FirebaseWorkshop

activity_main.xml

<?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:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/rcProducts"
        android:layout_width="0dp"
        android:layout_height="0dp"
        app:layoutManager="androidx.recyclerview.widget.LinearLayoutManager"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <com.google.android.material.floatingactionbutton.FloatingActionButton
        android:id="@+id/fabScan"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:srcCompat="@drawable/ic_add"
        app:useCompatPadding="true" />


</androidx.constraintlayout.widget.ConstraintLayout>

AdapterProducts.kt

import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import androidx.recyclerview.widget.RecyclerView
import com.gorrotowi.firebaseworkshop.R
import com.gorrotowi.firebaseworkshop.entities.FirebaseProduct
import kotlinx.android.synthetic.main.item_product.view.*
import kotlin.properties.Delegates

class AdapterProducts : RecyclerView.Adapter<AdapterProducts.ProducsViewHolder>() {

    var dataSource: List<FirebaseProduct> by Delegates.observable(emptyList()) { _, _, _ -> notifyDataSetChanged() }

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ProducsViewHolder =
        ProducsViewHolder(
            LayoutInflater.from(parent.context).inflate(
                R.layout.item_product,
                parent,
                false
            )
        )

    override fun getItemCount(): Int = dataSource.size

    override fun onBindViewHolder(holder: ProducsViewHolder, position: Int) {
        holder.bindView(dataSource[position])
    }

    class ProducsViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {
        fun bindView(data: FirebaseProduct) {
            with(itemView) {
                txtItemProductName?.text = data.name
                txtItemProductDescr?.text = data.url
            }
        }
    }
}

build.gradle

implementation 'androidx.recyclerview:recyclerview:1.1.0'
    implementation 'com.google.android.material:material:1.0.0'

    implementation 'androidx.lifecycle:lifecycle-viewmodel-ktx:2.1.0'
    implementation 'androidx.lifecycle:lifecycle-extensions:2.1.0'

    implementation 'org.jetbrains.kotlinx:kotlinx-coroutines-core:1.3.2'
    implementation 'org.jetbrains.kotlinx:kotlinx-coroutines-android:1.3.2'
    implementation 'org.jetbrains.kotlinx:kotlinx-coroutines-play-services:1.1.1'

    implementation 'com.github.bumptech.glide:glide:4.9.0'
    annotationProcessor 'com.github.bumptech.glide:compiler:4.9.0'

    implementation('com.journeyapps:zxing-android-embedded:3.6.0') { transitive = false }
    implementation 'com.google.zxing:core:3.3.0'

    implementation 'com.google.code.gson:gson:2.8.6'

    implementation 'ru.superjob:kotlin-permissions:1.0.3'

    implementation 'com.google.firebase:firebase-core:17.2.1'
    implementation 'com.google.firebase:firebase-firestore:21.3.1'

FirebaseProduct.kt

data class FirebaseProduct(
    val name: String = "",
    val description: String = "",
    val url: String = ""
)

ic_add.xml

<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="#FFFFFF"
        android:pathData="M19,13H13V19H11V13H5V11H11V5H13V11H19V13Z" />
</vector>

item_product.xml

<?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:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical">

    <ImageView
        android:id="@+id/imgItemProduct"
        android:layout_width="64dp"
        android:layout_height="64dp"
        android:layout_margin="10dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        tools:src="@tools:sample/avatars" />

    <TextView
        android:id="@+id/txtItemProductName"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_marginStart="5dp"
        android:layout_marginEnd="10dp"
        android:textSize="20sp"
        app:layout_constraintBottom_toTopOf="@id/txtItemProductDescr"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toEndOf="@id/imgItemProduct"
        app:layout_constraintTop_toTopOf="@id/imgItemProduct"
        tools:text="Product Name" />

    <TextView
        android:id="@+id/txtItemProductDescr"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_marginStart="5dp"
        android:layout_marginEnd="10dp"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toEndOf="@id/imgItemProduct"
        app:layout_constraintTop_toBottomOf="@id/txtItemProductName"
        tools:text="Product Description" />

</androidx.constraintlayout.widget.ConstraintLayout>

ProductJson.kt

import com.google.gson.annotations.SerializedName

data class ProductJson(

    @field:SerializedName("descrip")
    val descrip: String? = null,

    @field:SerializedName("name")
    val name: String? = null,

    @field:SerializedName("url")
    val url: String? = null
)

url

https://tinyurl.com/firebaseworkshopdevfest