ntakouris

public interface TextValidator {
    /*Outputs null for no errors, or else the error in a user friendly text*/
    String validate(String content);
}

ntakouris

public interface SimpleCallback<T> {
    void call(T payload);
}

ntakouris

public interface TextViewHelper {
    default String getTextAsString(TextView textView){
        return textView.getText().toString();
    }
}

ntakouris

public class AutoValidatedTextInputEditText extends TextInputEditText implements AutoValidatedUserInputComponent, TextViewHelper {

    List<TextValidator> validatorList = new ArrayList<>();
    boolean isValid = false;

    public AutoValidatedTextInputEditText(Context context) {
        super(context);
        SimpleCallback callback = payload -> validate();
        setOnFocusChangeListener(new OnFocusChangeListener(callback));
        addTextChangedListener(new OnTextChangeListener(callback));

ntakouris

public interface AutoValidatedUserInputComponent {
	    boolean hasValidInput();
	    boolean requestFocus();/* This one is usually already implemented on View objects*/
}

ntakouris

@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.FIELD)
public @interface ValidComponent {}

ntakouris

public class ComponentValidator {

    private static final ComponentValidator _instance;

    static {
        _instance = new ComponentValidator();
    }

    private ComponentValidator() {
    }

ntakouris

@ValidComponent
AutoValidatedTextInputEditText usernameEditText;

@ValidComponent
AutoValidatedTextInputEditText birthdateEditText;

Button submit;
    
/* ...   snip  ... */
final static String userFriendlyBirthdayDateFormat = "MM/dd/yy";

ntakouris

public interface Callback<T> {
        default void onSuccessfulResponse(ResponseBody<T> responseBody) {
        }

        default void onBadRequest(List<ErrorModel> errors) {
        }

        default void onServerError(Response response) {
        }

ntakouris

public class ApiResponseCallbackAdapter<T> implements Callback<ApiResponse<T>> {

    Callback<T> callback;

    public ApiResponseCallbackAdapter(Callback<T> callback) {
        this.callback = callback;
    }

    @Override
    public void onResponse(Call<ApiResponse<T>> call, Response<ApiResponse<T>> response) {