UI: allow drawer's gesture control only on Home and Settings screens; enable alert dialog on back navigation inside conversation and benchmark

examples/llama.android/app/src/main/java/com/example/llama/revamp/MainActivity.kt

@@ -3,12 +3,10 @@ package com.example.llama.revamp
 import android.os.Bundle
 import androidx.activity.ComponentActivity
 import androidx.activity.OnBackPressedCallback
-import androidx.activity.OnBackPressedDispatcher
 import androidx.activity.compose.BackHandler
 import androidx.activity.compose.LocalOnBackPressedDispatcherOwner
 import androidx.activity.compose.setContent
 import androidx.compose.foundation.layout.fillMaxSize
-import androidx.compose.material3.DrawerState
 import androidx.compose.material3.DrawerValue
 import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.Surface
@@ -39,8 +37,8 @@ import com.example.llama.revamp.ui.components.AppNavigationDrawer
 import com.example.llama.revamp.ui.components.UnloadModelConfirmationDialog
 import com.example.llama.revamp.ui.screens.BenchmarkScreen
 import com.example.llama.revamp.ui.screens.ConversationScreen
-import com.example.llama.revamp.ui.screens.ModelSelectionScreen
 import com.example.llama.revamp.ui.screens.ModeSelectionScreen
+import com.example.llama.revamp.ui.screens.ModelSelectionScreen
 import com.example.llama.revamp.ui.screens.SettingsScreen
 import com.example.llama.revamp.ui.screens.SettingsTab
 import com.example.llama.revamp.ui.theme.LlamaTheme
@@ -80,11 +78,7 @@ fun AppContent() {
     val viewModel: MainViewModel = viewModel(factory = factory)
 
     val engineState by viewModel.engineState.collectAsState()
-
-    // Track if model is loaded for gesture handling
-    val isModelLoaded = remember(engineState) {
-        viewModel.isModelLoaded()
-    }
+    val isModelLoaded = remember(engineState) { viewModel.isModelLoaded() }
 
     val navigationActions = remember(navController) {
         NavigationActions(navController)
@@ -97,7 +91,21 @@ fun AppContent() {
     // Get current route
     val navBackStackEntry by navController.currentBackStackEntryAsState()
     val currentRoute by remember {
-        derivedStateOf { navBackStackEntry?.destination?.route }
+        derivedStateOf { navBackStackEntry?.destination?.route ?: "" }
+    }
+
+    // Determine if drawer gestures should be enabled based on route
+    val drawerGesturesEnabled by remember(currentRoute, drawerState.currentValue) {
+        derivedStateOf {
+            // Always allow gesture dismissal when drawer is open
+            if (drawerState.currentValue == DrawerValue.Open) {
+                true
+            } else {
+                // Only enable drawer opening by gesture on these screens
+                currentRoute == AppDestinations.MODEL_SELECTION_ROUTE ||
+                    currentRoute.startsWith(AppDestinations.SETTINGS_ROUTE)
+            }
+        }
     }
 
     // Determine if current route requires model unloading
@@ -172,7 +180,7 @@ fun AppContent() {
     AppNavigationDrawer(
         drawerState = drawerState,
         navigationActions = navigationActions,
-        modelLoaded = isModelLoaded
+        gesturesEnabled = drawerGesturesEnabled
     ) {
         NavHost(
             navController = navController,

examples/llama.android/app/src/main/java/com/example/llama/revamp/ui/components/AppScaffold.kt

@@ -1,22 +1,17 @@
 package com.example.llama.revamp.ui.components
 
-import androidx.compose.foundation.layout.Box
 import androidx.compose.foundation.layout.PaddingValues
-import androidx.compose.foundation.layout.padding
 import androidx.compose.material3.DrawerState
 import androidx.compose.material3.DrawerValue
 import androidx.compose.material3.ExperimentalMaterial3Api
-import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.Scaffold
 import androidx.compose.material3.SnackbarHost
 import androidx.compose.material3.SnackbarHostState
-import androidx.compose.material3.Surface
 import androidx.compose.material3.rememberDrawerState
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.collectAsState
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.remember
-import androidx.compose.ui.Modifier
 import androidx.compose.ui.platform.LocalContext
 import androidx.lifecycle.viewmodel.compose.viewModel
 import com.example.llama.revamp.data.preferences.UserPreferences

examples/llama.android/app/src/main/java/com/example/llama/revamp/ui/components/NavigationDrawer.kt

@@ -12,7 +12,6 @@ import androidx.compose.foundation.layout.width
 import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.filled.Home
 import androidx.compose.material.icons.filled.Settings
-import androidx.compose.material3.Divider
 import androidx.compose.material3.DrawerState
 import androidx.compose.material3.DrawerValue
 import androidx.compose.material3.HorizontalDivider
@@ -23,10 +22,6 @@ import androidx.compose.material3.ModalNavigationDrawer
 import androidx.compose.material3.Surface
 import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
-import androidx.compose.runtime.LaunchedEffect
-import androidx.compose.runtime.derivedStateOf
-import androidx.compose.runtime.getValue
-import androidx.compose.runtime.remember
 import androidx.compose.runtime.rememberCoroutineScope
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.graphics.vector.ImageVector
@@ -38,14 +33,13 @@ import kotlinx.coroutines.launch
 
 /**
  * App navigation drawer that provides access to different sections of the app.
- * Gesture opening is disabled when a model is loaded to prevent accidental navigation,
- * but gesture dismissal is always enabled.
+ * Gesture opening can be controlled based on current screen.
  */
 @Composable
 fun AppNavigationDrawer(
     drawerState: DrawerState,
     navigationActions: NavigationActions,
-    modelLoaded: Boolean = false,
+    gesturesEnabled: Boolean,
     content: @Composable () -> Unit
 ) {
     val coroutineScope = rememberCoroutineScope()
@@ -54,15 +48,6 @@ fun AppNavigationDrawer(
     // Calculate drawer width (60% of screen width)
     val drawerWidth = (configuration.screenWidthDp * 0.6).dp
 
-    // Determine if gestures should be enabled
-    // Always enable when drawer is open (to allow dismissal)
-    // Only enable when model is not loaded (to prevent accidental opening)
-    val gesturesEnabled by remember(drawerState.currentValue, modelLoaded) {
-        derivedStateOf {
-            drawerState.currentValue == DrawerValue.Open || !modelLoaded
-        }
-    }
-
     // Handle back button to close drawer if open
     BackHandler(enabled = drawerState.currentValue == DrawerValue.Open) {
         coroutineScope.launch {

examples/llama.android/app/src/main/java/com/example/llama/revamp/ui/screens/ModelSelectionScreen.kt

@@ -14,20 +14,17 @@ import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.filled.PlayArrow
 import androidx.compose.material3.Card
 import androidx.compose.material3.CardDefaults
-import androidx.compose.material3.Divider
 import androidx.compose.material3.DrawerState
 import androidx.compose.material3.ExperimentalMaterial3Api
 import androidx.compose.material3.Icon
 import androidx.compose.material3.IconButton
 import androidx.compose.material3.MaterialTheme
-import androidx.compose.material3.Scaffold
 import androidx.compose.material3.Text
 import androidx.compose.material3.TextButton
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.remember
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
-import androidx.compose.ui.text.style.TextOverflow
 import androidx.compose.ui.unit.dp
 import com.example.llama.revamp.data.model.ModelInfo
 import com.example.llama.revamp.navigation.NavigationActions

examples/llama.android/app/src/main/java/com/example/llama/revamp/viewmodel/MainViewModel.kt

@@ -5,7 +5,6 @@ import androidx.lifecycle.ViewModelProvider
 import androidx.lifecycle.viewModelScope
 import com.example.llama.revamp.data.model.ModelInfo
 import com.example.llama.revamp.engine.InferenceEngine
-import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.asStateFlow