api support for sync job cancellation.

demo/src/main/java/com/google/android/fhir/demo/PeriodicSyncFragment.kt

@@ -1,5 +1,5 @@
 /*
- * Copyright 2024 Google LLC
+ * Copyright 2024-2025 Google LLC
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -21,6 +21,7 @@ import android.view.LayoutInflater
 import android.view.MenuItem
 import android.view.View
 import android.view.ViewGroup
+import android.widget.Button
 import android.widget.ProgressBar
 import android.widget.TextView
 import androidx.appcompat.app.AppCompatActivity
@@ -48,6 +49,7 @@ class PeriodicSyncFragment : Fragment() {
     setUpActionBar()
     setHasOptionsMenu(true)
     refreshPeriodicSynUi()
+    setUpSyncButtons(view)
   }
 
   override fun onOptionsItemSelected(item: MenuItem): Boolean {
@@ -67,6 +69,30 @@ class PeriodicSyncFragment : Fragment() {
     }
   }
 
+  private fun setUpSyncButtons(view: View) {
+    val syncNowButton = view.findViewById<Button>(R.id.sync_now_button)
+    val cancelSyncButton = view.findViewById<Button>(R.id.cancel_sync_button)
+    syncNowButton.apply {
+      setOnClickListener {
+        periodicSyncViewModel.collectPeriodicSyncJobStatus()
+        toggleButtonVisibility(hiddenButton = syncNowButton, visibleButton = cancelSyncButton)
+        visibility = View.GONE
+      }
+    }
+    cancelSyncButton.apply {
+      setOnClickListener {
+        periodicSyncViewModel.cancelPeriodicSyncJob()
+        toggleButtonVisibility(hiddenButton = cancelSyncButton, visibleButton = syncNowButton)
+        visibility = View.GONE
+      }
+    }
+  }
+
+  private fun toggleButtonVisibility(hiddenButton: View, visibleButton: View) {
+    hiddenButton.visibility = View.GONE
+    visibleButton.visibility = View.VISIBLE
+  }
+
   private fun refreshPeriodicSynUi() {
     viewLifecycleOwner.lifecycleScope.launch {
       viewLifecycleOwner.lifecycle.repeatOnLifecycle(Lifecycle.State.STARTED) {

demo/src/main/java/com/google/android/fhir/demo/PeriodicSyncViewModel.kt

@@ -1,5 +1,5 @@
 /*
- * Copyright 2024 Google LLC
+ * Copyright 2024-2025 Google LLC
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -31,36 +31,43 @@ import com.google.android.fhir.sync.RepeatInterval
 import com.google.android.fhir.sync.Sync
 import com.google.android.fhir.sync.SyncJobStatus
 import java.util.concurrent.TimeUnit
+import kotlinx.coroutines.flow.MutableSharedFlow
 import kotlinx.coroutines.flow.MutableStateFlow
-import kotlinx.coroutines.flow.SharedFlow
-import kotlinx.coroutines.flow.SharingStarted
 import kotlinx.coroutines.flow.StateFlow
-import kotlinx.coroutines.flow.shareIn
 import kotlinx.coroutines.launch
+import timber.log.Timber
 
 class PeriodicSyncViewModel(application: Application) : AndroidViewModel(application) {
 
-  val pollPeriodicSyncJobStatus: SharedFlow<PeriodicSyncJobStatus> =
-    Sync.periodicSync<DemoFhirSyncWorker>(
-        application.applicationContext,
+  private val _uiStateFlow = MutableStateFlow(PeriodicSyncUiState())
+  val uiStateFlow: StateFlow<PeriodicSyncUiState> = _uiStateFlow
+
+  private val _pollPeriodicSyncJobStatus = MutableSharedFlow<PeriodicSyncJobStatus>(replay = 10)
+
+  init {
+    viewModelScope.launch { initializePeriodicSync() }
+  }
+
+  private suspend fun initializePeriodicSync() {
+    val periodicSyncJobStatusFlow =
+      Sync.periodicSync<DemoFhirSyncWorker>(
+        context = getApplication<Application>().applicationContext,
         periodicSyncConfiguration =
           PeriodicSyncConfiguration(
             syncConstraints = Constraints.Builder().build(),
             repeat = RepeatInterval(interval = 15, timeUnit = TimeUnit.MINUTES),
           ),
       )
-      .shareIn(viewModelScope, SharingStarted.Eagerly, 10)
-
-  private val _uiStateFlow = MutableStateFlow(PeriodicSyncUiState())
-  val uiStateFlow: StateFlow<PeriodicSyncUiState> = _uiStateFlow
 
-  init {
-    collectPeriodicSyncJobStatus()
+    periodicSyncJobStatusFlow.collect { status -> _pollPeriodicSyncJobStatus.emit(status) }
   }
 
-  private fun collectPeriodicSyncJobStatus() {
+  fun collectPeriodicSyncJobStatus() {
     viewModelScope.launch {
-      pollPeriodicSyncJobStatus.collect { periodicSyncJobStatus ->
+      _pollPeriodicSyncJobStatus.collect { periodicSyncJobStatus ->
+        Timber.d(
+          "currentSyncJobStatus: ${periodicSyncJobStatus.currentSyncJobStatus}  lastSyncJobStatus ${periodicSyncJobStatus.lastSyncJobStatus}",
+        )
         val lastSyncStatus = getLastSyncStatus(periodicSyncJobStatus.lastSyncJobStatus)
         val lastSyncTime = getLastSyncTime(periodicSyncJobStatus.lastSyncJobStatus)
         val currentSyncStatus =
@@ -83,6 +90,14 @@ class PeriodicSyncViewModel(application: Application) : AndroidViewModel(applica
     }
   }
 
+  fun cancelPeriodicSyncJob() {
+    viewModelScope.launch {
+      Sync.cancelPeriodicSync<DemoFhirSyncWorker>(
+        getApplication<FhirApplication>().applicationContext,
+      )
+    }
+  }
+
   private fun getLastSyncStatus(lastSyncJobStatus: LastSyncJobStatus?): String? {
     return when (lastSyncJobStatus) {
       is LastSyncJobStatus.Succeeded ->

demo/src/main/java/com/google/android/fhir/demo/SyncFragment.kt

@@ -1,5 +1,5 @@
 /*
- * Copyright 2024 Google LLC
+ * Copyright 2024-2025 Google LLC
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -30,6 +30,7 @@ import androidx.fragment.app.viewModels
 import androidx.navigation.fragment.NavHostFragment
 import com.google.android.fhir.demo.extensions.launchAndRepeatStarted
 import com.google.android.fhir.sync.CurrentSyncJobStatus
+import timber.log.Timber
 
 class SyncFragment : Fragment() {
   private val syncFragmentViewModel: SyncFragmentViewModel by viewModels()
@@ -49,6 +50,9 @@ class SyncFragment : Fragment() {
     view.findViewById<Button>(R.id.sync_now_button).setOnClickListener {
       syncFragmentViewModel.triggerOneTimeSync()
     }
+    view.findViewById<Button>(R.id.cancel_sync_button).setOnClickListener {
+      syncFragmentViewModel.cancelOneTimeSyncWork()
+    }
     observeLastSyncTime()
     launchAndRepeatStarted(
       { syncFragmentViewModel.pollState.collect(::currentSyncJobStatus) },
@@ -73,24 +77,41 @@ class SyncFragment : Fragment() {
   }
 
   private fun currentSyncJobStatus(currentSyncJobStatus: CurrentSyncJobStatus) {
-    requireView().findViewById<TextView>(R.id.current_status).text =
+    Timber.d("currentSyncJobStatus: $currentSyncJobStatus")
+    // Update status text
+    val statusTextView = requireView().findViewById<TextView>(R.id.current_status)
+    statusTextView.text =
       getString(R.string.current_status, currentSyncJobStatus::class.java.simpleName)
 
-    // Update progress indicator visibility and handle status-specific actions
+    // Get views once to avoid repeated lookups
     val syncIndicator = requireView().findViewById<ProgressBar>(R.id.sync_indicator)
+    val syncNowButton = requireView().findViewById<Button>(R.id.sync_now_button)
+    val cancelSyncButton = requireView().findViewById<Button>(R.id.cancel_sync_button)
+
+    // Update view states based on sync status
     when (currentSyncJobStatus) {
       is CurrentSyncJobStatus.Running -> {
         syncIndicator.visibility = View.VISIBLE
+        syncNowButton.visibility = View.GONE
+        cancelSyncButton.visibility = View.VISIBLE
       }
       is CurrentSyncJobStatus.Succeeded -> {
         syncIndicator.visibility = View.GONE
         syncFragmentViewModel.updateLastSyncTimestamp(currentSyncJobStatus.timestamp)
+        syncNowButton.visibility = View.VISIBLE
+        cancelSyncButton.visibility = View.GONE
       }
       is CurrentSyncJobStatus.Failed,
+      is CurrentSyncJobStatus.Cancelled, -> {
+        syncIndicator.visibility = View.GONE
+        syncNowButton.visibility = View.VISIBLE
+        cancelSyncButton.visibility = View.GONE
+      }
       is CurrentSyncJobStatus.Enqueued,
-      is CurrentSyncJobStatus.Cancelled,
       is CurrentSyncJobStatus.Blocked, -> {
         syncIndicator.visibility = View.GONE
+        syncNowButton.visibility = View.GONE
+        cancelSyncButton.visibility = View.VISIBLE
       }
     }
   }

demo/src/main/java/com/google/android/fhir/demo/SyncFragmentViewModel.kt

@@ -1,5 +1,5 @@
 /*
- * Copyright 2023-2024 Google LLC
+ * Copyright 2023-2025 Google LLC
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -53,15 +53,21 @@ class SyncFragmentViewModel(application: Application) : AndroidViewModel(applica
   val pollState: SharedFlow<CurrentSyncJobStatus> =
     _oneTimeSyncTrigger
       .flatMapLatest {
-        Sync.oneTimeSync<DemoFhirSyncWorker>(context = application.applicationContext)
+        Sync.oneTimeSync<DemoFhirSyncWorker>(
+          context = application.applicationContext,
+        )
       }
       .map { it }
-      .shareIn(viewModelScope, SharingStarted.Eagerly, 0)
+      .shareIn(viewModelScope, SharingStarted.Eagerly, replay = 0)
 
   fun triggerOneTimeSync() {
     viewModelScope.launch { _oneTimeSyncTrigger.emit(true) }
   }
 
+  fun cancelOneTimeSyncWork() {
+    viewModelScope.launch { Sync.cancelOneTimeSync<DemoFhirSyncWorker>(getApplication()) }
+  }
+
   /** Emits last sync time. */
   fun updateLastSyncTimestamp(lastSync: OffsetDateTime? = null) {
     val formatter =

demo/src/main/res/layout/periodic_sync.xml

@@ -87,4 +87,42 @@
         android:layout_marginTop="8dp"
     />
 
+  <!-- Sync Now Button -->
+  <Button
+        android:id="@+id/sync_now_button"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintTop_toBottomOf="@id/progress_percentage_label"
+        app:layout_constraintBottom_toBottomOf="parent"
+        android:layout_marginTop="16dp"
+        android:layout_marginBottom="64dp"
+        android:paddingLeft="24dp"
+        android:paddingRight="24dp"
+        android:text="Sync Now"
+        android:backgroundTint="?attr/colorPrimary"
+        android:textColor="?attr/colorOnPrimary"
+        app:layout_goneMarginTop="16dp"
+    />
+
+  <Button
+        android:id="@+id/cancel_sync_button"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintTop_toBottomOf="@id/progress_percentage_label"
+        app:layout_constraintBottom_toBottomOf="parent"
+        android:layout_marginTop="16dp"
+        android:layout_marginBottom="64dp"
+        android:paddingLeft="24dp"
+        android:paddingRight="24dp"
+        android:text="Cancel Sync"
+        android:backgroundTint="?attr/colorPrimary"
+        android:textColor="?attr/colorOnPrimary"
+        android:visibility="gone"
+        app:layout_goneMarginTop="16dp"
+    />
+
 </androidx.constraintlayout.widget.ConstraintLayout>

demo/src/main/res/layout/sync.xml

@@ -79,4 +79,22 @@
         android:textColor="?attr/colorOnPrimary"
     />
 
+  <Button
+        android:id="@+id/cancel_sync_button"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintTop_toBottomOf="@id/sync_now_button"
+        app:layout_constraintBottom_toBottomOf="parent"
+        android:layout_marginTop="16dp"
+        android:layout_marginBottom="64dp"
+        android:paddingLeft="24dp"
+        android:paddingRight="24dp"
+        android:text="Cancel Sync"
+        android:backgroundTint="?attr/colorPrimary"
+        android:textColor="?attr/colorOnPrimary"
+        android:visibility="gone"
+    />
+
 </androidx.constraintlayout.widget.ConstraintLayout>