Minify VTIMEZONEs (f5dcc112) · Commits · e / os / ical4android

src/main/java/at/bitfire/ical4android/Event.kt

+6 −2

Original line number	Diff line number	Diff line
		@@ -221,8 +221,12 @@ class Event: ICalendar() {
		exception.dtEnd?.timeZone?.let(usedTimeZones::add)
		}

		// add VTIMEZONE components
		usedTimeZones.forEach { ical.components += it.vTimeZone }
		// add minified VTIMEZONE components
		usedTimeZones.forEach {
		val tz = it.vTimeZone
		dtStart?.let { minifyVTimeZone(tz, it.date) }
		ical.components += tz
		}

		CalendarOutputter(false).output(ical, os)
		}

src/main/java/at/bitfire/ical4android/ICalendar.kt

+57 −2

Original line number	Diff line number	Diff line
		@@ -12,10 +12,11 @@ import net.fortuna.ical4j.data.CalendarBuilder
		import net.fortuna.ical4j.data.CalendarParserFactory
		import net.fortuna.ical4j.data.ParserException
		import net.fortuna.ical4j.model.*
		import net.fortuna.ical4j.model.component.VAlarm
		import net.fortuna.ical4j.model.component.VTimeZone
		import net.fortuna.ical4j.model.Date
		import net.fortuna.ical4j.model.component.*
		import net.fortuna.ical4j.model.property.DateProperty
		import net.fortuna.ical4j.model.property.ProdId
		import net.fortuna.ical4j.model.property.TzUrl
		import net.fortuna.ical4j.util.Strings
		import java.io.StringReader
		import java.util.*
		@@ -60,6 +61,60 @@ open class ICalendar {

		fun isDateTime(date: DateProperty?) = date != null && date.date is DateTime

		/**
		* Minifies a VTIMEZONE so that only components after [start] are kept.
		* Doesn't return the smallest possible VTIMEZONE at the moment, but
		* reduces its size significantly.
		*
		* @param tz Time zone definition to minify. Attention: the observances of this object
		* will be modified!
		* @param start Start date for components
		*/
		fun minifyVTimeZone(tz: VTimeZone, start: Date) {
		// find latest matching STANDARD/DAYLIGHT component,
		// keep components at/after "start"
		val iter = tz.observances.iterator()
		var latestDaylight: Pair<Date, Observance>? = null
		var latestStandard: Pair<Date, Observance>? = null
		val keep = mutableSetOf<Observance>()
		while (iter.hasNext()) {
		val entry = iter.next() as Observance
		val latest = entry.getLatestOnset(start)

		if (latest == null /* observance begins after "start" */ \|\|
		latest >= start /* observance has onsets at/after "start" */ ) {
		keep += entry
		continue
		}

		when (entry) {
		is Standard -> {
		if (latestStandard == null \|\| latest.after(latestStandard.first))
		latestStandard = Pair(latest, entry)
		}
		is Daylight -> {
		if (latestDaylight == null \|\| latest.after(latestDaylight.first))
		latestDaylight = Pair(latest, entry)
		}
		}
		}
		latestStandard?.second?.let { keep += it }
		latestDaylight?.second?.let { keep += it }

		// actually remove all observances that shall not be kept
		val iter2 = tz.observances.iterator()
		while (iter2.hasNext()) {
		val entry = iter2.next() as Observance
		if (!keep.contains(entry))
		iter2.remove()
		}

		// remove TZURL
		tz.properties.filter { it is TzUrl }.forEach {
		tz.properties.remove(it)
		}
		}

		/**
		* Takes a string with a timezone definition and returns the time zone ID.
		* @param timezoneDef time zone definition (VCALENDAR with VTIMEZONE component)