如何使用TextWatcher检查给定的文本是否有效？

import android.text.Editable;
import android.text.TextWatcher;
import android.widget.EditText;

public class MainActivity extends AppCompatActivity {

    private EditText emailEditText;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        emailEditText = findViewById(R.id.emailEditText);

        emailEditText.addTextChangedListener(new TextWatcher() {
            @Override
            public void beforeTextChanged(CharSequence s, int start, int count, int after) {
                // 文本变化之前的操作
            }

            @Override
            public void onTextChanged(CharSequence s, int start, int before, int count) {
                // 文本变化时的操作
            }

            @Override
            public void afterTextChanged(Editable s) {
                String email = s.toString();
                if (isValidEmail(email)) {
                    emailEditText.setError(null); // 清除错误提示
                } else {
                    emailEditText.setError("Invalid email address"); // 设置错误提示
                }
            }
        });
    }

    private boolean isValidEmail(String email) {
        if (email == null) {
            return false;
        }
        // 简单的正则表达式检查电子邮件格式
        String emailPattern = "[a-zA-Z0-9._-]+@[a-z]+\\.+[a-z]+";
        return email.matches(emailPattern);
    }
}

import android.os.Handler;
import android.os.Looper;

public class DebouncedTextWatcher implements TextWatcher {
    private final TextWatcher delegate;
    private final Handler handler = new Handler(Looper.getMainLooper());
    private final long delay = 300; // 延迟时间，单位毫秒
    private Runnable pendingRunnable;

    public DebouncedTextWatcher(TextWatcher delegate) {
        this.delegate = delegate;
    }

    @Override
    public void beforeTextChanged(CharSequence s, int start, int count, int after) {
        delegate.beforeTextChanged(s, start, count, after);
    }

    @Override
    public void onTextChanged(CharSequence s, int start, int before, int count) {
        if (pendingRunnable != null) {
            handler.removeCallbacks(pendingRunnable);
        }
        pendingRunnable = () -> delegate.afterTextChanged(s);
        handler.postDelayed(pendingRunnable, delay);
    }

    @Override
    public void afterTextChanged(Editable s) {
        // 不需要实现，因为逻辑在 onTextChanged 中处理
    }
}