无法在可搜索Activity中通过搜索Intent显示PopupWindow问题排查

我开发的是单Activity（主Activity）应用，ActionBar中设有搜索按钮。主Activity已在清单文件中标记为可搜索Activity，且配置了Intent Filter拦截搜索Intent。
我希望在PopupWindow中展示搜索结果，已编写对应的Intent处理逻辑，Logcat显示能成功接收搜索Intent及查询字符串，但PopupWindow始终无法显示。请问问题出在哪里？是否遗漏了配置？恳请提供帮助。

主Activity代码 #

public class MainActivity extends AppCompatActivity {

    View popupView;
    PopupWindow popupWindow;
    ConstraintLayout constraintLayout;
    ArrayList foodList = DatabaseOpenHelper.foodList;
    Context context;
    
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        constraintLayout = (ConstraintLayout) findViewById(R.id.activity_main_constaint_layout);

        context = getApplicationContext();

        AssetCopier assetCopier = new AssetCopier(this, "foods.db", "foods.db");
        DatabaseOpenHelper databaseOpenHelper = new DatabaseOpenHelper(this);
        databaseOpenHelper.getAllRecords();

        MyAdapter adapter = new MyAdapter();

        RecyclerView recyclerView = (RecyclerView) findViewById(R.id.recycler_view);
        recyclerView.setLayoutManager(new LinearLayoutManager(this));
        recyclerView.setAdapter(adapter);
        
        Intent intent = getIntent();
        handleIntent(intent);
    }

    public void handleIntent(Intent intent) {
        if (Intent.ACTION_SEARCH.equals(intent.getAction())) {
            String query = intent.getStringExtra(SearchManager.QUERY);
            Log.e("Message :","The search intent was received");
            Log.e("Message :","The search query was: " + query);

            LayoutInflater inflater = LayoutInflater.from(context);
            popupView = inflater.inflate(R.layout.popup_window, null);
            TextView textBox = (TextView) popupView.findViewById(R.id.text_box);
            textBox.setText("This is the popup Window");
            popupWindow = new PopupWindow(popupView);
            popupWindow.showAtLocation(constraintLayout, Gravity.CENTER, 0, 0);

        }
    }

    @Override
    protected void onNewIntent(Intent intent) {
        super.onNewIntent(intent);
        setIntent(intent);
        handleIntent(intent);
    }


    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        MenuInflater inflater = getMenuInflater();
        inflater.inflate(R.menu.appbar_menu, menu);

        // associate searchable configuration with the SearchView
        SearchManager searchManager = (SearchManager) getSystemService(Context.SEARCH_SERVICE);
        SearchView searchView = (SearchView) menu.findItem(R.id.search_box).getActionView();

        searchView.setSearchableInfo(searchManager.getSearchableInfo(getComponentName()));

    return super.onCreateOptionsMenu(menu);
    }
}

PopupWindow布局文件代码 #

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <TextView
        android:id="@+id/text_box"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="40dp"
        android:layout_marginTop="40dp"
        android:text="TextView"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>

内容的提问来源于stack exchange，提问作者azeemofwalsall