Show a snackbar when import succeeded.

Also handle duplicated import better.

Android/src/app/src/main/java/com/google/aiedge/gallery/ui/home/HomeScreen.kt

@@ -54,6 +54,8 @@ import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.ModalBottomSheet
 import androidx.compose.material3.Scaffold
 import androidx.compose.material3.SmallFloatingActionButton
+import androidx.compose.material3.SnackbarHost
+import androidx.compose.material3.SnackbarHostState
 import androidx.compose.material3.Text
 import androidx.compose.material3.TopAppBarDefaults
 import androidx.compose.material3.rememberModalBottomSheetState
@@ -71,6 +73,7 @@ import androidx.compose.ui.Modifier
 import androidx.compose.ui.draw.alpha
 import androidx.compose.ui.draw.clip
 import androidx.compose.ui.draw.scale
+import androidx.compose.ui.focus.focusModifier
 import androidx.compose.ui.graphics.Brush
 import androidx.compose.ui.input.nestedscroll.nestedScroll
 import androidx.compose.ui.layout.layout
@@ -127,6 +130,8 @@ fun HomeScreen(
   val selectedLocalModelFileUri = remember { mutableStateOf<Uri?>(null) }
   val selectedImportedModelInfo = remember { mutableStateOf<ImportedModelInfo?>(null) }
   val coroutineScope = rememberCoroutineScope()
+  val snackbarHostState = remember { SnackbarHostState() }
+  val scope = rememberCoroutineScope()
 
   val tasks = uiState.tasks
   val loadingHfModels = uiState.loadingHfModels
@@ -173,12 +178,16 @@ fun HomeScreen(
       }
     }
   ) { innerPadding ->
-    TaskList(
+    Box(contentAlignment = Alignment.BottomCenter, modifier = Modifier.fillMaxSize()) {
-      tasks = tasks,
+      TaskList(
-      navigateToTaskScreen = navigateToTaskScreen,
+        tasks = tasks,
-      modifier = Modifier.fillMaxSize(),
+        navigateToTaskScreen = navigateToTaskScreen,
-      contentPadding = innerPadding,
+        modifier = Modifier.fillMaxSize(),
-    )
+        contentPadding = innerPadding,
+      )
+
+      SnackbarHost(hostState = snackbarHostState, modifier = Modifier.padding(bottom = 16.dp))
+    }
   }
 
   // Settings dialog.
@@ -270,6 +279,11 @@ fun HomeScreen(
               info = it,
             )
             showImportingDialog = false
+
+            // Show a snack bar for successful import.
+            scope.launch {
+              snackbarHostState.showSnackbar("✅ Model imported successfully")
+            }
           })
       }
     }

Android/src/app/src/main/java/com/google/aiedge/gallery/ui/modelmanager/ModelManagerViewModel.kt

@@ -424,6 +424,13 @@ open class ModelManagerViewModel(
   fun addImportedLlmModel(task: Task, info: ImportedModelInfo) {
     Log.d(TAG, "adding imported llm model: $info")
 
+    // Remove duplicated imported model if existed.
+    val modelIndex = task.models.indexOfFirst { info.fileName == it.name && it.imported }
+    if (modelIndex >= 0) {
+      Log.d(TAG, "duplicated imported model found in task. Removing it first")
+      task.models.removeAt(modelIndex)
+    }
+
     // Create model.
     val model = createModelFromImportedModelInfo(info = info, task = task)
     task.models.add(model)
@@ -451,6 +458,11 @@ open class ModelManagerViewModel(
 
     // Add to preference storage.
     val importedModels = dataStoreRepository.readImportedModels().toMutableList()
+    val importedModelIndex = importedModels.indexOfFirst { info.fileName == it.fileName }
+    if (importedModelIndex >= 0) {
+      Log.d(TAG, "duplicated imported model found in preference storage. Removing it first")
+      importedModels.removeAt(importedModelIndex)
+    }
     importedModels.add(info)
     dataStoreRepository.saveImportedModels(importedModels = importedModels)
   }