Improve spacing between recycleView items

Question

I have an activity with recycleView this is what I should show in design

I use this code to show it

    val arr:ArrayList<string> = arrayListOf("English","Intermediate","English","English","arr","UICollectionViewFlowLayoutFlowFlowFlow","English","UICollectionViewDelegate","English","Intermediate","UIViewController","viewDidLoad","Intermediate","String","Intermediate","arr","Intermediate","UIKit","Intermediate","English","columnLayout","English","languageLabel")

    recyclerView.setLayoutDirection(View.LAYOUT_DIRECTION_RTL)

    recyclerView.layoutManager = GridLayoutManager(this, 3)

    adaAdapter = CustomAdapter(this, arr)

    recyclerView.adapter = adaAdapter

With this adapter

class CustomAdapter(val context: DreamsActivity, val items: ArrayList<String>) : RecyclerView.Adapter<CustomAdapter.ViewHolderProductList>() {

    // holds this device's screen width,
    private var screenWidth = 0

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ViewHolderProductList {

        val displayMetrics = DisplayMetrics()

        context.windowManager.getDefaultDisplay().getMetrics(displayMetrics)

        screenWidth = displayMetrics.widthPixels

        val layoutInflater = LayoutInflater.from(parent.context)

        val cellForRow = layoutInflater.inflate(R.layout.dreams_collection,parent, false)

        val devicewidth: Int = (displayMetrics.widthPixels / 3) - 10

        val params = cellForRow.getLayoutParams() as GridLayoutManager.LayoutParams

        params.width = devicewidth

        cellForRow.setLayoutParams(params)

        return ViewHolderProductList(cellForRow)

    }

    override fun getItemCount(): Int {
        return items.size
    }

    override fun onBindViewHolder(holder: ViewHolderProductList, position: Int) {

        val item = items[position]

        holder.typeTv.text = item

    }

    inner class ViewHolderProductList(itemView: View) : RecyclerView.ViewHolder(itemView) {
        var typeTv: TextView =  itemView.findViewById(R.id.typeTv)
        var mainL: ConstraintLayout =  itemView.findViewById(R.id.mainL)


    }
}

With this 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">
  
    <RecyclerView
        android:id="@+id/recyclerView"
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:layout_marginStart="10dp"
        android:layout_marginTop="20dp"
        android:layout_marginEnd="10dp"
        android:layout_marginBottom="15dp"
        android:background="#FFFFFF"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" /> 

</androidx.constraintlayout.widget.ConstraintLayout>

And 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:id="@+id/mainL"
    android:layout_width="60dp"
    android:padding="10dp"
    android:layout_height="wrap_content">

    <androidx.constraintlayout.widget.ConstraintLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <TextView
            android:id="@+id/typeTv"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginStart="5dp"
            android:layout_marginTop="5dp"
            android:layout_marginEnd="5dp"
            android:layout_marginBottom="5dp"
            android:text="TextView"
            android:textSize="14sp"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toTopOf="parent" />
        </androidx.constraintlayout.widget.ConstraintLayout>

</androidx.constraintlayout.widget.ConstraintLayout>

But I got this

And don't know how to do it as I need the number of items to be dynamic according to the text length but the GridLayoutManager only sets the number of columns static.

Any help is greatly appreciated

Answer 1

What you're asking for is something with the visual look of a Chip from Material Components. While the documentation for Chips suggests putting them in a ChipGroup, this loses the benefit of recycling views if you have more than enough to cover the screen. On the other hand, if they need to behave like a RadioGroup, where you can select only one to be toggled at a time, then ChipGroup would be easier to use.

To do this with RecylerView, you can change your item view layouts to use a Chip instead of a TextView. Set the item's layout width to wrapContent. Then use Google's Flexbox Layout library to get the layout with variable length items.

In Gradle dependencies: implementation 'com.google.android.flexbox:flexbox:3.0.0'

In your activity:

recyclerView.layoutManager = FlexboxLayoutManager(this)
    .apply { flexDirection = FlexDirection.ROW }

Result:

There's a related question here that is helpful.

Answer 2

The desired layout tends to be Chips rather than a RecyclerView

Here is a demo:

Material app gradle dependency: implementation 'com.google.android.material:material:1.4.0'

Layout:

<com.google.android.material.chip.ChipGroup xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/my_chip_group"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:padding="8dp"
    app:chipSpacing="16dp"
    app:chipSpacingHorizontal="4dp"
    app:chipSpacingVertical="4dp" />

Adding chips:

val arr =
    arrayListOf(
        "English",
        "Intermediate",
        "English",
        "English",
        "arr",
        "UICollectionViewFlowLayoutFlowFlowFlow",
        "English",
        "UICollectionViewDelegate",
        "English",
        "Intermediate",
        "UIViewController",
        "viewDidLoad",
        "Intermediate",
        "String",
        "Intermediate",
        "arr",
        "Intermediate",
        "UIKit",
        "Intermediate",
        "English",
        "columnLayout",
        "English",
        "languageLabel"
    )

fun addChips(context: Context) {
    val chipGroup = findViewById<ChipGroup>(R.id.my_chip_group)
    
    for (i in 0 until arr.size) {
        val chip = Chip(context)
        chip.layoutParams = FrameLayout.LayoutParams(WRAP_CONTENT, WRAP_CONTENT)
        chip.text = arr[i]
        chipGroup.addView(chip)
    }
}