New branch

app/build.gradle.kts

@@ -19,6 +19,8 @@ plugins {
     id("org.jetbrains.kotlin.android")
     id("com.google.devtools.ksp") version "2.1.0-1.0.29"
     id("org.jetbrains.kotlin.plugin.compose")
+    //Room
+
 }
 
 android {
@@ -79,4 +81,9 @@ dependencies {
     // Testing
     androidTestImplementation("androidx.test.espresso:espresso-core:3.6.1")
     androidTestImplementation("androidx.test.ext:junit:1.2.1")
+
+    //Room
+    implementation("androidx.room:room-runtime:2.8.3")
+    ksp("androidx.room:room-compiler:${rootProject.extra["room_version"]}")
+//    implementation("android.room:room-ktx:${rootProject.extra["room_version"]}")
 }

app/src/main/java/com/example/inventory/InventoryApplication.kt

@@ -29,6 +29,6 @@ class InventoryApplication : Application() {
 
     override fun onCreate() {
         super.onCreate()
-        container = AppDataContainer(this)
+        container = AppDataContainer(context = this)
     }
-}
+}

app/src/main/java/com/example/inventory/data/AppContainer.kt

@@ -33,6 +33,6 @@ class AppDataContainer(private val context: Context) : AppContainer {
      * Implementation for [ItemsRepository]
      */
     override val itemsRepository: ItemsRepository by lazy {
-        OfflineItemsRepository()
+        OfflineItemsRepository(InventoryDatabase.getDatabase(context).itemDao())
     }
-}
+}

app/src/main/java/com/example/inventory/data/InventoryDatabase.kt

@@ -0,0 +1,28 @@
+package com.example.inventory.data
+
+import android.content.Context
+import androidx.room.Database
+import androidx.room.Room
+import androidx.room.RoomDatabase
+
+@Database(entities = [Item::class], version = 1, exportSchema = false)
+abstract class InventoryDatabase: RoomDatabase() {
+    abstract fun itemDao(): ItemDao
+
+    companion object {
+        @Volatile
+        private var Instance: InventoryDatabase? = null
+        fun getDatabase(context: Context): InventoryDatabase {
+            return Instance ?: synchronized(this) {
+                Room.databaseBuilder(
+                    context = context,
+                    InventoryDatabase::class.java,
+                    "item_database"
+                )
+                    .fallbackToDestructiveMigration(false)
+                    .build()
+                    .also { Instance = it }
+            }
+        }
+    }
+}

app/src/main/java/com/example/inventory/data/Item.kt

@@ -16,11 +16,16 @@
 
 package com.example.inventory.data
 
+import androidx.room.Entity
+import androidx.room.PrimaryKey
+
 
 /**
  * Entity data class represents a single row in the database.
  */
-class Item(
+@Entity(tableName = "items")
+data class Item(
+    @PrimaryKey(autoGenerate = true)
     val id: Int = 0,
     val name: String,
     val price: Double,

app/src/main/java/com/example/inventory/data/ItemDao.kt

@@ -0,0 +1,27 @@
+package com.example.inventory.data
+
+import androidx.room.Dao
+import androidx.room.Delete
+import androidx.room.Insert
+import androidx.room.OnConflictStrategy
+import androidx.room.Query
+import androidx.room.Update
+import kotlinx.coroutines.flow.Flow
+
+@Dao
+interface ItemDao {
+    @Insert(onConflict = OnConflictStrategy.IGNORE)
+    suspend fun insert(item: Item)
+
+    @Update
+    suspend fun update(item: Item)
+
+    @Delete
+    suspend fun delete(item: Item)
+
+    @Query("SELECT * FROM items WHERE id = :id")
+    fun getItem(id: Int): Flow<Item>
+
+    @Query("SELECT * FROM items ORDER BY name ASC")
+    fun getAllItems(): Flow<List<Item>>
+}

app/src/main/java/com/example/inventory/data/ItemsRepository.kt

@@ -16,7 +16,34 @@
 
 package com.example.inventory.data
 
+import kotlinx.coroutines.flow.Flow
+
 /**
  * Repository that provides insert, update, delete, and retrieve of [Item] from a given data source.
  */
-interface ItemsRepository
+interface ItemsRepository {
+    /**
+     * Retrieve all the items from the given data source
+     */
+    fun getAllItemsStream(): Flow<List<Item>>
+
+    /**
+     * Retrieve an item from the given data source that matches the given [id]
+     */
+    fun getItemStream(id: Int): Flow<Item?>
+
+    /**
+     * Insert [item] in the data source
+     */
+    suspend fun insertItem(item: Item)
+
+    /**
+     * Delete [item] from the data source
+     */
+    suspend fun deleteItem(item: Item)
+
+    /**
+     * Update [item] in the data source
+     */
+    suspend fun updateItem(item: Item)
+}

app/src/main/java/com/example/inventory/data/OfflineItemsRepository.kt

@@ -16,4 +16,17 @@
 
 package com.example.inventory.data
 
-class OfflineItemsRepository : ItemsRepository
+import kotlinx.coroutines.flow.Flow
+
+class OfflineItemsRepository(private val itemDao: ItemDao) : ItemsRepository {
+    override fun getAllItemsStream(): Flow<List<Item>> = itemDao.getAllItems()
+
+    override fun getItemStream(id: Int): Flow<Item?> = itemDao.getItem(id)
+
+    override suspend fun insertItem(item: Item) = itemDao.insert(item = item)
+
+    override suspend fun deleteItem(item: Item) = itemDao.delete(item = item)
+
+    override suspend fun updateItem(item: Item) = itemDao.update(item = item)
+}
+

app/src/main/java/com/example/inventory/ui/AppViewModelProvider.kt

@@ -41,7 +41,7 @@ object AppViewModelProvider {
         }
         // Initializer for ItemEntryViewModel
         initializer {
-            ItemEntryViewModel()
+            ItemEntryViewModel(inventoryApplication().container.itemsRepository)
         }
 
         // Initializer for ItemDetailsViewModel

app/src/main/java/com/example/inventory/ui/home/HomeScreen.kt

@@ -146,7 +146,8 @@ private fun InventoryList(
             InventoryItem(item = item,
                 modifier = Modifier
                     .padding(dimensionResource(id = R.dimen.padding_small))
-                    .clickable { onItemClick(item) })
+                    .clickable { onItemClick(item) }
+            )
         }
     }
 }

app/src/main/java/com/example/inventory/ui/item/ItemEntryScreen.kt

@@ -33,6 +33,7 @@ import androidx.compose.material3.OutlinedTextFieldDefaults
 import androidx.compose.material3.Scaffold
 import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.rememberCoroutineScope
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.platform.LocalLayoutDirection
 import androidx.compose.ui.res.dimensionResource
@@ -45,6 +46,7 @@ import com.example.inventory.R
 import com.example.inventory.ui.AppViewModelProvider
 import com.example.inventory.ui.navigation.NavigationDestination
 import com.example.inventory.ui.theme.InventoryTheme
+import kotlinx.coroutines.launch
 import java.util.Currency
 import java.util.Locale
 
@@ -59,29 +61,35 @@ fun ItemEntryScreen(
     navigateBack: () -> Unit,
     onNavigateUp: () -> Unit,
     canNavigateBack: Boolean = true,
-    viewModel: ItemEntryViewModel = viewModel(factory = AppViewModelProvider.Factory)
+    viewModel: ItemEntryViewModel = viewModel(factory = AppViewModelProvider.Factory),
 ) {
+    val coroutineScope = rememberCoroutineScope()
     Scaffold(
         topBar = {
             InventoryTopAppBar(
                 title = stringResource(ItemEntryDestination.titleRes),
                 canNavigateBack = canNavigateBack,
-                navigateUp = onNavigateUp
+                navigateUp = onNavigateUp,
             )
         }
     ) { innerPadding ->
         ItemEntryBody(
             itemUiState = viewModel.itemUiState,
             onItemValueChange = viewModel::updateUiState,
-            onSaveClick = { },
+            onSaveClick = {
+                coroutineScope.launch {
+                    viewModel.saveItem()
+                    navigateBack()
+                }
+            },
             modifier = Modifier
                 .padding(
                     start = innerPadding.calculateStartPadding(LocalLayoutDirection.current),
                     end = innerPadding.calculateEndPadding(LocalLayoutDirection.current),
                     top = innerPadding.calculateTopPadding()
                 )
                 .verticalScroll(rememberScrollState())
-                .fillMaxWidth()
+                .fillMaxWidth(),
         )
     }
 }
@@ -91,11 +99,11 @@ fun ItemEntryBody(
     itemUiState: ItemUiState,
     onItemValueChange: (ItemDetails) -> Unit,
     onSaveClick: () -> Unit,
-    modifier: Modifier = Modifier
+    modifier: Modifier = Modifier,
 ) {
     Column(
         verticalArrangement = Arrangement.spacedBy(dimensionResource(id = R.dimen.padding_large)),
-        modifier = modifier.padding(dimensionResource(id = R.dimen.padding_medium))
+        modifier = modifier.padding(dimensionResource(id = R.dimen.padding_medium)),
         ) {
         ItemInputForm(
             itemDetails = itemUiState.itemDetails,
@@ -175,7 +183,7 @@ fun ItemInputForm(
     }
 }
 
-@Preview(showBackground = true)
+@Preview(showBackground = true) // Preview
 @Composable
 private fun ItemEntryScreenPreview() {
     InventoryTheme {

app/src/main/java/com/example/inventory/ui/item/ItemEntryViewModel.kt

@@ -21,12 +21,13 @@ import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.setValue
 import androidx.lifecycle.ViewModel
 import com.example.inventory.data.Item
+import com.example.inventory.data.ItemsRepository
 import java.text.NumberFormat
 
 /**
  * ViewModel to validate and insert items in the Room database.
  */
-class ItemEntryViewModel : ViewModel() {
+class ItemEntryViewModel(private val itemsRepository: ItemsRepository) : ViewModel() {
 
     /**
      * Holds current item ui state
@@ -48,6 +49,12 @@ class ItemEntryViewModel : ViewModel() {
             name.isNotBlank() && price.isNotBlank() && quantity.isNotBlank()
         }
     }
+
+    suspend fun saveItem() {
+        if (validateInput()) {
+            itemsRepository.insertItem(itemUiState.itemDetails.toItem())
+        }
+    }
 }
 
 /**
@@ -97,4 +104,4 @@ fun Item.toItemDetails(): ItemDetails = ItemDetails(
     name = name,
     price = price.toString(),
     quantity = quantity.toString()
-)
+)

build.gradle.kts

@@ -20,14 +20,13 @@ buildscript {
         set("room_version", "2.6.0")
     }
 }
-
 plugins {
-    id("com.android.application") version "8.8.0" apply false
-    id("com.android.library") version "8.8.0" apply false
+    id("com.android.application") version "8.13.1" apply false
+    id("com.android.library") version "8.13.1" apply false
     id("org.jetbrains.kotlin.android") version "2.1.0" apply false
     id("org.jetbrains.kotlin.plugin.compose") version "2.1.0" apply false
 }
 
 tasks.register("clean", Delete::class) {
-    delete(rootProject.buildDir)
+    delete(rootProject.layout.buildDirectory)
 }

gradle/wrapper/gradle-wrapper.properties

@@ -1,6 +1,6 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-8.12-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.13-bin.zip
 networkTimeout=10000
 validateDistributionUrl=true
 zipStoreBase=GRADLE_USER_HOME