Challenge: More Dialogs, etc

Hello! I found this challenge pretty straightforward except for all the messing around I had to do with date and time formatting… but I think I cracked it. Would love any thoughts/improvements!

First of all, following the book exactly, I noticed that whenever a new date is chosen with DatePickerFragment, it would indeed send a new year, month, and day back to CrimeFragment, BUT reset the time to a default value (12:00 AM).

I addressed it by adding relevant hour and minute values to GregorianCalendar that were missing in the original (DatePickerFragment.kt):

... 

private const val ARG_DATE = "date"

class DatePickerFragment : DialogFragment() {

    interface Callbacks {
        fun onDateSelected(date:Date)
    }

    override fun onCreateDialog(savedInstanceState: Bundle?): Dialog {

        val date = arguments?.getSerializable(ARG_DATE) as Date
        val calendar = getInstance()
        calendar.time = date
        val calendarHour = calendar.get(HOUR_OF_DAY)
        val calendarMinute = calendar.get(MINUTE)

        val dateListener = DatePickerDialog.OnDateSetListener {
                _: DatePicker, year: Int, month: Int, day: Int ->
            val resultDate : Date =
                GregorianCalendar(year, month, day, calendarHour, calendarMinute).time

            targetFragment?.let { fragment ->
                (fragment as Callbacks).onDateSelected(resultDate)
                }
        }

        val initialYear = calendar.get(YEAR)
        val initialMonth = calendar.get(MONTH)
        val initialDay = calendar.get(DAY_OF_MONTH)

        return DatePickerDialog(
            requireContext(),
            dateListener,
            initialYear,
            initialMonth,
            initialDay
        )
    }
    ...
}

As for the challenge itself, I basically duplicated DatePickerFragment, adjusting as necessary to reflect the new TimePickerFragment, and of course adding a new button to fragment_crime.xml. Both DatePickerFragment and TimePickerFragment adjust the same Date object (the former changes year, month, and day; the latter hours and minutes). I also changed some of the Date formatting in CrimeFragment to make it a little neater.

TimePickerFragment.kt:

package com.bignerdranch.android.criminalintent

import android.app.Dialog
import android.app.TimePickerDialog
import android.os.Bundle
import android.widget.TimePicker
import androidx.fragment.app.DialogFragment
import java.util.*
import java.util.Calendar.*

private const val ARG_TIME = "time"

class TimePickerFragment: DialogFragment() {

    interface Callbacks {
        fun onTimeSelected(date: Date)
    }

    override fun onCreateDialog(SavedInstanceState: Bundle?): Dialog {
        val date = arguments?.getSerializable(ARG_TIME) as Date
        val calendar = getInstance()
        calendar.time = date
        val calendarYear = calendar.get(YEAR)
        val calendarMonth = calendar.get(MONTH)
        val calendarDay = calendar.get(DAY_OF_MONTH)

        val timeListener = TimePickerDialog.OnTimeSetListener {
                _: TimePicker, hourOfDay: Int, minute: Int ->
            val resultTime : Date =
                GregorianCalendar(calendarYear, calendarMonth, calendarDay, hourOfDay, minute).time

            targetFragment?.let { fragment ->
                (fragment as Callbacks).onTimeSelected(resultTime)
            }
        }

        val initialHour = calendar.get(HOUR_OF_DAY)
        val initialMinute = calendar.get(MINUTE)
        val is24HourView = false

        return TimePickerDialog(
            requireContext(),
            timeListener,
            initialHour,
            initialMinute,
            is24HourView
        )
    }

    companion object {
        fun newInstance(time: Date): TimePickerFragment {
            val args = Bundle().apply {
                putSerializable(ARG_TIME, time)
            }

            return TimePickerFragment().apply {
                arguments = args
            }
        }
    }
}

And here is CrimeFragment.kt:

package com.bignerdranch.android.criminalintent

import android.os.Bundle
import android.text.Editable
import android.text.TextWatcher
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import android.widget.Button
import android.widget.CheckBox
import android.widget.EditText
import androidx.fragment.app.Fragment
import androidx.lifecycle.Observer
import androidx.lifecycle.ViewModelProviders
import java.text.SimpleDateFormat
import java.util.*

private const val TAG = "CrimeFragment"
private const val ARG_CRIME_ID = "crime_id"
private const val DIALOG_DATE = "DialogDate"
private const val DIALOG_TIME = "DialogTime"
private const val REQUEST_DATE = 0
private const val REQUEST_TIME = 1

class CrimeFragment: Fragment(), DatePickerFragment.Callbacks, TimePickerFragment.Callbacks {

    private lateinit var crime: Crime
    private lateinit var titleField: EditText
    private lateinit var dateButton: Button
    private lateinit var timeButton: Button
    private lateinit var solvedCheckBox: CheckBox
    private val crimeDetailViewModel: CrimeDetailViewModel by lazy {
        ViewModelProviders.of(this).get(CrimeDetailViewModel::class.java)
    }

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        crime = Crime()
        val crimeId: UUID = arguments?.getSerializable(ARG_CRIME_ID) as UUID
     
        crimeDetailViewModel.loadCrime(crimeId)
    }

    override fun onCreateView(
        inflater: LayoutInflater,
        container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View? {
        val view = inflater.inflate(R.layout.fragment_crime, container, false)

        titleField = view.findViewById(R.id.crime_title) as EditText
        dateButton = view.findViewById(R.id.crime_date) as Button
        timeButton = view.findViewById(R.id.crime_time) as Button
        solvedCheckBox = view.findViewById(R.id.crime_solved) as CheckBox

        return view
    }
 
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
        super.onViewCreated(view, savedInstanceState)
        crimeDetailViewModel.crimeLiveData.observe(
            viewLifecycleOwner,
            Observer { crime -> crime?.let { this.crime = crime
                    updateUI()
                }
            })
    }

    override fun onStart() {
        super.onStart()

        val titleWatcher = object : TextWatcher {
            override fun beforeTextChanged(
                sequence: CharSequence?,
                start: Int,
                count: Int,
                after: Int
            ) {
                // This space intentionally left blank
            }

            override fun onTextChanged(
                sequence: CharSequence?,
                start: Int,
                before: Int,
                count: Int
            ) {
                crime.title = sequence.toString()
            }

            override fun afterTextChanged(sequence: Editable?) {
                // This one too
            }
        }

        titleField.addTextChangedListener(titleWatcher)

        solvedCheckBox.apply {
            setOnCheckedChangeListener { _, isChecked ->
                crime.isSolved = isChecked
            }
        }
        
        dateButton.setOnClickListener {
            DatePickerFragment.newInstance(crime.date).apply {       
                setTargetFragment(this@CrimeFragment, REQUEST_DATE)               
                show(this@CrimeFragment.requireFragmentManager(), DIALOG_DATE)
            }
        }

        timeButton.setOnClickListener {
            TimePickerFragment.newInstance(crime.date).apply {
                setTargetFragment(this@CrimeFragment, REQUEST_TIME)
                show(this@CrimeFragment.requireFragmentManager(), DIALOG_TIME)
            }
        }
    }

    override fun onStop() {
        super.onStop()
        crimeDetailViewModel.saveCrime(crime)
    }

    override fun onDateSelected(date: Date) {
        crime.date = date
        updateUI()
    }

    override fun onTimeSelected(date: Date) {
        crime.date = date
        updateUI()
    }

    private fun updateUI() {
        titleField.setText(crime.title)
        val crimeDate = SimpleDateFormat("EEEE, MMM d, YYYY")
            .format(this.crime.date)
        dateButton.text = crimeDate
        val crimeTime = SimpleDateFormat("hh:mm a")
            .format(this.crime.date)
        timeButton.text = crimeTime
        solvedCheckBox.apply {
            isChecked = crime.isSolved
            jumpDrawablesToCurrentState()
        }
    }

    companion object { 
        fun newInstance(crimeId: UUID): CrimeFragment { 
            val args = Bundle().apply {
                putSerializable(ARG_CRIME_ID, crimeId) 
            }
            return CrimeFragment().apply { 
                arguments = args
            }
        }
    }
}
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