Refactor account persistence to use Kotlin Coroutines Flow instead of LiveData

- Replace `LiveData` with `MutableStateFlow` in the `Account` model and `AccountStateViewModel` to observe and save account changes.
- Implement custom setters for `signPolicy` and `didBackup` in the `Account` class to trigger state updates automatically.
- Simplify `AccountStateViewModel` by using a `Job` to collect and save account state changes on a background dispatcher.
- Remove redundant manual calls to `LocalPreferences.saveToEncryptedStorage` across several UI components (`SignPolicySettingsScreen`, `ProfileSubscription`, `AccountBackupDialog`, etc.), as saving is now handled reactively.
- Remove `runtime-livedata` dependency from `build.gradle` and `libs.versions.toml`.
- Clean up unused imports and the obsolete `AccountLiveData` class.

app/build.gradle

@@ -189,14 +189,9 @@ dependencies {
     implementation libs.ui
     implementation libs.ui.tooling.preview
 
-    implementation libs.runtime.livedata
-
     // Navigation
     implementation libs.navigation.compose
 
-    // Observe Live data as State
-    implementation libs.runtime.livedata
-
     implementation libs.material3
     implementation libs.material.icons.extended
 

app/src/main/java/com/greenart7c3/nostrsigner/models/Account.kt

@@ -6,10 +6,8 @@ import androidx.compose.runtime.Immutable
 import androidx.compose.runtime.Stable
 import androidx.compose.ui.platform.ClipEntry
 import androidx.compose.ui.platform.Clipboard
-import androidx.lifecycle.LiveData
 import com.greenart7c3.nostrsigner.Amber
 import com.greenart7c3.nostrsigner.DataStoreAccess
-import com.greenart7c3.nostrsigner.LocalPreferences
 import com.greenart7c3.nostrsigner.R
 import com.vitorpamplona.quartz.nip01Core.core.Event
 import com.vitorpamplona.quartz.nip01Core.core.HexKey
@@ -26,6 +24,9 @@ import com.vitorpamplona.quartz.nip57Zaps.PrivateZapRequestBuilder
 import kotlinx.coroutines.CancellationException
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.asStateFlow
+import kotlinx.coroutines.flow.combine
+import kotlinx.coroutines.flow.drop
 import kotlinx.coroutines.launch
 
 @Stable
@@ -35,10 +36,35 @@ class Account(
     val npub: String,
     val name: MutableStateFlow<String>,
     val picture: MutableStateFlow<String>,
-    var signPolicy: Int,
-    var didBackup: Boolean,
+    signPolicy: Int,
+    didBackup: Boolean,
 ) {
-    val saveable: AccountLiveData = AccountLiveData(this)
+    var signPolicy: Int = signPolicy
+        set(value) {
+            if (field != value) {
+                field = value
+                _saveable.value = AccountState(this)
+            }
+        }
+
+    var didBackup: Boolean = didBackup
+        set(value) {
+            if (field != value) {
+                field = value
+                _saveable.value = AccountState(this)
+            }
+        }
+
+    private val _saveable = MutableStateFlow(AccountState(this))
+    val saveable = _saveable.asStateFlow()
+
+    init {
+        Amber.instance.applicationIOScope.launch {
+            combine(name, picture) { _, _ -> }.drop(1).collect {
+                _saveable.value = AccountState(this@Account)
+            }
+        }
+    }
 
     suspend fun <T : Event> sign(eventTemplate: EventTemplate<T>): T = signer.sign(eventTemplate)
 
@@ -87,7 +113,6 @@ class Account(
     fun copyToClipboard(clipboardManager: Clipboard) {
         Amber.instance.applicationIOScope.launch {
             didBackup = true
-            LocalPreferences.saveToEncryptedStorage(Amber.instance, this@Account, null, null, null)
             val nsec = getNsec()
             Amber.instance.applicationIOScope.launch(Dispatchers.Main) {
                 clipboardManager.setClipEntry(
@@ -106,7 +131,5 @@ class Account(
     }
 }
 
-class AccountLiveData(account: Account) : LiveData<AccountState>(AccountState(account))
-
 @Immutable
 class AccountState(val account: Account)

app/src/main/java/com/greenart7c3/nostrsigner/service/ProfileSubscription.kt

@@ -88,7 +88,6 @@ class ProfileSubscription(
 
                         if (atLeastOne) {
                             scope.launch {
-                                LocalPreferences.saveToEncryptedStorage(appContext, account, null, null, null)
                                 LocalPreferences.setLastMetadataUpdate(appContext, npub, TimeUtils.now())
                             }
                         }

app/src/main/java/com/greenart7c3/nostrsigner/ui/AccountStateViewModel.kt

@@ -17,6 +17,7 @@ import com.vitorpamplona.quartz.nip19Bech32.toNpub
 import com.vitorpamplona.quartz.nip49PrivKeyEnc.Nip49
 import com.vitorpamplona.quartz.utils.Hex
 import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.Job
 import kotlinx.coroutines.channels.BufferOverflow
 import kotlinx.coroutines.flow.MutableSharedFlow
 import kotlinx.coroutines.flow.MutableStateFlow
@@ -48,6 +49,7 @@ class AccountStateViewModel(npub: String?) : ViewModel() {
     private val _accountContent = MutableStateFlow<AccountState>(AccountState.LoggedOff)
     val accountContent = _accountContent.asStateFlow()
     val toasts = MutableSharedFlow<ToastMsg?>(0, 3, onBufferOverflow = BufferOverflow.DROP_OLDEST)
+    private var observerJob: Job? = null
 
     init {
         tryLoginExistingAccount(null, npub)
@@ -103,15 +105,7 @@ class AccountStateViewModel(npub: String?) : ViewModel() {
     }
 
     private fun prepareLogoutOrSwitch() {
-        when (val state = accountContent.value) {
-            is AccountState.LoggedIn -> {
-                Amber.instance.applicationIOScope.launch(Dispatchers.Main) {
-                    state.account.saveable.removeObserver(saveListener)
-                }
-            }
-            else -> {}
-        }
-
+        observerJob?.cancel()
         _accountContent.update { AccountState.LoggedOff }
     }
 
@@ -236,15 +230,12 @@ class AccountStateViewModel(npub: String?) : ViewModel() {
     ) {
         _accountContent.update { AccountState.LoggedIn(account, route) }
 
-        Amber.instance.applicationIOScope.launch(Dispatchers.Main) {
-            account.saveable.observeForever(saveListener)
-        }
-    }
-
-    private val saveListener: (com.greenart7c3.nostrsigner.models.AccountState) -> Unit = {
-        Amber.instance.applicationIOScope.launch(Dispatchers.Main) {
-            Log.d(Amber.TAG, "Account saved")
-            LocalPreferences.saveToEncryptedStorage(Amber.instance, it.account, null, null, null)
+        observerJob?.cancel()
+        observerJob = Amber.instance.applicationIOScope.launch(Dispatchers.IO) {
+            account.saveable.collect {
+                Log.d(Amber.TAG, "Account saved")
+                LocalPreferences.saveToEncryptedStorage(Amber.instance, it.account, null, null, null)
+            }
         }
     }
 }

app/src/main/java/com/greenart7c3/nostrsigner/ui/SignPolicySettingsScreen.kt

@@ -25,7 +25,6 @@ import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.unit.dp
 import androidx.navigation.NavController
-import com.greenart7c3.nostrsigner.LocalPreferences
 import com.greenart7c3.nostrsigner.R
 import com.greenart7c3.nostrsigner.models.Account
 import com.greenart7c3.nostrsigner.ui.components.AmberButton
@@ -107,7 +106,6 @@ fun SignPolicySettingsScreen(
             onClick = {
                 scope.launch(Dispatchers.IO) {
                     account.signPolicy = selectedOption
-                    LocalPreferences.saveToEncryptedStorage(context, account, null, null, null)
                     scope.launch(Dispatchers.Main) {
                         navController.navigateUp()
                     }

app/src/main/java/com/greenart7c3/nostrsigner/ui/actions/AccountBackupDialog.kt

@@ -330,7 +330,6 @@ private fun NSecQrButton(
             ) {
                 Amber.instance.applicationIOScope.launch {
                     account.didBackup = true
-                    LocalPreferences.saveToEncryptedStorage(context, account, null, null, null)
                     showDialog = false
                 }
             }
@@ -345,7 +344,6 @@ private fun NSecQrButton(
                         onLoading(true)
                         val ncryptsec = account.nip49Encrypt(password)
                         account.didBackup = true
-                        LocalPreferences.saveToEncryptedStorage(context, account, null, null, null)
                         Amber.instance.applicationIOScope.launch(Dispatchers.Main) {
                             navController.navigate(Route.QrCode.route.replace("{content}", ncryptsec))
                         }
@@ -369,7 +367,6 @@ private fun NSecQrButton(
                             onLoading(true)
                             val ncryptsec = account.nip49Encrypt(password)
                             account.didBackup = true
-                            LocalPreferences.saveToEncryptedStorage(context, account, null, null, null)
                             Amber.instance.applicationIOScope.launch(Dispatchers.Main) {
                                 navController.navigate(Route.QrCode.route.replace("{content}", ncryptsec))
                             }
@@ -533,9 +530,6 @@ private fun SeedWordsButton(
                     Amber.instance.applicationIOScope.launch {
                         account.didBackup = true
                         showSeedWords = true
-                        Amber.instance.applicationIOScope.launch {
-                            LocalPreferences.saveToEncryptedStorage(context, account, null, null, null)
-                        }
                     }
                 },
                 onError = { _, message ->
@@ -588,7 +582,6 @@ private fun NSecCopyButton(
                 onApproved = {
                     scope.launch(Dispatchers.IO) {
                         account.didBackup = true
-                        LocalPreferences.saveToEncryptedStorage(context, account, null, null, null)
                         if (password.isNotBlank()) {
                             encryptCopyNSec(password, Amber.instance, account, clipboardManager, onLoading)
                         } else {
@@ -645,7 +638,6 @@ private fun encryptCopyNSec(
             try {
                 val key = account.nip49Encrypt(password)
                 account.didBackup = true
-                LocalPreferences.saveToEncryptedStorage(context, account, null, null, null)
                 Amber.instance.applicationIOScope.launch(Dispatchers.Main) {
                     clipboardManager.setClipEntry(
                         ClipEntry(

app/src/main/java/com/greenart7c3/nostrsigner/ui/actions/ExportAllAccountsScreen.kt

@@ -122,7 +122,6 @@ fun ExportAllAccountsScreen(
                         LocalPreferences.allSavedAccounts(context).forEach { accountInfo ->
                             LocalPreferences.loadFromEncryptedStorage(context, accountInfo.npub)?.let { account ->
                                 account.didBackup = true
-                                LocalPreferences.saveToEncryptedStorage(context, account, null, null, null)
                             }
                         }
 

gradle/libs.versions.toml

@@ -58,7 +58,6 @@ room-compiler = { module = "androidx.room:room-compiler", version.ref = "roomKtx
 room-ktx = { module = "androidx.room:room-ktx", version.ref = "roomKtx" }
 room-runtime = { module = "androidx.room:room-runtime", version.ref = "roomKtx" }
 room-paging = { module = "androidx.room:room-paging", version.ref = "roomKtx" }
-runtime-livedata = { module = "androidx.compose.runtime:runtime-livedata", version.ref = "compose_ui" }
 security-crypto = { module = "androidx.security:security-crypto", version.ref = "securityCryptoKtx" }
 security-crypto-ktx = { module = "androidx.security:security-crypto-ktx", version.ref = "securityCryptoKtx" }
 ui = { module = "androidx.compose.ui:ui", version.ref = "compose_ui" }