如何在editText中高亮显示搜索结果，而不丢失分隔线

import android.graphics.Color;
import android.text.Spannable;
import android.text.SpannableStringBuilder;
import android.text.style.ForegroundColorSpan;
import android.widget.EditText;

public class MainActivity extends AppCompatActivity {

    private EditText editText;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        
        editText = findViewById(R.id.edit_text);
        
        // 输入框中的文本
        String text = editText.getText().toString();
        
        // 搜索关键词
        String keyword = "搜索关键词";
        
        // 获取匹配的位置
        List<Integer> positions = findKeywordPositions(text, keyword);
        
        // 构建Spannable字符串
        SpannableStringBuilder builder = new SpannableStringBuilder(text);
        
        // 遍历每个匹配位置，设置高亮显示
        for (Integer position : positions) {
            builder.setSpan(new ForegroundColorSpan(Color.RED), position, position + keyword.length(), Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
        }
        
        // 将Spannable字符串设置到editText中显示
        editText.setText(builder);
    }

    // 查找匹配的位置
    private List<Integer> findKeywordPositions(String text, String keyword) {
        List<Integer> positions = new ArrayList<>();
        int index = text.indexOf(keyword);
        while (index >= 0) {
            positions.add(index);
            index = text.indexOf(keyword, index + 1);
        }
        return positions;
    }
}