ДЗ по теме RecyclerView

app/src/main/java/ru/otus/cryptosample/coins/feature/CoinListFragment.kt

@@ -11,12 +11,15 @@ import androidx.lifecycle.Lifecycle
 import androidx.lifecycle.lifecycleScope
 import androidx.lifecycle.repeatOnLifecycle
 import androidx.recyclerview.widget.GridLayoutManager
+import androidx.recyclerview.widget.RecyclerView
 import kotlinx.coroutines.launch
 import ru.otus.cryptosample.CoinsSampleApp
 import ru.otus.cryptosample.coins.feature.adapter.CoinsAdapter
 import ru.otus.cryptosample.coins.feature.di.DaggerCoinListComponent
 import ru.otus.cryptosample.databinding.FragmentCoinListBinding
 import javax.inject.Inject
+import ru.otus.cryptosample.R
+import ru.otus.cryptosample.coins.feature.adapter.CoinItemAnimator
 
 class CoinListFragment : Fragment() {
 
@@ -59,14 +62,15 @@ class CoinListFragment : Fragment() {
     }
 
     private fun setupRecyclerView() {
-        coinsAdapter = CoinsAdapter()
+        coinsAdapter = CoinsAdapter(RecyclerView.RecycledViewPool())
 
         val gridLayoutManager = GridLayoutManager(requireContext(), 2)
         gridLayoutManager.spanSizeLookup = object : GridLayoutManager.SpanSizeLookup() {
             override fun getSpanSize(position: Int): Int {
                 return when (coinsAdapter.getItemViewType(position)) {
-                    0 -> 2 // Category header spans full width
-                    1 -> 1 // Coin item spans half width
+                    R.layout.item_category_header -> 2 // Category header spans full width
+                    R.layout.item_coin -> 1 // Coin item spans half-width
+                    R.layout.item_carousel -> 2 // The horizontal row spans full width
                     else -> 1
                 }
             }
@@ -75,6 +79,15 @@ class CoinListFragment : Fragment() {
         binding.recyclerView.apply {
             layoutManager = gridLayoutManager
             adapter = coinsAdapter
+            itemAnimator = CoinItemAnimator()
+        }
+
+        binding.btnAddCoin.setOnClickListener {
+            viewModel.addRandomCoin()
+        }
+
+        binding.btnRemoveCoins.setOnClickListener {
+            viewModel.removeRandomCoin()
         }
     }
 
@@ -99,7 +112,7 @@ class CoinListFragment : Fragment() {
     }
 
     private fun renderState(state: CoinsScreenState) {
-        coinsAdapter.setData(state.categories)
+        coinsAdapter.setData(state.categories, state.showAll)
     }
 
     override fun onDestroyView() {

app/src/main/java/ru/otus/cryptosample/coins/feature/CoinListViewModel.kt

@@ -38,6 +38,50 @@ class CoinListViewModel(
         updateUiState()
     }
 
+    fun addRandomCoin() {
+        if (fullCategories.isEmpty()) return
+
+        val allCoins = fullCategories.flatMap { it.coins }
+        if (allCoins.isEmpty()) return
+
+        val templateCoin = allCoins.random()
+
+        val newCoinId = "new_${System.currentTimeMillis()}"
+        val newCoin = templateCoin.copy(
+            id = newCoinId,
+            name = "New Coin ${(1..100).random()}",
+            price = "$${(1000..50000).random()}",
+        )
+
+        val randomCategory = fullCategories.random()
+
+        fullCategories = fullCategories.map { category ->
+            if (category.id == randomCategory.id) {
+                category.copy(coins = category.coins + newCoin)
+            } else {
+                category
+            }
+        }
+        updateUiState()
+    }
+
+    fun removeRandomCoin() {
+        if (fullCategories.isEmpty()) return
+
+        val allCoins = fullCategories.flatMap { it.coins }
+        if (allCoins.isEmpty()) return
+
+        val coinsToRemove = allCoins.shuffled().take(5.coerceAtMost(allCoins.size))
+        val coinsToRemoveIds = coinsToRemove.map { it.id }.toSet()
+
+        fullCategories = fullCategories.map { category ->
+            category.copy(
+                coins = category.coins.filter { coin -> coin.id !in coinsToRemoveIds }
+            )
+        }
+        updateUiState()
+    }
+
     private fun requestCoins() {
         consumeCoinsUseCase().map { categories ->
             categories.map { category -> coinsStateFactory.create(category) }
@@ -54,20 +98,20 @@ class CoinListViewModel(
     }
 
     private fun updateUiState() {
-        var processedCategories = if (showAll) {
-            fullCategories
-        } else {
-            fullCategories.map { category ->
-                category.copy(coins = category.coins.take(4))
-            }
-        }
+        var processedCategories = fullCategories
 
         processedCategories = processedCategories.map { category ->
-            category.copy(coins = category.coins.map { coin ->
-                coin.copy(highlight = highlightMovers && coin.isHotMover)
-            })
+            category.copy(
+                coins = category.coins.map { coin ->
+                    coin.copy(highlight = highlightMovers && coin.isHotMover)
+                })
         }
 
-        _state.update { it.copy(categories = processedCategories) }
+        _state.update {
+            it.copy(
+                categories = processedCategories,
+                showAll = showAll
+            )
+        }
     }
 }

app/src/main/java/ru/otus/cryptosample/coins/feature/CoinState.kt

@@ -2,7 +2,8 @@ package ru.otus.cryptosample.coins.feature
 
 data class CoinsScreenState(
     val categories: List<CoinCategoryState> = emptyList(),
-)
+    val showAll: Boolean = true,
+    )
 
 data class CoinCategoryState(
     val id: String,

app/src/main/java/ru/otus/cryptosample/coins/feature/adapter/CoinItemAnimator.kt

@@ -0,0 +1,71 @@
+package ru.otus.cryptosample.coins.feature.adapter
+
+import android.animation.Animator
+import android.animation.AnimatorListenerAdapter
+import android.animation.AnimatorSet
+import android.animation.ObjectAnimator
+import android.view.View
+import androidx.recyclerview.widget.DefaultItemAnimator
+import androidx.recyclerview.widget.RecyclerView
+
+class CoinItemAnimator : DefaultItemAnimator() {
+
+    override fun animateAdd(holder: RecyclerView.ViewHolder): Boolean {
+        holder.itemView.alpha = 0f
+        holder.itemView.translationX = -holder.itemView.width.toFloat()
+
+        val fadeIn = ObjectAnimator.ofFloat(holder.itemView, View.ALPHA, 0f, 1f)
+        val slideIn = ObjectAnimator.ofFloat(holder.itemView, View.TRANSLATION_X, -holder.itemView.width.toFloat(), 0f)
+
+        val animatorSet = AnimatorSet()
+        animatorSet.playTogether(fadeIn, slideIn)
+        animatorSet.duration = addDuration
+        animatorSet.addListener(object : AnimatorListenerAdapter() {
+            override fun onAnimationStart(animation: Animator) {
+                dispatchAddStarting(holder)
+            }
+
+            override fun onAnimationEnd(animation: Animator) {
+                dispatchAddFinished(holder)
+                holder.itemView.alpha = 1f
+                holder.itemView.translationX = 0f
+            }
+
+            override fun onAnimationCancel(animation: Animator) {
+                holder.itemView.alpha = 1f
+                holder.itemView.translationX = 0f
+            }
+        })
+        animatorSet.start()
+
+        return false
+    }
+
+    override fun animateRemove(holder: RecyclerView.ViewHolder): Boolean {
+        val fadeOut = ObjectAnimator.ofFloat(holder.itemView, View.ALPHA, 1f, 0f)
+        val slideOut = ObjectAnimator.ofFloat(holder.itemView, View.TRANSLATION_X, 0f, holder.itemView.width.toFloat())
+
+        val animatorSet = AnimatorSet()
+        animatorSet.playTogether(fadeOut, slideOut)
+        animatorSet.duration = removeDuration
+        animatorSet.addListener(object : AnimatorListenerAdapter() {
+            override fun onAnimationStart(animation: Animator) {
+                dispatchRemoveStarting(holder)
+            }
+
+            override fun onAnimationEnd(animation: Animator) {
+                dispatchRemoveFinished(holder)
+                holder.itemView.alpha = 1f
+                holder.itemView.translationX = 0f
+            }
+
+            override fun onAnimationCancel(animation: Animator) {
+                holder.itemView.alpha = 1f
+                holder.itemView.translationX = 0f
+            }
+        })
+        animatorSet.start()
+
+        return false
+    }
+}

app/src/main/java/ru/otus/cryptosample/coins/feature/adapter/CoinViewHolder.kt

@@ -12,6 +12,10 @@ class CoinViewHolder(
     private val binding: ItemCoinBinding
 ) : RecyclerView.ViewHolder(binding.root) {
 
+    sealed class Payload {
+        data class HighlightChanged(val isHighlighted: Boolean) : Payload()
+    }
+
     fun bind(coin: CoinState) {
         with(binding) {
             coinName.text = coin.name
@@ -33,4 +37,19 @@ class CoinViewHolder(
             fireBadge.isVisible = coin.highlight
         }
     }
+
+    fun bind(coin: CoinState, payloads: List<Any>) {
+        if (payloads.isEmpty()) {
+            bind(coin)
+            return
+        }
+
+        payloads.forEach { payload ->
+            when (payload) {
+                is Payload.HighlightChanged -> {
+                    binding.fireBadge.isVisible = payload.isHighlighted
+                }
+            }
+        }
+    }
 }