A current workaround is to associate your "data objects" to your Markers in a HashMap<Marker, MyDataObject>. This is not an ideal solution but this is what workaround are :s

I have actually decided to use an LruCache subclass instead of a HashMap so I can limit how many markers /records are attached at a time.

While HashMap's are a workaround, when your data objects are heavy in terms of memory, having to keep them around for this purpose is just a bad idea.

I never said you have to keep all of your data :) You can have a HashMap<Marker, Long> and load the data for the given Marker using its associated long identifier only when it is clicked.

=)

Yes that is true and I realized after I said it. Still, having to do this ourselves because of poor API design choices is just sad. =(

I agree. Moreover HashMap<Marker, Long> involves autoboxing overhead.

related problem: http://stackoverflow.com/questions/13762150/how-to-persist-marker-from-google-api-android-v2/13816635 

Agreed, having an Object field on Marker would make things a lot easier.

Kind of like what we do with ListAdapter and view.getTag()

If you go the HashMap route it is better to use Marker.getId rather than the Marker pointer as the Id survives a restart. Unfortunately there is no corresponding setId- the Id is auto-generated and appears to be 'm'+marker.count

Agreed, a setTag() and getTag() would be so useful! We need to make a lot of workarounds for now...

We also need this badly. :)

(No comment was entered for this change.)

(No comment was entered for this change.)

As MarkerOptions implements Parcelable (thus are saved and restored) I guess that the API should be something like:

- void setTag(Parcelable p) 
- Parcelable getTag()

or maybe better:

- void setData(Bundle b) 
- Bundle getData()

It seems the GoogleMap doesn't retain the Marker object it returns after calling addMarker(), so the workaround of keeping a HashMap<Marker, ?>, I found it was necessary to also keep a HashMap<LatLng, ?>. After some period of time (not sure the criteria), the GoogleMap passes a different Marker instance which happens to have the same data but is a different object, which causes the HashMap<Marker, ?> lookup to fail. There doesn't seem to be a callback for when the Marker object is replaced, so it's not possible to update your HashMap<Marker, ?> accordingly.

The Marker's position LatLng's latitude and longitude attributes seem to gain arbitrary precision, so to look up against the HashMap<LatLng, ?>, you must first construct a new LatLng with rounded values from the Marker's position. Hopefully your original precision is known and not subject to change!

Hopefully there will be an update with a Tag feature soon. It is very sorely needed.

There is a getTag() function which you can use to populate HashMaps but there is no way to set it- It's an arbitary 'M999'- The letter M followed by the Marker's position in the internal array.

@16, What object has the getTag() function? As far as I can tell, the Marker object does not.

Apologies, it's getId() and it is part of the Marker class.

The getId() method is good solution, becouse you can store id's of added markers and eventually map them to your objects. The problems comes, when you want to remove particular marker from the map, there is no getMarkerById(String gMarkerId) method in the GoogleMap class :-(

@15: I do not agree with you. The HashMap<Marker, ?> perfectly works because it retains a reference on the Marker. Moreover you don't have to care about Marker actually being different because HashMap internally uses hashCode() and equals(Object). These methods works perfectly even if the Marker is different but the underlying state is the same.

@19: Using a HashMap<Marker, ?> should solve your problems.

@20: In the December release of the v2 SDK, I noticed sometimes my OnMarkerClickListener couldn't find a value for the passed Marker in the HashMap<Marker, ?>, which received every Marker added to the map unconditionally. I suspect there must be some internal state in the Marker which is changing, and causing a different hashcode to return.

To clarify, the problem where the Marker cannot be matched in a HashMap<Marker, ?> only seemed to happen when there were many Markers (often 100 or more) on the map, and only after panning and zooming around different areas of the map (moving the Markers in and out of view) and periodically tapping Marker objects. After doing that for several minutes, the HashMap<Marker, ?> was no longer able to get a value for some (though not all) of the Marker objects passed into the OnMarkerClickListener. 

While waiting for this to be implemented in GM Android API v2 you may want to try a small library project of mine called Android Maps Extensions which adds getData and setData to Markers and other objects.

https://code.google.com/p/android-maps-extensions/

Hi Carlton,

That sounds like a bug. If you're able to reproduce it consistently, could you please file a bug report?

Thanks,
Chris

Hello all.

can any Project Member tell us which is the status of the issue. we really need add at least just a reference to other Object.

Methods setTag() and getTag() will work fine if you don´t really want let us extend Marker.

Thank you a lot.
Alvaro

Sure would be nice if the internal components of custom InfoWindow objects were able to  have listeners, instead of the whole view being turned into an image. If you were to touch a button inside a marker's info window on the actual Google Maps app, then why hasn't that functionality been offered in the Google Play services?

Hi,

I have noticed the same problem than Carlton on #21 #22, although for me it happened after opening another activity (on marker click) and going back to the map. I also noticed that:
- it doesn't seem to happen the first time you click a marker
- by clicking several times in a row on the same marker, I could get my object back even if it seemed to be lost at first

Tested on Android 2.3.3

#27, Pierre:

Are you able to reproduce this consistently? If so, could you please file a bug report? It would be most helpful!

#26 (miguelmora), that's completely unrelated to this feature request. Please see (and star) Issue 5035.

There is getId function associated with marker if use this marker.getId().substring(1) you will get the position you can use this to retrieve the data from arraylist or any other  datatype for that position .

I would like to extend Marker, because then we may be able to get additional data like tag or others in methods like onMarkerClick(Marker arg0) and onInfoWindowClick(Marker arg0) if it's not a security issue. This would simplify my code and speed up my app. 😀

 Issue 5019  has been merged into this issue.