RecyclerView patterns

README.md

RecyclerView:

1. Show Scrollbar on RecyclerView https://stackoverflow.com/questions/3103132/android-listview-scrollbarstyle
2. Show DividerItemDecoration between items in RecyclerView

RecyclerView1.xml

android:scrollbarSize="2dp"
android:scrollbarStyle="insideOverlay"
android:fadeScrollbars="false"
android:scrollbarThumbVertical="@drawable/app_scrollbar_recycler_view"//with margin
android:scrollbars="vertical"

<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:right="4dp"> <!-- Your Margin -->
        <shape>
            <solid android:color="@color/colorAccent" /> <!-- Your Color -->
            <corners android:radius="2dp" /> <!-- Your Radius -->
            <size android:width="4dp" /> <!-- Your Width -->
        </shape>
    </item>
</layer-list>

RecyclerView2.java

import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.drawable.Drawable;
import android.view.View;

import androidx.annotation.DrawableRes;
import androidx.annotation.NonNull;
import androidx.core.content.ContextCompat;
import androidx.recyclerview.widget.RecyclerView;

/**
 * Created by Nikolay Unuchek on 08.02.2017.
 */

public class DividerItemDecoration extends RecyclerView.ItemDecoration {

    private static final int[] ATTRS = new int[]{android.R.attr.listDivider};

    private Drawable mDivider;

    /**
     * Default divider will be used
     */
    public DividerItemDecoration(Context context) {
        final TypedArray styledAttributes = context.obtainStyledAttributes(ATTRS);
        mDivider = styledAttributes.getDrawable(0);
        styledAttributes.recycle();
    }

    /**
     * Custom divider will be used
     */
    public DividerItemDecoration(Context context, @DrawableRes int resId) {
        mDivider = ContextCompat.getDrawable(context, resId);
    }

    @Override
    public void onDraw(@NonNull Canvas canvas, @NonNull RecyclerView parent, @NonNull RecyclerView.State state) {
        int left = parent.getPaddingLeft();
        int right = parent.getWidth() - parent.getPaddingRight();

        int childCount = parent.getChildCount();
        for (int i = 0; i < childCount; i++) {
            View child = parent.getChildAt(i);

            RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child.getLayoutParams();

            int top = child.getBottom() + params.bottomMargin;
            int bottom = top + mDivider.getIntrinsicHeight();

            mDivider.setBounds(left, top, right, bottom);
            mDivider.draw(canvas);
        }
    }
}