SingleTileLayoutRenderer get versions wrong

[yschimke]

The tiles module was built with a false assumptions about resource version strategies.

However

The resource_ids field is not used at all in practice.

We originally came up with three strategies a) App has fixed resources, so has an immutable version and ships all resources at once. b) App has dynamic resources which all change on some frequency, bump the version at those points to get fresh resources. c) App has mostly static resources, that might occasionally change. Return a versioned resource id e.g. _

However c) is a false assumption given resources are only refreshed when the version changes.

https://cs.android.com/androidx/platform/frameworks/support/+/androidx-main:wear/tiles/tiles-renderer/src/main/java/androidx/wear/tiles/manager/TileUiClient.kt;l=153;bpv=1

[yschimke]

cc @castedmo @garanj

[yschimke]

I'm tempted to introduce a first class VersionStrategy into the horologist APIs, something like

sealed trait VersionStrategy {
  val versionId: String
}

object StaticVersion: VersionStrategy {
  val versionId: String = "0"
}
data class IncrementingVersionStrategy(val versionId: String): VersionStrategy
class CollectedVersionStrategy(): VersionStrategy {
  fun addResource(id: String)

  val versionId: String
    get() = // combine resources
}

[yschimke]

Now exposed as

    public open fun getResourcesVersionForTileState(state: T): String = PERMANENT_RESOURCES_VERSION

Apps can decide how to handle.