions.position(latLng);
markerOptions.title("title");
markerOptions.snippet("description");
mMap.addMarker(markerOptions);
bounds.include(new LatLng(lat.get(i), lng.get(i)));
}
mMap.moveCamera(CameraUpdateFactory.newLatLngBounds(bounds.build(), 150));
}
Updated code
public static void processMap()
{
int num = 0;
double lat2 = 0;
double lng2 = 0;
for (int l = 0; l < lat.size(); l++)
{
lat2 = lat.get(l);
lng2 = lng.get(l);
LatLng latLng = new LatLng(lat2, lng2);
MarkerOptions markerOptions = new MarkerOptions();
markerOptions.position(latLng);
markerOptions.title(title.get(l));
markerOptions.snippet(description.get(l));
mMap.addMarker(markerOptions);
bounds.include(new LatLng(lat2, lng2));
num++;
}
if (num == 1)
{
// if only 1 marker
LatLng latLng2 = new LatLng(lat2, lng2);
mMap.moveCamera(CameraUpdateFactory.newLatLngZoom(latLng2, 16));
}
else
{
// more than 1 marker
mMap.moveCamera(CameraUpdateFactory.newLatLngBounds(bounds.build(), 150));
}
}
Hi sorry I didn't reply earlier I was attempting to fix the problem. I managed to fix it, but is this the correct way of going about it?
The edit you made should fix your problem. Anyway you don't need to set new LatLng if you only have 1 marker. Passing the bound should do. I would make this little edit:
if (num == 1)
{
// if only 1 marker
mMap.moveCamera(CameraUpdateFactory.newLatLngZoom(bounds.build(), 16));
}
else
{
// more than 1 marker
mMap.moveCamera(CameraUpdateFactory.newLatLngBounds(bounds.build(), 150));
}
Hope it helps. Good luck!
Your code does not really tell why you are using .newLatLngBounds(), but this will center the map on your given bounding box and respecting the given 150px padding around the box.
The zoom is then adapted according to the elements inside the bounding box to show all of them. When there is only one marker inside the box, it will zoom to it (and probably too close). The docs say that the map will be centered "at the greatest possible zoom level".
So to prevent this, I would choose a good zoom level for the first marker, add it, move the camera with moveCamera(...) and after that continue with your code when there are other markers left.

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