How to create two even rows in recycler-view?

Question

Java

We need a recycler view (grid layout) with two even rows of images (the indents on the sides of the recycler view and between the images should be the same). How can I do that?
Here is the layout code on which the recycler-view works

Here is the layout code on which the recycler-view works

<android.support.v7.widget.CardView xmlns:tools="http://schemas.android.com/tools"
    xmlns:card_view="http://schemas.android.com/apk/res-auto"
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="150dp"
    android:layout_height="150dp"
    android:background="@color/colorPrimary"
    card_view:cardUseCompatPadding="true"
    card_view:cardCornerRadius="8dp"
    android:layout_marginBottom="16dp">

    <ImageView
        android:id="@+id/tile_picture"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:scaleType="centerCrop"
        tools:src="@drawable/kfc" />

</android.support.v7.widget.CardView>

And here's what happens.

Vertical orientation (to illustrate the problem)

Answer 1

Alternatively, you can set the width of the card to "match_parent", and specify the padding through RecyclerView.ItemDecorator.
spacing - расстояние между элементами
margin - отступ между крайними элементами и экраном, по умолчанию равно spacing

import android.graphics.Rect
import android.view.View
import androidx.recyclerview.widget.GridLayoutManager
import androidx.recyclerview.widget.RecyclerView

class GridItemDecorator(
        private val spacing: Int,
        private val margin: Int = spacing
) : RecyclerView.ItemDecoration() {

    private val halfSpacing = spacing / 2

    override fun getItemOffsets(outRect: Rect, view: View, parent: RecyclerView, state: RecyclerView.State) {
        val columns = (parent.layoutManager as? GridLayoutManager)?.spanCount ?: 1
        val rows = parent.adapter?.itemCount?.div(columns) ?: 1

        val pos = parent.getChildAdapterPosition(view)

        fun setTopSpacing() {
            if (pos / columns + 1 == 1) {
                outRect.top = margin
            } else {
                outRect.top = halfSpacing
            }
        }

        fun setBottomSpacing() {
            if (pos / columns + 1 == rows) {
                outRect.bottom = margin
            } else {
                outRect.bottom = halfSpacing
            }
        }

        fun setLeftSpacing() {
            if (pos % columns == 0) {
                outRect.left = margin
            } else {
                outRect.left = halfSpacing
            }
        }

        fun setRightSpacing() {
            if (pos % columns == columns - 1) {
                outRect.right = margin
            } else {
                outRect.right = halfSpacing
            }
        }

        setTopSpacing()
        setBottomSpacing()
        setLeftSpacing()
        setRightSpacing()
    }
}