ANDROID RECYCLERVIEW - FUNDAMENTALS 02

STEP 1 : Create the item layout

<?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">

    <ImageView
        android:id="@+id/quality_image"
        android:layout_width="@dimen/icon_size"
        android:layout_height="60dp"
        android:layout_marginStart="16dp"
        android:layout_marginTop="8dp"
        android:layout_marginBottom="8dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        tools:srcCompat="@drawable/ic_sleep_5"/>

    <TextView
        android:id="@+id/sleep_length"
        android:layout_width="0dp"
        android:layout_height="20dp"
        android:layout_marginStart="8dp"
        android:layout_marginTop="8dp"
        android:layout_marginEnd="16dp"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toEndOf="@id/quality_image"
        app:layout_constraintTop_toTopOf="@id/quality_image"
        tools:text="Wednesday" />
    
    <TextView
        android:id="@+id/quality_string"
        android:layout_width="0dp"
        android:layout_height="20dp"
        android:layout_marginTop="8dp"
        app:layout_constraintEnd_toEndOf="@+id/sleep_length"
        app:layout_constraintHorizontal_bias="0.0"
        app:layout_constraintStart_toStartOf="@+id/sleep_length"
        app:layout_constraintTop_toBottomOf="@+id/sleep_length"
        tools:text="Excellent!!!" />
    
</androidx.constraintlayout.widget.ConstraintLayout>

STEP 2 : Create ViewHolder

ViewHolder

class SleepNightAdapter : RecyclerView.Adapter<SleepNightAdapter.ViewHolder>() {
	...
	class ViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {
    		...
       }
}

Adapter

STEP 3 : Refactoring

Refactor onBindViewHolder()

In this step, you refactor the code and move all the view holder functionality into the ViewHolder. The purpose of this refactoring is not to change how the app looks to the user, but make it easier and safer for developers to work on the code. Fortunately, Android Studio has tools to help.

Refactor onCreateViewHolder

The onCreateViewHolder() method in the adapter currently inflates the view from the layout resource for the ViewHolder. However, inflation has nothing to do with the adapter, and everything to do with the ViewHolder. Inflation should happen in the ViewHolder.