My homework is done

app/build.gradle

@@ -30,6 +30,12 @@ android {
     kotlinOptions {
         jvmTarget = '1.8'
     }
+    buildFeatures {
+        viewBinding = true
+    }
+    dataBinding {
+        enabled = true
+    }
 }
 
 dependencies {
@@ -38,6 +44,11 @@ dependencies {
     implementation 'androidx.appcompat:appcompat:1.5.1'
     implementation 'com.google.android.material:material:1.7.0'
     implementation 'androidx.constraintlayout:constraintlayout:2.1.4'
+    implementation 'androidx.databinding:databinding-runtime:8.10.0'
+
+    implementation "androidx.paging:paging-runtime:3.2.0"
+    implementation 'it.xabaras.android:recyclerview-swipedecorator:1.4'
+
     testImplementation 'junit:junit:4.13.2'
     androidTestImplementation 'androidx.test.ext:junit:1.1.3'
     androidTestImplementation 'androidx.test.espresso:espresso-core:3.4.0'

app/src/main/java/otus/gpb/recyclerview/ChatAdapter.kt

@@ -0,0 +1,62 @@
+package otus.gpb.recyclerview
+
+import android.view.LayoutInflater
+import android.view.View
+import android.view.ViewGroup
+import androidx.recyclerview.widget.ListAdapter
+import otus.gpb.recyclerview.databinding.ChatItemBinding
+
+class ChatAdapter: ListAdapter<ChatItem, ChatItemViewHolder>(ChatItemDiffCallback()) {
+
+    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ChatItemViewHolder {
+        val binding = ChatItemBinding.inflate(LayoutInflater.from(parent.context), parent, false)
+        return ChatItemViewHolder(binding)
+    }
+
+    override fun onBindViewHolder(holder: ChatItemViewHolder, position: Int) {
+        val chatItem = getItem(position)
+        val binding = holder.binding
+        binding.textViewAuthor.setText(chatItem.author)
+        binding.textViewTittle.setText(chatItem.title)
+        binding.textViewMessage.setText(chatItem.messageLast)
+        binding.textViewTime.setText(chatItem.date)
+        when(chatItem.checkMark){
+            CheckMark.SENT_CHECKED.name -> {
+                binding.imageViewCheck.visibility = View.GONE
+                binding.imageViewTwoCheck.visibility = View.VISIBLE
+            }
+            CheckMark.SENT_UNCHECKED.name -> {
+                binding.imageViewCheck.visibility = View.VISIBLE
+                binding.imageViewTwoCheck.visibility = View.GONE
+            }
+            else -> {
+                binding.imageViewCheck.visibility = View.GONE
+                binding.imageViewTwoCheck.visibility = View.GONE
+            }
+        }
+        if (chatItem.isMentioned){
+            binding.imageViewAt.visibility = View.VISIBLE
+        } else {
+            binding.imageViewAt.visibility = View.GONE
+        }
+        if (chatItem.isPinned){
+            binding.imageViewPin.visibility = View.VISIBLE
+        } else {
+            binding.imageViewPin.visibility = View.GONE
+        }
+        if (chatItem.soundIsOn){
+            binding.imageViewVolume.visibility = View.GONE
+        } else {
+            binding.imageViewVolume.visibility = View.VISIBLE
+        }
+        binding.imageViewAvatar.setImageResource(chatItem.image)
+    }
+
+    fun submitAntSortList(list: List<ChatItem>){
+        val sortedList = list.sortedByDescending {
+            it.id
+            it.isPinned
+        }
+        submitList(sortedList)
+    }
+}

app/src/main/java/otus/gpb/recyclerview/ChatItem.kt

@@ -0,0 +1,15 @@
+package otus.gpb.recyclerview
+
+
+data class ChatItem(
+    val id: Int,
+    val checkMark: String,
+    val isPinned: Boolean,
+    val soundIsOn: Boolean,
+    val isMentioned: Boolean,
+    val date: String,
+    val title: String,
+    val author: String,
+    val messageLast: String,
+    val image: Int,
+)

app/src/main/java/otus/gpb/recyclerview/ChatItemDiffCallback.kt

@@ -0,0 +1,13 @@
+package otus.gpb.recyclerview
+
+import androidx.recyclerview.widget.DiffUtil
+
+class ChatItemDiffCallback: DiffUtil.ItemCallback<ChatItem>() {
+    override fun areItemsTheSame(oldItem: ChatItem, newItem: ChatItem): Boolean {
+        return oldItem.id == newItem.id
+    }
+
+    override fun areContentsTheSame(oldItem: ChatItem, newItem: ChatItem): Boolean {
+        return oldItem == newItem
+    }
+}

app/src/main/java/otus/gpb/recyclerview/ChatItemViewHolder.kt

@@ -0,0 +1,6 @@
+package otus.gpb.recyclerview
+
+import androidx.recyclerview.widget.RecyclerView.ViewHolder
+import otus.gpb.recyclerview.databinding.ChatItemBinding
+
+class ChatItemViewHolder(val binding: ChatItemBinding): ViewHolder(binding.root)

app/src/main/java/otus/gpb/recyclerview/CheckMark.kt

@@ -0,0 +1,5 @@
+package otus.gpb.recyclerview
+
+enum class CheckMark {
+    SENT_CHECKED, SENT_UNCHECKED, NOTHING_WAS_SENT
+}

app/src/main/java/otus/gpb/recyclerview/CustomDecorator.kt

@@ -0,0 +1,52 @@
+package otus.gpb.recyclerview
+
+import android.content.Context
+import android.graphics.Canvas
+import android.graphics.Paint
+import android.graphics.Rect
+import android.util.TypedValue
+import android.view.View
+import androidx.core.content.ContextCompat
+import androidx.recyclerview.widget.RecyclerView
+import androidx.recyclerview.widget.RecyclerView.ItemDecoration
+
+class CustomDecorator(context: Context): ItemDecoration() {
+
+
+    private val bounds = Rect()
+    private val paint = Paint().apply {
+        color = ContextCompat.getColor(context, R.color.gray_light)
+        strokeWidth = 1f
+    }
+    val leftMarginInPx = TypedValue.applyDimension(
+        TypedValue.COMPLEX_UNIT_DIP,
+        78f,
+        context.resources.displayMetrics
+    ).toInt()
+
+    override fun onDrawOver(c: Canvas, parent: RecyclerView, state: RecyclerView.State) {
+        super.onDraw(c, parent, state)
+
+        val childCount = parent.childCount
+        for (i in 0 until childCount) {
+            val child = parent.getChildAt(i)
+            parent.getDecoratedBoundsWithMargins(child, bounds)
+            val positionCurrent = parent.getChildAdapterPosition(child)
+            if (positionCurrent != RecyclerView.NO_POSITION) {
+                val lastElementPosition = parent.adapter?.itemCount?.minus(1)
+                if (positionCurrent != lastElementPosition) {
+                    c.drawLine(
+                        leftMarginInPx.toFloat(),
+                        bounds.bottom.toFloat(),
+                        bounds.right.toFloat(),
+                        bounds.bottom.toFloat(),
+                        paint,
+                    )
+                }
+            }
+        }
+    }
+}
+
+
+

app/src/main/java/otus/gpb/recyclerview/MainActivity.kt

@@ -1,12 +1,194 @@
 package otus.gpb.recyclerview
 
-import androidx.appcompat.app.AppCompatActivity
+import android.graphics.Canvas
 import android.os.Bundle
+import android.util.Log
+import androidx.appcompat.app.AppCompatActivity
+import androidx.core.content.ContextCompat
+import androidx.recyclerview.widget.ItemTouchHelper
+import androidx.recyclerview.widget.LinearLayoutManager
+import androidx.recyclerview.widget.RecyclerView
+import it.xabaras.android.recyclerview.swipedecorator.RecyclerViewSwipeDecorator
+import otus.gpb.recyclerview.databinding.ActivityMainBinding
+import kotlin.random.Random
+
 
 class MainActivity : AppCompatActivity() {
 
+    private lateinit var adapter: ChatAdapter
+    private var currentPage = 1
+    private val pageSize = 30
+    var id = 1
+    var previousTotalItemCount = 0
+    private var isLoading = false
+    private var chatList: MutableList<ChatItem> = mutableListOf()
+    private val archiveList: MutableList<ChatItem> = mutableListOf()
+    private val binding: ActivityMainBinding by lazy {
+        ActivityMainBinding.inflate(layoutInflater)
+    }
+
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
-        setContentView(R.layout.activity_main)
+        setContentView(binding.root)
+        initRecyclerView()
+        setFirstChats()
+        generateRandomChats(pageSize)
+        setScrolling()
+    }
+
+
+    private fun setScrolling(){
+        binding.recyclerView.addOnScrollListener(object : RecyclerView.OnScrollListener() {
+
+            override fun onScrolled(recyclerView: RecyclerView, dx: Int, dy: Int) {
+                super.onScrolled(recyclerView, dx, dy)
+                val layoutManager = recyclerView.layoutManager as LinearLayoutManager
+                val totalItemCount = layoutManager.itemCount
+                val lastVisibleItem = layoutManager.findLastCompletelyVisibleItemPosition()
+                if (isLoading && totalItemCount > previousTotalItemCount) {
+                    isLoading = false
+                    previousTotalItemCount = totalItemCount
+                }
+                if (!isLoading && lastVisibleItem >= totalItemCount - 5) {
+                    Log.d("MainActivity", currentPage.toString())
+                    loadNextPage()
+                }
+            }
+        })
+    }
+    private fun removeItem(position: Int){
+        val itemToDelete = adapter.currentList[position]
+        val newList = chatList.apply {
+            remove(itemToDelete)
+        }
+        adapter.submitAntSortList(newList)
+    }
+
+    private fun setFirstChats(){
+        chatList = generateRandomChats(currentPage).toMutableList()
+        adapter.submitAntSortList(chatList)
+    }
+
+    private fun addInArchiveList(position: Int){
+        val item = adapter.currentList[position]
+        archiveList.add(item)
+    }
+
+    private fun loadNextPage() {
+        isLoading = true
+        val newChats = generateRandomChats(pageSize)
+        chatList.addAll(newChats)
+        adapter.submitAntSortList(chatList.toList())
+        currentPage++
+    }
+
+    private fun generateRandomChats(size: Int): List<ChatItem>{
+        val listRandomChats = mutableListOf<ChatItem>()
+        for (i in 1..size) {
+            listRandomChats.add(
+                ChatItem(
+                    id++,
+                    getRandomCheckMark(),
+                    true,
+                    Random.nextBoolean(),
+                    Random.nextBoolean(),
+                    "12:10",
+                    "Just design",
+                    "Nicolay",
+                    "I want pizza",
+                    R.drawable.food_steak
+                )
+            )
+        }
+        return listRandomChats
+    }
+
+    private fun getRandomCheckMark(): String {
+        val values = CheckMark.values().toList()
+        val randomNumber = Random.nextInt(3)
+        return values[randomNumber].name
+    }
+
+    private fun initRecyclerView() {
+        adapter = ChatAdapter()
+        binding.recyclerView.adapter = adapter
+        binding.recyclerView.addItemDecoration(CustomDecorator(this))
+        val itemTouchHelper = ItemTouchHelper(object : ItemTouchHelper.SimpleCallback(
+            0, ItemTouchHelper.LEFT or ItemTouchHelper.RIGHT
+        ) {
+            override fun onMove(
+                recyclerView: RecyclerView,
+                viewHolder: RecyclerView.ViewHolder,
+                target: RecyclerView.ViewHolder
+            ): Boolean {
+                return false
+            }
+
+            override fun onSwiped(viewHolder: RecyclerView.ViewHolder, direction: Int) {
+                val position = viewHolder.adapterPosition
+                when(direction){
+                    ItemTouchHelper.LEFT -> {
+                        addInArchiveList(position)
+                        removeItem(position)
+                        Log.d("MainActivity", archiveList.toString())
+                    }
+                    ItemTouchHelper.RIGHT -> {
+                        removeItem(position)
+                    }
+                }
+            }
+
+            override fun onChildDraw(
+                c: Canvas,
+                recyclerView: RecyclerView,
+                viewHolder: RecyclerView.ViewHolder,
+                dX: Float,
+                dY: Float,
+                actionState: Int,
+                isCurrentlyActive: Boolean
+            ) {
+                RecyclerViewSwipeDecorator.Builder(
+                    c,
+                    recyclerView,
+                    viewHolder,
+                    dX,
+                    dY,
+                    actionState,
+                    isCurrentlyActive
+                )
+                    .addSwipeRightBackgroundColor(
+                        ContextCompat.getColor(
+                            this@MainActivity,
+                            R.color.red
+                        )
+                    )
+                    .addSwipeRightActionIcon(R.drawable.trash_can_outline)
+                    .addSwipeRightLabel("Delete")
+                    .setSwipeRightLabelColor(
+                        ContextCompat.getColor(
+                            this@MainActivity,
+                            R.color.white
+                        )
+                    )
+                    .addSwipeLeftBackgroundColor(
+                        ContextCompat.getColor(
+                            this@MainActivity,
+                            R.color.blue
+                        )
+                    )
+                    .addSwipeLeftActionIcon(R.drawable.package_down)
+                    .addSwipeLeftLabel("Archive")
+                    .setSwipeLeftLabelColor(
+                        ContextCompat.getColor(
+                            this@MainActivity,
+                            R.color.white
+                        )
+                    )
+                    .create()
+                    .decorate()
+                super.onChildDraw(c, recyclerView, viewHolder, dX, dY, actionState, isCurrentlyActive)
+            }
+        })
+        itemTouchHelper.attachToRecyclerView(binding.recyclerView)
     }
 }

app/src/main/res/drawable/at.xml

@@ -0,0 +1,9 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="24dp"
+    android:height="24dp"
+    android:viewportWidth="24"
+    android:viewportHeight="24">
+  <path
+      android:fillColor="@color/white"
+      android:pathData="M12,15C12.81,15 13.5,14.7 14.11,14.11C14.7,13.5 15,12.81 15,12C15,11.19 14.7,10.5 14.11,9.89C13.5,9.3 12.81,9 12,9C11.19,9 10.5,9.3 9.89,9.89C9.3,10.5 9,11.19 9,12C9,12.81 9.3,13.5 9.89,14.11C10.5,14.7 11.19,15 12,15M12,2C14.75,2 17.1,3 19.05,4.95C21,6.9 22,9.25 22,12V13.45C22,14.45 21.65,15.3 21,16C20.3,16.67 19.5,17 18.5,17C17.3,17 16.31,16.5 15.56,15.5C14.56,16.5 13.38,17 12,17C10.63,17 9.45,16.5 8.46,15.54C7.5,14.55 7,13.38 7,12C7,10.63 7.5,9.45 8.46,8.46C9.45,7.5 10.63,7 12,7C13.38,7 14.55,7.5 15.54,8.46C16.5,9.45 17,10.63 17,12V13.45C17,13.86 17.16,14.22 17.46,14.53C17.76,14.84 18.11,15 18.5,15C18.92,15 19.27,14.84 19.57,14.53C19.87,14.22 20,13.86 20,13.45V12C20,9.81 19.23,7.93 17.65,6.35C16.07,4.77 14.19,4 12,4C9.81,4 7.93,4.77 6.35,6.35C4.77,7.93 4,9.81 4,12C4,14.19 4.77,16.07 6.35,17.65C7.93,19.23 9.81,20 12,20H17V22H12C9.25,22 6.9,21 4.95,19.05C3,17.1 2,14.75 2,12C2,9.25 3,6.9 4.95,4.95C6.9,3 9.25,2 12,2Z"/>
+</vector>