allow customizing the time zone at the Event Details

app/src/main/kotlin/com/simplemobiletools/calendar/pro/activities/EventActivity.kt

@@ -1,5 +1,6 @@
 package com.simplemobiletools.calendar.pro.activities
 
+import android.app.Activity
 import android.app.DatePickerDialog
 import android.app.TimePickerDialog
 import android.content.Intent
@@ -61,6 +62,7 @@ class EventActivity : SimpleActivity() {
     private val ATTENDEES = "ATTENDEES"
     private val EVENT_TYPE_ID = "EVENT_TYPE_ID"
     private val EVENT_CALENDAR_ID = "EVENT_CALENDAR_ID"
+    private val SELECT_TIME_ZONE_INTENT = 1
 
     private var mReminder1Minutes = REMINDER_OFF
     private var mReminder2Minutes = REMINDER_OFF
@@ -310,6 +312,15 @@ class EventActivity : SimpleActivity() {
         checkAttendees()
     }
 
+    override fun onActivityResult(requestCode: Int, resultCode: Int, resultData: Intent?) {
+        if (requestCode == SELECT_TIME_ZONE_INTENT && resultCode == Activity.RESULT_OK && resultData?.hasExtra(TIME_ZONE) == true) {
+            val timeZone = resultData.getSerializableExtra(TIME_ZONE) as MyTimeZone
+            mEvent.timeZone = timeZone.zoneName
+            updateTimeZoneText()
+        }
+        super.onActivityResult(requestCode, resultCode, resultData)
+    }
+
     private fun updateTexts() {
         updateRepetitionText()
         checkReminderTexts()
@@ -1172,7 +1183,9 @@ class EventActivity : SimpleActivity() {
     }
 
     private fun setupTimeZone() {
-
+        Intent(this, SelectTimeZoneActivity::class.java).apply {
+            startActivityForResult(this, SELECT_TIME_ZONE_INTENT)
+        }
     }
 
     private fun checkRepeatRule() {

app/src/main/kotlin/com/simplemobiletools/calendar/pro/activities/SelectTimeZoneActivity.kt

@@ -2,6 +2,7 @@ package com.simplemobiletools.calendar.pro.activities
 
 import android.app.SearchManager
 import android.content.Context
+import android.content.Intent
 import android.os.Bundle
 import android.view.Menu
 import android.view.MenuItem
@@ -9,7 +10,9 @@ import androidx.appcompat.widget.SearchView
 import androidx.core.view.MenuItemCompat
 import com.simplemobiletools.calendar.pro.R
 import com.simplemobiletools.calendar.pro.adapters.SelectTimeZoneAdapter
+import com.simplemobiletools.calendar.pro.helpers.TIME_ZONE
 import com.simplemobiletools.calendar.pro.helpers.getAllTimeZones
+import com.simplemobiletools.calendar.pro.models.MyTimeZone
 import kotlinx.android.synthetic.main.activity_select_time_zone.*
 
 class SelectTimeZoneActivity : SimpleActivity() {
@@ -22,7 +25,10 @@ class SelectTimeZoneActivity : SimpleActivity() {
         title = ""
 
         SelectTimeZoneAdapter(this, getAllTimeZones()) {
-
+            val data = Intent()
+            data.putExtra(TIME_ZONE, it as MyTimeZone)
+            setResult(RESULT_OK, data)
+            finish()
         }.apply {
             select_time_zone_list.adapter = this
         }

app/src/main/kotlin/com/simplemobiletools/calendar/pro/helpers/Constants.kt

@@ -19,6 +19,7 @@ const val CALDAV = "Caldav"
 const val VIEW_TO_OPEN = "view_to_open"
 const val SHORTCUT_NEW_EVENT = "shortcut_new_event"
 const val REGULAR_EVENT_TYPE_ID = 1L
+const val TIME_ZONE = "time_zone"
 
 const val MONTHLY_VIEW = 1
 const val YEARLY_VIEW = 2

app/src/main/kotlin/com/simplemobiletools/calendar/pro/models/MyTimeZone.kt

@@ -1,3 +1,11 @@
 package com.simplemobiletools.calendar.pro.models
 
-data class MyTimeZone(val id: Int, var title: String, val zoneName: String)
+import java.io.Serializable
+
+// sample MyTimeZone(id=1, title="GMT+1", zoneName="Europe/Bratislava")
+data class MyTimeZone(val id: Int, var title: String, val zoneName: String) : Serializable {
+
+    companion object {
+        private const val serialVersionUID = -32456354132688616L
+    }
+}