如何在安卓系统中保持从baseAdapter收到的奇数个按钮呈三角形？

public class MyAdapter extends BaseAdapter {
    private List<String> data;
    private Context context;

    public MyAdapter(List<String> data, Context context) {
        this.data = data;
        this.context = context;
    }

    @Override
    public int getCount() {
        return data.size();
    }

    @Override
    public Object getItem(int position) {
        return data.get(position);
    }

    @Override
    public long getItemId(int position) {
        return position;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        ViewHolder holder;
        if (convertView == null) {
            convertView = LayoutInflater.from(context).inflate(R.layout.item_layout, parent, false);
            holder = new ViewHolder();
            holder.button = convertView.findViewById(R.id.button);
            convertView.setTag(holder);
        } else {
            holder = (ViewHolder) convertView.getTag();
        }

        // 判断按钮数量是否为奇数
        if (getCount() % 2 == 1) {
            // 如果是奇数，且当前位置为最后一个按钮，则设置形状为三角形
            if (position == getCount() - 1) {
                // 创建三角形形状
                ShapeDrawable triangle = new ShapeDrawable(new TriangleShape());
                holder.button.setBackground(triangle);
            } else {
                // 其他按钮形状设置为默认
                holder.button.setBackground(context.getDrawable(R.drawable.default_shape));
            }
        } else {
            // 按钮数量为偶数，所有按钮形状设置为默认
            holder.button.setBackground(context.getDrawable(R.drawable.default_shape));
        }

        return convertView;
    }

    private static class ViewHolder {
        Button button;
    }
}

// 自定义三角形形状
public class TriangleShape extends Shape {
    @Override
    public void draw(Canvas canvas, Paint paint) {
        Path path = new Path();
        path.moveTo(0, 0);
        path.lineTo(0, canvas.getHeight());
        path.lineTo(canvas.getWidth(), canvas.getHeight() / 2);
        path.close();
        canvas.drawPath(path, paint);
    }
}