├── .github └── ISSUE_TEMPLATE │ ├── android-basics--persist-data-with-room-template.md │ ├── android-basics--read-and-update-data-with-room-template.md │ └── android-basics-issue-template.md ├── .gitignore ├── CONTRIBUTING.md ├── LICENSE ├── README.md ├── app ├── .gitignore ├── build.gradle ├── proguard-rules.pro └── src │ └── main │ ├── AndroidManifest.xml │ ├── ic_launcher-playstore.png │ ├── java │ └── com │ │ └── example │ │ └── inventory │ │ ├── AddItemFragment.kt │ │ ├── InventoryApplication.kt │ │ ├── InventoryViewModel.kt │ │ ├── ItemDetailFragment.kt │ │ ├── ItemListAdapter.kt │ │ ├── ItemListFragment.kt │ │ ├── MainActivity.kt │ │ └── data │ │ ├── Item.kt │ │ ├── ItemDao.kt │ │ └── ItemRoomDatabase.kt │ └── res │ ├── drawable │ ├── ic_edit.xml │ ├── ic_launcher_background.xml │ └── ic_launcher_foreground.xml │ ├── layout │ ├── activity_main.xml │ ├── fragment_add_item.xml │ ├── fragment_item_detail.xml │ ├── item_list_fragment.xml │ └── item_list_item.xml │ ├── mipmap-anydpi-v26 │ ├── ic_launcher.xml │ └── ic_launcher_round.xml │ ├── navigation │ └── nav_graph.xml │ ├── values-night │ └── themes.xml │ └── values │ ├── colors.xml │ ├── dimens.xml │ ├── strings.xml │ ├── styles.xml │ └── themes.xml ├── build.gradle ├── code-of-conduct.md ├── gradle.properties ├── gradle └── wrapper │ ├── gradle-wrapper.jar │ └── gradle-wrapper.properties ├── gradlew ├── gradlew.bat └── settings.gradle /.github/ISSUE_TEMPLATE/android-basics--persist-data-with-room-template.md: -------------------------------------------------------------------------------- 1 | --- 2 | name: 'Android Basics: Persist data with Room template' 3 | about: Describe this issue template's purpose here. 4 | title: 'Android Basics: Persist data with Room' 5 | labels: '' 6 | assignees: '' 7 | 8 | --- 9 | 10 | **URL of codelab** 11 | 12 | 13 | **In which task and step of the codelab can this issue be found?** 14 | 15 | 16 | **Describe the problem** 17 | 18 | 19 | 20 | 21 | **Steps to reproduce?** 22 | 1. Go to... 23 | 2. Click on... 24 | 3. See error... 25 | 26 | **Versions** 27 | _Android Studio version:_ 28 | _API version of the emulator:_ 29 | 30 | 31 | **Additional information** 32 | _Include screenshots if they would be useful in clarifying the problem._ 33 | -------------------------------------------------------------------------------- /.github/ISSUE_TEMPLATE/android-basics--read-and-update-data-with-room-template.md: -------------------------------------------------------------------------------- 1 | --- 2 | name: 'Android Basics: Read and update data with Room template' 3 | about: Describe this issue template's purpose here. 4 | title: 'Android Basics: Read and update data with Room' 5 | labels: '' 6 | assignees: '' 7 | 8 | --- 9 | 10 | **URL of codelab** 11 | 12 | 13 | **In which task and step of the codelab can this issue be found?** 14 | 15 | 16 | **Describe the problem** 17 | 18 | 19 | 20 | 21 | **Steps to reproduce?** 22 | 1. Go to... 23 | 2. Click on... 24 | 3. See error... 25 | 26 | **Versions** 27 | _Android Studio version:_ 28 | _API version of the emulator:_ 29 | 30 | 31 | **Additional information** 32 | _Include screenshots if they would be useful in clarifying the problem._ 33 | -------------------------------------------------------------------------------- /.github/ISSUE_TEMPLATE/android-basics-issue-template.md: -------------------------------------------------------------------------------- 1 | --- 2 | name: Android Basics issue template 3 | about: Describe this issue template's purpose here. 4 | title: '' 5 | labels: '' 6 | assignees: '' 7 | 8 | --- 9 | 10 | **URL of codelab** 11 | 12 | 13 | **In which task and step of the codelab can this issue be found?** 14 | 15 | 16 | **Describe the problem** 17 | 18 | 19 | 20 | 21 | **Steps to reproduce?** 22 | 1. Go to... 23 | 2. Click on... 24 | 3. See error... 25 | 26 | **Versions** 27 | _Android Studio version:_ 28 | _API version of the emulator:_ 29 | 30 | 31 | **Additional information** 32 | _Include screenshots if they would be useful in clarifying the problem._ 33 | -------------------------------------------------------------------------------- /.gitignore: -------------------------------------------------------------------------------- 1 | # built application files 2 | *.apk 3 | *.ap_ 4 | 5 | # Mac files 6 | .DS_Store 7 | 8 | # files for the dex VM 9 | *.dex 10 | 11 | # Java class files 12 | *.class 13 | 14 | # generated files 15 | bin/ 16 | gen/ 17 | 18 | # Ignore gradle files 19 | .gradle/ 20 | build/ 21 | 22 | # Local configuration file (sdk path, etc) 23 | local.properties 24 | 25 | # Proguard folder generated by Eclipse 26 | proguard/ 27 | proguard-project.txt 28 | 29 | # Eclipse files 30 | .project 31 | .classpath 32 | .settings/ 33 | 34 | # Android Studio/IDEA 35 | *.iml 36 | .idea -------------------------------------------------------------------------------- /CONTRIBUTING.md: -------------------------------------------------------------------------------- 1 | # How to Contribute 2 | 3 | We'd love to accept your patches and contributions to this project. 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We also recommend that a 186 | file or class name and description of purpose be included on the 187 | same "printed page" as the copyright notice for easier 188 | identification within third-party archives. 189 | 190 | Copyright [yyyy] [name of copyright owner] 191 | 192 | Licensed under the Apache License, Version 2.0 (the "License"); 193 | you may not use this file except in compliance with the License. 194 | You may obtain a copy of the License at 195 | 196 | http://www.apache.org/licenses/LICENSE-2.0 197 | 198 | Unless required by applicable law or agreed to in writing, software 199 | distributed under the License is distributed on an "AS IS" BASIS, 200 | WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 201 | See the License for the specific language governing permissions and 202 | limitations under the License. 203 | -------------------------------------------------------------------------------- /README.md: -------------------------------------------------------------------------------- 1 | Inventory - Solution Code 2 | ================================== 3 | 4 | Solution code for Android Basics in Kotlin. 5 | Codelab: Android Jetpack - Room. 6 | 7 | Introduction 8 | ------------ 9 | 10 | This app is an Inventory tracking app. Demos how to add, update, sell, and delete items from the local database. 11 | This app demonstrated 12 | the use of Android Jetpack component [Room](https://developer.android.com/training/data-storage/room) database. 13 | 14 | The app also leverages [ViewModel](https://developer.android.com/topic/libraries/architecture/viewmodel), 15 | [LiveData](https://developer.android.com/topic/libraries/architecture/livedata), 16 | [Flow] (https://developer.android.com/kotlin/flow), 17 | [View Binding](https://developer.android.com/topic/libraries/view-binding), 18 | and [Navigation](https://developer.android.com/topic/libraries/architecture/navigation/) 19 | with the SafeArgs plugin for parameter passing between fragments. 20 | 21 | Pre-requisites 22 | -------------- 23 | 24 | You need to know: 25 | - How to create and use fragments. 26 | - How to navigate between fragments, and use safeArgs to pass data between fragments. 27 | - How to use architecture components including ViewModel, LiveData, and LiveData transformations. 28 | - How to use coroutines for long-running tasks. 29 | - RecyclerView and adapters 30 | - SQLite database and the SQLite query language 31 | 32 | 33 | Getting Started 34 | --------------- 35 | 36 | 1. Download and run the app. -------------------------------------------------------------------------------- /app/.gitignore: -------------------------------------------------------------------------------- 1 | /build -------------------------------------------------------------------------------- /app/build.gradle: -------------------------------------------------------------------------------- 1 | /* 2 | * Copyright (C) 2021 The Android Open Source Project. 3 | * 4 | * Licensed under the Apache License, Version 2.0 (the "License"); 5 | * you may not use this file except in compliance with the License. 6 | * You may obtain a copy of the License at 7 | * 8 | * http://www.apache.org/licenses/LICENSE-2.0 9 | * 10 | * Unless required by applicable law or agreed to in writing, software 11 | * distributed under the License is distributed on an "AS IS" BASIS, 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 | * See the License for the specific language governing permissions and 14 | * limitations under the License. 15 | */ 16 | 17 | plugins { 18 | id 'com.android.application' 19 | id 'kotlin-android' 20 | id 'androidx.navigation.safeargs.kotlin' 21 | id 'com.google.devtools.ksp' version '1.8.0-1.0.8' 22 | } 23 | 24 | android { 25 | compileSdkVersion 33 26 | 27 | defaultConfig { 28 | applicationId "com.example.inventory" 29 | minSdkVersion 19 30 | targetSdkVersion 33 31 | versionCode 1 32 | versionName "1.0" 33 | 34 | testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner" 35 | } 36 | 37 | buildTypes { 38 | release { 39 | minifyEnabled false 40 | proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 41 | 'proguard-rules.pro' 42 | } 43 | } 44 | buildFeatures { 45 | viewBinding true 46 | } 47 | compileOptions { 48 | sourceCompatibility JavaVersion.VERSION_1_8 49 | targetCompatibility JavaVersion.VERSION_1_8 50 | } 51 | kotlinOptions { 52 | jvmTarget = '1.8' 53 | } 54 | namespace 'com.example.inventory' 55 | } 56 | 57 | dependencies { 58 | 59 | implementation "androidx.appcompat:appcompat:$appcompat_version" 60 | implementation "androidx.constraintlayout:constraintlayout:$constraintlayout_version" 61 | implementation "androidx.core:core-ktx:$core_ktx_version" 62 | implementation "com.google.android.material:material:$material_version" 63 | 64 | // Lifecycle libraries 65 | implementation "androidx.lifecycle:lifecycle-viewmodel-ktx:$lifecycle_version" 66 | implementation "androidx.lifecycle:lifecycle-livedata-ktx:$lifecycle_version" 67 | 68 | // Navigation libraries 69 | implementation "androidx.navigation:navigation-fragment-ktx:$nav_version" 70 | implementation "androidx.navigation:navigation-ui-ktx:$nav_version" 71 | 72 | // Room libraries 73 | implementation "androidx.room:room-runtime:$room_version" 74 | ksp "androidx.room:room-compiler:$room_version" 75 | implementation "androidx.room:room-ktx:$room_version" 76 | } -------------------------------------------------------------------------------- /app/proguard-rules.pro: -------------------------------------------------------------------------------- 1 | # Add project specific ProGuard rules here. 2 | # You can control the set of applied configuration files using the 3 | # proguardFiles setting in build.gradle. 4 | # 5 | # For more details, see 6 | # http://developer.android.com/guide/developing/tools/proguard.html 7 | 8 | # If your project uses WebView with JS, uncomment the following 9 | # and specify the fully qualified class name to the JavaScript interface 10 | # class: 11 | #-keepclassmembers class fqcn.of.javascript.interface.for.webview { 12 | # public *; 13 | #} 14 | 15 | # Uncomment this to preserve the line number information for 16 | # debugging stack traces. 17 | #-keepattributes SourceFile,LineNumberTable 18 | 19 | # If you keep the line number information, uncomment this to 20 | # hide the original source file name. 21 | #-renamesourcefileattribute SourceFile -------------------------------------------------------------------------------- /app/src/main/AndroidManifest.xml: -------------------------------------------------------------------------------- 1 | 16 | 17 | 18 | 26 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | -------------------------------------------------------------------------------- /app/src/main/ic_launcher-playstore.png: -------------------------------------------------------------------------------- https://raw.githubusercontent.com/google-developer-training/android-basics-kotlin-inventory-app/ce377892b66380a006ec4b4d4fa2f4baa14c16d0/app/src/main/ic_launcher-playstore.png -------------------------------------------------------------------------------- /app/src/main/java/com/example/inventory/AddItemFragment.kt: -------------------------------------------------------------------------------- 1 | /* 2 | * Copyright (C) 2021 The Android Open Source Project. 3 | * 4 | * Licensed under the Apache License, Version 2.0 (the "License"); 5 | * you may not use this file except in compliance with the License. 6 | * You may obtain a copy of the License at 7 | * 8 | * http://www.apache.org/licenses/LICENSE-2.0 9 | * 10 | * Unless required by applicable law or agreed to in writing, software 11 | * distributed under the License is distributed on an "AS IS" BASIS, 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 | * See the License for the specific language governing permissions and 14 | * limitations under the License. 15 | */ 16 | package com.example.inventory 17 | 18 | import android.content.Context.INPUT_METHOD_SERVICE 19 | import android.os.Bundle 20 | import android.view.LayoutInflater 21 | import android.view.View 22 | import android.view.ViewGroup 23 | import android.view.inputmethod.InputMethodManager 24 | import android.widget.TextView 25 | import androidx.fragment.app.Fragment 26 | import androidx.fragment.app.activityViewModels 27 | import androidx.navigation.fragment.findNavController 28 | import androidx.navigation.fragment.navArgs 29 | import com.example.inventory.data.Item 30 | import com.example.inventory.databinding.FragmentAddItemBinding 31 | 32 | /** 33 | * Fragment to add or update an item in the Inventory database. 34 | */ 35 | class AddItemFragment : Fragment() { 36 | 37 | // Use the 'by activityViewModels()' Kotlin property delegate from the fragment-ktx artifact 38 | // to share the ViewModel across fragments. 39 | private val viewModel: InventoryViewModel by activityViewModels { 40 | InventoryViewModelFactory( 41 | (activity?.application as InventoryApplication).database 42 | .itemDao() 43 | ) 44 | } 45 | private val navigationArgs: ItemDetailFragmentArgs by navArgs() 46 | 47 | lateinit var item: Item 48 | 49 | // Binding object instance corresponding to the fragment_add_item.xml layout 50 | // This property is non-null between the onCreateView() and onDestroyView() lifecycle callbacks, 51 | // when the view hierarchy is attached to the fragment 52 | private var _binding: FragmentAddItemBinding? = null 53 | private val binding get() = _binding!! 54 | 55 | override fun onCreateView( 56 | inflater: LayoutInflater, 57 | container: ViewGroup?, 58 | savedInstanceState: Bundle? 59 | ): View? { 60 | _binding = FragmentAddItemBinding.inflate(inflater, container, false) 61 | return binding.root 62 | } 63 | 64 | /** 65 | * Returns true if the EditTexts are not empty 66 | */ 67 | private fun isEntryValid(): Boolean { 68 | return viewModel.isEntryValid( 69 | binding.itemName.text.toString(), 70 | binding.itemPrice.text.toString(), 71 | binding.itemCount.text.toString(), 72 | ) 73 | } 74 | 75 | /** 76 | * Binds views with the passed in [item] information. 77 | */ 78 | private fun bind(item: Item) { 79 | val price = "%.2f".format(item.itemPrice) 80 | binding.apply { 81 | itemName.setText(item.itemName, TextView.BufferType.SPANNABLE) 82 | itemPrice.setText(price, TextView.BufferType.SPANNABLE) 83 | itemCount.setText(item.quantityInStock.toString(), TextView.BufferType.SPANNABLE) 84 | saveAction.setOnClickListener { updateItem() } 85 | } 86 | } 87 | 88 | /** 89 | * Inserts the new Item into database and navigates up to list fragment. 90 | */ 91 | private fun addNewItem() { 92 | if (isEntryValid()) { 93 | viewModel.addNewItem( 94 | binding.itemName.text.toString(), 95 | binding.itemPrice.text.toString(), 96 | binding.itemCount.text.toString(), 97 | ) 98 | val action = AddItemFragmentDirections.actionAddItemFragmentToItemListFragment() 99 | findNavController().navigate(action) 100 | } 101 | } 102 | 103 | /** 104 | * Updates an existing Item in the database and navigates up to list fragment. 105 | */ 106 | private fun updateItem() { 107 | if (isEntryValid()) { 108 | viewModel.updateItem( 109 | this.navigationArgs.itemId, 110 | this.binding.itemName.text.toString(), 111 | this.binding.itemPrice.text.toString(), 112 | this.binding.itemCount.text.toString() 113 | ) 114 | val action = AddItemFragmentDirections.actionAddItemFragmentToItemListFragment() 115 | findNavController().navigate(action) 116 | } 117 | } 118 | 119 | /** 120 | * Called when the view is created. 121 | * The itemId Navigation argument determines the edit item or add new item. 122 | * If the itemId is positive, this method retrieves the information from the database and 123 | * allows the user to update it. 124 | */ 125 | override fun onViewCreated(view: View, savedInstanceState: Bundle?) { 126 | super.onViewCreated(view, savedInstanceState) 127 | 128 | val id = navigationArgs.itemId 129 | if (id > 0) { 130 | viewModel.retrieveItem(id).observe(this.viewLifecycleOwner) { selectedItem -> 131 | item = selectedItem 132 | bind(item) 133 | } 134 | } else { 135 | binding.saveAction.setOnClickListener { 136 | addNewItem() 137 | } 138 | } 139 | } 140 | 141 | /** 142 | * Called before fragment is destroyed. 143 | */ 144 | override fun onDestroyView() { 145 | super.onDestroyView() 146 | // Hide keyboard. 147 | val inputMethodManager = requireActivity().getSystemService(INPUT_METHOD_SERVICE) as 148 | InputMethodManager 149 | inputMethodManager.hideSoftInputFromWindow(requireActivity().currentFocus?.windowToken, 0) 150 | _binding = null 151 | } 152 | } 153 | -------------------------------------------------------------------------------- /app/src/main/java/com/example/inventory/InventoryApplication.kt: -------------------------------------------------------------------------------- 1 | /* 2 | * Copyright (C) 2021 The Android Open Source Project. 3 | * 4 | * Licensed under the Apache License, Version 2.0 (the "License"); 5 | * you may not use this file except in compliance with the License. 6 | * You may obtain a copy of the License at 7 | * 8 | * http://www.apache.org/licenses/LICENSE-2.0 9 | * 10 | * Unless required by applicable law or agreed to in writing, software 11 | * distributed under the License is distributed on an "AS IS" BASIS, 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 | * See the License for the specific language governing permissions and 14 | * limitations under the License. 15 | */ 16 | package com.example.inventory 17 | 18 | import android.app.Application 19 | import com.example.inventory.data.ItemRoomDatabase 20 | 21 | 22 | class InventoryApplication : Application() { 23 | // Using by lazy so the database is only created when needed 24 | // rather than when the application starts 25 | val database: ItemRoomDatabase by lazy { ItemRoomDatabase.getDatabase(this) } 26 | } 27 | -------------------------------------------------------------------------------- /app/src/main/java/com/example/inventory/InventoryViewModel.kt: -------------------------------------------------------------------------------- 1 | /* 2 | * Copyright (C) 2021 The Android Open Source Project. 3 | * 4 | * Licensed under the Apache License, Version 2.0 (the "License"); 5 | * you may not use this file except in compliance with the License. 6 | * You may obtain a copy of the License at 7 | * 8 | * http://www.apache.org/licenses/LICENSE-2.0 9 | * 10 | * Unless required by applicable law or agreed to in writing, software 11 | * distributed under the License is distributed on an "AS IS" BASIS, 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 | * See the License for the specific language governing permissions and 14 | * limitations under the License. 15 | */ 16 | 17 | package com.example.inventory 18 | 19 | import androidx.lifecycle.LiveData 20 | import androidx.lifecycle.ViewModel 21 | import androidx.lifecycle.ViewModelProvider 22 | import androidx.lifecycle.asLiveData 23 | import androidx.lifecycle.viewModelScope 24 | import com.example.inventory.data.Item 25 | import com.example.inventory.data.ItemDao 26 | import kotlinx.coroutines.launch 27 | 28 | /** 29 | * View Model to keep a reference to the Inventory repository and an up-to-date list of all items. 30 | * 31 | */ 32 | class InventoryViewModel(private val itemDao: ItemDao) : ViewModel() { 33 | 34 | // Cache all items form the database using LiveData. 35 | val allItems: LiveData> = itemDao.getItems().asLiveData() 36 | 37 | /** 38 | * Returns true if stock is available to sell, false otherwise. 39 | */ 40 | fun isStockAvailable(item: Item): Boolean { 41 | return (item.quantityInStock > 0) 42 | } 43 | 44 | /** 45 | * Updates an existing Item in the database. 46 | */ 47 | fun updateItem( 48 | itemId: Int, 49 | itemName: String, 50 | itemPrice: String, 51 | itemCount: String 52 | ) { 53 | val updatedItem = getUpdatedItemEntry(itemId, itemName, itemPrice, itemCount) 54 | updateItem(updatedItem) 55 | } 56 | 57 | 58 | /** 59 | * Launching a new coroutine to update an item in a non-blocking way 60 | */ 61 | private fun updateItem(item: Item) { 62 | viewModelScope.launch { 63 | itemDao.update(item) 64 | } 65 | } 66 | 67 | /** 68 | * Decreases the stock by one unit and updates the database. 69 | */ 70 | fun sellItem(item: Item) { 71 | if (item.quantityInStock > 0) { 72 | // Decrease the quantity by 1 73 | val newItem = item.copy(quantityInStock = item.quantityInStock - 1) 74 | updateItem(newItem) 75 | } 76 | } 77 | 78 | /** 79 | * Inserts the new Item into database. 80 | */ 81 | fun addNewItem(itemName: String, itemPrice: String, itemCount: String) { 82 | val newItem = getNewItemEntry(itemName, itemPrice, itemCount) 83 | insertItem(newItem) 84 | } 85 | 86 | /** 87 | * Launching a new coroutine to insert an item in a non-blocking way 88 | */ 89 | private fun insertItem(item: Item) { 90 | viewModelScope.launch { 91 | itemDao.insert(item) 92 | } 93 | } 94 | 95 | /** 96 | * Launching a new coroutine to delete an item in a non-blocking way 97 | */ 98 | fun deleteItem(item: Item) { 99 | viewModelScope.launch { 100 | itemDao.delete(item) 101 | } 102 | } 103 | 104 | /** 105 | * Retrieve an item from the repository. 106 | */ 107 | fun retrieveItem(id: Int): LiveData { 108 | return itemDao.getItem(id).asLiveData() 109 | } 110 | 111 | /** 112 | * Returns true if the EditTexts are not empty 113 | */ 114 | fun isEntryValid(itemName: String, itemPrice: String, itemCount: String): Boolean { 115 | if (itemName.isBlank() || itemPrice.isBlank() || itemCount.isBlank()) { 116 | return false 117 | } 118 | return true 119 | } 120 | 121 | /** 122 | * Returns an instance of the [Item] entity class with the item info entered by the user. 123 | * This will be used to add a new entry to the Inventory database. 124 | */ 125 | private fun getNewItemEntry(itemName: String, itemPrice: String, itemCount: String): Item { 126 | return Item( 127 | itemName = itemName, 128 | itemPrice = itemPrice.toDouble(), 129 | quantityInStock = itemCount.toInt() 130 | ) 131 | } 132 | 133 | /** 134 | * Called to update an existing entry in the Inventory database. 135 | * Returns an instance of the [Item] entity class with the item info updated by the user. 136 | */ 137 | private fun getUpdatedItemEntry( 138 | itemId: Int, 139 | itemName: String, 140 | itemPrice: String, 141 | itemCount: String 142 | ): Item { 143 | return Item( 144 | id = itemId, 145 | itemName = itemName, 146 | itemPrice = itemPrice.toDouble(), 147 | quantityInStock = itemCount.toInt() 148 | ) 149 | } 150 | } 151 | 152 | /** 153 | * Factory class to instantiate the [ViewModel] instance. 154 | */ 155 | class InventoryViewModelFactory(private val itemDao: ItemDao) : ViewModelProvider.Factory { 156 | override fun create(modelClass: Class): T { 157 | if (modelClass.isAssignableFrom(InventoryViewModel::class.java)) { 158 | @Suppress("UNCHECKED_CAST") 159 | return InventoryViewModel(itemDao) as T 160 | } 161 | throw IllegalArgumentException("Unknown ViewModel class") 162 | } 163 | } 164 | 165 | -------------------------------------------------------------------------------- /app/src/main/java/com/example/inventory/ItemDetailFragment.kt: -------------------------------------------------------------------------------- 1 | /* 2 | * Copyright (C) 2021 The Android Open Source Project. 3 | * 4 | * Licensed under the Apache License, Version 2.0 (the "License"); 5 | * you may not use this file except in compliance with the License. 6 | * You may obtain a copy of the License at 7 | * 8 | * http://www.apache.org/licenses/LICENSE-2.0 9 | * 10 | * Unless required by applicable law or agreed to in writing, software 11 | * distributed under the License is distributed on an "AS IS" BASIS, 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 | * See the License for the specific language governing permissions and 14 | * limitations under the License. 15 | */ 16 | 17 | package com.example.inventory 18 | 19 | import android.os.Bundle 20 | import android.view.LayoutInflater 21 | import android.view.View 22 | import android.view.ViewGroup 23 | import androidx.fragment.app.Fragment 24 | import androidx.fragment.app.activityViewModels 25 | import androidx.navigation.fragment.findNavController 26 | import androidx.navigation.fragment.navArgs 27 | import com.example.inventory.data.Item 28 | import com.example.inventory.data.getFormattedPrice 29 | import com.example.inventory.databinding.FragmentItemDetailBinding 30 | import com.google.android.material.dialog.MaterialAlertDialogBuilder 31 | 32 | /** 33 | * [ItemDetailFragment] displays the details of the selected item. 34 | */ 35 | class ItemDetailFragment : Fragment() { 36 | private val navigationArgs: ItemDetailFragmentArgs by navArgs() 37 | lateinit var item: Item 38 | 39 | private val viewModel: InventoryViewModel by activityViewModels { 40 | InventoryViewModelFactory( 41 | (activity?.application as InventoryApplication).database.itemDao() 42 | ) 43 | } 44 | 45 | private var _binding: FragmentItemDetailBinding? = null 46 | private val binding get() = _binding!! 47 | 48 | override fun onCreateView( 49 | inflater: LayoutInflater, 50 | container: ViewGroup?, 51 | savedInstanceState: Bundle? 52 | ): View? { 53 | _binding = FragmentItemDetailBinding.inflate(inflater, container, false) 54 | return binding.root 55 | } 56 | 57 | /** 58 | * Binds views with the passed in item data. 59 | */ 60 | private fun bind(item: Item) { 61 | binding.apply { 62 | itemName.text = item.itemName 63 | itemPrice.text = item.getFormattedPrice() 64 | itemCount.text = item.quantityInStock.toString() 65 | sellItem.isEnabled = viewModel.isStockAvailable(item) 66 | sellItem.setOnClickListener { viewModel.sellItem(item) } 67 | deleteItem.setOnClickListener { showConfirmationDialog() } 68 | editItem.setOnClickListener { editItem() } 69 | } 70 | } 71 | 72 | /** 73 | * Navigate to the Edit item screen. 74 | */ 75 | private fun editItem() { 76 | val action = ItemDetailFragmentDirections.actionItemDetailFragmentToAddItemFragment( 77 | getString(R.string.edit_fragment_title), 78 | item.id 79 | ) 80 | this.findNavController().navigate(action) 81 | } 82 | 83 | /** 84 | * Displays an alert dialog to get the user's confirmation before deleting the item. 85 | */ 86 | private fun showConfirmationDialog() { 87 | MaterialAlertDialogBuilder(requireContext()) 88 | .setTitle(getString(android.R.string.dialog_alert_title)) 89 | .setMessage(getString(R.string.delete_question)) 90 | .setCancelable(false) 91 | .setNegativeButton(getString(R.string.no)) { _, _ -> } 92 | .setPositiveButton(getString(R.string.yes)) { _, _ -> 93 | deleteItem() 94 | } 95 | .show() 96 | } 97 | 98 | /** 99 | * Deletes the current item and navigates to the list fragment. 100 | */ 101 | private fun deleteItem() { 102 | viewModel.deleteItem(item) 103 | findNavController().navigateUp() 104 | } 105 | 106 | override fun onViewCreated(view: View, savedInstanceState: Bundle?) { 107 | super.onViewCreated(view, savedInstanceState) 108 | val id = navigationArgs.itemId 109 | // Retrieve the item details using the itemId. 110 | // Attach an observer on the data (instead of polling for changes) and only update the 111 | // the UI when the data actually changes. 112 | viewModel.retrieveItem(id).observe(this.viewLifecycleOwner) { selectedItem -> 113 | item = selectedItem 114 | bind(item) 115 | } 116 | } 117 | 118 | /** 119 | * Called when fragment is destroyed. 120 | */ 121 | override fun onDestroyView() { 122 | super.onDestroyView() 123 | _binding = null 124 | } 125 | } 126 | -------------------------------------------------------------------------------- /app/src/main/java/com/example/inventory/ItemListAdapter.kt: -------------------------------------------------------------------------------- 1 | /* 2 | * Copyright (C) 2021 The Android Open Source Project. 3 | * 4 | * Licensed under the Apache License, Version 2.0 (the "License"); 5 | * you may not use this file except in compliance with the License. 6 | * You may obtain a copy of the License at 7 | * 8 | * http://www.apache.org/licenses/LICENSE-2.0 9 | * 10 | * Unless required by applicable law or agreed to in writing, software 11 | * distributed under the License is distributed on an "AS IS" BASIS, 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 | * See the License for the specific language governing permissions and 14 | * limitations under the License. 15 | */ 16 | package com.example.inventory 17 | 18 | import android.view.LayoutInflater 19 | import android.view.ViewGroup 20 | import androidx.recyclerview.widget.DiffUtil 21 | import androidx.recyclerview.widget.ListAdapter 22 | import androidx.recyclerview.widget.RecyclerView 23 | import com.example.inventory.data.Item 24 | import com.example.inventory.data.getFormattedPrice 25 | import com.example.inventory.databinding.ItemListItemBinding 26 | 27 | /** 28 | * [ListAdapter] implementation for the recyclerview. 29 | */ 30 | 31 | class ItemListAdapter(private val onItemClicked: (Item) -> Unit) : 32 | ListAdapter(DiffCallback) { 33 | 34 | override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ItemViewHolder { 35 | return ItemViewHolder( 36 | ItemListItemBinding.inflate( 37 | LayoutInflater.from( 38 | parent.context 39 | ) 40 | ) 41 | ) 42 | } 43 | 44 | override fun onBindViewHolder(holder: ItemViewHolder, position: Int) { 45 | val current = getItem(position) 46 | holder.itemView.setOnClickListener { 47 | onItemClicked(current) 48 | } 49 | holder.bind(current) 50 | } 51 | 52 | class ItemViewHolder(private var binding: ItemListItemBinding) : 53 | RecyclerView.ViewHolder(binding.root) { 54 | 55 | fun bind(item: Item) { 56 | binding.itemName.text = item.itemName 57 | binding.itemPrice.text = item.getFormattedPrice() 58 | binding.itemQuantity.text = item.quantityInStock.toString() 59 | } 60 | } 61 | 62 | companion object { 63 | private val DiffCallback = object : DiffUtil.ItemCallback() { 64 | override fun areItemsTheSame(oldItem: Item, newItem: Item): Boolean { 65 | return oldItem === newItem 66 | } 67 | 68 | override fun areContentsTheSame(oldItem: Item, newItem: Item): Boolean { 69 | return oldItem.itemName == newItem.itemName 70 | } 71 | } 72 | } 73 | } 74 | -------------------------------------------------------------------------------- /app/src/main/java/com/example/inventory/ItemListFragment.kt: -------------------------------------------------------------------------------- 1 | /* 2 | * Copyright (C) 2021 The Android Open Source Project. 3 | * 4 | * Licensed under the Apache License, Version 2.0 (the "License"); 5 | * you may not use this file except in compliance with the License. 6 | * You may obtain a copy of the License at 7 | * 8 | * http://www.apache.org/licenses/LICENSE-2.0 9 | * 10 | * Unless required by applicable law or agreed to in writing, software 11 | * distributed under the License is distributed on an "AS IS" BASIS, 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 | * See the License for the specific language governing permissions and 14 | * limitations under the License. 15 | */ 16 | 17 | package com.example.inventory 18 | 19 | import android.os.Bundle 20 | import android.view.LayoutInflater 21 | import android.view.View 22 | import android.view.ViewGroup 23 | import androidx.fragment.app.Fragment 24 | import androidx.fragment.app.activityViewModels 25 | import androidx.navigation.fragment.findNavController 26 | import androidx.recyclerview.widget.LinearLayoutManager 27 | import com.example.inventory.databinding.ItemListFragmentBinding 28 | 29 | /** 30 | * Main fragment displaying details for all items in the database. 31 | */ 32 | class ItemListFragment : Fragment() { 33 | private val viewModel: InventoryViewModel by activityViewModels { 34 | InventoryViewModelFactory( 35 | (activity?.application as InventoryApplication).database.itemDao() 36 | ) 37 | } 38 | 39 | private var _binding: ItemListFragmentBinding? = null 40 | private val binding get() = _binding!! 41 | 42 | override fun onCreateView( 43 | inflater: LayoutInflater, 44 | container: ViewGroup?, 45 | savedInstanceState: Bundle? 46 | ): View? { 47 | _binding = ItemListFragmentBinding.inflate(inflater, container, false) 48 | return binding.root 49 | } 50 | 51 | override fun onViewCreated(view: View, savedInstanceState: Bundle?) { 52 | super.onViewCreated(view, savedInstanceState) 53 | 54 | val adapter = ItemListAdapter { 55 | val action = 56 | ItemListFragmentDirections.actionItemListFragmentToItemDetailFragment(it.id) 57 | this.findNavController().navigate(action) 58 | } 59 | binding.recyclerView.layoutManager = LinearLayoutManager(this.context) 60 | binding.recyclerView.adapter = adapter 61 | // Attach an observer on the allItems list to update the UI automatically when the data 62 | // changes. 63 | viewModel.allItems.observe(this.viewLifecycleOwner) { items -> 64 | items.let { 65 | adapter.submitList(it) 66 | } 67 | } 68 | 69 | binding.floatingActionButton.setOnClickListener { 70 | val action = ItemListFragmentDirections.actionItemListFragmentToAddItemFragment( 71 | getString(R.string.add_fragment_title) 72 | ) 73 | this.findNavController().navigate(action) 74 | } 75 | } 76 | } 77 | -------------------------------------------------------------------------------- /app/src/main/java/com/example/inventory/MainActivity.kt: -------------------------------------------------------------------------------- 1 | /* 2 | * Copyright (C) 2021 The Android Open Source Project. 3 | * 4 | * Licensed under the Apache License, Version 2.0 (the "License"); 5 | * you may not use this file except in compliance with the License. 6 | * You may obtain a copy of the License at 7 | * 8 | * http://www.apache.org/licenses/LICENSE-2.0 9 | * 10 | * Unless required by applicable law or agreed to in writing, software 11 | * distributed under the License is distributed on an "AS IS" BASIS, 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 | * See the License for the specific language governing permissions and 14 | * limitations under the License. 15 | */ 16 | package com.example.inventory 17 | 18 | import android.os.Bundle 19 | import androidx.appcompat.app.AppCompatActivity 20 | import androidx.navigation.NavController 21 | import androidx.navigation.fragment.NavHostFragment 22 | import androidx.navigation.ui.NavigationUI.setupActionBarWithNavController 23 | 24 | class MainActivity : AppCompatActivity(R.layout.activity_main) { 25 | 26 | private lateinit var navController: NavController 27 | 28 | override fun onCreate(savedInstanceState: Bundle?) { 29 | super.onCreate(savedInstanceState) 30 | 31 | // Retrieve NavController from the NavHostFragment 32 | val navHostFragment = supportFragmentManager 33 | .findFragmentById(R.id.nav_host_fragment) as NavHostFragment 34 | navController = navHostFragment.navController 35 | // Set up the action bar for use with the NavController 36 | setupActionBarWithNavController(this, navController) 37 | } 38 | 39 | /** 40 | * Handle navigation when the user chooses Up from the action bar. 41 | */ 42 | override fun onSupportNavigateUp(): Boolean { 43 | return navController.navigateUp() || super.onSupportNavigateUp() 44 | } 45 | } 46 | -------------------------------------------------------------------------------- /app/src/main/java/com/example/inventory/data/Item.kt: -------------------------------------------------------------------------------- 1 | /* 2 | * Copyright (C) 2021 The Android Open Source Project. 3 | * 4 | * Licensed under the Apache License, Version 2.0 (the "License"); 5 | * you may not use this file except in compliance with the License. 6 | * You may obtain a copy of the License at 7 | * 8 | * http://www.apache.org/licenses/LICENSE-2.0 9 | * 10 | * Unless required by applicable law or agreed to in writing, software 11 | * distributed under the License is distributed on an "AS IS" BASIS, 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 | * See the License for the specific language governing permissions and 14 | * limitations under the License. 15 | */ 16 | package com.example.inventory.data 17 | 18 | import androidx.room.ColumnInfo 19 | import androidx.room.Entity 20 | import androidx.room.PrimaryKey 21 | import java.text.NumberFormat 22 | 23 | /** 24 | * Entity data class represents a single row in the database. 25 | */ 26 | @Entity 27 | data class Item( 28 | @PrimaryKey(autoGenerate = true) 29 | val id: Int = 0, 30 | @ColumnInfo(name = "name") 31 | val itemName: String, 32 | @ColumnInfo(name = "price") 33 | val itemPrice: Double, 34 | @ColumnInfo(name = "quantity") 35 | val quantityInStock: Int, 36 | ) 37 | /** 38 | * Returns the passed in price in currency format. 39 | */ 40 | fun Item.getFormattedPrice(): String = 41 | NumberFormat.getCurrencyInstance().format(itemPrice) -------------------------------------------------------------------------------- /app/src/main/java/com/example/inventory/data/ItemDao.kt: -------------------------------------------------------------------------------- 1 | /* 2 | * Copyright (C) 2021 The Android Open Source Project. 3 | * 4 | * Licensed under the Apache License, Version 2.0 (the "License"); 5 | * you may not use this file except in compliance with the License. 6 | * You may obtain a copy of the License at 7 | * 8 | * http://www.apache.org/licenses/LICENSE-2.0 9 | * 10 | * Unless required by applicable law or agreed to in writing, software 11 | * distributed under the License is distributed on an "AS IS" BASIS, 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 | * See the License for the specific language governing permissions and 14 | * limitations under the License. 15 | */ 16 | package com.example.inventory.data 17 | 18 | import androidx.room.Dao 19 | import androidx.room.Delete 20 | import androidx.room.Insert 21 | import androidx.room.OnConflictStrategy 22 | import androidx.room.Query 23 | import androidx.room.Update 24 | import kotlinx.coroutines.flow.Flow 25 | 26 | /** 27 | * Database access object to access the Inventory database 28 | */ 29 | @Dao 30 | interface ItemDao { 31 | 32 | @Query("SELECT * from item ORDER BY name ASC") 33 | fun getItems(): Flow> 34 | 35 | @Query("SELECT * from item WHERE id = :id") 36 | fun getItem(id: Int): Flow 37 | 38 | // Specify the conflict strategy as IGNORE, when the user tries to add an 39 | // existing Item into the database Room ignores the conflict. 40 | @Insert(onConflict = OnConflictStrategy.IGNORE) 41 | suspend fun insert(item: Item) 42 | 43 | @Update 44 | suspend fun update(item: Item) 45 | 46 | @Delete 47 | suspend fun delete(item: Item) 48 | } 49 | -------------------------------------------------------------------------------- /app/src/main/java/com/example/inventory/data/ItemRoomDatabase.kt: -------------------------------------------------------------------------------- 1 | /* 2 | * Copyright (C) 2021 The Android Open Source Project. 3 | * 4 | * Licensed under the Apache License, Version 2.0 (the "License"); 5 | * you may not use this file except in compliance with the License. 6 | * You may obtain a copy of the License at 7 | * 8 | * http://www.apache.org/licenses/LICENSE-2.0 9 | * 10 | * Unless required by applicable law or agreed to in writing, software 11 | * distributed under the License is distributed on an "AS IS" BASIS, 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 | * See the License for the specific language governing permissions and 14 | * limitations under the License. 15 | */ 16 | 17 | package com.example.inventory.data 18 | 19 | import android.content.Context 20 | import androidx.room.Database 21 | import androidx.room.Room 22 | import androidx.room.RoomDatabase 23 | 24 | /** 25 | * Database class with a singleton INSTANCE object. 26 | */ 27 | @Database(entities = [Item::class], version = 1, exportSchema = false) 28 | abstract class ItemRoomDatabase : RoomDatabase() { 29 | 30 | abstract fun itemDao(): ItemDao 31 | 32 | companion object { 33 | @Volatile 34 | private var INSTANCE: ItemRoomDatabase? = null 35 | 36 | fun getDatabase(context: Context): ItemRoomDatabase { 37 | // if the INSTANCE is not null, then return it, 38 | // if it is, then create the database 39 | return INSTANCE ?: synchronized(this) { 40 | val instance = Room.databaseBuilder( 41 | context.applicationContext, 42 | ItemRoomDatabase::class.java, 43 | "item_database" 44 | ) 45 | // Wipes and rebuilds instead of migrating if no Migration object. 46 | // Migration is not part of this codelab. 47 | .fallbackToDestructiveMigration() 48 | .build() 49 | INSTANCE = instance 50 | // return instance 51 | instance 52 | } 53 | } 54 | } 55 | } -------------------------------------------------------------------------------- /app/src/main/res/drawable/ic_edit.xml: -------------------------------------------------------------------------------- 1 | 16 | 17 | 23 | 26 | 27 | -------------------------------------------------------------------------------- /app/src/main/res/drawable/ic_launcher_background.xml: -------------------------------------------------------------------------------- 1 | 6 | 9 | 10 | -------------------------------------------------------------------------------- /app/src/main/res/drawable/ic_launcher_foreground.xml: -------------------------------------------------------------------------------- 1 | 6 | 10 | 13 | 16 | 19 | 22 | 25 | 28 | 31 | 37 | 40 | 46 | 49 | 55 | 56 | 57 | -------------------------------------------------------------------------------- /app/src/main/res/layout/activity_main.xml: -------------------------------------------------------------------------------- 1 | 16 | 23 | 24 | 35 | 36 | -------------------------------------------------------------------------------- /app/src/main/res/layout/fragment_add_item.xml: -------------------------------------------------------------------------------- 1 | 16 | 17 | 21 | 22 | 26 | 27 | 36 | 37 | 43 | 44 | 45 | 55 | 56 | 62 | 63 | 64 | 74 | 75 | 81 | 82 | 83 |