Implement NavigationBar theme

app/src/main/java/io/heckel/ntfy/ui/MainSettingsActivity.kt

@@ -1,25 +1,60 @@
 package io.heckel.ntfy.ui
 
+import android.content.res.Configuration
+import android.os.Build
 import android.os.Bundle
+import android.view.WindowInsetsController
+import androidx.annotation.RequiresApi
 import androidx.appcompat.app.AppCompatActivity
 import io.heckel.ntfy.R
 import io.heckel.ntfy.databinding.MainSettingsActivityBinding
 
-
 class MainSettingsActivity : AppCompatActivity() {
 
     private lateinit var mBinding: MainSettingsActivityBinding
 
+    @RequiresApi(Build.VERSION_CODES.R)
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
 
         mBinding = MainSettingsActivityBinding.inflate(layoutInflater)
         setContentView(mBinding.root)
 
-        mBinding.toolbar.setNavigationOnClickListener {
+        setupToolbar()
-            onBackPressed()
+        setSystemBarsAppearance()
+        showPreferencesFragment()
     }
 
+    private fun setupToolbar() {
+        mBinding.toolbar.setNavigationOnClickListener {
+            onBackPressedDispatcher.onBackPressed()
+        }
+    }
+
+    @RequiresApi(Build.VERSION_CODES.R)
+    private fun setSystemBarsAppearance() {
+        val insetsController = window.insetsController ?: return
+
+        val isLightMode = isSystemInLightMode()
+        if (isLightMode) {
+            insetsController.setSystemBarsAppearance(
+                WindowInsetsController.APPEARANCE_LIGHT_NAVIGATION_BARS,
+                WindowInsetsController.APPEARANCE_LIGHT_NAVIGATION_BARS
+            )
+        } else {
+            insetsController.setSystemBarsAppearance(
+                0,
+                WindowInsetsController.APPEARANCE_LIGHT_NAVIGATION_BARS
+            )
+        }
+    }
+
+    private fun isSystemInLightMode(): Boolean {
+        val nightModeFlags = resources.configuration.uiMode and Configuration.UI_MODE_NIGHT_MASK
+        return nightModeFlags != Configuration.UI_MODE_NIGHT_YES
+    }
+
+    private fun showPreferencesFragment() {
         supportFragmentManager
             .beginTransaction()
             .replace(R.id.fragment_container, PreferencesFragment())