android-cpp: Restore Sync control

android-cpp/QuickStartTasksCPP/app/build.gradle.kts

@@ -158,5 +158,6 @@ dependencies {
     debugImplementation(libs.androidx.ui.test.manifest)
 
     // Ditto C++ SDK
-    implementation("live.ditto:ditto-cpp:4.10.0")
+    implementation("live.ditto:ditto-cpp:4.10.2")
+
 }

android-cpp/QuickStartTasksCPP/app/src/main/cpp/tasks_peer.cpp

@@ -131,16 +131,18 @@ class TasksPeer::Impl { // NOLINT(cppcoreguidelines-special-member-functions)
 
     ditto->start_sync();
     tasks_subscription =
-        ditto->sync().register_subscription("SELECT * FROM tasks");
+        ditto->get_sync().register_subscription("SELECT * FROM tasks");
   }
 
   void stop_sync() {
     if (!is_sync_active()) {
       return;
     }
 
-    tasks_subscription->cancel();
-    tasks_subscription.reset();
+    if (tasks_subscription) {
+      tasks_subscription->cancel();
+      tasks_subscription.reset();
+    }
     ditto->stop_sync();
   }
 

android-cpp/QuickStartTasksCPP/app/src/main/cpp/taskslib.cpp

@@ -172,7 +172,6 @@ Java_live_ditto_quickstart_tasks_TasksLib_stopSync(JNIEnv *env, jobject thiz) {
       throw_java_illegal_state_exception(env, "TasksLib has not been initialized");
       return;
     }
-    remove_observer(env);
     peer->stop_sync();
   } catch (const std::exception &err) {
     __android_log_print(ANDROID_LOG_ERROR, TAG, "stopSync failed: %s", err.what());

android-cpp/QuickStartTasksCPP/app/src/main/java/live/ditto/quickstart/tasks/list/TasksListScreen.kt

@@ -2,6 +2,7 @@ package live.ditto.quickstart.tasks.list
 
 import androidx.compose.foundation.layout.Box
 import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Row
 import androidx.compose.foundation.layout.fillMaxSize
 import androidx.compose.foundation.layout.fillMaxWidth
 import androidx.compose.foundation.layout.padding
@@ -18,6 +19,7 @@ import androidx.compose.material3.FloatingActionButtonDefaults
 import androidx.compose.material3.Icon
 import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.Scaffold
+import androidx.compose.material3.Switch
 import androidx.compose.material3.Text
 import androidx.compose.material3.TextButton
 import androidx.compose.material3.TopAppBar
@@ -28,6 +30,7 @@ import androidx.compose.runtime.livedata.observeAsState
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
 import androidx.compose.runtime.setValue
+import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.res.colorResource
@@ -48,6 +51,7 @@ import java.util.UUID
 fun TasksListScreen(navController: NavController) {
     val tasksListViewModel: TasksListScreenViewModel = viewModel()
     val tasks: List<Task> by tasksListViewModel.tasks.observeAsState(emptyList())
+    val syncEnabled: Boolean by tasksListViewModel.syncEnabled.observeAsState(true)
 
     var showDeleteDialog by remember { mutableStateOf(false) }
     var deleteDialogTaskId by remember { mutableStateOf("") }
@@ -80,7 +84,23 @@ fun TasksListScreen(navController: NavController) {
                 colors = TopAppBarDefaults.topAppBarColors(
                     containerColor = colorResource(id = R.color.blue_700),
                     titleContentColor = Color.White
-                )
+                ),
+                actions = {
+                    Row(verticalAlignment = Alignment.CenterVertically) {
+                        Text(
+                            text = "Sync",
+                            style = MaterialTheme.typography.bodySmall,
+                            modifier = Modifier.padding(end = 10.dp),
+                            color = Color.White
+                        )
+                        Switch(
+                            checked = syncEnabled,
+                            onCheckedChange = { isChecked ->
+                                tasksListViewModel.setSyncEnabled(isChecked)
+                            }
+                        )
+                    }
+                }
             )
         },
         floatingActionButton = {

android-cpp/QuickStartTasksCPP/app/src/main/java/live/ditto/quickstart/tasks/list/TasksListScreenViewModel.kt

@@ -1,14 +1,26 @@
 package live.ditto.quickstart.tasks.list
 
+import android.content.Context
 import android.util.Log
+import androidx.datastore.preferences.core.booleanPreferencesKey
+import androidx.datastore.preferences.core.edit
+import androidx.datastore.preferences.preferencesDataStore
+import androidx.lifecycle.LiveData
 import androidx.lifecycle.MutableLiveData
 import androidx.lifecycle.ViewModel
 import androidx.lifecycle.viewModelScope
+import kotlinx.coroutines.flow.first
+import kotlinx.coroutines.flow.map
 import kotlinx.coroutines.launch
+import live.ditto.quickstart.tasks.TasksApplication
 import live.ditto.quickstart.tasks.TasksLib
 import live.ditto.quickstart.tasks.TasksObserver
 import live.ditto.quickstart.tasks.data.Task
 
+// The value of the Sync switch is stored in persistent settings
+private val Context.preferencesDataStore by preferencesDataStore("tasks_list_settings")
+private val SYNC_ENABLED_KEY = booleanPreferencesKey("sync_enabled")
+
 class TasksListScreenViewModel : ViewModel() {
 
     companion object {
@@ -24,13 +36,46 @@ class TasksListScreenViewModel : ViewModel() {
         }
     }
 
+    private val preferencesDataStore = TasksApplication.applicationContext().preferencesDataStore
+
     val tasks: MutableLiveData<List<Task>> = MutableLiveData(emptyList())
 
     private val updateHandler: UpdateHandler = UpdateHandler()
 
+    private val _syncEnabled = MutableLiveData(true)
+    val syncEnabled: LiveData<Boolean> = _syncEnabled
+
+    fun setSyncEnabled(enabled: Boolean) {
+        viewModelScope.launch {
+            preferencesDataStore.edit { settings ->
+                settings[SYNC_ENABLED_KEY] = enabled
+            }
+            _syncEnabled.value = enabled
+
+            if (enabled && !TasksLib.isSyncActive()) {
+                try {
+                    TasksLib.startSync()
+                } catch (e: Exception) {
+                    Log.e(TAG, "Unable to start sync", e)
+                }
+            } else if (!enabled && TasksLib.isSyncActive()) {
+                try {
+                    TasksLib.stopSync()
+                } catch (e: Exception) {
+                    Log.e(TAG, "Unable to stop sync", e)
+                }
+            }
+        }
+    }
+
     init {
         viewModelScope.launch {
             TasksLib.insertInitialDocuments()
+
+            setSyncEnabled(
+                preferencesDataStore.data.map { prefs -> prefs[SYNC_ENABLED_KEY] ?: true }.first()
+            )
+
             TasksLib.setTasksObserver(updateHandler)
         }
     }