Homework 12

app/build.gradle

@@ -35,9 +35,11 @@ android {
 dependencies {
 
     implementation 'androidx.core:core-ktx:1.7.0'
-    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.appcompat:appcompat:1.7.0'
+    implementation 'com.google.android.material:material:1.12.0'
+    implementation 'androidx.constraintlayout:constraintlayout:2.2.0'
+    implementation 'androidx.activity:activity-ktx:1.9.3'
+    implementation 'androidx.recyclerview:recyclerview:1.3.2'
     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 +1,54 @@
+package otus.gpb.recyclerview
+
+import android.view.LayoutInflater
+import android.view.ViewGroup
+import androidx.recyclerview.widget.DiffUtil
+import androidx.recyclerview.widget.ListAdapter
+import androidx.recyclerview.widget.RecyclerView
+import java.util.Collections
+
+class ChatAdapter() : ListAdapter<ChatItem, RecyclerView.ViewHolder>(DiffUtilItem()) {
+
+    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): RecyclerView.ViewHolder {
+        val view = LayoutInflater.from(parent.context).inflate(R.layout.chat, parent, false)
+        return ChatViewHolder(view)
+    }
+
+    override fun onBindViewHolder(holder: RecyclerView.ViewHolder, position: Int) {
+        val item = currentList.getOrNull(position)
+        if (item != null) {
+            (holder as ChatViewHolder).bind(item)
+        }
+    }
+
+    fun exchange(fromPosition: Int, toPosition: Int) {
+        val list = currentList.toMutableList()
+        if (fromPosition < toPosition) {
+            for (index in fromPosition until toPosition) {
+                Collections.swap(list, index, index + 1)
+            }
+        } else {
+            for (index in fromPosition downTo toPosition + 1) {
+                Collections.swap(list, index, index - 1)
+            }
+        }
+        submitList(list)
+    }
+
+    fun removeItem(fromPosition: Int) {
+        val list = currentList.toMutableList()
+        list.removeAt(fromPosition)
+        submitList(list)
+    }
+}
+
+class DiffUtilItem : 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/ChatItem.kt

@@ -0,0 +1,9 @@
+package otus.gpb.recyclerview
+data class ChatItem(
+    val id: Int,
+    val date: String,
+    val name: String,
+    val surname: String,
+    val message: String,
+    val background: Int
+)

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

@@ -0,0 +1,30 @@
+package otus.gpb.recyclerview
+
+import android.annotation.SuppressLint
+import android.view.View
+import android.widget.TextView
+import androidx.recyclerview.widget.RecyclerView
+
+class ChatViewHolder(
+    private val view: View,
+) : RecyclerView.ViewHolder(view) {
+
+    init {
+        println(this)
+    }
+
+    private val name: TextView by lazy { view.findViewById(R.id.name) }
+    private val avatar: TextView by lazy { view.findViewById(R.id.avatar) }
+    private val message: TextView by lazy { view.findViewById(R.id.message) }
+    private val date: TextView by lazy { view.findViewById(R.id.date) }
+
+    @SuppressLint("SetTextI18n")
+    fun bind(item: ChatItem) {
+        println("bind item ${item.id}")
+        name.text = "${item.name} ${item.surname}"
+        message.text = item.message
+        date.text = item.date
+        avatar.text = item.name.substring(0, 1) + item.surname.substring(0,1)
+        avatar.setBackgroundColor(item.background)
+    }
+}

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

@@ -0,0 +1,13 @@
+package otus.gpb.recyclerview
+
+import android.graphics.Color
+import java.util.Random
+
+object ColorGenerator {
+
+    fun generateColor(): Int {
+        val nextInt = Random().nextInt(0xffffff + 1)
+        val colorCode = String.format("#%06x", nextInt)
+        return Color.parseColor(colorCode)
+    }
+}

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

@@ -0,0 +1,40 @@
+package otus.gpb.recyclerview
+
+import android.graphics.Canvas
+import android.graphics.Color
+import android.graphics.Paint
+import android.graphics.Rect
+import androidx.recyclerview.widget.RecyclerView
+import androidx.recyclerview.widget.RecyclerView.ItemDecoration
+
+class CustomDecorator : ItemDecoration() {
+
+    private val bounds = Rect()
+    private val paint = Paint().apply {
+        color = Color.GRAY
+        strokeWidth = 1f
+    }
+    override fun onDraw(canvas: Canvas, parent: RecyclerView, state: RecyclerView.State) {
+        super.onDraw(canvas, parent, state)
+
+        val childCount = parent.childCount
+        for (index in 0 until childCount) {
+            val child = parent.getChildAt(index)
+            parent.getDecoratedBoundsWithMargins(child, bounds)
+
+            val positionCurrent = parent.getChildAdapterPosition(child)
+            if (positionCurrent != RecyclerView.NO_POSITION) {
+                val lastElementPosition = parent.adapter?.itemCount?.minus(1)
+                if (positionCurrent != lastElementPosition) {
+                    canvas.drawLine(
+                        bounds.left.toFloat() + 150f,
+                        bounds.bottom.toFloat(),
+                        bounds.right.toFloat(),
+                        bounds.bottom.toFloat(),
+                        paint
+                    )
+                }
+            }
+        }
+    }
+}

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

@@ -0,0 +1,37 @@
+package otus.gpb.recyclerview
+
+import androidx.recyclerview.widget.ItemTouchHelper
+import androidx.recyclerview.widget.RecyclerView
+
+class ItemTouchCallback : ItemTouchHelper.Callback() {
+
+    override fun getMovementFlags(recyclerView: RecyclerView, viewHolder: RecyclerView.ViewHolder): Int {
+        return makeMovementFlags(
+            ItemTouchHelper.UP or ItemTouchHelper.DOWN,
+            ItemTouchHelper.LEFT
+        )
+    }
+
+    override fun onMove(
+        recyclerView: RecyclerView,
+        viewHolder: RecyclerView.ViewHolder,
+        target: RecyclerView.ViewHolder
+    ): Boolean {
+        viewHolder.chatAdapter.exchange(
+            viewHolder.bindingAdapterPosition,
+            target.bindingAdapterPosition
+        )
+        return true
+    }
+
+    override fun getSwipeThreshold(viewHolder: RecyclerView.ViewHolder): Float {
+        return 0.25f
+    }
+
+    override fun onSwiped(viewHolder: RecyclerView.ViewHolder, direction: Int) {
+        viewHolder.chatAdapter.removeItem(viewHolder.absoluteAdapterPosition)
+    }
+
+    private val RecyclerView.ViewHolder.chatAdapter: ChatAdapter
+        get() = bindingAdapter as? ChatAdapter ?: error("Not ChatAdapter")
+}

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

@@ -1,12 +1,68 @@
 package otus.gpb.recyclerview
 
-import androidx.appcompat.app.AppCompatActivity
 import android.os.Bundle
+import androidx.activity.enableEdgeToEdge
+import androidx.appcompat.app.AppCompatActivity
+import androidx.core.view.ViewCompat
+import androidx.core.view.WindowInsetsCompat
+import androidx.recyclerview.widget.ItemTouchHelper
+import androidx.recyclerview.widget.RecyclerView
+import com.google.android.material.floatingactionbutton.FloatingActionButton
+import kotlin.random.Random
 
 class MainActivity : AppCompatActivity() {
 
+    private val adapter: ChatAdapter by lazy { ChatAdapter() }
+    private var list: List<ChatItem> = emptyList()
+    private val names: List<String> = listOf("Sam", "Paul", "Jean", "Jo", "Jacob", "Winter", "Summer", "Olly")
+    private val surnames: List<String> = listOf("Brown", "Potter", "Sol", "Dew", "Moss", "Triple", "Kenzie", "Martin")
+
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
+        enableEdgeToEdge()
         setContentView(R.layout.activity_main)
+        ViewCompat.setOnApplyWindowInsetsListener(findViewById(R.id.main)) { v, insets ->
+            val systemBars = insets.getInsets(WindowInsetsCompat.Type.systemBars())
+            v.setPadding(systemBars.left, systemBars.top, systemBars.right, systemBars.bottom)
+            insets
+        }
+
+        val recyclerView = findViewById<RecyclerView>(R.id.list)
+        recyclerView.addItemDecoration(
+            CustomDecorator()
+        )
+
+        ItemTouchHelper(ItemTouchCallback()).attachToRecyclerView(recyclerView)
+
+        recyclerView.adapter = adapter
+        list = generateList(15)
+        adapter.submitList(list)
+
+        findViewById<FloatingActionButton>(R.id.loadMore).setOnClickListener { addChats() }
+    }
+
+    private fun addChats() {
+        val currentList = list.toMutableList()
+        currentList.addAll(generateList(5))
+        adapter.submitList(currentList)
+    }
+
+    private fun generateList(number: Int) = run {
+        val list = mutableListOf<ChatItem>()
+        repeat(number) {
+            val nameIdx = Random.nextInt(0, names.size - 1)
+            val surnameIdx = Random.nextInt(0, surnames.size - 1)
+            val personItem = ChatItem(
+                id = it,
+                name = names[nameIdx],
+                surname = surnames[surnameIdx],
+                message = "Some message from ${names[nameIdx]}",
+                date = "12:05",
+                background = ColorGenerator.generateColor()
+            )
+            list.add(personItem)
+        }
+
+        list.toList()
     }
 }

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

@@ -1,13 +1,34 @@
 <?xml version="1.0" encoding="utf-8"?>
-<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
+
+
+<androidx.constraintlayout.widget.ConstraintLayout
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
     xmlns:tools="http://schemas.android.com/tools"
+    android:id="@+id/main"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
+    android:orientation="vertical"
     tools:context=".MainActivity">
 
     <androidx.recyclerview.widget.RecyclerView
-        android:id="@+id/recyclerView"
+        android:id="@+id/list"
         android:layout_width="match_parent"
-        android:layout_height="match_parent" />
+        android:layout_height="match_parent"
+        android:orientation="vertical"
+        app:layoutManager="androidx.recyclerview.widget.LinearLayoutManager"
+        tools:itemCount="5"
+        tools:listitem="@layout/chat" />
 
-</androidx.constraintlayout.widget.ConstraintLayout>
+    <com.google.android.material.floatingactionbutton.FloatingActionButton
+        android:id="@+id/loadMore"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_gravity="bottom"
+        android:contentDescription="@string/load_more"
+        android:src="@android:drawable/ic_dialog_email"
+        android:layout_marginEnd="20dp"
+        android:layout_marginBottom="20dp"
+        app:layout_constraintBottom_toBottomOf="parent"
+        app:layout_constraintRight_toRightOf="parent"/>
+</androidx.constraintlayout.widget.ConstraintLayout  >

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

@@ -0,0 +1,59 @@
+<?xml version="1.0" encoding="utf-8"?>
+<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    xmlns:tools="http://schemas.android.com/tools"
+    android:id="@+id/root"
+    android:layout_width="match_parent"
+    android:layout_height="wrap_content"
+    android:layout_margin="0dp"
+    android:padding="8dp"
+    tools:background="@color/white">
+
+    <TextView
+        android:id="@+id/avatar"
+        android:layout_width="50dp"
+        android:layout_height="50dp"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toTopOf="parent"
+        android:textColor="@color/white"
+        android:gravity="center"
+        android:textSize="28sp"
+        />
+
+    <TextView
+        android:id="@+id/name"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_marginStart="8dp"
+        android:textSize="18sp"
+        android:textStyle="bold"
+        app:layout_constraintEnd_toStartOf="@id/date"
+        app:layout_constraintHorizontal_bias="0.0"
+        app:layout_constraintStart_toEndOf="@id/avatar"
+        app:layout_constraintTop_toTopOf="parent"
+        tools:text="Name" />
+
+    <TextView
+        android:id="@+id/message"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_marginStart="8dp"
+        android:textSize="16sp"
+        app:layout_constraintBottom_toBottomOf="parent"
+        app:layout_constraintEnd_toStartOf="@id/date"
+        app:layout_constraintHorizontal_bias="0.0"
+        app:layout_constraintStart_toEndOf="@id/avatar"
+        app:layout_constraintTop_toBottomOf="@id/name"
+        tools:text="Hello world" />
+
+    <TextView
+        android:id="@+id/date"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_marginStart="8dp"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintTop_toTopOf="parent"
+        tools:text="12:04" />
+
+
+</androidx.constraintlayout.widget.ConstraintLayout>

app/src/main/res/values-night/themes.xml

@@ -1,6 +1,6 @@
 <resources xmlns:tools="http://schemas.android.com/tools">
     <!-- Base application theme. -->
-    <style name="Theme.RecyclerView" parent="Theme.MaterialComponents.DayNight.DarkActionBar">
+    <style name="Theme.RecyclerView" parent="Theme.MaterialComponents.DayNight.NoActionBar">
         <!-- Primary brand color. -->
         <item name="colorPrimary">@color/purple_200</item>
         <item name="colorPrimaryVariant">@color/purple_700</item>

app/src/main/res/values/strings.xml

@@ -1,3 +1,4 @@
 <resources>
     <string name="app_name">RecyclerView</string>
+    <string name="load_more">Load more</string>
 </resources>