Fix issue with OpenTasks causing a lot of syncs in some rare cases.

We weren't setting a default sync interval which meant that in some
cases it was just syncing every 10 seconds.

This fix also fixes #66.

app/src/main/java/com/etesync/syncadapter/App.kt

@@ -12,10 +12,7 @@ import android.accounts.AccountManager
 import android.annotation.SuppressLint
 import android.annotation.TargetApi
 import android.app.Application
-import android.content.BroadcastReceiver
+import android.content.*
-import android.content.ContentValues
-import android.content.Context
-import android.content.Intent
 import android.database.DatabaseUtils
 import android.database.sqlite.SQLiteDatabase
 import android.graphics.Bitmap
@@ -48,6 +45,7 @@ import io.requery.sql.EntityDataStore
 import okhttp3.internal.tls.OkHostnameVerifier
 import org.acra.ACRA
 import org.apache.commons.lang3.time.DateFormatUtils
+import org.jetbrains.anko.doAsync
 import java.io.File
 import java.io.IOException
 import java.util.*
@@ -93,6 +91,19 @@ class App : Application() {
         addressBooksAuthority = getString(R.string.address_books_authority)
 
         loadLanguage()
+
+        // don't block UI for some background checks
+        doAsync {
+            // watch installed/removed apps
+            val tasksFilter = IntentFilter()
+            tasksFilter.addAction(Intent.ACTION_PACKAGE_ADDED)
+            tasksFilter.addAction(Intent.ACTION_PACKAGE_FULLY_REMOVED)
+            tasksFilter.addDataScheme("package")
+            registerReceiver(PackageChangedReceiver(), tasksFilter)
+
+            // check whether a tasks app is currently installed
+            PackageChangedReceiver.updateTaskSync(this@App)
+        }
     }
 
     override fun attachBaseContext(base: Context) {

app/src/main/java/com/etesync/syncadapter/PackageChangedReceiver.kt

@@ -8,11 +8,14 @@
 
 package com.etesync.syncadapter
 
+import android.accounts.AccountManager
 import android.annotation.SuppressLint
 import android.content.BroadcastReceiver
+import android.content.ContentResolver
 import android.content.Context
 import android.content.Intent
-
+import android.provider.CalendarContract
+import at.bitfire.ical4android.TaskProvider
 import com.etesync.syncadapter.resource.LocalTaskList
 
 class PackageChangedReceiver : BroadcastReceiver() {
@@ -29,8 +32,21 @@ class PackageChangedReceiver : BroadcastReceiver() {
             val tasksInstalled = LocalTaskList.tasksProviderAvailable(context)
             App.log.info("Package (un)installed; OpenTasks provider now available = $tasksInstalled")
 
-            // check all accounts and (de)activate OpenTasks if a CalDAV service is defined
+            for (account in AccountManager.get(context).getAccountsByType(App.accountType)) {
-            // FIXME: Do something if we ever bring back tasks.
+                val settings = AccountSettings(context, account)
+                val calendarSyncInterval = settings.getSyncInterval(CalendarContract.AUTHORITY)
+
+                if (tasksInstalled) {
+                    if (calendarSyncInterval == null) {
+                        // do nothing atm
+                    } else if (ContentResolver.getIsSyncable(account, TaskProvider.ProviderName.OpenTasks.authority) <= 0) {
+                        ContentResolver.setIsSyncable(account, TaskProvider.ProviderName.OpenTasks.authority, 1)
+                        settings.setSyncInterval(TaskProvider.ProviderName.OpenTasks.authority, calendarSyncInterval)
+                    }
+                } else {
+                    ContentResolver.setIsSyncable(account, TaskProvider.ProviderName.OpenTasks.authority, 0)
+                }
+            }
         }
     }
 

app/src/main/java/com/etesync/syncadapter/syncadapter/TasksSyncAdapterService.kt

@@ -16,6 +16,7 @@ import android.content.SyncResult
 import android.database.sqlite.SQLiteException
 import android.os.Build
 import android.os.Bundle
+import android.provider.CalendarContract
 import at.bitfire.ical4android.AndroidTaskList
 import at.bitfire.ical4android.TaskProvider
 import com.etesync.syncadapter.*
@@ -63,6 +64,7 @@ class TasksSyncAdapterService: SyncAdapterService() {
                 if (!extras.containsKey(ContentResolver.SYNC_EXTRAS_MANUAL) && !checkSyncConditions(accountSettings))
                     return
 
+
                 RefreshCollections(account, CollectionInfo.Type.TASKS).run()
 
                 updateLocalTaskLists(taskProvider, account, accountSettings)