Report channel file export failures and preserve attachment choices

tools/chatgui-android/app/src/main/java/com/utun/chat/ui/components/ConversationComposer.kt

@@ -77,8 +77,8 @@ fun ConversationComposer(target: ConversationTarget, viewModel: ChatViewModel,
     var preparing by remember(target) { mutableStateOf(false) }
     var error by remember(target) { mutableStateOf<Int?>(null) }
     var menu by remember(target) { mutableStateOf(false) }
-    var chooseVideo by remember(target) { mutableStateOf(false) }
-    var sendAsVideo by remember(target) { mutableStateOf(false) }
+    var chooseVideo by rememberSaveable(target) { mutableStateOf(false) }
+    var sendAsVideo by rememberSaveable(target) { mutableStateOf(false) }
     val recording by viewModel.isRecording.collectAsState()
     val locked by viewModel.isRecordingLocked.collectAsState()
     val duration by viewModel.recordingDurationMs.collectAsState()

tools/chatgui-android/app/src/main/java/com/utun/chat/ui/screens/ChatScreen.kt

@@ -5,6 +5,7 @@ import com.utun.chat.data.NativeLib
 import com.utun.chat.R
 import androidx.compose.ui.res.stringResource
 import android.os.SystemClock
+import android.widget.Toast
 import android.view.ViewConfiguration
 import androidx.activity.compose.rememberLauncherForActivityResult
 import androidx.activity.result.contract.ActivityResultContracts
@@ -74,7 +75,12 @@ import com.utun.chat.data.StreamSource
 import androidx.compose.material.icons.filled.LiveTv
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.launch
+import kotlinx.coroutines.withContext
+import kotlinx.coroutines.CancellationException
 
+/** Канальный чат: история/ответы/правки принадлежат ViewModel, draft и выбор вложения — общему composer.
+ * Кнопка PTT удерживает источник CHAT_BUTTON до отпускания/dispose; двойной короткий тап фиксирует передачу.
+ * Просмотр трансляций исключает собственный источник. SAF export не изменяет оригинал и сообщает об отказе записи. */
 @OptIn(ExperimentalMaterial3Api::class)
 @Composable
 fun ChatScreen(
@@ -95,7 +101,7 @@ fun ChatScreen(
     onWatchStream: (StreamSource) -> Unit = {},
     onWatchAllStreams: () -> Unit = {}
 ) {
-    val listState = rememberLazyListState()
+    val listState = key(channel.id) { rememberLazyListState() }
     val context = LocalContext.current
     val view = LocalView.current
     val pttCenterOffset = with(LocalDensity.current) { 60.dp.toPx() }
@@ -138,22 +144,24 @@ fun ChatScreen(
     val soundOn by viewModel.soundOn.collectAsState()
     val reactionCatalog by viewModel.reactionCatalog.collectAsState()
     val interactionFailed by viewModel.interactionFailed.collectAsState()
-    var createPoll by rememberSaveable { mutableStateOf(false) }
+    var createPoll by rememberSaveable(channel.id) { mutableStateOf(false) }
     if (createPoll) CreatePollDialog({ createPoll = false }, viewModel::createPoll)
     if (interactionFailed) AlertDialog(onDismissRequest = viewModel::dismissInteractionError,
         text = { Text(stringResource(R.string.poll_interaction_failed)) },
         confirmButton = { TextButton(onClick = viewModel::dismissInteractionError) { Text(stringResource(R.string.close)) } })
 
     /* save dialog for downloaded files */
-    var pendingSaveFilePath by remember { mutableStateOf<String?>(null) }
+    var pendingSaveFilePath by rememberSaveable { mutableStateOf<String?>(null) }
+    var saveError by remember(channel.id) { mutableStateOf(false) }
     val saveFileLauncher = rememberLauncherForActivityResult(ActivityResultContracts.CreateDocument("*/*")) { saveUri ->
-        if (saveUri != null) {
-            val filePath = pendingSaveFilePath
-            pendingSaveFilePath = null
-            if (filePath != null) {
-                scope.launch(Dispatchers.IO) {
-                    viewModel.saveDownloadedFile(filePath, saveUri)
-                }
+        val filePath = pendingSaveFilePath
+        pendingSaveFilePath = null
+        if (saveUri != null && filePath != null) scope.launch {
+            try { saveError = !withContext(Dispatchers.IO) { viewModel.saveDownloadedFile(filePath, saveUri) } }
+            catch (e: CancellationException) { throw e }
+            catch (e: Exception) {
+                saveError = true
+                LogManager.addLog("ERROR", "Attachment", "File export failed: $e")
             }
         }
     }
@@ -249,6 +257,8 @@ fun ChatScreen(
         if (radioActive) {
             RadioSourceBar(viewModel)
         }
+        if (saveError) Text(stringResource(R.string.file_save_failed), color = MaterialTheme.colorScheme.error,
+            modifier = Modifier.padding(8.dp))
         if (radioTalking != null) {
             Surface(color = MaterialTheme.colorScheme.primaryContainer) {
                 Text(
@@ -274,7 +284,15 @@ fun ChatScreen(
                 onPlayVoice = { path, duration -> viewModel.playVoiceMessage(path, duration) },
                 onSeekVoice = { path, position, duration -> viewModel.seekVoice(path, position, duration) },
                 onDownloadFile = { viewModel.downloadAttachment(it) },
-                onOpenFile = { if (it.filePath.isNotEmpty()) { pendingSaveFilePath = it.filePath; saveFileLauncher.launch(it.text) } },
+                onOpenFile = {
+                    if (it.filePath.isNotEmpty() && pendingSaveFilePath == null) {
+                        pendingSaveFilePath = it.filePath; saveError = false
+                        try { saveFileLauncher.launch(it.text) } catch (e: Exception) {
+                            pendingSaveFilePath = null; saveError = true
+                            LogManager.addLog("ERROR", "Attachment", "Cannot launch file export: $e")
+                        }
+                    }
+                },
                 onOpenImage = onViewPhoto, onPlayVideo = onPlayVideo, onInviteLink = viewModel::openInviteLink,
                 reactionCatalog = reactionCatalog, onVote = viewModel::vote, onReact = viewModel::react, authorName = viewModel::radioName,
                 onReply = viewModel::selectReply, onOriginal = viewModel::showOriginal, originals = originals, highlightedId = highlighted,
@@ -368,6 +386,7 @@ private fun RadioPttButton(
 /* Единый выбор входа/выхода, PTT громкостью, VAD и плавающая PTT-кнопка. */
 @Composable
 private fun RadioSourceBar(viewModel: ChatViewModel) {
+    val context = LocalContext.current
     val provider = ChatApplication.instance.configProvider
     val scope = rememberCoroutineScope()
     val overlayEnabled by provider.radioOverlayEnabled.collectAsState(initial = provider.getRadioOverlay())
@@ -398,9 +417,15 @@ private fun RadioSourceBar(viewModel: ChatViewModel) {
                 RadioAutomaticButton(autoSettings) { viewModel.setRadioAutomatic(!autoSettings.enabled) }
                 RadioControlButton(null, stringResource(R.string.floating_ptt), overlayShown, floating = true) {
                     scope.launch {
-                    if (overlayEnabled && !overlayShown) RadioOverlayService.requestPermissions()
-                    else RadioOverlayService.setEnabled(!overlayEnabled)
-                }
+                        try {
+                            if (overlayEnabled && !overlayShown) RadioOverlayService.requestPermissions()
+                            else RadioOverlayService.setEnabled(!overlayEnabled)
+                        } catch (e: CancellationException) { throw e }
+                        catch (e: Exception) {
+                            LogManager.addLog("ERROR", "radio", "Cannot change overlay setting enabled=${!overlayEnabled}: $e")
+                            Toast.makeText(context, R.string.overlay_start_failed, Toast.LENGTH_LONG).show()
+                        }
+                    }
                 }
             }
             if (overlayEnabled && !overlayShown) overlayStatus?.let { message ->

tools/chatgui-android/app/src/main/java/com/utun/chat/viewmodel/ChatViewModel.kt

@@ -1804,20 +1804,25 @@ class ChatViewModel : ViewModel() {
         }
     }
 
-    fun saveDownloadedFile(srcPath: String, saveUri: Uri) {
+    /** IO caller: копирует локальный файл в выбранный SAF-документ; true только после закрытия обоих потоков. */
+    fun saveDownloadedFile(srcPath: String, saveUri: Uri): Boolean {
         try {
             val src = File(srcPath)
-            if (!src.exists()) {
+            if (!src.isFile) {
                 LogManager.addLog("ERROR", "VM", "saveDownloadedFile: src not found $srcPath")
-                return
+                return false
             }
             val ctx = ChatApplication.instance
             ctx.contentResolver.openOutputStream(saveUri)?.use { output ->
                 src.inputStream().use { input -> input.copyTo(output) }
-            }
+            } ?: throw java.io.IOException("Cannot open selected document")
             LogManager.addLog("INFO", "VM", "file saved: $srcPath -> $saveUri")
+            return true
+        } catch (e: kotlinx.coroutines.CancellationException) {
+            throw e
         } catch (e: Exception) {
             LogManager.addLog("ERROR", "VM", "saveDownloadedFile failed: ${e.message}")
+            return false
         }
     }