DatePickerFragment.java

package ru.orlovph.criminalintent2020;

import android.app.Activity;
import android.app.Dialog;
import android.content.DialogInterface;
import android.content.Intent;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.widget.DatePicker;

import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.appcompat.app.AlertDialog;
import androidx.fragment.app.DialogFragment;

import java.util.Calendar;
import java.util.Date;
import java.util.GregorianCalendar;

public class DatePickerFragment extends DialogFragment {
    private static final String ARG_DATE = "date";
    public static final String EXTRA_DATE = "ru.orlovph.criminalintent2020.date";

    private DatePicker mDatePicker;

    public static DatePickerFragment newInstance(Date date){
        Bundle args = new Bundle();
        args.putSerializable(ARG_DATE,date);

        DatePickerFragment fragment = new DatePickerFragment();
        fragment.setArguments(args);
        return fragment;
    }

    @NonNull
    @Override
    public Dialog onCreateDialog(@Nullable Bundle savedInstanceState) {
        Date date = (Date) getArguments().getSerializable(ARG_DATE);

        Calendar calendar = Calendar.getInstance();
        calendar.setTime(date);
        int year = calendar.get(Calendar.YEAR);
        int month = calendar.get(Calendar.MONTH);
        int day = calendar.get(Calendar.DAY_OF_MONTH);

        View view = LayoutInflater.from(getActivity())
                .inflate(R.layout.dialog_date,null);

        mDatePicker = view.findViewById(R.id.dialog_date_picker);
        mDatePicker.init(year,month,day,null);

        return new AlertDialog.Builder(getActivity())
                .setView(view)
                .setTitle(R.string.date_picker_title)
                .setPositiveButton(android.R.string.ok,
                        new DialogInterface.OnClickListener() {
                            @Override
                            public void onClick(DialogInterface dialog, int which) {
                                int year = mDatePicker.getYear();
                                int month = mDatePicker.getMonth();
                                int day = mDatePicker.getDayOfMonth();
                                Date date = new GregorianCalendar(year,month,day).getTime();
                                sendResult(Activity.RESULT_OK,date);
                            }
                        })
                .create();
    }

    private void sendResult(int resultCode, Date date){
        if (getTargetFragment() == null){
            return;
        }

        Intent intent = new Intent();
        intent.putExtra(EXTRA_DATE, date);

        getTargetFragment()
                .onActivityResult(getTargetRequestCode(),resultCode,intent);
    }
}