Реализовано домашнее задание по теме RecyclerView.

app/build.gradle.kts

@@ -0,0 +1,56 @@
+import org.jetbrains.kotlin.gradle.dsl.JvmTarget
+
+plugins {
+    alias(libs.plugins.android.application)
+    alias(libs.plugins.jetbrains.kotlin.android)
+}
+
+android {
+    namespace = "otus.gpb.recyclerview"
+    compileSdk = 36
+
+    defaultConfig {
+        applicationId = "otus.gpb.recyclerview"
+        minSdk = 26
+        targetSdk = 36
+        versionCode = 1
+        versionName = "1.0"
+
+        testInstrumentationRunner = "androidx.test.runner.AndroidJUnitRunner"
+    }
+
+    buildTypes {
+        release {
+            isMinifyEnabled = false
+            proguardFiles(
+                getDefaultProguardFile("proguard-android-optimize.txt"),
+                "proguard-rules.pro"
+            )
+        }
+    }
+    compileOptions {
+        sourceCompatibility = JavaVersion.VERSION_17
+        targetCompatibility = JavaVersion.VERSION_17
+    }
+    buildFeatures {
+        viewBinding = true
+    }
+
+    kotlin {
+        compilerOptions {
+            jvmTarget = JvmTarget.JVM_17
+        }
+    }
+}
+
+dependencies {
+    implementation(libs.androidx.core.ktx)
+    implementation(libs.androidx.appcompat)
+    implementation(libs.material)
+    implementation(libs.androidx.activity)
+    implementation(libs.androidx.constraintlayout)
+    implementation(libs.androidx.recyclerview)
+    testImplementation(libs.junit)
+    androidTestImplementation(libs.androidx.junit)
+    androidTestImplementation(libs.androidx.espresso.core)
+}

app/src/main/AndroidManifest.xml

@@ -4,6 +4,7 @@
 
     <application
         android:allowBackup="true"
+        android:name=".App"
         android:dataExtractionRules="@xml/data_extraction_rules"
         android:fullBackupContent="@xml/backup_rules"
         android:icon="@mipmap/ic_launcher"

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

@@ -0,0 +1,28 @@
+package otus.gpb.recyclerview
+
+import android.app.Application
+import otus.gpb.recyclerview.prefs.KeyValueStorage
+import otus.gpb.recyclerview.prefs.SharedPreferencesStorage
+import otus.gpb.recyclerview.repository.ChatRepository
+import otus.gpb.recyclerview.stat.StatService
+
+
+class App : Application() {
+    /**
+     * Stat service
+     */
+    val statService = StatService.Logger()
+
+    /**
+     * Preferences storage
+     * Можно подписаться через LiveData на изменение по ключу и получасть изменения в разных activities
+     */
+    val preferences: KeyValueStorage by lazy {
+        SharedPreferencesStorage(this, "prefs")
+    }
+
+    val chatRepository by lazy {
+        ChatRepository()
+    }
+
+}

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

@@ -0,0 +1,35 @@
+package otus.gpb.recyclerview
+
+import android.view.LayoutInflater
+import android.view.ViewGroup
+import androidx.recyclerview.widget.RecyclerView
+import otus.gpb.recyclerview.databinding.ChatItemBinding
+import otus.gpb.recyclerview.model.ChatItem
+
+class ChatAdapter(
+    private val dataSet: MutableList<ChatItem>,
+    private val itemListener: ItemListener,
+) : RecyclerView.Adapter<ChatViewHolder>() {
+
+    override fun onCreateViewHolder(
+        parent: ViewGroup,
+        viewType: Int
+    ): ChatViewHolder {
+        val chatItemBinding =
+            ChatItemBinding.inflate(
+                LayoutInflater.from(parent.context),
+                parent,
+                false
+            )
+        return ChatViewHolder(chatItemBinding, itemListener)
+    }
+
+    override fun onBindViewHolder(
+        holder: ChatViewHolder,
+        position: Int
+    ) {
+        holder.bind(dataSet[position])
+    }
+
+    override fun getItemCount() = dataSet.size
+}

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

@@ -0,0 +1,37 @@
+package otus.gpb.recyclerview
+
+import android.view.LayoutInflater
+import android.view.ViewGroup
+import androidx.recyclerview.widget.DiffUtil
+import androidx.recyclerview.widget.ListAdapter
+import otus.gpb.recyclerview.databinding.ChatItemBinding
+import otus.gpb.recyclerview.model.ChatItem
+
+class ChatDiffAdapter(
+    private val itemListener: ItemListener,
+) : ListAdapter<ChatItem, ChatViewHolder>(DiffUtilItem()) {
+
+    override fun onCreateViewHolder(
+        parent: ViewGroup,
+        viewType: Int
+    ): ChatViewHolder {
+        val chatItemBinding =
+            ChatItemBinding.inflate(LayoutInflater.from(parent.context), parent, false)
+        return ChatViewHolder(chatItemBinding, itemListener)
+    }
+
+    override fun onBindViewHolder(holder: ChatViewHolder, position: Int) =
+        holder.bind(getItem(position))
+
+}
+
+private class DiffUtilItem : DiffUtil.ItemCallback<ChatItem>() {
+    override fun areItemsTheSame(oldItem: ChatItem, newItem: ChatItem): Boolean {
+        return oldItem::class == newItem::class && oldItem.id == newItem.id
+    }
+
+    override fun areContentsTheSame(oldItem: ChatItem, newItem: ChatItem): Boolean {
+        return oldItem == newItem
+    }
+
+}

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

@@ -0,0 +1,121 @@
+package otus.gpb.recyclerview
+
+import android.content.Context
+import android.content.res.Resources
+import android.graphics.Bitmap
+import android.graphics.Canvas
+import android.graphics.Paint
+import android.graphics.drawable.VectorDrawable
+import android.util.DisplayMetrics
+import androidx.core.content.ContextCompat
+import androidx.core.graphics.createBitmap
+import androidx.recyclerview.widget.ItemTouchHelper
+import androidx.recyclerview.widget.RecyclerView
+import java.util.UUID
+import kotlin.math.roundToInt
+
+
+class ChatItemTouchHelper(private val listener: ItemListener) : ItemTouchHelper.SimpleCallback(
+    ItemTouchHelper.ACTION_STATE_IDLE,
+    ItemTouchHelper.LEFT
+) {
+    override fun onMove(
+        recyclerView: RecyclerView,
+        viewHolder: RecyclerView.ViewHolder,
+        target: RecyclerView.ViewHolder
+    ) = false
+
+    override fun onSwiped(
+        viewHolder: RecyclerView.ViewHolder,
+        direction: Int
+    ) {
+        viewHolder.getElementId()?.let { listener.onSwipe(it) }
+    }
+
+    /**
+     * source: https://stackoverflow.com/questions/30820806/adding-a-colored-background-with-text-icon-under-swiped-row-when-using-androids
+     * Источник из ДЗ (не загружается без vpn) https://www.digitalocean.com/community/tutorials/android-recyclerview-swipe-to-delete-undo
+     * */
+    override fun onChildDraw(
+        c: Canvas,
+        recyclerView: RecyclerView,
+        viewHolder: RecyclerView.ViewHolder,
+        dX: Float,
+        dY: Float,
+        actionState: Int,
+        isCurrentlyActive: Boolean
+    ) {
+
+        // Get RecyclerView item from the ViewHolder
+        val itemView = viewHolder.itemView
+
+        val p = Paint()
+        val context = itemView.context
+        val resources: Resources = context.resources
+
+        if (dX < 0) {
+            /* Set your color for negative displacement */
+            p.setColor(ContextCompat.getColor(context, R.color.light_blue))
+            // Draw Rect with varying left side, equal to the item's right side plus negative displacement dX
+
+            val itemViewTop = itemView.top.toFloat()
+            val itemViewRight = itemView.right.toFloat()
+            val itemViewBottom = itemView.bottom.toFloat()
+            c.drawRect(
+                /* left = */ itemViewRight + dX,
+                /* top = */ itemViewTop,
+                /* right = */ itemViewRight,
+                /* bottom = */ itemViewBottom,
+                /* paint = */ p
+            )
+
+//            fixme magic numbers to dimensions, add relative counters
+            getVectorBitmap(context, R.drawable.archive)?.let { bitmap ->
+                val left = itemViewRight - convertDpToPx(50, resources) - bitmap.getWidth()
+                val top = itemViewTop + (itemViewBottom - itemViewTop - bitmap.getHeight()) * 0.4f
+                c.drawBitmap(
+                    /* bitmap = */ bitmap,
+                    /* left = */ left,
+                    /* top = */ top,
+                    /* paint = */ p
+                )
+
+                c.drawText(
+                    "Archive",
+                    left - convertDpToPx(30, resources),
+                    top + convertDpToPx(50, resources),
+                    Paint().apply {
+                        color = ContextCompat.getColor(context, R.color.white)
+                        textSize = 36f
+                    }
+                )
+            }
+        }
+
+        super.onChildDraw(c, recyclerView, viewHolder, dX, dY, actionState, isCurrentlyActive)
+    }
+
+    /**
+     * source https://stackoverflow.com/questions/44612353/using-vector-drawable-by-drawing-in-canvas
+     * */
+    private fun getVectorBitmap(context: Context, drawableId: Int) =
+        ContextCompat.getDrawable(context, drawableId)?.asClass<VectorDrawable>()
+            ?.let { drawable ->
+                val bitmap: Bitmap = createBitmap(drawable.intrinsicWidth, drawable.intrinsicHeight)
+                val canvas = Canvas(bitmap)
+                drawable.setBounds(0, 0, canvas.width, canvas.height)
+                drawable.draw(canvas)
+                bitmap
+            }
+
+    private fun convertDpToPx(dp: Int, resources: Resources): Int {
+        return (dp * (resources.displayMetrics.xdpi / DisplayMetrics.DENSITY_DEFAULT)).roundToInt()
+    }
+
+    private fun RecyclerView.ViewHolder.getElementId(): UUID? {
+        return bindingAdapter
+            ?.asClass<ChatDiffAdapter>()
+            ?.currentList
+            ?.getOrNull(bindingAdapterPosition)?.id
+    }
+}

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

@@ -0,0 +1,49 @@
+package otus.gpb.recyclerview
+
+import android.view.View
+import android.widget.ImageView
+import android.widget.TextView
+import androidx.core.content.ContextCompat
+import androidx.recyclerview.widget.RecyclerView
+import otus.gpb.recyclerview.databinding.ChatItemBinding
+import otus.gpb.recyclerview.model.ChatItem
+
+class ChatViewHolder(
+    private val cartItemBinding: ChatItemBinding,
+    private val itemListener: ItemListener
+) : RecyclerView.ViewHolder(cartItemBinding.root) {
+
+    val chatImage: ImageView = cartItemBinding.chatImage
+    val chatNameText: TextView = cartItemBinding.chatName
+    val lastUserNameText: TextView = cartItemBinding.lastUserName
+    val lastMessageText: TextView = cartItemBinding.lastMessage
+    val verifiedImage: ImageView = cartItemBinding.verified
+    val muteImage: ImageView = cartItemBinding.mute
+    val messageStatusImage: ImageView = cartItemBinding.messageStatus
+    val lastMessageTimeText: TextView = cartItemBinding.lastMessageTime
+    val chatPinnedImage: ImageView = cartItemBinding.pinned
+
+
+
+    fun bind(chatItem: ChatItem) {
+        with(chatItem) {
+            chatImage.setImageResource(imageId)
+            chatNameText.text = chatName
+            lastUserNameText.text = lastUserName
+            lastMessageText.text = lastMessage
+            verifiedImage.visibility = if (isVerified) View.VISIBLE else View.GONE
+            muteImage.visibility = if (isMuted) View.VISIBLE else View.GONE
+
+            messageStatusImage.setImageResource(messageStatus.iconId)
+            messageStatusImage.setColorFilter(ContextCompat.getColor(cartItemBinding.root.context, messageStatus.colorId),
+                android.graphics.PorterDuff.Mode.SRC_IN)
+            lastMessageTimeText.text = lastMessageViewTime
+            chatPinnedImage.visibility = if (isPinned) View.VISIBLE else View.GONE
+            cartItemBinding.root.setOnClickListener {
+                itemListener.onItemClick(id)
+            }
+        }
+
+    }
+
+}