homework

app/build.gradle

@@ -30,6 +30,9 @@ android {
     kotlinOptions {
         jvmTarget = '1.8'
     }
+    buildFeatures {
+        viewBinding = true
+    }
 }
 
 dependencies {
@@ -38,6 +41,10 @@ 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.legacy:legacy-support-v4:1.0.0'
+    implementation 'androidx.lifecycle:lifecycle-livedata-ktx:2.8.7'
+    implementation 'androidx.lifecycle:lifecycle-viewmodel-ktx:2.8.7'
+    implementation 'androidx.fragment:fragment-ktx:1.8.6'
     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 +1,58 @@
+package otus.gpb.recyclerview
+
+import android.view.LayoutInflater
+import android.view.ViewGroup
+import androidx.recyclerview.widget.ItemTouchHelper
+import androidx.recyclerview.widget.RecyclerView
+
+class ChatAdapter(private val listener: Listener): RecyclerView.Adapter<RecyclerView.ViewHolder>() {
+    private var list = listOf<ChatListItem>()
+
+    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): RecyclerView.ViewHolder {
+        return when (viewType) {
+            ViewTypes.CHAT.id -> {
+                val view = LayoutInflater.from(parent.context).inflate(R.layout.chat_item, parent, false)
+
+                ChatViewHolder(view, listener)
+            }
+            ViewTypes.LOAD.id -> {
+                val view = LayoutInflater.from(parent.context).inflate(R.layout.load_item, parent, false)
+
+                LoadViewHolder(view)
+            }
+            else -> throw IllegalArgumentException("Not found view type for chat adapter")
+        }
+    }
+
+    override fun onBindViewHolder(holder: RecyclerView.ViewHolder, position: Int) {
+        val item = list.getOrNull(position) ?: return
+
+        when (item) {
+            is ChatListItem.ChatItem -> {
+                (holder as? ChatViewHolder)?.bind(item)
+            }
+            is ChatListItem.LoadItem -> {
+                return
+            }
+        }
+    }
+
+    override fun getItemViewType(position: Int): Int {
+        return when (list[position]) {
+            is ChatListItem.ChatItem -> ViewTypes.CHAT.id
+            is ChatListItem.LoadItem -> ViewTypes.LOAD.id
+        }
+    }
+
+    override fun getItemCount(): Int = list.size
+
+    fun setItems(items: List<ChatListItem>) {
+        list = items
+        notifyDataSetChanged()
+    }
+
+    enum class ViewTypes(val id: Int) {
+        CHAT(R.layout.chat_item),
+        LOAD(R.layout.load_item)
+    }
+}

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

@@ -0,0 +1,84 @@
+package otus.gpb.recyclerview
+
+import android.graphics.Canvas
+import android.graphics.Color
+import android.graphics.drawable.ColorDrawable
+import androidx.fragment.app.viewModels
+import android.os.Bundle
+import androidx.fragment.app.Fragment
+import android.view.LayoutInflater
+import android.view.View
+import android.view.ViewGroup
+import androidx.core.content.ContextCompat
+import androidx.recyclerview.widget.DividerItemDecoration
+import androidx.recyclerview.widget.ItemTouchHelper
+import androidx.recyclerview.widget.LinearLayoutManager
+import androidx.recyclerview.widget.RecyclerView
+
+class ChatFragment : Fragment() {
+    companion object {
+        fun newInstance() = ChatFragment()
+    }
+
+    private lateinit var recyclerView: RecyclerView
+    private val viewModel: ChatViewModel by viewModels()
+
+    private val itemTouchHelperCallback = object : ItemTouchHelper.SimpleCallback(
+        0,
+        ItemTouchHelper.LEFT
+    ) {
+        override fun onMove(
+            recyclerView: RecyclerView,
+            viewHolder: RecyclerView.ViewHolder,
+            target: RecyclerView.ViewHolder
+        ): Boolean {
+            return false
+        }
+
+        override fun onSwiped(viewHolder: RecyclerView.ViewHolder, direction: Int) {
+            viewModel.removeItem(viewHolder.adapterPosition)
+        }
+    }
+
+    override fun onCreateView(
+        inflater: LayoutInflater,
+        container: ViewGroup?,
+        savedInstanceState: Bundle?
+    ): View {
+        return inflater.inflate(R.layout.fragment_chat, container, false)
+    }
+
+    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
+        super.onViewCreated(view, savedInstanceState)
+        setupRecyclerView(view)
+    }
+
+    private fun setupRecyclerView(view: View) {
+        recyclerView = view.findViewById(R.id.recyclerView)
+
+        val dividerItemDecoration = DividerItemDecoration(context, LinearLayoutManager.VERTICAL)
+        recyclerView.addItemDecoration(dividerItemDecoration)
+        recyclerView.adapter = viewModel.chatAdapter
+
+        val itemTouchHelper = ItemTouchHelper(itemTouchHelperCallback)
+        itemTouchHelper.attachToRecyclerView(recyclerView)
+
+        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 visibleItemCount = layoutManager.childCount
+                val totalItemCount = layoutManager.itemCount
+                val firstVisibleItemPosition = layoutManager.findFirstVisibleItemPosition()
+
+                if ((visibleItemCount + firstVisibleItemPosition) >= totalItemCount
+                    && firstVisibleItemPosition >= 0) {
+                    viewModel.loadNewData()
+                }
+            }
+        })
+
+        viewModel.setupData()
+    }
+}

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

@@ -0,0 +1,25 @@
+package otus.gpb.recyclerview
+
+import androidx.annotation.LayoutRes
+import java.time.LocalDate
+
+sealed class ChatListItem: WithLayoutId {
+    data class ChatItem(private val chatMessage: ChatMessage) : ChatListItem(), WithLayoutId by ChatItem  {
+        companion object : WithLayoutId {
+            @get:LayoutRes
+            override val layoutId: Int = R.layout.chat_item
+        }
+
+        val user: String get() = chatMessage.user
+        val message: String get() = chatMessage.message
+        val date: LocalDate get() = chatMessage.date
+    }
+
+    data class LoadItem(private val id: String = "1") : ChatListItem(), WithLayoutId by LoadItem {
+        companion object : WithLayoutId {
+            @get:LayoutRes
+            override val layoutId: Int = R.layout.load_item
+        }
+    }
+}
+

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

@@ -0,0 +1,24 @@
+package otus.gpb.recyclerview
+
+import java.sql.Date
+import java.time.LocalDate
+
+data class ChatMessage(
+    val id: Int,
+    val user: String,
+    val message: String,
+    val date: LocalDate
+)
+
+val chatMessages = listOf(
+    ChatListItem.ChatItem(ChatMessage(0, "Dave", message = "Hello everyone!", date = LocalDate.now())),
+    ChatListItem.ChatItem(ChatMessage(1, "Ana", message = "I want pizza for lunch", date = LocalDate.now().plusDays(1))),
+    ChatListItem.ChatItem(ChatMessage(2, "Micky", message = "TDS helps you create your own concepts and learn new things", date = LocalDate.now().plusDays(2))),
+    ChatListItem.ChatItem(ChatMessage(3, "Sarah", message = "Has anyone finished the project yet?", date = LocalDate.now().minusDays(1))),
+    ChatListItem.ChatItem(ChatMessage(4, "John", message = "Meeting at 3 PM tomorrow", date = LocalDate.now().plusDays(3))),
+    ChatListItem.ChatItem(ChatMessage(5, "Emma", message = "Don't forget to submit your reports", date = LocalDate.now().plusDays(1))),
+    ChatListItem.ChatItem(ChatMessage(6, "Mike", message = "The new update is amazing!", date = LocalDate.now().minusDays(2))),
+    ChatListItem.ChatItem(ChatMessage(7, "Lisa", message = "Can someone help me with Kotlin?", date = LocalDate.now())),
+    ChatListItem.ChatItem(ChatMessage(8, "Alex", message = "Let's schedule a team building event", date = LocalDate.now().plusDays(5))),
+    ChatListItem.ChatItem(ChatMessage(9, "Tina", message = "Happy Friday everyone!", date = LocalDate.now().plusDays(4)))
+)

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

@@ -0,0 +1,32 @@
+package otus.gpb.recyclerview
+
+import android.view.View
+import android.widget.ImageView
+import android.widget.TextView
+import androidx.recyclerview.widget.RecyclerView
+import java.time.LocalDate
+import java.time.format.DateTimeFormatter
+import java.util.Locale
+
+class ChatViewHolder(private val view: View, private val listener: Listener) : RecyclerView.ViewHolder(view) {
+    private val nameTV: TextView by lazy { view.findViewById(R.id.nameTV) }
+    private val userTV: TextView by lazy { view.findViewById(R.id.userTV) }
+    private val messageTV: TextView by lazy { view.findViewById(R.id.messageTV) }
+    private val dateTV: TextView by lazy { view.findViewById(R.id.dateTV) }
+
+    fun bind(item: ChatListItem.ChatItem) {
+        nameTV.text = item.user.firstOrNull().toString()
+        userTV.text = item.user
+        messageTV.text = item.message
+        dateTV.text = formatDate(item.date)
+
+        view.setOnClickListener {
+            listener.onItemClicked(layoutPosition)
+        }
+    }
+
+    private fun formatDate(date: LocalDate): String {
+        val formatter = DateTimeFormatter.ofPattern("EEE d", Locale.getDefault())
+        return date.format(formatter)
+    }
+}

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

@@ -0,0 +1,42 @@
+package otus.gpb.recyclerview
+
+import androidx.lifecycle.ViewModel
+import androidx.lifecycle.viewModelScope
+import kotlinx.coroutines.delay
+import kotlinx.coroutines.launch
+
+class ChatViewModel : ViewModel(), Listener {
+    val chatAdapter = ChatAdapter(this)
+
+    private var items: MutableList<ChatListItem> = chatMessages.toMutableList()
+    private var isDataLoading: Boolean = false
+
+    fun setupData() {
+        chatAdapter.setItems(items)
+    }
+
+    fun removeItem(id: Int) {
+        items.removeAt(id)
+        setupData()
+    }
+
+    fun loadNewData() {
+        if (isDataLoading) { return }
+
+        isDataLoading = true
+
+        viewModelScope.launch {
+            items.add(ChatListItem.LoadItem())
+            setupData()
+
+            delay(3000L)
+
+            items.removeLast()
+            items.addAll(chatMessages)
+            setupData()
+            isDataLoading = false
+        }
+    }
+
+    override fun onItemClicked(id: Int) { }
+}

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

@@ -0,0 +1,5 @@
+package otus.gpb.recyclerview
+
+interface Listener {
+    fun onItemClicked(id: Int)
+}

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

@@ -0,0 +1,10 @@
+package otus.gpb.recyclerview
+
+import android.view.View
+import android.widget.TextView
+import androidx.recyclerview.widget.RecyclerView
+import java.time.LocalDate
+import java.time.format.DateTimeFormatter
+import java.util.Locale
+
+class LoadViewHolder(private val view: View) : RecyclerView.ViewHolder(view) { }

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

@@ -8,5 +8,9 @@ class MainActivity : AppCompatActivity() {
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
         setContentView(R.layout.activity_main)
+
+        supportFragmentManager.beginTransaction()
+            .replace(R.id.container, ChatFragment.newInstance())
+            .commit()
     }
 }

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

@@ -0,0 +1,8 @@
+package otus.gpb.recyclerview
+
+import androidx.annotation.LayoutRes
+
+interface WithLayoutId {
+    @get:LayoutRes
+    val layoutId: Int
+}

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

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="utf-8"?>
+<shape xmlns:android="http://schemas.android.com/apk/res/android"
+    android:shape="rectangle">
+    <size android:height="1dp" />
+    <solid android:color="@android:color/darker_gray" />
+</shape>

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

@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="utf-8"?>
+<shape xmlns:android="http://schemas.android.com/apk/res/android">
+    <corners android:radius="30dp"/>
+    <solid android:color="@android:color/transparent"/>
+</shape>

app/src/main/res/layout/activity_main.xml

@@ -1,13 +1,9 @@
 <?xml version="1.0" encoding="utf-8"?>
-<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
+<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:tools="http://schemas.android.com/tools"
+    android:id="@+id/container"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
     tools:context=".MainActivity">
 
-    <androidx.recyclerview.widget.RecyclerView
-        android:id="@+id/recyclerView"
-        android:layout_width="match_parent"
-        android:layout_height="match_parent" />
-
-</androidx.constraintlayout.widget.ConstraintLayout>
+</FrameLayout>