Пагинация, стагнация, ампутация, цивилизация, синхронизация, фракция, грация, конкатанация, нация, рация, сублимация, аннотация, субстанция

app/build.gradle

@@ -83,4 +83,8 @@ dependencies {
     implementation("androidx.hilt:hilt-navigation-compose:1.0.0")
     implementation 'androidx.compose.runtime:runtime-livedata:1.0.0-beta01'
     implementation "androidx.datastore:datastore-preferences:1.0.0"
+
+
+    implementation("androidx.room:room-paging:2.5.0")
+    implementation("androidx.paging:paging-compose:3.2.1")
 }

app/src/main/java/com/example/shawarma/data/interfaces/dao/OrderDao.kt

@@ -24,6 +24,6 @@ interface OrderDao {
     fun getByUserId(userId: Int): Flow<List<OrderWithProducts>>
     @Query("select * from orders where orders.user_id =:userId and orders.order_status = 'Неоплачено'")
     fun getUnpaidByUser(userId: Int) : Flow<OrderWithProducts>
-    @Query("select * from orders where orders.user_id =:userId and orders.order_status = 'Готовится'")
+    @Query("select * from orders where orders.user_id =:userId and (orders.order_status = 'Готовится' or orders.order_status = 'Готово')")
     fun getPaidByUser(userId: Int) : Flow<List<OrderWithProducts>>
 }

app/src/main/java/com/example/shawarma/data/interfaces/dao/ProductDao.kt

@@ -1,5 +1,6 @@
 package com.example.shawarma.data.interfaces.dao
 
+import androidx.paging.PagingSource
 import androidx.room.Dao
 import androidx.room.Delete
 import androidx.room.Insert
@@ -30,4 +31,12 @@ interface ProductDao {
     @Query("select * from products where products.id = :id")
     fun getById(id: Int): Flow<ProductModel>
 
+    @Query("select * from products where products.product_old_price is null")
+    fun getPaged(): PagingSource<Int, ProductModel>
+
+    @Query("select * from products where products.product_old_price is not null")
+    fun getPagedDiscounts(): PagingSource<Int, ProductModel>
+
+    @Query("select * from products")
+    fun getPagedItems(): PagingSource<Int, ProductModel>
 }

app/src/main/java/com/example/shawarma/data/models/OrderProductModelWithProduct.kt

@@ -7,5 +7,6 @@ data class OrderProductModelWithProduct(
     @Embedded
     val orderProductModel: OrderProductModel,
     @Relation(entity = ProductModel::class, parentColumn = "product_id", entityColumn = "id")
-    val product: ProductModel
+    val product: ProductModel,
+
 )

app/src/main/java/com/example/shawarma/data/repos/ProductRepository.kt

@@ -1,5 +1,8 @@
 package com.example.shawarma.data.repos
 
+import androidx.paging.Pager
+import androidx.paging.PagingConfig
+import androidx.paging.PagingData
 import com.example.shawarma.data.interfaces.dao.OrderProductDao
 import com.example.shawarma.data.interfaces.dao.ProductDao
 import com.example.shawarma.data.models.ProductModel
@@ -20,7 +23,7 @@ class ProductRepository @Inject constructor(
         orderProductDao.deleteByProductId(product.id!!)
         return productDao.delete(product)
     }
-    fun getAll(): Flow<List<ProductModel>> {
+    /*fun getAll(): Flow<List<ProductModel>> {
         return productDao.getAll()
     }
     fun getDiscounts(): Flow<List<ProductModel>> {
@@ -28,8 +31,32 @@ class ProductRepository @Inject constructor(
     }
     fun getItems(): Flow<List<ProductModel>> {
         return productDao.getItems()
-    }
+    }*/
     fun getById(id: Int): Flow<ProductModel> {
         return productDao.getById(id)
     }
+    fun getAllProductsPaged(): Flow<PagingData<ProductModel>> = Pager(
+        config = PagingConfig(
+            pageSize = 6,
+            enablePlaceholders = false
+        ),
+        pagingSourceFactory = productDao::getPaged
+    ).flow
+
+    fun getAllDiscountsPaged(): Flow<PagingData<ProductModel>> = Pager(
+        config = PagingConfig(
+            pageSize = 6,
+            enablePlaceholders = false
+        ),
+        pagingSourceFactory = productDao::getPagedDiscounts
+    ).flow
+
+    fun getAllItemsPaged(): Flow<PagingData<ProductModel>> = Pager(
+        config = PagingConfig(
+            pageSize = 6,
+            enablePlaceholders = false
+        ),
+        pagingSourceFactory = productDao::getPagedItems
+    ).flow
+
 }

app/src/main/java/com/example/shawarma/screens/cart/CartScreen.kt

@@ -199,7 +199,7 @@ fun PaidItem(order : OrderWithProducts) {
                             fontWeight = FontWeight.Bold
                         )
                         Text(
-                            text = order.orderWithProducts[index].orderProductModel.totalPrice.toString() + " руб.",
+                            text = (order.orderWithProducts[index].orderProductModel.quantity * order.orderWithProducts[index].product.price).toString() + " руб.",
                             fontFamily = NunitoFamily,
                             fontSize = 20.sp,
                             modifier = Modifier.padding(top = 15.dp),
@@ -250,7 +250,7 @@ fun CartItem(order : OrderWithProducts) {
                                 fontWeight = FontWeight.Bold
                             )
                             Text(
-                                text = order.orderWithProducts[index].orderProductModel.totalPrice.toString() + " руб.",
+                                text = (order.orderWithProducts[index].orderProductModel.quantity * order.orderWithProducts[index].product.price).toString() + " руб.",
                                 fontFamily = NunitoFamily,
                                 fontSize = 18.sp,
                                 fontWeight = FontWeight.Bold

app/src/main/java/com/example/shawarma/screens/discount/DiscountScreen.kt

@@ -20,7 +20,6 @@ import androidx.compose.material.ButtonDefaults
 import androidx.compose.material.Card
 import androidx.compose.material.Text
 import androidx.compose.runtime.Composable
-import androidx.compose.runtime.livedata.observeAsState
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.draw.clip
@@ -33,6 +32,7 @@ import androidx.compose.ui.unit.dp
 import androidx.compose.ui.unit.sp
 import androidx.compose.ui.zIndex
 import androidx.hilt.navigation.compose.hiltViewModel
+import androidx.paging.compose.collectAsLazyPagingItems
 import com.example.shawarma.R
 import com.example.shawarma.data.models.ProductModel
 import com.example.shawarma.data.sharedpref.PreferencesManager
@@ -60,7 +60,7 @@ fun DiscountScreen() {
 fun DiscountList(){
     val homeViewModel: HomeViewModel = hiltViewModel<HomeViewModel>()
 
-    val products = homeViewModel.discounts.observeAsState().value
+    val productsListUiState = homeViewModel.discountListUiState.collectAsLazyPagingItems()
 
     Box(
         modifier = Modifier
@@ -83,16 +83,15 @@ fun DiscountList(){
             modifier = Modifier.padding(top = 80.dp)
         )
         {
-            if (products != null) {
+            items(productsListUiState.itemCount) { index ->
-                items(products.size) { index ->
+                if (index % 2 == 0 && index == productsListUiState.itemCount - 1) {
-                    if (index % 2 == 0 && index == products.size - 1) {
                     Row(
                         horizontalArrangement = Arrangement.SpaceAround,
                         modifier = Modifier
                             .fillMaxWidth()
                             .padding(top = 10.dp)
                     ) {
-                            DiscountCard(products[index])
+                        DiscountCard(productsListUiState[index]!!)
                     }
                 } else {
                     if (index % 2 != 1) {
@@ -102,19 +101,18 @@ fun DiscountList(){
                                 .fillMaxWidth()
                                 .padding(top = 10.dp)
                         ) {
-                                DiscountCard(products[index])
+                            DiscountCard(productsListUiState[index]!!)
-                                DiscountCard(products[index+1])
+                            DiscountCard(productsListUiState[index+1]!!)
                         }
                     }
                 }
-                    if (index == products.size - 1) {
+                if (index == productsListUiState.itemCount - 1) {
                     Spacer(modifier = Modifier.height(70.dp))
                 }
             }
         }
     }
 }
-}
 
 @Composable
 fun DiscountCard(product : ProductModel){

app/src/main/java/com/example/shawarma/screens/home/HomeScreen.kt

@@ -20,7 +20,6 @@ import androidx.compose.material.ButtonDefaults
 import androidx.compose.material.Card
 import androidx.compose.material.Text
 import androidx.compose.runtime.Composable
-import androidx.compose.runtime.livedata.observeAsState
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.draw.clip
@@ -32,6 +31,8 @@ import androidx.compose.ui.unit.dp
 import androidx.compose.ui.unit.sp
 import androidx.compose.ui.zIndex
 import androidx.hilt.navigation.compose.hiltViewModel
+import androidx.paging.compose.collectAsLazyPagingItems
+import androidx.paging.compose.itemKey
 import com.example.shawarma.R
 import com.example.shawarma.data.models.ProductModel
 import com.example.shawarma.data.sharedpref.PreferencesManager
@@ -58,7 +59,7 @@ fun HomeScreen() {
 fun HomeList(){
     val homeViewModel: HomeViewModel = hiltViewModel<HomeViewModel>()
 
-    val products = homeViewModel.products.observeAsState().value
+    val productsListUiState = homeViewModel.productListUiState.collectAsLazyPagingItems()
 
 
     Box(
@@ -81,16 +82,18 @@ fun HomeList(){
             modifier = Modifier.padding(top = 80.dp)
         )
         {
-            if (products != null) {
+            items(
-                items(products.size) { index ->
+                count = productsListUiState.itemCount,
-                    if (index % 2 == 0 && index == products.size - 1) {
+                key = productsListUiState.itemKey()
+            ) { index ->
+                if (index % 2 == 0 && index == productsListUiState.itemCount - 1) {
                     Row(
                         horizontalArrangement = Arrangement.SpaceAround,
                         modifier = Modifier
                             .fillMaxWidth()
                             .padding(top = 10.dp)
                     ) {
-                            ProductCard(products[index])
+                        ProductCard(productsListUiState[index]!!)
                     }
                 } else {
                     if (index % 2 != 1) {
@@ -100,19 +103,18 @@ fun HomeList(){
                                 .fillMaxWidth()
                                 .padding(top = 10.dp)
                         ) {
-                                ProductCard(products[index])
+                            ProductCard(productsListUiState[index]!!)
-                                ProductCard(products[index + 1])
+                            ProductCard(productsListUiState[index + 1]!!)
                         }
                     }
                 }
-                    if (index == products.size - 1) {
+                if (index == productsListUiState.itemCount - 1) {
                     Spacer(modifier = Modifier.height(70.dp))
                 }
             }
         }
     }
 }
-}
 
 @Composable
 fun ProductCard(product: ProductModel){

app/src/main/java/com/example/shawarma/screens/products/ProductsScreen.kt

@@ -20,7 +20,6 @@ import androidx.compose.material.Card
 import androidx.compose.material.Icon
 import androidx.compose.material.Text
 import androidx.compose.runtime.Composable
-import androidx.compose.runtime.livedata.observeAsState
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.draw.clip
@@ -32,6 +31,8 @@ import androidx.compose.ui.unit.sp
 import androidx.compose.ui.zIndex
 import androidx.hilt.navigation.compose.hiltViewModel
 import androidx.navigation.NavHostController
+import androidx.paging.compose.collectAsLazyPagingItems
+import androidx.paging.compose.itemKey
 import com.example.shawarma.R
 import com.example.shawarma.data.models.ProductModel
 import com.example.shawarma.ui.theme.MarckFamily
@@ -60,7 +61,7 @@ fun ProductsScreen(navHostController: NavHostController) {
 fun ProductsList(navHostController: NavHostController){
     val productsViewModel: ProductsViewModel = hiltViewModel<ProductsViewModel>()
 
-    val products = productsViewModel.products.observeAsState().value
+    val products = productsViewModel.productListUiState.collectAsLazyPagingItems()
 
     Box(
         modifier = Modifier
@@ -103,16 +104,17 @@ fun ProductsList(navHostController: NavHostController){
             modifier = Modifier.padding(top = 160.dp)
         )
         {
-            if (products != null) {
+            items(
-                items(products.size) { index ->
+                products.itemCount,
-                    ProductItem(products[index], navHostController)
+                key = products.itemKey()
+            ) { index ->
+                ProductItem(products[index]!!, navHostController)
                 Spacer(modifier = Modifier.height(20.dp))
-                    if (index == products.size - 1) {
+                if (index == products.itemCount - 1) {
                     Spacer(modifier = Modifier.height(70.dp))
                 }
             }
         }
-        }
 
     }
 }

app/src/main/java/com/example/shawarma/viewmodels/HomeViewModel.kt

@@ -1,9 +1,8 @@
 package com.example.shawarma.viewmodels
 
-import androidx.lifecycle.LiveData
-import androidx.lifecycle.MutableLiveData
 import androidx.lifecycle.ViewModel
 import androidx.lifecycle.viewModelScope
+import androidx.paging.PagingData
 import com.example.shawarma.data.models.OrderModel
 import com.example.shawarma.data.models.OrderProductModel
 import com.example.shawarma.data.models.OrderStatus
@@ -12,6 +11,7 @@ import com.example.shawarma.data.repos.OrderProductRepository
 import com.example.shawarma.data.repos.OrderRepository
 import com.example.shawarma.data.repos.ProductRepository
 import dagger.hilt.android.lifecycle.HiltViewModel
+import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.first
 import kotlinx.coroutines.launch
 import java.util.Date
@@ -23,26 +23,11 @@ class HomeViewModel @Inject constructor(
     private val orderRepository: OrderRepository,
     private val orderProductRepository: OrderProductRepository
 ) : ViewModel() {
-    private val _products =  MutableLiveData<List<ProductModel>>()
-    val products: LiveData<List<ProductModel>>
-        get() = _products
 
-    private val _discounts=  MutableLiveData<List<ProductModel>>()
+    val productListUiState: Flow<PagingData<ProductModel>> = productRepository.getAllProductsPaged()
-    val discounts: LiveData<List<ProductModel>>
+
-        get() = _discounts
+    val discountListUiState: Flow<PagingData<ProductModel>> = productRepository.getAllDiscountsPaged()
 
-    init {
-        viewModelScope.launch {
-            productRepository.getAll().collect {
-                _products.postValue(it)
-            }
-        }
-        viewModelScope.launch {
-            productRepository.getDiscounts().collect {
-                _discounts.postValue(it)
-            }
-        }
-    }
 
     fun addProductToCart(productId: Int, userId: String) {
         if (userId == "null") return

app/src/main/java/com/example/shawarma/viewmodels/ProductsViewModel.kt

@@ -4,9 +4,11 @@ import androidx.lifecycle.LiveData
 import androidx.lifecycle.MutableLiveData
 import androidx.lifecycle.ViewModel
 import androidx.lifecycle.viewModelScope
+import androidx.paging.PagingData
 import com.example.shawarma.data.models.ProductModel
 import com.example.shawarma.data.repos.ProductRepository
 import dagger.hilt.android.lifecycle.HiltViewModel
+import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.launch
 import javax.inject.Inject
 
@@ -18,13 +20,7 @@ class ProductsViewModel  @Inject constructor(
     val products: LiveData<List<ProductModel>>
         get() = _products
 
-    init {
+    val productListUiState: Flow<PagingData<ProductModel>> = productRepository.getAllItemsPaged()
-        viewModelScope.launch {
-            productRepository.getItems().collect {
-                _products.postValue(it)
-            }
-        }
-    }
 
     fun deleteProduct(product: ProductModel) {
         viewModelScope.launch {

app/src/main/java/com/example/shawarma/viewmodels/UserViewModel.kt

@@ -54,11 +54,11 @@ class UserViewModel @Inject constructor(
             _registrationState.postValue(false)
             return
         }
-        if (login.length < 8 || login.length > 20) {
+        if (login.length < 5 || login.length > 20) {
             _registrationState.postValue(false)
             return
         }
-        if (password.length < 8 || password.length > 20) {
+        if (password.length < 5 || password.length > 20) {
             _registrationState.postValue(false)
             return
         }