chore(mvvm): CalendarActivity ViewModel

This commit is contained in:
Peter Vacho 2025-01-22 21:59:54 +01:00
parent 6832d25163
commit 851b3c1f38
Signed by: school
GPG key ID: 8CFC3837052871B4
3 changed files with 179 additions and 127 deletions

View file

@ -5,35 +5,27 @@ import android.os.Bundle
import android.widget.ImageButton
import android.widget.TextView
import androidx.activity.enableEdgeToEdge
import androidx.activity.viewModels
import androidx.appcompat.app.AppCompatActivity
import androidx.core.view.ViewCompat
import androidx.core.view.WindowInsetsCompat
import androidx.recyclerview.widget.GridLayoutManager
import androidx.recyclerview.widget.RecyclerView
import androidx.lifecycle.lifecycleScope
import com.p_vacho.neat_calendar.MyApplication
import com.p_vacho.neat_calendar.R
import com.p_vacho.neat_calendar.adapters.CalendarDayItemAdapter
import com.p_vacho.neat_calendar.api.RetrofitClient
import com.p_vacho.neat_calendar.api.models.EventResponse
import com.p_vacho.neat_calendar.models.CalendarDay
import kotlinx.coroutines.launch
import com.p_vacho.neat_calendar.viewmodels.CalendarViewModel
import java.time.YearMonth
import java.time.ZoneId
import java.time.format.TextStyle
import java.util.Locale
class CalendarActivity : AppCompatActivity() {
private val viewModel: CalendarViewModel by viewModels()
private lateinit var adapter: CalendarDayItemAdapter
private lateinit var tvMonthYear: TextView
private lateinit var rvCalendar: RecyclerView
private lateinit var btnPreviousMonth: ImageButton
private lateinit var btnNextMonth: ImageButton
private val tokenManager by lazy { (application as MyApplication).tokenManager }
private var currentYearMonth: YearMonth = YearMonth.now()
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
enableEdgeToEdge()
@ -44,125 +36,31 @@ class CalendarActivity : AppCompatActivity() {
insets
}
initializeViews()
// Observers
viewModel.monthYearText.observe(this) { text -> tvMonthYear.text = text }
viewModel.calendarDays.observe(this) {days -> adapter.updateDays(days) }
// Listeners
btnPreviousMonth.setOnClickListener { viewModel.prevMonth() }
btnNextMonth.setOnClickListener { viewModel.nextMonth() }
// Setup for current month
viewModel.setCalendarMonth(YearMonth.now())
}
private fun initializeViews() {
tvMonthYear = findViewById(R.id.tvMonthYear)
rvCalendar = findViewById(R.id.rvCalendar)
btnPreviousMonth = findViewById(R.id.btnPreviousMonth)
btnNextMonth = findViewById(R.id.btnNextMonth)
setCalendarForMonth(currentYearMonth)
btnPreviousMonth.setOnClickListener {
currentYearMonth = currentYearMonth.minusMonths(1)
setCalendarForMonth(currentYearMonth)
}
btnNextMonth.setOnClickListener {
currentYearMonth = currentYearMonth.plusMonths(1)
setCalendarForMonth(currentYearMonth)
}
adapter = CalendarDayItemAdapter(listOf(), ::navigateToDayActivity)
rvCalendar.layoutManager = GridLayoutManager(this@CalendarActivity, 7) // 7 columns for days of the week
rvCalendar.adapter = adapter
}
/**
* Obtain all of the events that occur for each day in the given month from the API.
*
* The returned structure is a hashmap with int keys, being the day numbers in the month.
* If an event spans multiple days, it will be added for each of those days.
*
* Note that this also includes the events this user was invited into.
*/
private suspend fun fetchEventsForMonth(yearMonth: YearMonth): Map<Int, List<EventResponse>> {
// Use the system's default time zone
val zoneId = ZoneId.systemDefault()
// Get the start and end of the month in the local time zone
val startFrom = yearMonth.atDay(1).atStartOfDay(zoneId).toOffsetDateTime()
val endTo = yearMonth.atEndOfMonth().atTime(23, 59, 59).atZone(zoneId).toOffsetDateTime()
val userId = tokenManager.userId
if (userId.isNullOrEmpty()) {
navigateToMainActivity()
return emptyMap()
}
// BUG: Events that last longer than a month will not show
// up in the following month due to the startFrom filter here.
val userEvents = RetrofitClient.eventsService.userEvents(
userId = userId,
startFrom = startFrom,
startTo = endTo
)
val invitedEvents = RetrofitClient.eventsService.userEventsInvited(
userId = userId,
startFrom = startFrom,
startTo = endTo,
inviteStatus = "accepted"
)
val allEvents = userEvents + invitedEvents
// Create a mapping of days to events
val eventsByDay = mutableMapOf<Int, MutableList<EventResponse>>()
for (event in allEvents) {
val startDay = maxOf(event.start_time.dayOfMonth, 1)
val endDay = minOf(event.end_time.dayOfMonth, yearMonth.lengthOfMonth())
for (day in startDay..endDay) {
eventsByDay.computeIfAbsent(day) { mutableListOf() }.add(event)
}
}
return eventsByDay
}
private fun setCalendarForMonth(yearMonth: YearMonth) {
lifecycleScope.launch {
val firstDayOfMonth = yearMonth.atDay(1)
val daysInMonth = yearMonth.lengthOfMonth()
val eventsByDay = fetchEventsForMonth(yearMonth)
// Get localized month name and year
val monthYearText = "${
yearMonth.month.getDisplayName(
TextStyle.FULL,
Locale.getDefault()
)
} ${yearMonth.year}"
tvMonthYear.text = monthYearText
// Calculate the amount of placeholder slots until the first day in the month
// (Our calendar starts from Monday, but not all months start on monday, so we need fillers)
val startOffset = firstDayOfMonth.dayOfWeek.ordinal // Gives 0 (Monday) to 6 (Sunday)
// Generate calendar days
val days = mutableListOf<CalendarDay?>()
// Add padding (placeholder items) for days of the previous month
for (i in 1..startOffset) {
days.add(null)
}
// Add the actual days of the current month
for (i in 1..daysInMonth) {
val fullDate = yearMonth.atDay(i)
val eventsForDay = eventsByDay[i] ?: emptyList()
days.add(CalendarDay(date = fullDate, events = eventsForDay))
}
// Set up RecyclerView
rvCalendar.layoutManager = GridLayoutManager(this@CalendarActivity, 7) // 7 columns for days of the week
rvCalendar.adapter = CalendarDayItemAdapter(days) { day -> navigateToDayActivity(day) }
}
}
private fun navigateToMainActivity() {
val intent = Intent(this, MainActivity::class.java)
intent.flags = Intent.FLAG_ACTIVITY_CLEAR_TOP or Intent.FLAG_ACTIVITY_NEW_TASK
startActivity(intent)
finish() // Close the login screen
}
private fun navigateToDayActivity(day: CalendarDay) {
var intent = Intent(this, DayViewActivity::class.java)
@ -177,6 +75,6 @@ class CalendarActivity : AppCompatActivity() {
// Events could've been modified or even deleted, so make sure we have a fresh copy
// it would probably be better to pass these around through extras, this extra lookup
// isn't a huge deal, it's a potential future optimization though
setCalendarForMonth(currentYearMonth)
viewModel.refetch()
}
}

View file

@ -9,7 +9,7 @@ import androidx.recyclerview.widget.RecyclerView
import com.p_vacho.neat_calendar.R
import com.p_vacho.neat_calendar.models.CalendarDay
class CalendarDayItemAdapter(private val days: List<CalendarDay?>, private val onDayClicked: (CalendarDay) -> Unit) :
class CalendarDayItemAdapter(private var days: List<CalendarDay?>, private val onDayClicked: (CalendarDay) -> Unit) :
RecyclerView.Adapter<CalendarDayItemAdapter.DayViewHolder>() {
class DayViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {
@ -49,4 +49,17 @@ class CalendarDayItemAdapter(private val days: List<CalendarDay?>, private val o
}
override fun getItemCount(): Int = days.size
/**
* This function allows updating the day list.
*
* This will entirely overwrite the original data.
*/
fun updateDays(newDays: List<CalendarDay?>) {
days = newDays
// We're resetting to an entirely new list, this is needed
@Suppress("NotifyDataSetChanged")
notifyDataSetChanged()
}
}

View file

@ -0,0 +1,141 @@
package com.p_vacho.neat_calendar.viewmodels
import android.app.Application
import androidx.lifecycle.AndroidViewModel
import androidx.lifecycle.LiveData
import androidx.lifecycle.MutableLiveData
import androidx.lifecycle.viewModelScope
import com.p_vacho.neat_calendar.MyApplication
import com.p_vacho.neat_calendar.api.RetrofitClient
import com.p_vacho.neat_calendar.api.models.EventResponse
import com.p_vacho.neat_calendar.models.CalendarDay
import kotlinx.coroutines.Dispatchers
import kotlinx.coroutines.launch
import kotlinx.coroutines.withContext
import java.time.YearMonth
import java.time.ZoneId
import java.time.format.TextStyle
import java.util.Locale
class CalendarViewModel(application: Application) : AndroidViewModel(application) {
private var currentYearMonth: YearMonth? = null
private val _calendarDays = MutableLiveData<List<CalendarDay?>>()
val calendarDays: LiveData<List<CalendarDay?>> = _calendarDays
private val _monthYearText = MutableLiveData<String>()
val monthYearText: LiveData<String> = _monthYearText
/**
* Move to the next month.
*
* Can only be used after the initial setCalendarMonth.
*/
fun prevMonth() {
setCalendarMonth(currentYearMonth!!.minusMonths(1))
}
/**
* Move to the next month.
*
* Can only be used after the initial setCalendarMonth.
*/
fun nextMonth() {
setCalendarMonth(currentYearMonth!!.plusMonths(1))
}
/**
* Refetch the data for the currently selected month.
*
* Can only be used after the initial setCalendarMonth.
*/
fun refetch() {
setCalendarMonth(currentYearMonth!!)
}
/**
* Set up the view model for a specific month.
*/
fun setCalendarMonth(yearMonth: YearMonth) {
currentYearMonth = yearMonth
val firstDayOfMonth = yearMonth.atDay(1)
val daysInMonth = yearMonth.lengthOfMonth()
// Get localized month name and year name
val monthYearText = "${
yearMonth.month.getDisplayName(
TextStyle.FULL,
Locale.getDefault()
)
} ${yearMonth.year}"
_monthYearText.value = monthYearText
viewModelScope.launch {
val eventsByDay = withContext(Dispatchers.IO) { fetchEventsForMonthInternal(yearMonth) }
val startOffset = firstDayOfMonth.dayOfWeek.ordinal
val days = mutableListOf<CalendarDay?>()
for (i in 1..startOffset) {
days.add(null)
}
for (i in 1..daysInMonth) {
val fullDate = yearMonth.atDay(i)
val eventsForDay = eventsByDay[i] ?: emptyList()
days.add(CalendarDay(date = fullDate, events = eventsForDay))
}
_calendarDays.value = days
}
}
/**
* Obtain all of the events that occur for each day in the given month from the API.
*
* The returned structure is a hashmap with int keys, being the day numbers in the month.
* If an event spans multiple days, it will be added for each of those days.
*
* Note that this also includes the events this user was invited into.
*/
private suspend fun fetchEventsForMonthInternal(yearMonth: YearMonth): Map<Int, List<EventResponse>> {
// Use the system's default time zone
val zoneId = ZoneId.systemDefault()
// Get the start and end of the month in the local time zone
val startFrom = yearMonth.atDay(1).atStartOfDay(zoneId).toOffsetDateTime()
val endTo = yearMonth.atEndOfMonth().atTime(23, 59, 59).atZone(zoneId).toOffsetDateTime()
// Obtain current (logged in) user ID
val userId = (getApplication<MyApplication>()).tokenManager.userId ?: throw IllegalStateException("User ID is not set")
// BUG: Events that last longer than a month will not show
// up in the following month due to the startFrom filter here.
val userEvents = RetrofitClient.eventsService.userEvents(
userId = userId,
startFrom = startFrom,
startTo = endTo
)
val invitedEvents = RetrofitClient.eventsService.userEventsInvited(
userId = userId,
startFrom = startFrom,
startTo = endTo,
inviteStatus = "accepted"
)
val allEvents = userEvents + invitedEvents
// Create a mapping of days to events
val eventsByDay = mutableMapOf<Int, MutableList<EventResponse>>()
for (event in allEvents) {
val startDay = maxOf(event.start_time.dayOfMonth, 1)
val endDay = minOf(event.end_time.dayOfMonth, yearMonth.lengthOfMonth())
for (day in startDay..endDay) {
eventsByDay.computeIfAbsent(day) { mutableListOf() }.add(event)
}
}
return eventsByDay
}
}