show relay error messages to the user

app/src/main/java/com/greenart7c3/nostrsigner/relays/Relay.kt

@@ -309,7 +309,11 @@ class Relay(
 
                     Log.w("Relay", "Relay on OK $url, $eventId, $success, $message")
                     it.onSendResponse(this@Relay, eventId, success, message)
-                    onOk?.let { it() }
+                    if (success) {
+                        onOk?.let { it() }
+                    } else if (message.isNotEmpty()) {
+                        RelayPool.accountStateViewModel?.toast("Relay", message)
+                    }
                 }
             "AUTH" ->
                 listeners.forEach {

app/src/main/java/com/greenart7c3/nostrsigner/relays/RelayPool.kt

@@ -22,6 +22,7 @@ package com.greenart7c3.nostrsigner.relays
 
 import androidx.compose.runtime.Immutable
 import com.greenart7c3.nostrsigner.checkNotInMainThread
+import com.greenart7c3.nostrsigner.ui.AccountStateViewModel
 import com.vitorpamplona.quartz.events.Event
 import com.vitorpamplona.quartz.events.EventInterface
 import kotlinx.coroutines.DelicateCoroutinesApi
@@ -36,6 +37,7 @@ import kotlinx.coroutines.launch
  * RelayPool manages the connection to multiple Relays and lets consumers deal with simple events.
  */
 object RelayPool : Relay.Listener {
+    var accountStateViewModel: AccountStateViewModel? = null
     private var relays = listOf<Relay>()
     private var listeners = setOf<Listener>()
 

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

@@ -5,6 +5,19 @@ import android.content.Intent
 import androidx.compose.animation.Crossfade
 import androidx.compose.animation.core.tween
 import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.PaddingValues
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.width
+import androidx.compose.foundation.text.selection.SelectionContainer
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.outlined.Done
+import androidx.compose.material3.AlertDialog
+import androidx.compose.material3.Button
+import androidx.compose.material3.ButtonColors
+import androidx.compose.material3.ButtonDefaults
+import androidx.compose.material3.Icon
+import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.SideEffect
@@ -14,12 +27,20 @@ import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
 import androidx.compose.runtime.rememberCoroutineScope
 import androidx.compose.runtime.setValue
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.platform.LocalContext
+import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.unit.dp
+import androidx.lifecycle.compose.collectAsStateWithLifecycle
 import com.greenart7c3.nostrsigner.BuildConfig
 import com.greenart7c3.nostrsigner.LocalPreferences
 import com.greenart7c3.nostrsigner.NostrSigner
+import com.greenart7c3.nostrsigner.R
 import com.greenart7c3.nostrsigner.models.IntentData
 import com.greenart7c3.nostrsigner.relays.Client
 import com.greenart7c3.nostrsigner.relays.Relay
+import com.greenart7c3.nostrsigner.relays.RelayPool
 import com.greenart7c3.nostrsigner.service.ConnectivityService
 import com.greenart7c3.nostrsigner.service.IntentUtils
 import com.greenart7c3.nostrsigner.service.NotificationDataSource
@@ -120,9 +141,79 @@ fun AccountScreen(
                         }
                     }
 
+                    RelayPool.accountStateViewModel = accountStateViewModel
+
+                    DisplayErrorMessages(accountStateViewModel)
                     MainScreen(state.account, accountStateViewModel, newIntents, packageName, appName, localRoute, database)
                 }
             }
         }
     }
 }
+
+@Composable
+private fun DisplayErrorMessages(accountViewModel: AccountStateViewModel) {
+    val context = LocalContext.current
+    val openDialogMsg = accountViewModel.toasts.collectAsStateWithLifecycle(null)
+
+    openDialogMsg.value?.let { obj ->
+        when (obj) {
+            is ResourceToastMsg ->
+                if (obj.params != null) {
+                    InformationDialog(
+                        context.getString(obj.titleResId),
+                        context.getString(obj.resourceId, *obj.params),
+                    ) {
+                        accountViewModel.clearToasts()
+                    }
+                } else {
+                    InformationDialog(
+                        context.getString(obj.titleResId),
+                        context.getString(obj.resourceId),
+                    ) {
+                        accountViewModel.clearToasts()
+                    }
+                }
+
+            is StringToastMsg ->
+                InformationDialog(
+                    obj.title,
+                    obj.msg,
+                ) {
+                    accountViewModel.clearToasts()
+                }
+        }
+    }
+}
+
+@Composable
+fun InformationDialog(
+    title: String,
+    textContent: String,
+    buttonColors: ButtonColors = ButtonDefaults.buttonColors(),
+    onDismiss: () -> Unit,
+) {
+    AlertDialog(
+        onDismissRequest = onDismiss,
+        title = { Text(title) },
+        text = { SelectionContainer { Text(textContent) } },
+        confirmButton = {
+            Button(
+                onClick = onDismiss,
+                colors = buttonColors,
+                contentPadding = PaddingValues(horizontal = 16.dp),
+            ) {
+                Row(
+                    verticalAlignment = Alignment.CenterVertically,
+                ) {
+                    Icon(
+                        imageVector = Icons.Outlined.Done,
+                        contentDescription = null,
+                    )
+                    Spacer(Modifier.width(5.dp))
+                    Text(stringResource(R.string.ok))
+                }
+            }
+        },
+    )
+}

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

@@ -1,7 +1,9 @@
 package com.greenart7c3.nostrsigner.ui
 
+import androidx.compose.runtime.Immutable
 import androidx.compose.runtime.Stable
 import androidx.lifecycle.ViewModel
+import androidx.lifecycle.viewModelScope
 import com.greenart7c3.nostrsigner.LocalPreferences
 import com.greenart7c3.nostrsigner.models.Account
 import com.vitorpamplona.quartz.crypto.CryptoUtils
@@ -11,20 +13,47 @@ import fr.acinq.secp256k1.Hex
 import kotlinx.coroutines.DelicateCoroutinesApi
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.GlobalScope
+import kotlinx.coroutines.channels.BufferOverflow
+import kotlinx.coroutines.flow.MutableSharedFlow
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.asStateFlow
 import kotlinx.coroutines.flow.update
 import kotlinx.coroutines.launch
 
+@Immutable
+open class ToastMsg()
+
+@Immutable
+class StringToastMsg(val title: String, val msg: String) : ToastMsg()
+
+@Immutable
+class ResourceToastMsg(
+    val titleResId: Int,
+    val resourceId: Int,
+    val params: Array<out String>? = null,
+) : ToastMsg()
+
 @Stable
 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)
 
     init {
         tryLoginExistingAccount(null, npub)
     }
 
+    fun clearToasts() {
+        viewModelScope.launch { toasts.emit(null) }
+    }
+
+    fun toast(
+        title: String,
+        message: String,
+    ) {
+        viewModelScope.launch { toasts.emit(StringToastMsg(title, message)) }
+    }
+
     private fun tryLoginExistingAccount(
         route: String?,
         npub: String?,

app/src/main/res/values/strings.xml

@@ -127,4 +127,5 @@
     <string name="no_activities_found">No activities found</string>
     <string name="home">Home</string>
     <string name="settings">Settings</string>
+    <string name="ok">OK</string>
 </resources>