Issue
Guys I have to show markers on google maps with zoom.When user zoom in or zoom out markers will be visible covering the map area which is on the screen.How can I do this using Android google map?
Solution
Okay so you can use a CameraChangeListener:
private HashMap<Integer, Marker> courseMarkers = new HashMap<Integer, Marker>();
//all your visible markers
ArrayList<Item> yourMarkerList = new ArrayList<Item>();
//method to add all your markers with unique ids
addItemsToMap(); //first call to initially show the markers you want
googleMap.setOnCameraChangeListener(new OnCameraChangeListener() {
private float currentZoom = -1; //keep track of your current zoom level
@Override
public void onCameraChange(CameraPosition camera) {
if (camera.zoom != currentZoom){
currentZoom = camera.zoom;
//here you will then check your markers
addItemsToMap(yourMarkerList);
}
}
});
You will need a class Item that has a variable for a unique int id and a MarkerOptions
private void addItemsToMap(List<Item> items)
{
if(this.mMap != null)
{
//This is the current user-viewable region of the map
LatLngBounds bounds = this.mMap.getProjection().getVisibleRegion().latLngBounds;
//Loop through all the items that are available to be placed on the map
for(Item m : item)
{
//If the item is within the the bounds of the screen
if(bounds.contains(item.getMarker().getPosition()))
{
//If the item isn't already being displayed
if(!courseMarkers.containsKey(item.getId()))
{
//Add the Marker to the Map and keep track of it with the HashMap
//getMarkerForItem just returns a MarkerOptions object
this.courseMarkers.put(item.getId(), this.googleMap.addMarker(item.getMarker())); //getmarkerforitem
}
}
//If the marker is off screen
else
{
//If the course was previously on screen
if(courseMarkers.containsKey(item.getId()))
{
//1. Remove the Marker from the GoogleMap
courseMarkers.get(item.getId()).remove();
//2. Remove the reference to the Marker from the HashMap
courseMarkers.remove(item.getId());
}
}
}
}
}
This should do it
Answered By - Evan
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