Crash fixes

app/src/main/java/de/kuschku/quasseldroid/ui/clientsettings/client/ClientSettingsActivity.kt

@@ -33,7 +33,7 @@ class ClientSettingsActivity : SettingsActivity(ClientSettingsFragment()),
     when (pref) {
       is ListPreference -> {
         val f = ListPreferenceDialogFragmentCompat.newInstance(pref.getKey())
-        f.setTargetFragment(fragment, 0)
+        f.setTargetFragment(actualFragment, 0)
         f.show(supportFragmentManager, DIALOG_FRAGMENT_TAG)
         true
       }

app/src/main/java/de/kuschku/quasseldroid/util/ui/settings/ServiceBoundSettingsActivity.kt

@@ -35,6 +35,7 @@ abstract class ServiceBoundSettingsActivity(private val fragment: Fragment? = nu
   protected open fun fragment(): Fragment? = null
 
   private var changeable: Changeable? = null
+  protected var actualFragment: Fragment? = null
 
   @BindView(R.id.toolbar)
   lateinit var toolbar: Toolbar
@@ -48,19 +49,30 @@ abstract class ServiceBoundSettingsActivity(private val fragment: Fragment? = nu
     setSupportActionBar(toolbar)
     supportActionBar?.setDisplayHomeAsUpEnabled(true)
 
-    val fragment = supportFragmentManager.findFragmentById(R.id.fragment_container)
-                   ?: this.fragment
-                   ?: this.fragment()
-    if (fragment != null) {
+    val existingFragment = savedInstanceState?.let {
+      supportFragmentManager.getFragment(it, "settings_content")
+    }
+
+    actualFragment = existingFragment ?: this.fragment ?: this.fragment()
+    if (existingFragment == null) {
+      actualFragment?.let {
         val transaction = supportFragmentManager.beginTransaction()
-      fragment.arguments = arguments
-      transaction.replace(R.id.fragment_container, fragment)
+        it.arguments = arguments
+        transaction.replace(R.id.fragment_container, it)
         transaction.commit()
       }
+    }
 
     this.changeable = fragment as? Changeable
   }
 
+  override fun onSaveInstanceState(outState: Bundle) {
+    super.onSaveInstanceState(outState)
+    actualFragment?.let {
+      supportFragmentManager.putFragment(outState, "settings_content", it)
+    }
+  }
+
   private fun shouldNavigateAway(callback: () -> Unit) {
     val changeable = this.changeable
     if (changeable?.hasChanged() == true) {

app/src/main/java/de/kuschku/quasseldroid/util/ui/settings/SettingsActivity.kt

@@ -34,6 +34,7 @@ abstract class SettingsActivity(protected val fragment: Fragment? = null) : Them
   protected open fun fragment(): Fragment? = null
 
   private var changeable: Changeable? = null
+  protected var actualFragment: Fragment? = null
 
   @BindView(R.id.toolbar)
   lateinit var toolbar: Toolbar
@@ -47,19 +48,30 @@ abstract class SettingsActivity(protected val fragment: Fragment? = null) : Them
     setSupportActionBar(toolbar)
     supportActionBar?.setDisplayHomeAsUpEnabled(true)
 
-    val fragment = supportFragmentManager.findFragmentById(R.id.fragment_container)
-                   ?: this.fragment
-                   ?: this.fragment()
-    if (fragment != null) {
+    val existingFragment = savedInstanceState?.let {
+      supportFragmentManager.getFragment(it, "settings_content")
+    }
+
+    actualFragment = existingFragment ?: this.fragment ?: this.fragment()
+    if (existingFragment == null) {
+      actualFragment?.let {
         val transaction = supportFragmentManager.beginTransaction()
-      fragment.arguments = arguments
-      transaction.replace(R.id.fragment_container, fragment)
+        it.arguments = arguments
+        transaction.replace(R.id.fragment_container, it)
         transaction.commit()
       }
+    }
 
     this.changeable = fragment as? Changeable
   }
 
+  override fun onSaveInstanceState(outState: Bundle) {
+    super.onSaveInstanceState(outState)
+    actualFragment?.let {
+      supportFragmentManager.putFragment(outState, "settings_content", it)
+    }
+  }
+
   private fun shouldNavigateAway(callback: () -> Unit) {
     val changeable = this.changeable
     if (changeable?.hasChanged() == true) {