Add setting to manually enable/disable night mode (fixes #35)

app/src/main/java/net/vonforst/evmap/fragment/SettingsFragment.kt

@@ -3,6 +3,7 @@ package net.vonforst.evmap.fragment
 import android.content.SharedPreferences
 import android.os.Bundle
 import android.view.View
+import androidx.appcompat.app.AppCompatDelegate
 import androidx.appcompat.widget.Toolbar
 import androidx.navigation.fragment.findNavController
 import androidx.navigation.ui.setupWithNavController
@@ -10,13 +11,17 @@ import androidx.preference.Preference
 import androidx.preference.PreferenceFragmentCompat
 import net.vonforst.evmap.MapsActivity
 import net.vonforst.evmap.R
+import net.vonforst.evmap.storage.PreferenceDataSource
 
 
 class SettingsFragment : PreferenceFragmentCompat(),
     SharedPreferences.OnSharedPreferenceChangeListener {
+    private lateinit var prefs: PreferenceDataSource
+
     override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
         super.onViewCreated(view, savedInstanceState)
         val toolbar = view.findViewById(R.id.toolbar) as Toolbar
+        prefs = PreferenceDataSource(requireContext())
 
         val navController = findNavController()
         toolbar.setupWithNavController(
@@ -43,6 +48,15 @@ class SettingsFragment : PreferenceFragmentCompat(),
                     it.startActivity(it.intent);
                 }
             }
+            "darkmode" -> {
+                AppCompatDelegate.setDefaultNightMode(
+                    when (prefs.darkmode) {
+                        "on" -> AppCompatDelegate.MODE_NIGHT_YES
+                        "off" -> AppCompatDelegate.MODE_NIGHT_NO
+                        else -> AppCompatDelegate.MODE_NIGHT_FOLLOW_SYSTEM
+                    }
+                )
+            }
         }
     }
 

app/src/main/java/net/vonforst/evmap/storage/PreferenceDataSource.kt

@@ -39,4 +39,7 @@ class PreferenceDataSource(context: Context) {
 
     val language: String
         get() = sp.getString("language", "default")!!
+
+    val darkmode: String
+        get() = sp.getString("darkmode", "default")!!
 }