Is there any possibility to delete certain Google Map markers and having to do map.clear ()? Because in my app I have several checkbox marking and unmarked some markers ...
How can I achieve this?
I have done a similar thing in the past.
The trick is to maintain a list of the Marker objects, but within your own custom class (I have created a class called MapPoint which has the latlng, title, icon, snippet and holds a Marker).
Then when you want to push an update to the map you create a list of MapPoint objects (with the Marker set to null) with the current list of active MapPoint objects, remove duplicates and empty ones that no longer exist. This allows you to update the map as little as possible, rather than doing an entire refresh of everything.
Code snippet with comments for easier reading:
// holds the current list of MapPoint objects
public ArrayList<MapPoint> mCurrentPoints = new ArrayList<MapPoint>();
public void addMapPoints(ArrayList<MapPoint> mapPoints) {
// only process if we have an valid list
if (mapPoints.size() > 0) {
// iterate backwards as we may need to remove entries
for (int i = mCurrentPoints.size() - 1; i >= 0; i--) {
// get the MapPoint at this position
final MapPoint point = mCurrentPoints.get(i);
// check if this point exists in the new list
if (!mapPoints.contains(point)) {
// if it doesn't exist and has a marker (null check), remove
if (point.mMarker != null) {
// removes Marker from mMap
point.mMarker.remove();
}
// remove our MapPoint from the current list
mCurrentPoints.remove(i);
} else {
// already exists, remove from the new list
mapPoints.remove(point);
}
}
// add all the remaining new points to the current list
mCurrentPoints.addAll(mapPoints);
// go through every current point. If no mMarker, create one
for (MapPoint mapPoint : mCurrentPoints) {
if (mapPoint.mMarker == null) {
// create Marker object via mMap, save it to mapPoint
mapPoint.mMarker = mMap.addMarker(new MarkerOptions()
.position(mapPoint.getLatLng())
.title(mapPoint.getTitle())
.icon(mapPoint.getMarker())
.snippet(mapPoint.getInfoSnippetText()));
}
}
}
}
So you will want a method that determines what Marker objects are to be shown, create a MapPoint objects for them, then send the list of them to this addMapPoints() method.
A couple of good ideas: synchronize on the mCurrentPoints list (removed to make code snippet simpler) and ensuring you run on UI thread for the adding/removing markers. (Good idea to do this processing off the main thread then hop on to it for the actual adding/removing of Markers). And adapt to your own situation of course.
Use setVisible(true) on a Marker object (not a MarkerOptions, this is important). Add all the markers you want as visible/invisible, keep the references to the Marker objects, and toggle them on demand.
Related
After I remove a marker from Google Map, using marker.remove(), I want to add the same marker again. Like, I want to Hide and Show the marker.
I don't want to create MarkerOptions every time. Is there a simple way? though there should have been an intuitive way to do this simple thing.
I can't understand what you expect to get as a result but if you just want to reuse marker with same values, you can create a var of MarkerOptions and store MarkerOptions options in it and reuse it.
creating the marker var:
MarkerOptions markerOptions = new MarkerOptions();
reuse it(mMap is your googleMap var):
mMap.addMarker(markerOptions);
There are two possible ways and with both ways, you only need to maintain one object against a marker. The main difference between these two approaches is that you need to make marker object mutable if you want to use the add and remove marker.
Using Visibility
marker?.isVisible = true/false
Using Adding and removing:
var marker = mMap?.addMarker(MarkerOptions().position(Location))
marker?.remove()
// To add again
marker = mMap?.addMarker(MarkerOptions().position(marker!!.position))
Edit 1: After reading your comment, the second approach needs to be modified
According to docs: tag property can be used to store any data and it's never read/written by the map, so it can be used to store ID of your data model
use the following data class
data class MarkerData(val id: String, val title: String, var icon: BitmapDescriptor?, val position: LatLng)
You can add/remove variables as you desired.
copy the following function in your class
private fun getMarkerOption(model: MarkerData? = null,marker: Marker? = null): Pair<String,MarkerOptions>{
check(!(model == null && marker == null)) { "Both options can't be null" }
var m = model ?: array.first { it.id == marker!!.id }
val markerOptions = MarkerOptions().position(m.position).icon(m.icon).title(m.title)
return Pair(m.id,markerOptions)
}
Customize the third line val markerOptions according to your requirement
Note that array refers to your list where you will store all the data for markers.
How to use (with model):
var options = getMarkerOption(array.first())
var marker = mMap?.addMarker(options.second)
marker?.tag = options.first
How to use(with marker):
options = getMarkerOption(marker = marker)
marker = mMap?.addMarker(options.second)
marker?.tag = options.first
The answer I found is:
If you just want to hide and show, the use this
marker.isVisible = true/false Or marker.setVisibility(true/false) //for java
There is no direct way to add a Removed marker again, unless u keep reference to MarkerOptions. You can save its reference like marker.tag = markerOptions. Although, in the function description of remove() it says it doesnt guarantee any operation on marker after remove() is called. But i think TAG wont go anywhere.
I trying to set marker visible on the map when I am in range and set invisible when i am not in range. When am moving and enter area marker appear - but when I get out of range marker is still visible. Here is my code onLocationUpdate.
I iterate over my database and adding markers. getDeviceLocation return Ltglng with my current location. I implement this also for GPS provider. Any ideas will be helpfull ty!
locManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 1000, 1, new LocationListener() {
#Override
public void onLocationChanged(Location location) {
Cursor res = activityA.myDB.getAllData();
while (res.moveToNext()) {
double ltd = Double.valueOf(res.getString(3));
double lng = Double.valueOf(res.getString(4));
LatLng hole = new LatLng(ltd, lng);
Marker marker = mMap.addMarker(new MarkerOptions().position(hole)
.title(res.getString(1)).visible(false));
if (SphericalUtil.computeDistanceBetween(getDeviceLocation(), marker.getPosition()) <3 ) {
marker.setVisible(true);
}
}
}
From what you have provided this is what I can gather.
You are adding the marker (originally set to invisible), and then if it meets your if statement, you make them invisible. The problem is, I don't see any place, where you would make them invisible again, or remove them.
Do you save these markers in your activity? For example in an ArrayList?
I have two suggestions:
1)Either call mMap.clear() before before your while statement. This will clear the map of any markers, and then adds the new ones as they are created.
2)Save all your markers in an ArrayList and then in your onLocationChanged, use a for loop to go through all your markers and make the ones out of range invisible. Here is an example:
for (Marker marker: mMarkerArrayList) {
if (outOfRange()) {
marker.visible(false);
}
}
Here mMarkerArrayList is the ArrayList containing all your markers. outOfRange() is a helper function that returns a boolean if the marker is outOfRange.
What I am trying to do is when someone clicks on a marker on the google map, I need to get the info on that marker from my ArrayList and then pass it on to the next activity so I can display additional details about that marker. The only options that I know of when it comes to markers is getSnippet, getTitle and getPosition. Is there a way to assign a unique key to the marker so I can pull it from my list? Reason for this is there could be two markers with the same name. Right now it doesn't even find the marker by name when I do a search for it.
// WHEN A USER CLICKS A MAKER ON THE MAP
#Override
public void onInfoWindowClick(Marker marker)
{
// TESTING TO SEE WHAT MY VALUE WOULD BE IN THE LIST RETURNS - TEST MARKER
// DISPLAY ON SCREEN SO I CAN SEE WHAT THE VALUE IS
Toast.makeText(this, "Found " + marker.getTitle(), Toast.LENGTH_SHORT).show();
// SEARCH MY LIST FOR VALUE
for(int i = 0; i < marker_list.size(); i++)
{
// IF THIS VALUE IS SAME AS MARKER TITLE
String value = marker_list.get(i);
if(value == marker.getTitle())
{
Toast.makeText(this, "Found " + value,Toast.LENGTH_SHORT).show();
break;
}
}
}
How about marker.toString() ?
Instead of using an ArrayList to store the markers and running through the list to find your value, you could use a HashMap. When you add your markers, you put marker.toString() as the key and whatever information you want to associate with the marker as the value into the HashMap.
By the way: you're method to find the clicked marker is probably not working because of the way you compare Strings:
value == marker.getTitle()
This checks if two String references are the exact same String object. To compare the String values, do
value.equals(marker.getTitle())
I work on google map .I add Markers first with type and then add marker again with distance so problem is there at some location two markers are add . so when i click on that it alternatively change. so i need to check marker is already there or not when add with distance.thanx.
I think your best way is to store already added markers to a collection, and then search for equal markers.
ArrayList<Marker> collection = new ArrayList()<Marker>;
collection.add(map.addMarker(Marker));
Something like this to add items, and then a function to check if exists
static boolean isMarkerOnArray(ArrayList<Marker> array, Marker m)
{
for(int c=0;c<array.size();c++)
{
Marker current = array.get(c);
if((current.getPosition().latitude == m.getPosition().latitude) &&(current.getPosition().longitude == m.getPosition().longitude) )
return true; //Both markers are equal
}
return false;
}
HandWrite code, it can be wrong, but i think thats the proper way to do it.
Hope this helps.
I have an ArrayList of a custom class. There are about 10 objects in the list, each with details like Title, Snippet, LatLng. I have successfully added all 10 to a Map by using my custom class functions like getTitle, getSnippet, getLatLng etc.
Now, when I click the info window (of the marker), I want to be able to somehow KNOW which object of my custom class does that marker correspond to.
For example, if I click the McDonald's market, I want to be able to know which item from my ArrayList did that marker belong to.
I've been looking at the MarkerOptions and there doesn't seem to be anything in there that I can use to identify the relevant custom object with.
If the question is too confusing, let me make it simple:
ArrayList<CustomObj> objects = blah
map.addMarker(new MarkerOptions().position(new LatLng(
Double.parseDouble(result.get(i).getCompanyLatLng()
.split(",")[0]), Double.parseDouble(result
.get(i).getCompanyLatLng().split(",")[1])))
.title(result.get(i).getCompanyName())
.snippet(result.get(i).getCompanyType())
.icon(BitmapDescriptorFactory
.fromResource(R.drawable.pin)));
Now when this is clicked, I go on to the next page. The next page needs to know WHICH object was clicked so that I can send the other details to that page (e.g. Image URLs that need to be loaded etc).
How do I add a unique integer or any identifier to my marker?
One correct way is to use Map<Marker, CustomObj> which stores all markers:
Marker marker = map.addMarker(...);
map.put(marker, result.get(i));
and in onInfoWindowClick:
CustomObj obj = map.get(marker);
Another try is using Android Maps Extensions, which add getData and setData method to Marker, so you can assign your CustomObj object after creating marker and retrieve it in any callback.
I used the the snippet text for saving an unique ID. If you need the snippet it's will be for the popup and there you can just make your own (by finding the object from the ID) so you wont miss it but you'll certainly miss a unique ID for identifying the objects.
To find the right object I just iterate through them:
for(SomeObject anObject : someObjects) {
if(marker.getSnippet().equalsIgnoreCase(anObject.getID())) {
//you got at match
}
}
According to the discussion at the following link, Marker.equals and Marker.hashCode don't work sometimes. For example, when the map is panned or zoomed, or it's restarted/resumed.
Add Tag / Identifier to Markers
So Marker's ID is a better key than Marker itself for a HashMap.
Map<String, MyObject> markerMap = new HashMap<String, MyObject>();
Marker marker = map.addMarker(...);
MyObject myObject = new MyObject();
markerMap.put(marker.getId(), myObject);
I think using latitude and longitude, this could be done
map.setOnMarkerClickListener(new GoogleMap.OnMarkerClickListener() {
#Override
public boolean onMarkerClick(final Marker marker) {
LatLng pos = marker.getPosition();
int arryListPosition = getArrayListPosition(pos);
return true;
}
});
and the method getArrayListPosition is
private int getArrayListPosition(LatLng pos) {
for (int i = 0; i < result.size(); i++) {
if (pos.latitude == result.get(i).getCompanyLatLng().split(",")[0]) {
if (pos.longitude == result.get(i).getCompanyLatLng()
.split(",")[1])
return i;
}
}
return 0;
}
This method will return you the position of your ArrayList who's Marker you have clicked. and you can get data from that position.
Hope it helps...
I am 4 years late to answer but I really amazed why no-one talked about marker.setTag and marker.getTag method.
As written in google API docs,
This is easier than storing a separate Map<Marker, Object>
They have introduce setTag and getTag to avoid use of Map<...>. You can use it as following way.
Marker marker = map.addMarker(...);
marker.setTag(result.get(i)); //Store your marker information here.
//To fetch your object...
map.setOnMarkerClickListener(new GoogleMap.OnMarkerClickListener() {
#Override
public boolean onMarkerClick(Marker marker) {
CustomObj obj = (CustomObj)marker.getTag();
//Your click handle event
// Pass the obj to another activity and you are done
return false;
}
});