New: Expose network height as a StateFlow.

We already had latest height but that would require polling. Having a state flow makes it easier for views to be pushed the latest height.

src/main/java/cash/z/ecc/android/sdk/SdkSynchronizer.kt

@@ -66,6 +66,7 @@ import kotlinx.coroutines.SupervisorJob
 import kotlinx.coroutines.cancel
 import kotlinx.coroutines.channels.ConflatedBroadcastChannel
 import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.asFlow
 import kotlinx.coroutines.flow.distinctUntilChanged
 import kotlinx.coroutines.flow.first
@@ -170,6 +171,8 @@ class SdkSynchronizer internal constructor(
      */
     override val processorInfo: Flow<CompactBlockProcessor.ProcessorInfo> = processor.processorInfo
 
+    override val networkHeight: StateFlow<Int> = processor.networkHeight
+
     //
     // Error Handling
     //

src/main/java/cash/z/ecc/android/sdk/Synchronizer.kt

@@ -12,6 +12,7 @@ import cash.z.ecc.android.sdk.type.ZcashNetwork
 import cash.z.wallet.sdk.rpc.Service
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.StateFlow
 
 /**
  * Primary interface for interacting with the SDK. Defines the contract that specific
@@ -91,6 +92,8 @@ interface Synchronizer {
      */
     val processorInfo: Flow<CompactBlockProcessor.ProcessorInfo>
 
+    val networkHeight: StateFlow<Int>
+
     /**
      * A stream of balance values, separately reflecting both the available and total balance.
      */

src/main/java/cash/z/ecc/android/sdk/block/CompactBlockProcessor.kt

@@ -47,6 +47,7 @@ import kotlinx.coroutines.channels.ConflatedBroadcastChannel
 import kotlinx.coroutines.delay
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.asFlow
+import kotlinx.coroutines.flow.asStateFlow
 import kotlinx.coroutines.flow.first
 import kotlinx.coroutines.isActive
 import kotlinx.coroutines.sync.Mutex
@@ -120,6 +121,7 @@ class CompactBlockProcessor(
     private val _state: ConflatedBroadcastChannel<State> = ConflatedBroadcastChannel(Initialized)
     private val _progress = ConflatedBroadcastChannel(0)
     private val _processorInfo = ConflatedBroadcastChannel(ProcessorInfo())
+    private val _networkHeight = MutableStateFlow(-1)
     private val processingMutex = Mutex()
 
     /**
@@ -161,6 +163,8 @@ class CompactBlockProcessor(
      */
     val processorInfo = _processorInfo.asFlow()
 
+    val networkHeight = _networkHeight.asStateFlow()
+
     /**
      * The first block this wallet cares about anything prior can be ignored. If a wallet has no
      * transactions, this value will later update to 100 blocks before the first transaction,
@@ -583,6 +587,7 @@ class CompactBlockProcessor(
             lastScanRange = lastScanRange,
             lastDownloadRange = lastDownloadRange
         )
+        _networkHeight.value = networkBlockHeight
         _processorInfo.send(currentInfo)
     }