ClusterManager.clearItems() doesn't clear cache

[g012]

Hello,

When we clearItems in ClusterManager, it seems the markers cache of DefaultClusterRenderer is not cleared. Calling getMarker() on it will return a marker not matching the current Map, causing an exception.

I resorted to recreate the whole renderer on each clear to avoid that.

Thank you.

[jeffdgr8]

The only place ClusterManager updates ClusterRenderer's markers is in the result of cluster() with the call to onClustersChanged(). So clearItems() doesn't actually update the map markers at all until cluster() is called. This is the same behavior as any of the ClusterManager methods that add or remove ClusterItems, addItems(), addItem(), removeItems(), or removeItem(). All of these methods modify the ClusterItems in the Algorithm, which will change what Clusters are generated on the next call to cluster(). You should call cluster() after calling clearItems() and potentially any other methods afterwards to add or remove ClusterItems from the map.

Could you elaborate more on what your code is doing and what exception is being thrown?

[barbeau]

@g012 While looking into #90 I can confirm that after calling ClusterManager.clearItems() there are markers remaining in DefaultClusterRenderer's mMarkerCache cache, but this seems to be by design to allow updating the cluster markers without markers on the map flickering (which would happen if they were removed and then quickly re-added).

If you want to clear the map of all cluster markers, just do:

mClusterManager.clearItems();
mClusterManager.cluster();

I'm adding better Javadocs in a pull request I'm working on for #90 to describe this and related cases (as well as fixing an issue that prevented updating the marker contents from the cache).

I'm going to close out this issue, but if you can provide more information about the specific use case you're attempting with some sample code we can certainly revisit.