DividerItemDecoration

DividerItemDecoration

import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Rect;
import android.graphics.drawable.Drawable;
import android.support.annotation.DimenRes;
import android.support.annotation.DrawableRes;
import android.support.v7.widget.RecyclerView;
import android.view.View;


public class DividerItemDecoration extends RecyclerView.ItemDecoration {

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

    private Drawable divider;
    private int insets;
    private Context context;
    private boolean addInsets = false;

    public DividerItemDecoration(Context context, Drawable divider) {
        this.context = context;
        this.divider = divider;
    }

    public DividerItemDecoration(Context context) {
        this.context = context;
        TypedArray a = context.obtainStyledAttributes(ATTRS);
        divider = a.getDrawable(0);
        a.recycle();
    }

    public void setDivider(@DrawableRes int dividerDrawableRes) {
        divider = context.getResources().getDrawable(dividerDrawableRes);
    }

    public void setInsets(@DimenRes int insets) {
        addInsets = true;
        this.insets = context.getResources().getDimensionPixelSize(insets);
    }

    @Override
    public void onDrawOver(Canvas canvas, RecyclerView parent, RecyclerView.State state) {
        drawHorizontal(canvas, parent);
        drawToTheRightOfEachChildren(canvas, parent);
    }

    public void drawHorizontal(Canvas c, RecyclerView parent) {
        int childCount = parent.getChildCount();
        if (childCount == 0) return;
        int left, top , right, bottom;
        View currentChild;
        for (int i = 0; i < childCount; i++) {
            currentChild = parent.getChildAt(i);
            int currentChildBottom = currentChild.getBottom();
            if (currentChildBottom > parent.getPaddingTop() && currentChildBottom < parent.getBottom() - parent.getPaddingBottom()) {
                left = currentChild.getLeft();
                right = currentChild.getRight();
                top = currentChildBottom;
                bottom = top + divider.getIntrinsicHeight();
                divider.setBounds(left, top, right, bottom);
                divider.draw(c);
            }
        }
    }

    public void drawToTheRightOfEachChildren(Canvas c, RecyclerView parent) {
        if (parent.getChildCount() == 0) return;
        int top, left, right, bottom;
        int childCount = parent.getChildCount();
        View currentChild;
        for (int i = 0; i < childCount; i++) {
            currentChild = parent.getChildAt(i);
            int offset = 2;
            if (currentChild.getRight() < parent.getRight() - parent.getPaddingRight() - offset) {
                //Avoid drawing over top padding
                top = currentChild.getTop();
                if (top < parent.getPaddingTop()) {
                    top = parent.getPaddingTop();
                }
                bottom = currentChild.getBottom() + divider.getIntrinsicHeight();
                //Avoid drawing over bottom padding
                int parentBottom = parent.getBottom() - parent.getPaddingBottom();
                if (bottom > parentBottom) {
                    bottom = parentBottom;
                }
                left = currentChild.getRight();
                right = left + divider.getIntrinsicWidth();
                divider.setBounds(left, top, right, bottom);
                divider.draw(c);
            }
        }
    }

    @Override
    public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
        //We can supply forced insets for each item view here in the Rect
        if (addInsets) {
            outRect.set(insets, insets, insets, insets);
        }
    }
}

//HOW TO USE:

Just create the DividerItemDecoration object and either provide a divider or default will be used:

    DividerItemDecoration dividerItemDecoration = new DividerItemDecoration(activity, getResources().getDrawable(R.drawable.list_divider));

or 
    DividerItemDecoration dividerItemDecoration = new DividerItemDecoration(activity);

and then set it to he recyclerView:

        gesturesRecyclerView.addItemDecoration(dividerItemDecoration);