Improve settings migration logic

Signed-off-by: Janne Koschinski <janne@kuschku.de>

app/src/main/java/de/kuschku/quasseldroid/Quasseldroid.kt

@@ -21,7 +21,6 @@ package de.kuschku.quasseldroid
 
 import android.os.Build
 import android.os.StrictMode
-import android.support.v7.preference.PreferenceManager
 import com.squareup.leakcanary.LeakCanary
 import dagger.android.AndroidInjector
 import dagger.android.support.DaggerApplication
@@ -66,7 +65,9 @@ class Quasseldroid : DaggerApplication() {
     applicationInjector().inject(this)
 
     // Migrate preferences
-    SettingsMigrationManager(listOf(
+    SettingsMigrationManager(
+      R.xml.preferences,
+      listOf(
         SettingsMigration.migrationOf(0, 1) { prefs, edit ->
           // Migrating database
           val database = LegacyAccountDatabase.Creator.init(this)
@@ -148,10 +149,10 @@ class Quasseldroid : DaggerApplication() {
             edit.remove("showlag")
           }
         }
-    )).migrate(PreferenceManager.getDefaultSharedPreferences(this))
+      )
+    ).migrate(this)
 
     // Initialize preferences unless already set
-    PreferenceManager.setDefaultValues(this, R.xml.preferences, false)
 
     /*
     if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {

app/src/main/java/de/kuschku/quasseldroid/settings/SettingsMigrationManager.kt

@@ -20,9 +20,14 @@
 package de.kuschku.quasseldroid.settings
 
 import android.annotation.SuppressLint
-import android.content.SharedPreferences
+import android.content.Context
+import android.support.annotation.XmlRes
+import android.support.v7.preference.PreferenceManager
+import android.support.v7.preference.PreferenceManager.KEY_HAS_SET_DEFAULT_VALUES
+import de.kuschku.quasseldroid.R.xml.preferences
 
 class SettingsMigrationManager(
+  @XmlRes preferences: Int,
   migrations: List<SettingsMigration>
 ) {
   private val migrationMap = migrations.associateBy(SettingsMigration::from)
@@ -30,7 +35,12 @@ class SettingsMigrationManager(
 
   // This runs during initial start and has to run synchronously
   @SuppressLint("ApplySharedPref")
-  fun migrate(preferences: SharedPreferences) {
+  fun migrate(context: Context) {
+    val defaultValueSp = context.getSharedPreferences(KEY_HAS_SET_DEFAULT_VALUES,
+                                                      Context.MODE_PRIVATE)
+
+    if (!defaultValueSp.getBoolean(KEY_HAS_SET_DEFAULT_VALUES, false)) {
+      val preferences = PreferenceManager.getDefaultSharedPreferences(context)
       var version = preferences.getInt(SETTINGS_VERSION, 0)
       while (version != currentVersion) {
         val migration = migrationMap[version]
@@ -42,6 +52,8 @@ class SettingsMigrationManager(
         editor.commit()
       }
     }
+    PreferenceManager.setDefaultValues(context, preferences, false)
+  }
 
   companion object {
     private const val SETTINGS_VERSION = "settings_version"