back gesture works

app/src/main/java/com/bitchat/android/MainActivity.kt

@@ -18,6 +18,8 @@ import androidx.compose.ui.Modifier
 import androidx.compose.ui.platform.LocalContext
 import androidx.lifecycle.lifecycleScope
 import androidx.lifecycle.ViewModelProvider
+import androidx.activity.OnBackPressedCallback
+import androidx.activity.addCallback
 import com.bitchat.android.mesh.BluetoothMeshService
 import com.bitchat.android.onboarding.*
 import com.bitchat.android.ui.ChatScreen
@@ -138,6 +140,24 @@ class MainActivity : ComponentActivity() {
             }
             
             OnboardingState.COMPLETE -> {
+                // Set up back navigation handling for the chat screen
+                val backCallback = object : OnBackPressedCallback(true) {
+                    override fun handleOnBackPressed() {
+                        // Let ChatViewModel handle navigation state
+                        val handled = chatViewModel.handleBackPressed()
+                        if (!handled) {
+                            // If ChatViewModel doesn't handle it, disable this callback 
+                            // and let the system handle it (which will exit the app)
+                            this.isEnabled = false
+                            onBackPressedDispatcher.onBackPressed()
+                            this.isEnabled = true
+                        }
+                    }
+                }
+                
+                // Add the callback - this will be automatically removed when the activity is destroyed
+                onBackPressedDispatcher.addCallback(this, backCallback)
+                
                 ChatScreen(viewModel = chatViewModel)
             }
             

app/src/main/java/com/bitchat/android/ui/ChatScreen.kt

@@ -60,15 +60,15 @@ fun ChatScreen(viewModel: ChatViewModel) {
     val hasUnreadPrivateMessages by viewModel.unreadPrivateMessages.observeAsState(emptySet())
     val privateChats by viewModel.privateChats.observeAsState(emptyMap())
     val channelMessages by viewModel.channelMessages.observeAsState(emptyMap())
-    var showSidebar by remember { mutableStateOf(false) }
+    val showSidebar by viewModel.showSidebar.observeAsState(false)
     val showCommandSuggestions by viewModel.showCommandSuggestions.observeAsState(false)
     val commandSuggestions by viewModel.commandSuggestions.observeAsState(emptyList())
+    val showAppInfo by viewModel.showAppInfo.observeAsState(false)
     
     var messageText by remember { mutableStateOf("") }
     var showPasswordPrompt by remember { mutableStateOf(false) }
     var showPasswordDialog by remember { mutableStateOf(false) }
     var passwordInput by remember { mutableStateOf("") }
-    var showAppInfo by remember { mutableStateOf(false) }
     
     // Show password dialog when needed
     LaunchedEffect(showPasswordPrompt) {
@@ -142,8 +142,8 @@ fun ChatScreen(viewModel: ChatViewModel) {
             nickname = nickname,
             viewModel = viewModel,
             colorScheme = colorScheme,
-            onSidebarToggle = { showSidebar = true },
+            onSidebarToggle = { viewModel.showSidebar() },
-            onShowAppInfo = { showAppInfo = true },
+            onShowAppInfo = { viewModel.showAppInfo() },
             onPanicClear = { viewModel.panicClearAllData() }
         )
         
@@ -162,7 +162,7 @@ fun ChatScreen(viewModel: ChatViewModel) {
         ) {
             SidebarOverlay(
                 viewModel = viewModel,
-                onDismiss = { showSidebar = false },
+                onDismiss = { viewModel.hideSidebar() },
                 modifier = Modifier.fillMaxSize()
             )
         }
@@ -188,7 +188,7 @@ fun ChatScreen(viewModel: ChatViewModel) {
             passwordInput = ""
         },
         showAppInfo = showAppInfo,
-        onAppInfoDismiss = { showAppInfo = false }
+        onAppInfoDismiss = { viewModel.hideAppInfo() }
     )
 }
 

app/src/main/java/com/bitchat/android/ui/ChatState.kt

@@ -85,6 +85,10 @@ class ChatState {
     
     val peerIDToPublicKeyFingerprint = mutableMapOf<String, String>()
     
+    // Navigation state
+    private val _showAppInfo = MutableLiveData<Boolean>(false)
+    val showAppInfo: LiveData<Boolean> = _showAppInfo
+    
     // Unread state computed properties
     val hasUnreadChannels: MediatorLiveData<Boolean> = MediatorLiveData<Boolean>()
     val hasUnreadPrivateMessages: MediatorLiveData<Boolean> = MediatorLiveData<Boolean>()
@@ -118,6 +122,7 @@ class ChatState {
     fun getShowCommandSuggestionsValue() = _showCommandSuggestions.value ?: false
     fun getCommandSuggestionsValue() = _commandSuggestions.value ?: emptyList()
     fun getFavoritePeersValue() = _favoritePeers.value ?: emptySet()
+    fun getShowAppInfoValue() = _showAppInfo.value ?: false
     
     // Setters for state updates
     fun setMessages(messages: List<BitchatMessage>) {
@@ -202,4 +207,8 @@ class ChatState {
         Log.d("ChatState", "LiveData has active observers: ${_favoritePeers.hasActiveObservers()}")
     }
     
+    fun setShowAppInfo(show: Boolean) {
+        _showAppInfo.value = show
+    }
+
 }

app/src/main/java/com/bitchat/android/ui/ChatViewModel.kt

@@ -71,6 +71,7 @@ class ChatViewModel(
     val showCommandSuggestions: LiveData<Boolean> = state.showCommandSuggestions
     val commandSuggestions: LiveData<List<CommandSuggestion>> = state.commandSuggestions
     val favoritePeers: LiveData<Set<String>> = state.favoritePeers
+    val showAppInfo: LiveData<Boolean> = state.showAppInfo
     
     init {
         // Note: Mesh service delegate is now set by MainActivity
@@ -366,4 +367,59 @@ class ChatViewModel(
         // Note: Mesh service restart is now handled by MainActivity
         // This method now only clears data, not mesh service lifecycle
     }
+    
+    // MARK: - Navigation Management
+    
+    fun showAppInfo() {
+        state.setShowAppInfo(true)
+    }
+    
+    fun hideAppInfo() {
+        state.setShowAppInfo(false)
+    }
+    
+    fun showSidebar() {
+        state.setShowSidebar(true)
+    }
+    
+    fun hideSidebar() {
+        state.setShowSidebar(false)
+    }
+    
+    /**
+     * Handle Android back navigation
+     * Returns true if the back press was handled, false if it should be passed to the system
+     */
+    fun handleBackPressed(): Boolean {
+        return when {
+            // Close app info dialog
+            state.getShowAppInfoValue() -> {
+                hideAppInfo()
+                true
+            }
+            // Close sidebar
+            state.getShowSidebarValue() -> {
+                hideSidebar()
+                true
+            }
+            // Close password dialog
+            state.getShowPasswordPromptValue() -> {
+                state.setShowPasswordPrompt(false)
+                state.setPasswordPromptChannel(null)
+                true
+            }
+            // Exit private chat
+            state.getSelectedPrivateChatPeerValue() != null -> {
+                endPrivateChat()
+                true
+            }
+            // Exit channel view
+            state.getCurrentChannelValue() != null -> {
+                switchToChannel(null)
+                true
+            }
+            // No special navigation state - let system handle (usually exits app)
+            else -> false
+        }
+    }
 }