Как понять, что пользователь закончил ввод текста в поле?

EditText searchField;
 
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        searchField = (EditText) findViewById(R.id.searchField);
 
        createSearchFieldObservable()
                .debounce(500, TimeUnit.MILLISECONDS)
                .observeOn(AndroidSchedulers.mainThread())
                .subscribe(new Consumer<String>() {
                    @Override
                    public void accept(@NonNull String text) throws Exception {
                        Toast.makeText(MainActivity.this, text, Toast.LENGTH_SHORT).show();
                    }
                });
    }
 
    private Observable<String> createSearchFieldObservable() {
        return Observable.create(new ObservableOnSubscribe<String>() {
            @Override
            public void subscribe(@NonNull final ObservableEmitter<String> emitter) throws Exception {
                final TextWatcher textChangeObserver = new TextWatcher() {
                    @Override
                    public void onTextChanged(CharSequence s, int start, int before, int count) {
                        emitter.onNext(s.toString());
                    }
 
                    @Override
                    public void beforeTextChanged(CharSequence s, int start, int count, int after) { /*NOP*/ }
 
                    @Override
                    public void afterTextChanged(Editable s) { /*NOP*/ }
                };
 
                searchField.addTextChangedListener(textChangeObserver);
 
                emitter.setCancellable(new Cancellable() {
                    @Override
                    public void cancel() throws Exception {
                        searchField.removeTextChangedListener(textChangeObserver);
                    }
                });
            }
        });
    }

RxTextView.textChanges(searchField)
                .debounce(500, TimeUnit.MILLISECONDS)
                .observeOn(AndroidSchedulers.mainThread())
                .subscribe(new Consumer<CharSequence>() {
                    @Override
                    public void accept(@NonNull CharSequence text) throws Exception {
                        // do some stuff
                    }
                });

import android.os.Handler;
import android.os.Looper;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import android.text.Editable;
import android.text.TextWatcher;
import android.widget.EditText;
 
import java.lang.ref.WeakReference;
 
public final class EditTextDebounce {
    private final WeakReference<EditText> editTextWeakReference;
    private final Handler debounceHandler;
    private DebounceCallback debounceCallback;
    private Runnable debounceWorker;
    private int delayMillis;
    private final TextWatcher textWatcher;
 
    public static EditTextDebounce create(@NonNull EditText editText) {
        return new EditTextDebounce(editText);
    }
 
    public static EditTextDebounce create(@NonNull EditText editText, int delayMillis) {
        EditTextDebounce editTextDebounce = new EditTextDebounce(editText);
        editTextDebounce.setDelayMillis(delayMillis);
        return editTextDebounce;
    }
 
    private EditTextDebounce(@NonNull EditText editText) {
        this.debounceHandler = new Handler(Looper.getMainLooper());
        this.debounceWorker = new DebounceRunnable("", null);
        this.delayMillis = 300;
        this.textWatcher = new TextWatcher() {
            @Override
            public void beforeTextChanged(CharSequence s, int start, int count, int after) {
                //unused
            }
 
            @Override
            public void onTextChanged(CharSequence s, int start, int before, int count) {
                //unused
            }
 
            @Override
            public void afterTextChanged(Editable s) {
                debounceHandler.removeCallbacks(debounceWorker);
                debounceWorker = new DebounceRunnable(s.toString(), debounceCallback);
                debounceHandler.postDelayed(debounceWorker, delayMillis);
            }
        };
        this.editTextWeakReference = new WeakReference<>(editText);
        EditText editTextInternal = this.editTextWeakReference.get();
        if (editTextInternal != null) {
            editTextInternal.addTextChangedListener(textWatcher);
        }
    }
 
    public void watch(@Nullable DebounceCallback debounceCallback) {
        this.debounceCallback = debounceCallback;
    }
 
    public void watch(@Nullable DebounceCallback debounceCallback, int delayMillis) {
        this.debounceCallback = debounceCallback;
        this.delayMillis = delayMillis;
    }
 
    public void unwatch() {
        if (editTextWeakReference != null) {
            EditText editText = editTextWeakReference.get();
            if (editText != null) {
                editText.removeTextChangedListener(textWatcher);
                editTextWeakReference.clear();
                debounceHandler.removeCallbacks(debounceWorker);
            }
        }
    }
 
    private void setDelayMillis(int delayMillis) {
        this.delayMillis = delayMillis;
    }
 
    private static class DebounceRunnable implements Runnable {
 
        private final String result;
        private final DebounceCallback debounceCallback;
 
        DebounceRunnable(String result, DebounceCallback debounceCallback) {
            this.result = result;
            this.debounceCallback = debounceCallback;
        }
 
        @Override
        public void run() {
            if (debounceCallback != null) {
                debounceCallback.onFinished(result);
            }
        }
    }
 
    public interface DebounceCallback {
        void onFinished(@NonNull String result);
    }
 
}

        EditTextDebounce.create(fieldName)
                .watch(new EditTextDebounce.DebounceCallback() {
                    @Override
                    public void onFinished(@NonNull String result) {
                        Log.i(getClass().getSimpleName(), "onFinished: " + result);
                    }
                }, 1000);