import android.content.Context;
import android.graphics.Rect;
import android.support.annotation.DimenRes;
import android.support.annotation.NonNull;
import android.support.v7.widget.RecyclerView;
import android.view.View;

/**
 * Created by wrewolf on 13.02.18.
 */

public class GridSpacingItemDecoration extends RecyclerView.ItemDecoration {

    private int columnCount;
    private int f_spasing;
    private int h_spasing;

    public GridSpacingItemDecoration(@NonNull Context context, @DimenRes int itemOffsetId, @NonNull int columnCount) {
        this(context.getResources().getDimensionPixelSize(itemOffsetId), columnCount);
    }

    public GridSpacingItemDecoration(int spacing, int columnCount) {
        this.columnCount = columnCount;
        this.f_spasing = spacing;
        this.h_spasing = spacing / 2;
    }

    @Override
    public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
        super.getItemOffsets(outRect, view, parent, state);
        int position = parent.getChildAdapterPosition(view); // item position

        outRect.top = 0;
        outRect.left = 0;
        outRect.right = 0;
        outRect.bottom = 0;
        if (position > 0) {
            outRect.top = f_spasing;
            if (this.columnCount == 2) {
                if (position % 2 == 0) {
                    outRect.left = h_spasing;
                    outRect.right = f_spasing;
                } else {
                    outRect.left = f_spasing;
                    outRect.right = h_spasing;
                }
            } else {
                if (position % columnCount == 0) {
                    outRect.left = h_spasing;
                    outRect.right = f_spasing;
                } else if (position % columnCount == 1) {
                    outRect.left = f_spasing;
                    outRect.right = h_spasing;
                } else {
                    outRect.left = h_spasing;
                    outRect.right = h_spasing;
                }
            }
        }
    }
}