[악어] 장바구니 미션 제출합니다.

.editor.config

@@ -0,0 +1,2 @@
+[*.{kt,kts}]
+ktlint_function_naming_ignore_when_annotated_with=Composable, Test

README.md

@@ -1 +1,41 @@
-# android-shopping-cart
+# android-shopping-cart
+
+## Step1
+### 기능 요구 사항
+- [x] 상품 목록 화면을 구현한다.
+
+### 프로그래밍 요구 사항
+- ViewModel, Hilt 등은 장바구니 미션에서 활용하지 않는다. 컴포즈 학습에 집중하자.
+- 상품 목록 화면을 구현할 때 Lazy 컴포넌트를 활용한다.
+- 컴포저블 함수가 너무 많은 일을 하지 않도록 분리하기 위해 노력해 본다.
+- 의미있는 단위의 함수를 모아 별도의 파일로 분리해본다.
+
+
+## Step 2
+### 기능 요구 사항
+- [x] 상품 상세 화면을 구현한다.
+- [x] 상품 목록에서 상품을 누르면 상품 상세 화면으로 이동한다.
+- [x] 뒤로 가기 버튼이나 아이콘을 누르면 직전 화면으로 돌아간다.
+- [x] 장바구니 화면의 빈 껍데기를 연결한다.
+- [x] 상품 목록에서 장바구니 아이콘을 누르면 장바구니 화면으로 이동한다.
+- [x] 상품 상세에서 장바구니 담기 버튼을 누르면 장바구니 화면으로 이동한다.
+- [x] 뒤로 가기 버튼이나 아이콘을 누르면 직전 화면으로 돌아간다.
+- [x] 장바구니에 실제로 상품이 담기는 기능은 이 단계에서 고려하지 않는다.
+
+### 프로그래밍 요구 사항
+- 장바구니에 실제로 상품이 담기는 기능은 이 단계에서 고려하지 않는다.
+- 컴포저블 함수가 너무 많은 일을 하지 않도록 분리하기 위해 노력해 본다.
+- 의미있는 단위의 함수를 모아 별도의 파일로 분리해본다.
+
+
+## Step3
+### 기능 요구 사항
+- [x] 상품을 장바구니에 담는 기능을 구현한다.
+- [x] 장바구니 화면을 구현한다.
+  - [x] 담긴 상품의 수량을 조절할 수 있어야 한다. 
+  - [x] 수량을 1보다 작게 하면 장바구니에서 상품이 제거된다
+  - [x] 담긴 상품 가격의 총합이 주문하기 버튼에 표시된다. 
+
+### 프로그래밍 요구 사항
+- 상품을 주문하는 기능에 대해서는 구현하지 않아도 된다.
+- ~~장바구니 화면에 대한 테스트 코드를 작성한다.~~ 😅

app/build.gradle.kts

@@ -1,6 +1,7 @@
 plugins {
     alias(libs.plugins.android.application)
     alias(libs.plugins.jetbrains.kotlin.android)
+    alias(libs.plugins.ktlint)
 }
 
 android {
@@ -66,4 +67,8 @@ dependencies {
     androidTestImplementation(libs.androidx.ui.test.junit4)
     debugImplementation(libs.androidx.ui.tooling)
     debugImplementation(libs.androidx.ui.test.manifest)
+
+    // coil
+    implementation(libs.coil)
+    implementation(libs.coil.compose)
 }

app/src/main/AndroidManifest.xml

@@ -2,6 +2,8 @@
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:tools="http://schemas.android.com/tools">
 
+    <uses-permission android:name="android.permission.INTERNET" />
+
     <application
         android:allowBackup="true"
         android:dataExtractionRules="@xml/data_extraction_rules"
@@ -13,7 +15,17 @@
         android:theme="@style/Theme.ShoppingCart"
         tools:targetApi="31">
         <activity
-            android:name=".MainActivity"
+            android:name="nextstep.shoppingcart.presentation.CartActivity"
+            android:exported="false"
+            android:label="@string/title_activity_cart"
+            android:theme="@style/Theme.ShoppingCart" />
+        <activity
+            android:name="nextstep.shoppingcart.presentation.DetailActivity"
+            android:exported="false"
+            android:label="@string/title_activity_detail"
+            android:theme="@style/Theme.ShoppingCart" />
+        <activity
+            android:name="nextstep.shoppingcart.presentation.HomeActivity"
             android:exported="true"
             android:label="@string/app_name"
             android:theme="@style/Theme.ShoppingCart">

app/src/main/java/nextstep/shoppingcart/data/CachedProductDataSource.kt

@@ -0,0 +1,67 @@
+package nextstep.shoppingcart.data
+
+import nextstep.shoppingcart.domain.model.Product
+
+class CachedProductDataSource : ProductDataSource {
+    private val products: MutableList<Product> =
+        mutableListOf<Product>(
+            Product(
+                id = 1,
+                name = "PET보틀-정사각형 용기 (1L)",
+                price = 10_000,
+                imageUrl = "https://s3-alpha-sig.figma.com/img/05ef/e578/d81445480aff1872344a6b1b35323488?Expires=1731888000&Key-Pair-Id=APKAQ4GOSFWCVNEHN3O4&Signature=KNMX7pZxzQz578ovhuWIBF2ilsQACu~sph~2fwFZyhO3pX9vhCd-kXHJmW5lpogb2IhP6bvH1N8qCKX~jHluc-tDSLD4EbUsGI9yJqanYsdOSRY6KKPyrh1SekXEH8u4-A77xal1TEj99wTnMMGKGXlI4UJhQJhg6hhBRL3ONv5Y1N5~2yMw4M54bGJi4HQYh3eG5rcPrK96KWonhd7BtZDwo4MMwK1TQ0FjuIBMdoabOACAwRwzE-EJ8znP71oTiOsZES6wASv21meilUhN~A8C72-qqNhyybuDTNqZQfQIHWT7kh-Lm0McKRQUg7~OSs3nWVJR7O-USQCwHhhclQ__"
+            ),
+            Product(
+                id = 2,
+                name = "PET보틀-밀크티 용기",
+                price = 12_000,
+                imageUrl = "https://s3-alpha-sig.figma.com/img/f081/71c9/4a1459fb4310f704c34be19a15f662a4?Expires=1731888000&Key-Pair-Id=APKAQ4GOSFWCVNEHN3O4&Signature=ZKYEUR3xhp1aA4aULlmTfL1WE3xPvkK14FKZ6ih6JJyFdt54d3srSsB3OG2qUffmjzxsN-SgL4vtdmJgAyVeUh4JZlgBrrDOeBnsvqx3E3myqzO3iBZMsqG54zici8-pht8vl22MhbV7rzqNA5WSbSGbVztUhS1J8Rm9u9wDH5RY9vfbf-92vvfkRzakG84NghCmq~8fNusILMtEMlUBM~aY02owPo7MIsDLmwHBhGSThU5mnNCawKmmZc1ESwvjzeYhgY6HY~U9v24M1nlKL6KFA4wu8KuIfDv9G1-pve6P3i4DZKbgir19Q46pHGp0VErbA2yNhpWwu4MvYKJ~5w__"
+            ),
+            Product(
+                id = 3,
+                name = "PET보틀-정사각형 용기 (500ml)",
+                price = 10_000,
+                imageUrl = "https://s3-alpha-sig.figma.com/img/ff9f/d83e/b40e670bfc38dbcddbcec8b3ca363d50?Expires=1731888000&Key-Pair-Id=APKAQ4GOSFWCVNEHN3O4&Signature=DzhgzJzS4g6I3SO2RtuhKgWdng1dPjM2aPUASlWNq8VvjOZMd9tfYaruZLALMCKtx~cmq~Q6~hWr1vAnbHBZsRW~8EIwneiuNLE-fxFuTjFBV24G2u8LpY5n91oMgGYzNqxtuTVVqE28~GUhDHsxQt5BL5tUukHeER0-mUg4wUP-4uWA-zN9m864LZwYpTLxzcNCOAuvgFAR2HHsGMJCDyC~Fzd7lSLVuFQVwxF7kolB9ErqqVUA2SO0wjfCoHoWJUwuTlSr9jSGW4-h4lJafTpGvYJCS4foasIYy3ODeeOgBOCgnXkHdrJivZlkR0gNPCOOx2x~KDWV547AsrO5YA__"
+            ),
+            Product(
+                id = 4,
+                name = "PET보틀-납작 용기 (500ml)",
+                price = 12_000,
+                imageUrl = "https://s3-alpha-sig.figma.com/img/b8b6/a740/d8661b91e8210779ce9db930d260230d?Expires=1731888000&Key-Pair-Id=APKAQ4GOSFWCVNEHN3O4&Signature=lYXFy7NZnn2Pe7vn29qkin2d9HPRXteVaHuLXIH2pxjspZP1GMyr8d9It1WcYND8apF~LTd13z-ckQ9WrZO-ExycyxF6H1oVSOQmDQfxAgzpGDfmJlNiEh7BoFllbnQVPsHwfFYaGxSFr93zYkzNKfwQGUTltozO8fElpK0dQePtyIzuZpmyHegnizh~hqdlx9YlyJdfeuV-AlAtyKZjSFDcphz3RJ5YujI0xzf5XEGoYGBN5piSwr-41UWXY664LcmUVRZF9Ge8hZdyV1vu2Coty54x7ns5FbTu3GUhcZ3bSrTYaQcDzlvggtYXel~SPoV20d8xPwXMFRCbSuUxhw__"
+            ),
+            Product(
+                id = 5,
+                name = "PET보틀-원형 용기 (500ml)",
+                price = 10_000,
+                imageUrl = "https://s3-alpha-sig.figma.com/img/8f83/c0e8/c17365cdfe5a00fa17c0283d520f4a99?Expires=1731888000&Key-Pair-Id=APKAQ4GOSFWCVNEHN3O4&Signature=Pt91VGcwcypqZ0ZiBhcXNVlgJ7x7yrNsh0ucdfSZ1Ct12CR0eTe7G4a4doBtthWGWIL-Tmj4VYvqbMNMT3McEbGmgR~jvfIYhAO1rQaSO6Ry69kSV1K3qpaqNyW7WkfoKi2-qj4w9665rOYY~ss-H3Le7YAkpnbEKbZUBfGFodaHSEwRplcT5V~ECB65DGoevOqMg4ArLdtJSDNpOdbb166Q8LSzcmZ0sOksimWDBLKegKjWtwi30Fe6WBJzmLD5i7TBXpxKgOOlL92M0zT~kgLIAIEM2C4g8qvJWqE74d4NX~y2c-AsU7pcLQqrHOU7oElPyPXhlnZkxvPd86cyIw__"
+            ),
+            Product(
+                id = 6,
+                name = "PET보틀-납작 용기 (200mL)",
+                price = 12_000,
+                imageUrl = "https://s3-alpha-sig.figma.com/img/b9f2/403d/b915b1b22edac0877abb7b97129296b6?Expires=1731888000&Key-Pair-Id=APKAQ4GOSFWCVNEHN3O4&Signature=YUOtsuzD0QhxPGoaGPNVb3IfJu015CI0LkvUaywB3qcTHOmBclM6YsRCba5lGrMq3PY5MbG7U4VPbbhq8z5RBcGyxIb9M31qTYIEYTstE1-C2zq0IR3YXwMqaV5t9A7hjClBnoZl~jT2DTH4k5YxrIRy2D~qqR57C-4TF-Doo3Xhs~jNvRCyYYZBvFqg0PerspsQHnruNK9sJCVvWB4dC9DN290uU7jmbOrO6ku0SCtFp7BSCAP2l4FwW3LcIGAJpPRZSAqZu-z-n8QnEFJnWWDBqGynQqQQq9jQqxEW15gOna8a3X0nTM4RrTR6gZX2aKWMhOtRcciMoLwaiar5bw__"
+            ),
+            Product(
+                id = 7,
+                name = "name1",
+                price = 1000,
+                imageUrl = "https://thumbnail7.coupangcdn.com/thumbnails/remote/292x292ex/image/retail/images/1263603036762773-f6291401-9c64-4944-8189-86e5aead6049.png"
+            ),
+            Product(
+                id = 8,
+                name = "name2",
+                price = 2000,
+                imageUrl = "https://thumbnail7.coupangcdn.com/thumbnails/remote/292x292ex/image/vendor_inventory/e294/d78edd81a8f38ae32984e9ad3393a840bd9ccdc91161838a8036f4d90434.jpg"
+            ),
+            Product(
+                id = 9,
+                name = "name3",
+                price = 3000,
+                imageUrl = "https://thumbnail7.coupangcdn.com/thumbnails/remote/292x292ex/image/1025_amir_coupang_oct_80k/e308/9c53df34079cb2e6a8123f93355a796ae18b7979bc61bd360da0793314af.jpg"
+            )
+        )
+
+    override fun fetchProducts(): List<Product> = products.toList()
+
+    override fun findProduct(id: Long): Product = products.firstOrNull { it.id == id } ?: Product.NULL_PRODUCT
+}

app/src/main/java/nextstep/shoppingcart/data/Cart.kt

@@ -0,0 +1,46 @@
+package nextstep.shoppingcart.data
+
+import androidx.compose.runtime.mutableIntStateOf
+import androidx.compose.runtime.snapshots.SnapshotStateList
+import androidx.compose.runtime.toMutableStateList
+import nextstep.shoppingcart.domain.model.CartItem
+import nextstep.shoppingcart.domain.model.Product
+
+object Cart {
+    val items: SnapshotStateList<CartItem> = emptyList<CartItem>().toMutableStateList()
+
+    val totalPrice = mutableIntStateOf(0)
+
+    fun addOne(product: Product) {
+        val item = items.find { it.product == product }
+        if (item != null) {
+            val index = items.indexOf(item)
+            items[index] = item.copy(count = item.count + 1)
+        } else {
+            items.add(CartItem(product = product, count = 1))
+        }
+        updateState()
+    }
+
+    fun removeOne(product: Product) {
+        val item = items.find { it.product == product }
+        if (item != null) {
+            if (item.count > 1) {
+                val index = items.indexOf(item)
+                items[index] = item.copy(count = item.count - 1)
+            } else {
+                items.remove(item)
+            }
+            updateState()
+        }
+    }
+
+    fun removeAll(product: Product) {
+        items.removeAll { it.product == product }
+        updateState()
+    }
+
+    private fun updateState() {
+        totalPrice.value = items.sumOf { it.product.price * it.count }
+    }
+}

app/src/main/java/nextstep/shoppingcart/data/DefaultProductRepository.kt

@@ -0,0 +1,11 @@
+package nextstep.shoppingcart.data
+
+import nextstep.shoppingcart.domain.model.Product
+
+class DefaultProductRepository(
+    private val productDataSource: ProductDataSource
+) : ProductRepository {
+    override fun fetchProducts(): List<Product> = productDataSource.fetchProducts()
+
+    override fun findProduct(id: Long): Product = productDataSource.findProduct(id)
+}

app/src/main/java/nextstep/shoppingcart/data/ProductDataSource.kt

@@ -0,0 +1,8 @@
+package nextstep.shoppingcart.data
+
+import nextstep.shoppingcart.domain.model.Product
+
+interface ProductDataSource {
+    fun fetchProducts(): List<Product>
+    fun findProduct(id: Long): Product
+}

app/src/main/java/nextstep/shoppingcart/data/ProductRepository.kt

@@ -0,0 +1,8 @@
+package nextstep.shoppingcart.data
+
+import nextstep.shoppingcart.domain.model.Product
+
+interface ProductRepository {
+    fun fetchProducts(): List<Product>
+    fun findProduct(id: Long): Product
+}

app/src/main/java/nextstep/shoppingcart/domain/model/CartItem.kt

@@ -0,0 +1,11 @@
+package nextstep.shoppingcart.domain.model
+
+data class CartItem(
+    val id: Long = maxCartItemId++,
+    val product: Product,
+    val count: Int
+) {
+    companion object {
+        private var maxCartItemId: Long = 0L
+    }
+}

app/src/main/java/nextstep/shoppingcart/domain/model/Price.kt

@@ -0,0 +1,12 @@
+package nextstep.shoppingcart.domain.model
+
+import java.text.DecimalFormat
+
+data class Price(
+    private val amount: Int
+) {
+    fun format(): String {
+        val decimal = DecimalFormat("#,###")
+        return decimal.format(amount) + "원"
+    }
+}

app/src/main/java/nextstep/shoppingcart/domain/model/Product.kt

@@ -0,0 +1,13 @@
+package nextstep.shoppingcart.domain.model
+
+data class Product(
+    val id: Long,
+    val name: String,
+    val price: Int,
+    val imageUrl: String,
+    val isAddedToCart: Boolean = false
+) {
+    companion object {
+        val NULL_PRODUCT = Product(-1, "Null Product", -1000000, "", false)
+    }
+}

app/src/main/java/nextstep/shoppingcart/presentation/CartActivity.kt

@@ -0,0 +1,40 @@
+package nextstep.shoppingcart.presentation
+
+import android.content.Context
+import android.content.Intent
+import android.os.Bundle
+import androidx.activity.ComponentActivity
+import androidx.activity.compose.setContent
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.remember
+import nextstep.shoppingcart.data.Cart
+import nextstep.shoppingcart.domain.model.Product
+import nextstep.shoppingcart.presentation.components.screens.CartScreen
+
+class CartActivity : ComponentActivity() {
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+        setContent {
+            val cartItems = remember { Cart.items }
+            val totalPrice by Cart.totalPrice
+            CartScreen(
+                navigation = { finish() },
+                cartItems = cartItems,
+                totalPrice = totalPrice,
+                onIncrease = { addItem(it.product) },
+                onDecrease = { subItem(it.product) },
+                onClear = { removeItem(it.product) }
+            )
+        }
+    }
+
+    private fun addItem(item: Product) = Cart.addOne(item)
+
+    private fun subItem(item: Product) = Cart.removeOne(item)
+
+    private fun removeItem(item: Product) = Cart.removeAll(item)
+
+    companion object {
+        fun createIntent(context: Context): Intent = Intent(context, CartActivity::class.java)
+    }
+}