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Hopefully fixed timezone handling once and for all!
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@Wilm0r
Wilm0r committed Sep 11, 2021
1 parent f27ca6e commit a079f48
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Showing 7 changed files with 117 additions and 101 deletions.
156 changes: 71 additions & 85 deletions app/src/main/java/net/gaast/giggity/Schedule.java
View file
Original file line number Diff line number Diff line change
Expand Up @@ -24,7 +24,6 @@
import android.text.Spannable;
import android.text.Spanned;
import android.util.Log;
import android.util.Xml;
import android.widget.CheckBox;

import org.json.JSONArray;
Expand All @@ -34,7 +33,6 @@
import org.xml.sax.ContentHandler;
import org.xml.sax.InputSource;
import org.xml.sax.Locator;
import org.xml.sax.Parser;
import org.xml.sax.SAXException;
import org.xml.sax.XMLReader;
import org.xml.sax.helpers.AttributesImpl;
Expand Down Expand Up @@ -81,9 +79,6 @@
import java.util.zip.Deflater;
import java.util.zip.Inflater;

import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;

public class Schedule implements Serializable {
private final int detectHeaderSize = 1024;

Expand All @@ -105,9 +100,9 @@ public class Schedule implements Serializable {
private LinkedList<ZonedDateTime> day0List = new LinkedList<>();
private boolean showHidden; // So hidden items are shown but with a different colour.

private ZoneId nativeTz = ZoneId.systemDefault();
private HashSet<Double> tzOffset = new HashSet<>();
private int dayChangeOffsetMins = 6 * 60; // 06:00. Raw int so it can be negative (will include tzOffset).
private ZoneId inTZ = ZoneId.systemDefault(); // TZ-less/UTC times to be interpreted as/converted to this.
private ZoneId outTZ = ZoneId.systemDefault(); // Usually our local timezone, this is returned externally.
private LocalTime dayChange = LocalTime.of(6, 0);

private HashSet<String> languages = new HashSet<>();

Expand Down Expand Up @@ -161,7 +156,7 @@ public void loadSchedule(BufferedReader in, String url_) throws IOException, Loa
throw new LoadException(getString(R.string.schedule_empty));
}

ZonedDateTime day = firstTime.truncatedTo(ChronoUnit.DAYS).plus(dayChangeOffsetMins, ChronoUnit.MINUTES);
ZonedDateTime day = firstTime.truncatedTo(ChronoUnit.DAYS).with(dayChange);
/* Add a day 0 (maybe there's an event before the first day officially
* starts?). Saw this in the CCC Fahrplan for example. */
if (day.isAfter(firstTime))
Expand All @@ -173,12 +168,12 @@ public void loadSchedule(BufferedReader in, String url_) throws IOException, Loa
while (day.isBefore(lastTime)) {
/* Some schedules have empty days in between. :-/ Skip those. */
for (Schedule.Item item : allItems.values()) {
if (item.getStartTimeZoned().compareTo(day) >= 0 &&
item.getEndTimeZoned().compareTo(dayEnd) <= 0) {
if (item.startTime.compareTo(day) >= 0 &&
item.endTime.compareTo(dayEnd) <= 0) {
// Exact start time of day (could be "yesterday")
dayList.add(day);
// Midnight date-only for display purpose.
day0List.add(day.minus(dayChangeOffsetMins, ChronoUnit.MINUTES).truncatedTo(ChronoUnit.DAYS));
day0List.add(day.truncatedTo(ChronoUnit.DAYS));
break;
}
}
Expand Down Expand Up @@ -238,17 +233,21 @@ public long eventLength() {
return lastTime.toEpochSecond() - firstTime.toEpochSecond();
}

public void setNativeTz(ZoneId nativeTz) {
public void setInTZ(ZoneId inTZ) {
if (fullyLoaded) {
throw new RuntimeException("Can't change nativeTz after loading.");
throw new RuntimeException("Can't change inTZ after loading.");
}

this.nativeTz = nativeTz;
this.inTZ = inTZ;
}

public void setOutTZ(ZoneId outTZ) {
this.outTZ = outTZ;
}

public ZonedDateTime getDay() {
if (curDayNum != -1) {
return day0List.get(curDayNum);
return day0List.get(curDayNum).withZoneSameInstant(outTZ);
} else {
return null;
}
Expand All @@ -271,32 +270,28 @@ public ZonedDateTime setDay(int day) {

dayFirstTime = dayLastTime = null;
for (Schedule.Item item : allItems.values()) {
if (item.getStartTimeZoned().compareTo(curDay) >= 0 &&
item.getEndTimeZoned().compareTo(curDayEnd) <= 0) {
if (dayFirstTime == null || item.getStartTimeZoned().isBefore(dayFirstTime))
dayFirstTime = item.getStartTimeZoned();
if (dayLastTime == null || item.getEndTimeZoned().isAfter(dayLastTime))
dayLastTime = item.getEndTimeZoned();
if (item.startTime.compareTo(curDay) >= 0 &&
item.endTime.compareTo(curDayEnd) <= 0) {
if (dayFirstTime == null || item.startTime.isBefore(dayFirstTime))
dayFirstTime = item.startTime;
if (dayLastTime == null || item.endTime.isAfter(dayLastTime))
dayLastTime = item.endTime;
}
}
}
return getDay();
}

private void addTzOffset(ZonedDateTime origStart, ZonedDateTime localStart) { // TODO: Difference, not offset!
double hoursOff = localStart.toLocalDateTime().until(origStart, ChronoUnit.MINUTES) / 60.0;
if (tzOffset.isEmpty()) {
// Integrate the first tz offset we run into into the day change time.
dayChangeOffsetMins -= hoursOff * 60;
}
tzOffset.add(hoursOff);
}

public double getTzOffset() {
if (tzOffset.size() == 1) {
return tzOffset.iterator().next();
public double getTzDiff() {
// Calculate difference *now* if the event is current, otherwise at the start of the conf.
// (Just in case there's a DST change on one of the sides mid-event?)
ZonedDateTime mp = ZonedDateTime.now().withZoneSameInstant(inTZ);
if (!isToday()) {
mp = firstTime;
}
return 0;
int diff = inTZ.getRules().getOffset(mp.toInstant()).getTotalSeconds() -
outTZ.getRules().getOffset(mp.toInstant()).getTotalSeconds();
return diff / 3600.0;
}

/* Sets day to one overlapping given moment in time and returns day number, or -1 if no match. */
Expand All @@ -323,18 +318,18 @@ public DateTimeFormatter getDayFormat() {
/** Get earliest item.startTime */
public ZonedDateTime getFirstTimeZoned() {
if (curDay == null) {
return firstTime;
return firstTime.withZoneSameInstant(outTZ);
} else {
return dayFirstTime;
return dayFirstTime.withZoneSameInstant(outTZ);
}
}

/** Get highest item.endTime */
public ZonedDateTime getLastTimeZoned() {
if (curDay == null) {
return lastTime;
return lastTime.withZoneSameInstant(outTZ);
} else {
return dayLastTime;
return dayLastTime.withZoneSameInstant(outTZ);
}
}

Expand Down Expand Up @@ -438,7 +433,7 @@ private void loadIcal(BufferedReader in) {
private void loadJson(BufferedReader in) {

StringBuffer buffer = new StringBuffer();
DateTimeFormatter df = DateTimeFormatter.ofPattern("yyyy-MM-dd'T'HH:mm:ss").withZone(nativeTz);
DateTimeFormatter df = DateTimeFormatter.ofPattern("yyyy-MM-dd'T'HH:mm:ss").withZone(inTZ);
HashMap<String, Schedule.Line> tentMap = new HashMap<String, Schedule.Line>();
Boolean hasMicrolocs = false;
Scanner s = new Scanner(in);
Expand Down Expand Up @@ -789,21 +784,22 @@ public XcalParser() {
tentMap = new HashMap<String,Schedule.Line>();

dfUtc = DateTimeFormatter.ofPattern("yyyyMMdd'T'HHmmss'Z'").withZone(ZoneId.of("UTC"));
dfLocal = DateTimeFormatter.ofPattern("yyyyMMdd'T'HHmmss").withZone(nativeTz);
dfLocal = DateTimeFormatter.ofPattern("yyyyMMdd'T'HHmmss").withZone(inTZ);
}

private ZonedDateTime parseTime(String s, String tz) throws ParseException {
TemporalAccessor ret;
try {
ret = dfUtc.parse(s, new ParsePosition(0));
return ZonedDateTime.from(ret).withZoneSameInstant(inTZ);
} catch (DateTimeParseException e) {
if (tz == null) {
ret = dfLocal.parse(s, new ParsePosition(0));
} else {
ret = dfLocal.withZone(ZoneId.of(tz)).parse(s, new ParsePosition(0));
}
return ZonedDateTime.from(ret);
}
return ZonedDateTime.from(ret);
}

/* Yay I'll just write my own parser... Spec is at https://www.kanzaki.com/docs/ical/duration-t.html
Expand Down Expand Up @@ -876,22 +872,12 @@ public void endElement(String uri, String localName, String qName)
tz = at.getValue("tzid");
}

ZonedDateTime origStart = parseTime(startTimeS, tz);
Duration d;
startTime = parseTime(startTimeS, tz);
if (durationS != null) {
d = parseDuration(durationS);
endTime = startTime.plus(parseDuration(durationS));
} else {
// If dtend has a different tz then you're a terrible person.
d = Duration.between(origStart, parseTime(endTimeS, tz));
}

startTime = origStart.withZoneSameInstant(nativeTz);
endTime = startTime.plus(d);

if (tz != null) {
// If the event/schedule seems to have a native timezone instead of just raw UTC
// timestamps, record the time difference so it can be shared with the user.
addTzOffset(origStart, startTime);
endTime = parseTime(endTimeS, tz);
}
} catch (ParseException e) {
Log.w("Schedule.loadXcal", "Can't parse date: " + e);
Expand Down Expand Up @@ -973,7 +959,7 @@ public PentabarfParser() {
tentMap = new HashMap<>();

df = DateTimeFormatter.ISO_LOCAL_DATE;
//tf = DateTimeFormatter.ISO_LOCAL_TIME;
// tf = DateTimeFormatter.ISO_LOCAL_TIME; // Nope, won't take the optional seconds. :<
tf = DateTimeFormatter.ofPattern("H:mm[:ss]");

// zoned date+time format in the <date/> tag, not used by all schedules BUT the only one
Expand Down Expand Up @@ -1026,8 +1012,14 @@ public void endElement(String uri, String localName, String qName)
if (localName.equals("conference")) {
title = propMap.get("title");
if (propMap.get("day_change") != null) {
dayChangeOffsetMins = LocalTime.parse(propMap.get("day_change"), tf).toSecondOfDay() / 60;
// TODO: PARSE ERROR?
dayChange = LocalTime.parse(propMap.get("day_change"), tf);
}
if (propMap.get("time_zone_name") != null) {
ZoneId fTZ = ZoneId.of(propMap.get("time_zone_name"));
if (!fTZ.normalized().equals(inTZ.normalized())) {
Log.w("ScheduleTZ", "In-file timezone " + fTZ + " seems to mismatch our records: " + inTZ);
}
inTZ = fTZ;
}
} else if (localName.equals("event")) {
String id, title, startTimeS, startZonedTimeS, durationS, s, desc, wl;
Expand All @@ -1047,23 +1039,17 @@ public void endElement(String uri, String localName, String qName)
startTime = null;
try {
if (startZonedTimeS != null) {
// This will be the tz-native starting time in the conf's zone
ZonedDateTime origStart = ZonedDateTime.parse(startZonedTimeS, zdf);
// What we'll save is a ZDT in the phone's local tz since during COVID-19 that's
// all what's going to matter. Shout out to future Wilmer or whomever is going
// to extend tz awareness further when things are back to normal.
startTime = origStart.withZoneSameInstant(nativeTz);
// Save the offset so it can be reported to the user.
addTzOffset(origStart, startTime);
// All internal timestamps must be the tz-native times, in the conf's zone
startTime = ZonedDateTime.parse(startZonedTimeS, zdf);
}
} catch (DateTimeParseException e){
startZonedTimeS = null;
}
if (startZonedTimeS == null) {
LocalTime rawTime = LocalTime.parse(startTimeS, tf);
startTime = ZonedDateTime.of(curDay, rawTime, nativeTz);
startTime = ZonedDateTime.of(curDay, rawTime, inTZ);

if (rawTime.toSecondOfDay() < (dayChangeOffsetMins * 60)) {
if (rawTime.isBefore(dayChange)) {
// In Frab files, if a time is before day_change it's after midnight, thus
// date should be incremented by one. (Not needed when using zoned *full*
// timestamp above.)
Expand Down Expand Up @@ -1184,8 +1170,8 @@ public AbstractSet<Schedule.Item> getItems() {

for (Item item : items) {
if ((!item.isHidden() || showHidden) &&
(curDay == null || (!item.getStartTimeZoned().isBefore(curDay) &&
!item.getEndTimeZoned().isAfter(curDayEnd))))
(curDay == null || (!item.startTime.isBefore(curDay) &&
!item.endTime.isAfter(curDayEnd))))
ret.add(item);
}
return ret;
Expand Down Expand Up @@ -1217,10 +1203,10 @@ public void addItem(Schedule.Item item) {
/* The rest really should be in the caller, but there are several callsites, one per parser. TODO. */
allItems.put(item.getId(), item);

if (firstTime == null || item.getStartTimeZoned().isBefore(firstTime))
firstTime = item.getStartTimeZoned();
if (lastTime == null || item.getEndTimeZoned().isAfter(lastTime))
lastTime = item.getEndTimeZoned();
if (firstTime == null || item.startTime.isBefore(firstTime))
firstTime = item.startTime;
if (lastTime == null || item.endTime.isAfter(lastTime))
lastTime = item.endTime;

if (item.getLanguage() != null) {
languages.add(item.getLanguage());
Expand Down Expand Up @@ -1392,19 +1378,19 @@ public void setSubtitle(String s) {
}

public ZonedDateTime getStartTimeZoned() {
return startTime;
return startTime.withZoneSameInstant(outTZ);
}

public ZonedDateTime getEndTimeZoned() {
return endTime;
return endTime.withZoneSameInstant(outTZ);
}

public Date getStartTime() {
return Date.from(getStartTimeZoned().toInstant());
return Date.from(startTime.toInstant());
}

public Date getEndTime() {
return Date.from(getEndTimeZoned().toInstant());
return Date.from(endTime.toInstant());
}

public Track getTrack() {
Expand Down Expand Up @@ -1532,15 +1518,15 @@ public void commit() {
@Override
public int compareTo(Item another) {
int ret;
if (this == null || getStartTimeZoned() == null || getTitle() == null ||
another == null || another.getStartTimeZoned() == null || another.getTitle() == null) {
if (this == null || startTime == null || getTitle() == null ||
another == null || another.startTime == null || another.getTitle() == null) {
// Shouldn't happen in normal operation anyway, but it does happen during
// de-serialisation for some reason :-( (Possibly because a "hollow" duplicate of an
// object is restored before the filled in original?)
// Log.d("Schedule.Item.compareTo", "null-ish object passed");
return -123;
}
if ((ret = getStartTimeZoned().compareTo(another.getStartTimeZoned())) != 0) {
if ((ret = startTime.compareTo(another.startTime)) != 0) {
return ret;
} else if ((ret = getTitle().compareTo(another.getTitle())) != 0)
return ret;
Expand All @@ -1565,18 +1551,18 @@ public int compareTo(ZonedDateTime d) {
/* 0 if the event is "now" (d==now),
* -1 if it's in the future,
* 1 if it's in the past. */
if (d.isBefore(getStartTimeZoned()))
if (d.isBefore(startTime))
return -1;
else if (getEndTimeZoned().isAfter(d))
else if (endTime.isAfter(d))
return 0;
else
return 1;
}

public boolean overlaps(Item other) {
// True if other's start- or end-time is during our event, or if it starts before and ends after ours.
return (compareTo(other.getStartTimeZoned()) == 0 || compareTo(other.getEndTimeZoned().minusSeconds(1)) == 0 ||
(!other.getStartTimeZoned().isAfter(getStartTimeZoned()) && !other.getEndTimeZoned().isBefore(getEndTimeZoned())));
return (compareTo(other.startTime) == 0 || compareTo(other.endTime.minusSeconds(1)) == 0 ||
(!other.startTime.isAfter(startTime) && !other.endTime.isBefore(endTime)));
}
}

Expand Down
2 changes: 1 addition & 1 deletion app/src/main/java/net/gaast/giggity/ScheduleViewActivity.java
View file
Original file line number Diff line number Diff line change
Expand Up @@ -606,7 +606,7 @@ public void finishNavDrawer() {
TextView dr = (TextView) drawerLayout.findViewById(R.id.drawer_date_range);
dr.setText(Giggity.dateRange(days.getFirst(), days.getLast()));

double offset = sched.getTzOffset();
double offset = sched.getTzDiff();
if (offset != 0) {
String plus = offset > 0 ? "+" : "";
dr.setText(dr.getText() + "\n" + getString(R.string.drw_tz_offset) + " " + plus + offset);
Expand Down
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