fix "Delete all events" for cases when there is a huge amount of events

app/src/main/kotlin/com/simplemobiletools/calendar/pro/extensions/MutableList.kt

@@ -0,0 +1,16 @@
+package com.simplemobiletools.calendar.pro.extensions
+
+import com.simplemobiletools.calendar.pro.helpers.CHOPPED_LIST_DEFAULT_SIZE
+
+// inspired by https://stackoverflow.com/questions/2895342/java-how-can-i-split-an-arraylist-in-multiple-small-arraylists/2895365#2895365
+fun MutableList<Long>.getChoppedList(chunkSize: Int = CHOPPED_LIST_DEFAULT_SIZE): ArrayList<ArrayList<Long>> {
+    val parts = ArrayList<ArrayList<Long>>()
+    val listSize = this.size
+    var i = 0
+    while (i < listSize) {
+        val newList = subList(i, Math.min(listSize, i + chunkSize)).toMutableList() as ArrayList<Long>
+        parts.add(newList)
+        i += chunkSize
+    }
+    return parts
+}

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

@@ -16,6 +16,7 @@ const val WEEK_START_DATE_TIME = "week_start_date_time"
 const val CALDAV = "Caldav"
 const val VIEW_TO_OPEN = "view_to_open"
 const val REGULAR_EVENT_TYPE_ID = 1L
+const val CHOPPED_LIST_DEFAULT_SIZE = 100
 
 const val MONTHLY_VIEW = 1
 const val YEARLY_VIEW = 2

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

@@ -132,21 +132,23 @@ class EventsHelper(val context: Context) {
             return
         }
 
-        val eventsWithImportId = eventsDB.getEventsByIdsWithImportIds(ids)
-        eventsDB.deleteEvents(ids)
+        ids.getChoppedList().forEach {
+            val eventsWithImportId = eventsDB.getEventsByIdsWithImportIds(it)
+            eventsDB.deleteEvents(it)
 
-        ids.forEach {
-            context.cancelNotification(it)
-        }
-
-        if (deleteFromCalDAV && config.caldavSync) {
-            eventsWithImportId.forEach {
-                context.calDAVHelper.deleteCalDAVEvent(it)
+            it.forEach {
+                context.cancelNotification(it)
             }
-        }
 
-        deleteChildEvents(ids, deleteFromCalDAV)
-        context.updateWidgets()
+            if (deleteFromCalDAV && config.caldavSync) {
+                eventsWithImportId.forEach {
+                    context.calDAVHelper.deleteCalDAVEvent(it)
+                }
+            }
+
+            deleteChildEvents(it, deleteFromCalDAV)
+            context.updateWidgets()
+        }
     }
 
     private fun deleteChildEvents(ids: MutableList<Long>, deleteFromCalDAV: Boolean) {