UI: add model loading in progress view; polish the empty model info view

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

@@ -293,6 +293,10 @@ fun AppContent(
 
                         ModelScreenUiMode.MANAGING ->
                             BottomBarConfig.Models.Management(
+                                isDeletionEnabled = filteredModels?.isNotEmpty() == true,
+                                onToggleDeleting = {
+                                    modelsViewModel.toggleMode(ModelScreenUiMode.DELETING)
+                                },
                                 sorting = BottomBarConfig.Models.Management.SortingConfig(
                                     currentOrder = sortOrder,
                                     isMenuVisible = showSortMenu,
@@ -322,9 +326,6 @@ fun AppContent(
                                         modelsManagementViewModel.toggleImportMenu(false)
                                     }
                                 ),
-                                onToggleDeleting = {
-                                    modelsViewModel.toggleMode(ModelScreenUiMode.DELETING)
-                                }
                             )
 
                         ModelScreenUiMode.DELETING ->
@@ -334,10 +335,12 @@ fun AppContent(
                                 },
                                 selectedModels = selectedModelsToDelete,
                                 selectAllFilteredModels = {
-                                    modelsManagementViewModel.selectAllFilteredModelsToDelete(filteredModels)
+                                    filteredModels?.let {
+                                        modelsManagementViewModel.selectModelsToDelete(it)
+                                    }
                                 },
                                 clearAllSelectedModels = {
-                                    modelsManagementViewModel.clearAllSelectedModelsToDelete()
+                                    modelsManagementViewModel.clearSelectedModelsToDelete()
                                 },
                                 deleteSelected = {
                                     selectedModelsToDelete.let {

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

@@ -32,23 +32,43 @@ fun InfoView(
     message: String? = null,
     action: InfoAction? = null
 ) {
-    Column(
+    InfoView(
-        modifier = modifier.padding(16.dp),
+        modifier = modifier,
-        horizontalAlignment = Alignment.CenterHorizontally,
+        title = title,
-        verticalArrangement = Arrangement.Center
+        icon = {
-    ) {
             Icon(
                 imageVector = icon,
                 contentDescription = null,
                 modifier = Modifier.size(64.dp),
                 tint = MaterialTheme.colorScheme.primary.copy(alpha = 0.6f)
             )
+        },
+        message = message,
+        action = action
+    )
+}
+
+@Composable
+fun InfoView(
+    modifier: Modifier = Modifier,
+    title: String,
+    icon: @Composable () -> Unit,
+    message: String? = null,
+    action: InfoAction? = null
+) {
+    Column(
+        modifier = modifier.padding(16.dp),
+        horizontalAlignment = Alignment.CenterHorizontally,
+        verticalArrangement = Arrangement.Center
+    ) {
+        icon()
 
         Spacer(modifier = Modifier.height(16.dp))
 
         Text(
             text = title,
-            style = MaterialTheme.typography.headlineSmall
+            style = MaterialTheme.typography.headlineSmall,
+            textAlign = TextAlign.Center
         )
 
         message?.let {

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

@@ -125,10 +125,11 @@ fun AppScaffold(
 
             is BottomBarConfig.Models.Management -> {
                 ModelsManagementBottomBar(
+                    isDeletionEnabled = config.isDeletionEnabled,
+                    onToggleDeleting = config.onToggleDeleting,
                     sortingConfig = config.sorting,
                     filteringConfig = config.filtering,
-                    importingConfig = config.importing,
+                    importingConfig = config.importing
-                    onToggleDeleting = config.onToggleDeleting
                 )
             }
 

examples/llama.android/app/src/main/java/com/example/llama/ui/scaffold/bottombar/BottomBarConfig.kt

@@ -46,10 +46,11 @@ sealed class BottomBarConfig {
         ) : BottomBarConfig()
 
         data class Management(
+            val isDeletionEnabled: Boolean,
+            val onToggleDeleting: () -> Unit,
             val sorting: SortingConfig,
             val filtering: FilteringConfig,
             val importing: ImportConfig,
-            val onToggleDeleting: () -> Unit,
         ) : BottomBarConfig() {
             data class SortingConfig(
                 val currentOrder: ModelSortOrder,

examples/llama.android/app/src/main/java/com/example/llama/ui/scaffold/bottombar/ModelsBrowsingBottomBar.kt

@@ -104,7 +104,10 @@ fun ModelsBrowsingBottomBar(
                     imageVector =
                         if (filteringConfig.isActive) Icons.Default.FilterAlt
                         else Icons.Outlined.FilterAlt,
-                    contentDescription = "Filter models"
+                    contentDescription = "Filter models",
+                    tint =
+                        if (filteringConfig.isActive) MaterialTheme.colorScheme.primary
+                        else MaterialTheme.colorScheme.onSurfaceVariant
                 )
             }
 

examples/llama.android/app/src/main/java/com/example/llama/ui/scaffold/bottombar/ModelsManagementBottomBar.kt

@@ -31,19 +31,19 @@ import com.example.llama.data.model.ModelSortOrder
 
 @Composable
 fun ModelsManagementBottomBar(
+    isDeletionEnabled: Boolean,
+    onToggleDeleting: () -> Unit,
     sortingConfig: BottomBarConfig.Models.Management.SortingConfig,
     filteringConfig: BottomBarConfig.Models.Management.FilteringConfig,
     importingConfig: BottomBarConfig.Models.Management.ImportConfig,
-    onToggleDeleting: () -> Unit,
 ) {
     BottomAppBar(
         actions = {
             // Batch-deletion action
-            IconButton(onClick = onToggleDeleting) {
+            IconButton(enabled = isDeletionEnabled, onClick = onToggleDeleting) {
                 Icon(
                     imageVector = Icons.Outlined.DeleteSweep,
-                    contentDescription = "Delete models"
+                    contentDescription = "Delete models",)
-                )
             }
 
             // Sorting action
@@ -104,7 +104,10 @@ fun ModelsManagementBottomBar(
                     imageVector =
                         if (filteringConfig.isActive) Icons.Default.FilterAlt
                         else Icons.Outlined.FilterAlt,
-                    contentDescription = "Filter models"
+                    contentDescription = "Filter models",
+                    tint =
+                        if (filteringConfig.isActive) MaterialTheme.colorScheme.primary
+                        else MaterialTheme.colorScheme.onSurfaceVariant
                 )
             }
 

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

@@ -20,13 +20,15 @@ import com.example.llama.viewmodel.PreselectedModelToRun
 
 @Composable
 fun ModelsBrowsingScreen(
-    filteredModels: List<ModelInfo>,
+    filteredModels: List<ModelInfo>?,
     activeFiltersCount: Int,
     preselection: PreselectedModelToRun?,
     onManageModelsClicked: () -> Unit,
     viewModel: ModelsViewModel,
 ) {
-    if (filteredModels.isEmpty()) {
+    if (filteredModels == null) {
+        ModelsLoadingInProgressView()
+    } else if (filteredModels.isEmpty()) {
         // Empty model prompt
         EmptyModelsView(activeFiltersCount, onManageModelsClicked)
     } else {

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

@@ -1,5 +1,6 @@
 package com.example.llama.ui.screens
 
+import android.content.Context
 import android.content.Intent
 import androidx.activity.compose.BackHandler
 import androidx.compose.foundation.basicMarquee
@@ -18,6 +19,7 @@ import androidx.compose.foundation.layout.width
 import androidx.compose.foundation.lazy.LazyColumn
 import androidx.compose.foundation.lazy.items
 import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.automirrored.filled.Help
 import androidx.compose.material.icons.automirrored.outlined.ContactSupport
 import androidx.compose.material.icons.filled.Attribution
 import androidx.compose.material.icons.filled.Download
@@ -78,13 +80,15 @@ import java.util.Locale
  */
 @Composable
 fun ModelsManagementAndDeletingScreen(
-    filteredModels: List<ModelInfo>,
+    filteredModels: List<ModelInfo>?,
     activeFiltersCount: Int,
     isDeleting: Boolean,
     onScaffoldEvent: (ScaffoldEvent) -> Unit,
     modelsViewModel: ModelsViewModel,
     managementViewModel: ModelsManagementViewModel,
 ) {
+    val context = LocalContext.current
+
     // Selection state
     val selectedModels by managementViewModel.selectedModelsToDelete.collectAsState()
 
@@ -102,18 +106,29 @@ fun ModelsManagementAndDeletingScreen(
     }
 
     Box(modifier = Modifier.fillMaxSize()) {
-        if (filteredModels.isEmpty()) {
+        if (filteredModels == null) {
+            ModelsLoadingInProgressView()
+        } else if (filteredModels.isEmpty()) {
             // Import model prompt
             val message = when (activeFiltersCount) {
-                0 -> "Tap the \"+\" button to import a model!"
+                0 -> "Tap the \"+\" button\n to import a model"
-                1 -> "No models match the selected filter"
+                1 -> "No models match\n the selected filter"
-                else -> "No models match the selected filters"
+                else -> "No models match\n the selected filters"
             }
             InfoView(
-                modifier = Modifier.fillMaxSize(),
+                modifier = Modifier.fillMaxSize(0.8f).align(Alignment.Center),
-                title = "No Models Available",
+                title = message,
                 icon = Icons.Default.FolderOpen,
-                message = message,
+                message = "Import a local GGUF model file, or download directly from HuggingFace!",
+                action = InfoAction(
+                    label = "Learn more",
+                    icon = Icons.AutoMirrored.Default.Help,
+                    onAction = {
+                        val url = "https://huggingface.co/docs/hub/en/gguf"
+                        val intent = Intent(Intent.ACTION_VIEW, url.toUri())
+                        context.startActivity(intent)
+                    }
+                )
             )
         } else {
             // Model cards
@@ -178,6 +193,7 @@ fun ModelsManagementAndDeletingScreen(
 
             is Importation.Error -> {
                 ErrorDialog(
+                    context = context,
                     title = "Import Failed",
                     message = state.message,
                     learnMoreUrl = state.learnMoreUrl,
@@ -241,6 +257,7 @@ fun ModelsManagementAndDeletingScreen(
 
             is Download.Error -> {
                 ErrorDialog(
+                    context = context,
                     title = "Download Failed",
                     message = state.message,
                     onDismiss = { managementViewModel.resetManagementState() }
@@ -267,6 +284,7 @@ fun ModelsManagementAndDeletingScreen(
 
             is Deletion.Error -> {
                 ErrorDialog(
+                    context = context,
                     title = "Deletion Failed",
                     message = state.message,
                     onDismiss = { managementViewModel.resetManagementState() }
@@ -660,13 +678,12 @@ private fun BatchDeleteConfirmationDialog(
 
 @Composable
 private fun ErrorDialog(
+    context: Context,
     title: String,
     message: String,
     learnMoreUrl: String? = null,
     onDismiss: () -> Unit
 ) {
-    val context = LocalContext.current
-
     val action = learnMoreUrl?.let { url ->
          InfoAction(
             label = "Learn More",

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

@@ -4,11 +4,14 @@ import androidx.activity.compose.BackHandler
 import androidx.compose.foundation.layout.Box
 import androidx.compose.foundation.layout.fillMaxSize
 import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.size
 import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.filled.Warning
 import androidx.compose.material3.AlertDialog
+import androidx.compose.material3.CircularProgressIndicator
 import androidx.compose.material3.ExperimentalMaterial3Api
 import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.ProgressIndicatorDefaults
 import androidx.compose.material3.Text
 import androidx.compose.material3.TextButton
 import androidx.compose.runtime.Composable
@@ -17,6 +20,7 @@ import androidx.compose.runtime.derivedStateOf
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.remember
 import androidx.compose.ui.Modifier
+import androidx.compose.ui.unit.dp
 import com.example.llama.data.model.ModelInfo
 import com.example.llama.ui.components.InfoView
 import com.example.llama.ui.scaffold.ScaffoldEvent
@@ -63,7 +67,7 @@ fun ModelsScreen(
                 modelsViewModel.toggleMode(ModelScreenUiMode.BROWSING)
             }
             ModelScreenUiMode.DELETING -> {
-                managementViewModel.clearAllSelectedModelsToDelete()
+                managementViewModel.clearSelectedModelsToDelete()
                 modelsViewModel.toggleMode(ModelScreenUiMode.MANAGING)
             }
         }
@@ -77,7 +81,10 @@ fun ModelsScreen(
                 ModelsBrowsingScreen(
                     filteredModels = filteredModels,
                     preselection = preselection,
-                    onManageModelsClicked = { /* TODO-han.yin */ },
+                    onManageModelsClicked = {
+                        managementViewModel.toggleImportMenu(true)
+                        modelsViewModel.toggleMode(ModelScreenUiMode.MANAGING)
+                    },
                     activeFiltersCount = activeFiltersCount,
                     viewModel = modelsViewModel,
                 )
@@ -112,6 +119,21 @@ fun ModelsScreen(
     }
 }
 
+@Composable
+fun ModelsLoadingInProgressView() {
+    InfoView(
+        modifier = Modifier.fillMaxSize(),
+        title = "Loading...",
+        icon = {
+            CircularProgressIndicator(
+                modifier = Modifier.size(64.dp),
+                strokeWidth = ProgressIndicatorDefaults.CircularStrokeWidth * 1.5f
+            )
+        },
+        message = "Searching for installed models on your device...",
+    )
+}
+
 @Composable
 private fun RamErrorDialog(
     ramError: RamWarning,

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

@@ -101,7 +101,8 @@ fun ModelsSearchingScreen(
             expanded = true,
             onExpandedChange = handleExpanded
         ) {
-            if (queryResults.isEmpty()) {
+            queryResults?.let { results ->
+                if (results.isEmpty()) {
                     if (searchQuery.isNotBlank()) {
                         // If no results under current query, show "no results" message
                         EmptySearchResultsView(
@@ -117,7 +118,7 @@ fun ModelsSearchingScreen(
                         verticalArrangement = Arrangement.spacedBy(12.dp),
                         contentPadding = PaddingValues(vertical = 12.dp, horizontal = 16.dp),
                     ) {
-                    items(items = queryResults, key = { it.id }) { model ->
+                        items(items = results, key = { it.id }) { model ->
                             ModelCardFullExpandable(
                                 model = model,
                                 isSelected = if (model == preselection?.modelInfo) true else null,
@@ -138,6 +139,7 @@ fun ModelsSearchingScreen(
                         }
                     }
                 }
+            } ?: ModelsLoadingInProgressView()
         }
     }
 }

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

@@ -61,11 +61,11 @@ class ModelsManagementViewModel @Inject constructor(
         }
     }
 
-    fun selectAllFilteredModelsToDelete(filteredModels: List<ModelInfo>) {
+    fun selectModelsToDelete(models: List<ModelInfo>) {
-        _selectedModelsToDelete.value = filteredModels.associateBy { it.id }
+        _selectedModelsToDelete.value = models.associateBy { it.id }
     }
 
-    fun clearAllSelectedModelsToDelete() {
+    fun clearSelectedModelsToDelete() {
         _selectedModelsToDelete.value = emptyMap()
     }
 
@@ -100,7 +100,7 @@ class ModelsManagementViewModel @Inject constructor(
         huggingFaceQueryJob?.let {
             if (it.isActive) { it.cancel() }
         }
-        clearAllSelectedModelsToDelete()
+        clearSelectedModelsToDelete()
         _managementState.value = ModelManagementState.Idle
     }
 
@@ -288,7 +288,7 @@ class ModelsManagementViewModel @Inject constructor(
                 _managementState.value = Deletion.Deleting(deleted.toFloat() / total, modelsToDelete)
             }
             _managementState.value = Deletion.Success(modelsToDelete.values.toList())
-            clearAllSelectedModelsToDelete()
+            clearSelectedModelsToDelete()
 
             // Reset state after a delay
             delay(DELETE_SUCCESS_RESET_TIMEOUT_MS)

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

@@ -39,6 +39,9 @@ class ModelsViewModel @Inject constructor(
 ) : ViewModel() {
 
     // UI state: model management mode
+    private val _allModels = MutableStateFlow<List<ModelInfo>?>(null)
+    val allModels = _allModels.asStateFlow()
+
     private val _modelScreenUiMode = MutableStateFlow(ModelScreenUiMode.BROWSING)
     val modelScreenUiMode = _modelScreenUiMode.asStateFlow()
 
@@ -128,11 +131,11 @@ class ModelsViewModel @Inject constructor(
     }
 
     // Data: filtered & sorted models
-    private val _filteredModels = MutableStateFlow<List<ModelInfo>>(emptyList())
+    private val _filteredModels = MutableStateFlow<List<ModelInfo>?>(null)
     val filteredModels = _filteredModels.asStateFlow()
 
     // Data: queried models
-    private val _queryResults = MutableStateFlow<List<ModelInfo>>(emptyList())
+    private val _queryResults = MutableStateFlow<List<ModelInfo>?>(null)
     val queryResults = _queryResults.asStateFlow()
 
     // Data: pre-selected model in expansion mode
@@ -161,32 +164,42 @@ class ModelsViewModel @Inject constructor(
 
     init {
         viewModelScope.launch {
+            launch {
+                modelRepository.getModels().collectLatest {
+                    _allModels.value = it
+                }
+            }
+
+            launch {
                 combine(
-                modelRepository.getModels(),
+                    _allModels,
                     _activeFilters,
                     _sortOrder,
                 ) { models, filters, sortOrder ->
-                models.filterBy(filters).sortByOrder(sortOrder)
+                    models?.filterBy(filters)?.sortByOrder(sortOrder)
                 }.collectLatest {
                     _filteredModels.value = it
                 }
             }
 
-        viewModelScope.launch {
+            launch {
                 combine(
-                modelRepository.getModels(),
+                    _allModels,
                     snapshotFlow { searchFieldState.text }.debounce(QUERY_DEBOUNCE_TIMEOUT_MS)
                 ) { models, query ->
                     if (query.isBlank()) {
                         emptyList()
                     } else {
-                    models.queryBy(query.toString()).sortedBy { it.dateLastUsed ?: it.dateAdded }
+                        models?.queryBy(query.toString())?.sortedBy {
+                            it.dateLastUsed ?: it.dateAdded
+                        }
                     }
                 }.collectLatest {
                     _queryResults.value = it
                 }
             }
         }
+    }
 
     /**
      * Pre-select a model to expand its details and show Run FAB