RecyclerView ItemDecorator to add dividers to vertical LinearLayoutManager items

DividerItemDecoration.java

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.v7.widget.RecyclerView;
import android.view.View;

public class ItemDividerDecoration extends RecyclerView.ItemDecoration {
  private final Drawable divider;

  public ItemDividerDecoration(Context context) {
    final TypedArray a = context.obtainStyledAttributes(new int[]{ android.R.attr.listDivider });
    divider = a.getDrawable(0);
    a.recycle();
  }

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

    for (int idx = 0; idx < childCount; idx++) {
      View view = parent.getChildAt(idx);
      if (shouldDraw(parent, view)) {
        RecyclerView.LayoutParams lp = (RecyclerView.LayoutParams) view.getLayoutParams();
        final int top = view.getBottom() + lp.bottomMargin;
        final int bottom = top + divider.getIntrinsicHeight();
        divider.setBounds(left, top, right, bottom);
        divider.draw(c);
      }
    }
  }

  @Override public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
    if (shouldDraw(parent, view)) {
      outRect.bottom = divider.getIntrinsicHeight();
    } else {
      super.getItemOffsets(outRect, view, parent, state);
    }
  }

  protected boolean shouldDraw(RecyclerView parent, View view) {
    return !isLast(parent, view);
  }

  protected boolean isLast(RecyclerView parent, View view) {
    return parent.getChildAdapterPosition(view) == parent.getAdapter().getItemCount() - 1;
  }
}