Clustering: ClusterContent's and ItemContent's `contentDescription` is not taken into account for talkback accessibility .

[esalavastru]

Environment details

Android API 35
Library Version: 6.1.1

Steps to reproduce

1. Create a GoogleMap composable with a Clustering composable inside of it.
2. The Clustering's ItemContent and ClusterContent params are setup with custom composables which have their contentDescription set to different texts(i.e. for cluster: "Cluster of x items" and for markers "Marker with y title").
3. Activate Talkback on the Android OS.
4. Run the app
5. Try to select a cluster or a marker
6. Actual result: Talkback says "Map Marker" instead of the expected "Cluster of x items"/"Marker with y title"

Code example

This is an example how we have setup the renderer for the Clustering:

 val renderer = rememberClusterRenderer(
        clusterContent = { cluster ->
           ClusterContent(
                numberOfItems = totalItemCount,
                isSelected = isSelected
            )
        },
        clusterItemContent = { mapItemGroup ->
            if (isStacked()) {
                StackedMarkerContent(
                    items = items,
                )
            } else {
                CustomItemMarkerContent(
                    item = items.first()
                )
            }
        },
        clusterManager = clusterManager
    )

Please note that i've noticed that in the top left corner of the map there are some invisible marker/cluster views which are selectable by talkback and those have the content description correctly read by talkback.

[kikoso]

Hi @esalavastru,

This option is not supported out of the box. Clustering in Maps Compose works under the hood using the ClusteringManager and Renderer from android-maps-utils. To keep things simple, Compose Clustering doesn't deal with individual markers directly, but rather with a list of items or a Composable representing the content.

As a result, contentDescription (which you would typically set via the marker’s title) is not currently passed to the underlying ClusteringManager, which is responsible for setting accessibility properties like the title.

Supporting this would require an update to android-maps-utils to allow setting the title on a marker via some exposed property, which could then be integrated into Maps Compose. In the meantime, it's technically possible (though not trivial) to achieve this by implementing a custom renderer/manager, as shown in this example.

I'll take a closer look at this after Google I/O.

[kikoso]

Related to #683

[esalavastru]

Thank you for the clarification and suggestions, @kikoso .
Do you think I should create a ticket on the android-maps-utils repo or anything like that, maybe it might help ?

[kikoso]

Hi @esalavastru ,

I have created it in googlemaps/android-maps-utils#1510.

[esalavastru]

In the meantime, it's technically possible (though not trivial) to achieve this by implementing a custom renderer/manager, as shown in this example.

Hi @kikoso,
Sorry for bugging you again, but I just took a closer look at the example.
If you were referring specifically to CustomRendererClustering implementation, that is our current way of implementing the map, specifically using rememberClusterRenderer to initialise a renderer which is passed to the Clustering.

Also, just for context, we've looked for an example on creating a custom renderer class, but couldn't find any.
So we've tried creating a custom renderer class. which proved pretty hard to do, since it seems that we either need to create a renderer from the ground-up or we were "blocked" by internal fields/classes of the lib when trying to recreate the rememberClusterRenderer function.

Maybe we are doing/thinking about things the wrong way, when creating the renderer. But just wanted to give a bit of a bigger idea of our current implementation. Any other guidance regarding the renderer would be greatly appreciated.

[kikoso]

Hi @esalavastru ,

There is a sample extending the DefaultClusterRenderer in the android-maps-utils. Here you can see it in practice.

[esalavastru]

Thank you, @kikoso.
We've tried creating our own custom renderer class.

Is there a way of passing the custom renderer instance (in the map-utils example, it would be PersonRenderer ) to rememberClusterRenderer() ?
From what I know we need to make the renderer and clustermanager be "remembered" across recompositions in order for things to work properly in the Compose part of Google Maps, right?

Even if we have our own custom renderer instance, we wouldn't be able to use it with the android-maps-compose lib without using rememberClusterRenderer, am I correct?