• Support customizable alarms per subscription (for instance: add an alarm 10 min before the event for every event in the subscription)
  • [x] Create UI for setting per subscription: "Add custom alarm" (Edit calendar activity)
    • [x] Give multiple alarm options (see METHOD_*).
    • [x] Make sure the calendar supports the selected option.
  • [x] Save setting per subscription: "Add custom alarm"
  • [x] Actually make this setting work
• Possibility to disable alarms which come with the .ics
  • [x] Create UI for setting per subscription: "Ignore alarms from file" (Edit calendar activity)
  • [x] Save setting per subscription: "Ignore alarms from file"
  • [x] Actually make this setting work

Discussed in https://github.com/bitfireAT/icsx5/discussions/40

Since Android 10, file URIs shouldn't/can't access files outside the own application anymore. Since Android 11, file URIs for shared files are possible again, but the better method is SAF and content URIs.

So ICSx⁵ should support SAF instead of file:// URIs.

Raise target level to Android 13

• [x] handle notification permission (docs)
• [x] predictive back gesture (docs)
  • [x] Update androidx.appcompat:appcompat to 1.6.0-rc01 (Release notes)
• [x] per-app language preferences (docs)
• [x] themed icon (monochrome) (docs)
• [ ] check whether anything else has changed
• [x] update libraries and dependencies
  • [x] Update AGP to 7.3.1
    • [x] Move package from Android manifest to build files (see)
    • [x] Update desugaring lib to 1.2.0 (docs)
  • [x] Update Kotlin to 1.7.20
  • [x] Update androidx.test.runner to 1.5.0 (no breaking changes - Release notes)
  • [x] Update androidx.test:rules to 1.5.0 (no breaking changes - Release notes)
  • [x] Update com.google.android.material:material to 1.7.0 (Release notes)
    • [x] Requirement of AGP >=7.2.0 (we are using 7.2.2 -> 7.3.1)
    • [x] Requirement of Gradle >=7.3.3 (we are using 7.4.2)
    • [x] Requirement of Java 8
  • [x] Update androidx.core:core-ktx to 1.9.0 (Release notes - Improves compatibility with Android 13)
  • [x] Update androidx.fragment:fragment-ktx to 1.5.4 (Release notes - Just bugfixes)
• [x] raise target level (targetSdkVersion) to 33
• [x] raise compile level (compileSdkVersion) to 33 and build tools (buildToolsVersion) to 33.0.0

Calendars (Webcal feeds) can contain a color that shall be used for the whole calendar.

Possible representation:

• COLOR (RFC 7986)
• X-APPLE-CALENDAR-COLOR, see https://github.com/bitfireAT/icsx5/discussions/29#discussioncomment-2328294

This color could be used as a suggestion when adding a calendar.

• [ ] ResourceInfo: add calendarColor like calendarName
• [ ] AddCalendarValidationFragment.ValidationModel: get calendar color like calendar name
• [ ] AddCalendarValidationFragment: set initial color from calendar color (fall back to lightblue)

This has been reported by a user when adding certain calendars to ICSx5.

Adding: webcal://hhv-handball.liga.nu/cgi-bin/WebObjects/nuLigaHBDE.woa/wa/getTeamMeetingsWebcal?teamid=1457876 will throw an error:

HTTP 401 Apple WebObjects java.io.IOException: HTTP 401 Apple WebObjects at at.bitfire.icsdroid.CalendarFetcher.fetchNetwork$icsx5_62_2_0_2_gplayRelease(CalendarFetcher.kt:179) at at.bitfire.icsdroid.CalendarFetcher.onRedirect(CalendarFetcher.kt:83) at at.bitfire.icsdroid.CalendarFetcher.fetchNetwork$icsx5_62_2_0_2_gplayRelease(CalendarFetcher.kt:171) at at.bitfire.icsdroid.CalendarFetcher.run(CalendarFetcher.kt:46) at java.lang.Thread.run(Thread.java:1012)

While calendars from the same source with different events work:

webcal://hhv-handball.liga.nu/cgi-bin/WebObjects/nuLigaHBDE.woa/wa/getTeamMeetingsWebcal?teamid=1458151 webcal://hhv-handball.liga.nu/cgi-bin/WebObjects/nuLigaHBDE.woa/wa/getTeamMeetingsWebcal?teamid=1457879

Not super urgent but we should take look at this if we can workaround this.

1. (Switch device to dark mode)
2. Install latest ICSx5 from Google Play, launch it, allow calendar access
3. Add a subscription
4. The subscription is there, but not shown – only a black screen, see screenshot below.

When the theme is changed to light theme or when ICSx⁵ is killed in the task manager and started again, everything works.

At the moment the user only sees a message like the following

java.lang.SecurityException: Permission Denial: reading com.android.providers.downloads.DownloadStorageProvider uri content://com.android.providers.downloads.documents/document/msf%3A68 from pid=20876, uid=10151 requires that you obtain access using ACTION_OPEN_DOCUMENT or related APIs

To reproduce either

• Pick a file, then before adding it,
• delete the file using filemanager,
• return to the app and "add" the file.

or

• Add the file normally, then
• delete it via filemanager
• try to sync manually

Fixes #43

As per https://developer.android.com/training/articles/security-config Previous behaviour: only validated certificates in the system certificate authority store New behaviour: validates against both system CAs and user-installed CAs

Closes #1

Bugs:

• [x] The alerts removal for when the "ignore embed alarms" option is checked only works the first time you add the calendar. This is caused by ProcessEventsTask: https://github.com/bitfireAT/icsx5/blob/a52b5a3ef1af1014b3ad8d75b1683cb69bb5d459/app/src/main/java/at/bitfire/icsdroid/ProcessEventsTask.kt#L87 Since the calendar is technically not modified, only locally, onNotModified is called. There should be logic to handle changes to the ignore embed alarms switch, which add back again all the alarms.

TODO:

• [x] Custom reminders only get stored for the synchronization, they don't get added to the events.

Steps to reproduce:

1. Go to meetup.com > My Events
2. Click on Sync Calendar > Outlook . Copy the link
3. In ICS X5 , click on + button and paste link in ICSX5 in URL box
4. Click on Next arrow on top right

Observed behavior

1. Error message "Couldn't parse iCalendar

Couldn't parse iCalendar

at.bitfire.ical4android.InvalidCalendarException: Couldn't parse iCalendar
	at at.bitfire.ical4android.ICalendar$Companion.fromReader(ICalendar.kt:84)
	at at.bitfire.ical4android.Event$Companion.eventsFromReader(Event.kt:84)
	at at.bitfire.icsdroid.ui.AddCalendarValidationFragment$ValidationModel$initialize$downloader$1.onSuccess(AddCalendarValidationFragment.kt:114)
	at at.bitfire.icsdroid.CalendarFetcher.fetchNetwork(CalendarFetcher.kt:133)
	at at.bitfire.icsdroid.CalendarFetcher.onRedirect(CalendarFetcher.kt:79)
	at at.bitfire.icsdroid.CalendarFetcher.fetchNetwork(CalendarFetcher.kt:147)
	at at.bitfire.icsdroid.CalendarFetcher.run(CalendarFetcher.kt:44)
	at java.lang.Thread.run(Thread.java:764)
Caused by: net.fortuna.ical4j.data.ParserException: Error at line 149:Attempt to invoke virtual method 'void java.util.Calendar.setTimeZone(java.util.TimeZone)' on a null object reference
	at net.fortuna.ical4j.data.CalendarParserImpl.parse(CalendarParserImpl.java:162)
	at net.fortuna.ical4j.data.CalendarBuilder.build(CalendarBuilder.java:183)
	at net.fortuna.ical4j.data.CalendarBuilder.build(CalendarBuilder.java:171)
	at at.bitfire.ical4android.ICalendar$Companion.fromReader(ICalendar.kt:82)
	... 7 more
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void java.util.Calendar.setTimeZone(java.util.TimeZone)' on a null object reference
	at java.text.DateFormat.setTimeZone(DateFormat.java:690)
	at net.fortuna.ical4j.model.Iso8601.<init>(Iso8601.java:78)
	at net.fortuna.ical4j.model.Date.<init>(Date.java:150)
	at net.fortuna.ical4j.model.DateTime.<init>(DateTime.java:262)
	at net.fortuna.ical4j.model.TimeZone.inDaylightTime(TimeZone.java:143)
	at java.util.TimeZone.getOffsets(TimeZone.java:246)
	at java.util.GregorianCalendar.adjustForZoneAndDaylightSavingsTime(GregorianCalendar.java:2916)
	at java.util.GregorianCalendar.computeTime(GregorianCalendar.java:2807)
	at java.util.Calendar.updateTime(Calendar.java:3397)
	at java.util.Calendar.getTimeInMillis(Calendar.java:1761)
	at java.util.Calendar.getTime(Calendar.java:1734)
	at java.text.SimpleDateFormat.parseInternal(SimpleDateFormat.java:1633)
	at java.text.SimpleDateFormat.parse(SimpleDateFormat.java:1528)
	at java.text.DateFormat.parse(DateFormat.java:360)
	at net.fortuna.ical4j.model.DateTime.setTime(DateTime.java:418)
	at net.fortuna.ical4j.model.DateTime.<init>(DateTime.java:325)
	at net.fortuna.ical4j.model.property.DateProperty.setValue(DateProperty.java:138)
	at net.fortuna.ical4j.data.DefaultContentHandler.resolveTimezones(DefaultContentHandler.java:218)
	at net.fortuna.ical4j.data.DefaultContentHandler.endCalendar(DefaultContentHandler.java:86)
	at net.fortuna.ical4j.data.CalendarParserImpl.parseCalendar(CalendarParserImpl.java:130)
	at net.fortuna.ical4j.data.CalendarParserImpl.parseCalendarList(CalendarParserImpl.java:184)
	at net.fortuna.ical4j.data.CalendarParserImpl.parse(CalendarParserImpl.java:153)
	... 10 more`

Right now, credentials are being stored inside regular SharedPreferences in CalendarCredentials: https://github.com/bitfireAT/icsx5/blob/0b1443de38e0e32f147351ae36358c01af710236/app/src/main/java/at/bitfire/icsdroid/db/CalendarCredentials.kt#L17-L19

EncryptedSharedPreferences shall be used.

The change is quite simple, they provide a good example:

MasterKey masterKey = new MasterKey.Builder(context)
     .setKeyScheme(MasterKey.KeyScheme.AES256_GCM)
     .build();

 SharedPreferences sharedPreferences = EncryptedSharedPreferences.create(
     context,
     "secret_shared_prefs",
     masterKey,
     EncryptedSharedPreferences.PrefKeyEncryptionScheme.AES256_SIV,
     EncryptedSharedPreferences.PrefValueEncryptionScheme.AES256_GCM
 );

 // use the shared preferences and editor as you normally would
 SharedPreferences.Editor editor = sharedPreferences.edit();

If we would move the subscriptions to an app-local database (instead of creating them directly in the Calendar Provider as calendars), we wouldn't have to rely on the Calendar Provider anymore. This would bring some beneftis:

• For authentication we already use some kind of DB (encrypted shared preferences); a real DB would allow to store authentication and other settings together with the subscription without having to use a limited number of _SYNC columns
• Settings wouldn't be exposed to other apps.
• Sometimes accounts are removed by devices (for instance on system upgrades). Then all subscriptions are gone. If we store them ourselves, they would still be there and the calendars can be re-created on sync.
• Same for backup (#4) – we could then just use autoFullBackup without any extra code.
• We only need to ask for calendar permissions when there are active subscriptions :)

Steps to implement:

1. Manage subscriptions locally – Room DB (or maybe shared preferences or whatever seems feasible – but I think other things than Room will again add more "dirtyness").
2. The sync worker would have to

• create the account (if it's not already there),
• create/update calendars from the local subscription DB,
• sync the calendars.

Updating the calendars doesn't work regularly. Error message: "Couldn't connec to server."

Seems like the Internet connection is not ready yet when the work manager initiates the synchronization.

Similar to #24

It seems the system can't access the calendar list of an ICSx⁵ account (at.bitfire.icsdroid.AppAccount.get)? Maybe we should just try-catch this and handle this case properly?

This happens on many different Samsung devices so far as well as on a Google Pixel 5 and so far only on Android 11 and 12.

java.lang.RuntimeException: 
  at android.app.ActivityThread.performLaunchActivity (ActivityThread.java:4022)
  at android.app.ActivityThread.handleLaunchActivity (ActivityThread.java:4188)
  at android.app.servertransaction.LaunchActivityItem.execute (LaunchActivityItem.java:103)
  at android.app.servertransaction.TransactionExecutor.executeCallbacks (TransactionExecutor.java:135)
  at android.app.servertransaction.TransactionExecutor.execute (TransactionExecutor.java:95)
  at android.app.ActivityThread$H.handleMessage (ActivityThread.java:2425)
  at android.os.Handler.dispatchMessage (Handler.java:106)
  at android.os.Looper.loopOnce (Looper.java:226)
  at android.os.Looper.loop (Looper.java:313)
  at android.app.ActivityThread.main (ActivityThread.java:8582)
  at java.lang.reflect.Method.invoke (Native Method)
  at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run (RuntimeInit.java:563)
  at com.android.internal.os.ZygoteInit.main (ZygoteInit.java:1133)
Caused by: java.lang.SecurityException: 
  at android.os.Parcel.createExceptionOrNull (Parcel.java:2437)
  at android.os.Parcel.createException (Parcel.java:2421)
  at android.os.Parcel.readException (Parcel.java:2404)
  at android.os.Parcel.readException (Parcel.java:2346)
  at android.accounts.IAccountManager$Stub$Proxy.addAccountExplicitly (IAccountManager.java:1550)
  at android.accounts.AccountManager.addAccountExplicitly (AccountManager.java:1030)
  at at.bitfire.icsdroid.AppAccount.get (AppAccount.kt:50)
  at at.bitfire.icsdroid.ui.CalendarListActivity$CalendarModel.loadCalendars (CalendarListActivity.kt:332)
  at at.bitfire.icsdroid.ui.CalendarListActivity$CalendarModel.startWatchingCalendars (CalendarListActivity.kt:318)
  at at.bitfire.icsdroid.ui.CalendarListActivity$CalendarModel.reinit (CalendarListActivity.kt:301)
  at at.bitfire.icsdroid.ui.CalendarListActivity.onCreate (CalendarListActivity.kt:98)
  at android.app.Activity.performCreate (Activity.java:8282)
  at android.app.Activity.performCreate (Activity.java:8262)
  at android.app.Instrumentation.callActivityOnCreate (Instrumentation.java:1329)
  at android.app.ActivityThread.performLaunchActivity (ActivityThread.java:3996)
  at android.app.ActivityThread.handleLaunchActivity (ActivityThread.java:4188)
  at android.app.servertransaction.LaunchActivityItem.execute (LaunchActivityItem.java:103)
  at android.app.servertransaction.TransactionExecutor.executeCallbacks (TransactionExecutor.java:135)
  at android.app.servertransaction.TransactionExecutor.execute (TransactionExecutor.java:95)
  at android.app.ActivityThread$H.handleMessage (ActivityThread.java:2425)
  at android.os.Handler.dispatchMessage (Handler.java:106)
  at android.os.Looper.loopOnce (Looper.java:226)
  at android.os.Looper.loop (Looper.java:313)
  at android.app.ActivityThread.main (ActivityThread.java:8582)
  at java.lang.reflect.Method.invoke (Native Method)
  at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run (RuntimeInit.java:563)
  at com.android.internal.os.ZygoteInit.main (ZygoteInit.java:1133)
Caused by: android.os.RemoteException: 
  at com.android.server.accounts.AccountManagerService.addAccountExplicitlyWithVisibility (AccountManagerService.java:501)
  at com.android.server.accounts.AccountManagerService.addAccountExplicitly (AccountManagerService.java:1776)
  at android.accounts.IAccountManager$Stub.onTransact (IAccountManager.java:583)
  at com.android.server.accounts.AccountManagerService.onTransact (AccountManagerService.java:1119)
  at android.os.Binder.execTransactInternal (Binder.java:1215)