Black navigation bar in dark theme

app/src/main/java/eu/faircode/email/ActivityBase.java

@@ -25,9 +25,12 @@ import android.content.Context;
 import android.content.Intent;
 import android.content.SharedPreferences;
 import android.content.res.Configuration;
+import android.os.Build;
 import android.os.Bundle;
 import android.os.PowerManager;
 import android.view.MenuItem;
+import android.view.View;
+import android.view.Window;
 import android.view.WindowManager;
 import android.widget.Toast;
 
@@ -102,6 +105,16 @@ abstract class ActivityBase extends AppCompatActivity implements SharedPreferenc
                 else
                     setTheme(R.style.AppThemeGreyLight);
             }
+
+            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
+                boolean dark = Helper.isDarkTheme(this);
+                Window window = getWindow();
+                View view = window.getDecorView();
+                int flags = view.getSystemUiVisibility();
+                if (dark)
+                    flags &= ~View.SYSTEM_UI_FLAG_LIGHT_NAVIGATION_BAR;
+                view.setSystemUiVisibility(flags);
+            }
         }
 
         prefs.registerOnSharedPreferenceChangeListener(this);

app/src/main/res/values/styles.xml

@@ -70,6 +70,8 @@
         <item name="themeName">dark</item>
         <item name="android:windowDisablePreview">true</item>
 
+        <item name="android:navigationBarColor">@color/black</item>
+
         <item name="colorPrimary">@color/darkPrimary</item>
         <item name="colorPrimaryDark">@color/darkPrimaryDark</item>
         <item name="colorAccent">@color/colorAccent</item>