Prevent BottomSheetDialogFragment covering navigation bar

I had the same problem and I finally found a solution which is not hacky or needs an exorbitant amount of code.

This Method replaced the window background with a LayerDrawable which consists of two elements: the background dim and the navigation bar background.

@RequiresApi(api = Build.VERSION_CODES.M)
private void setWhiteNavigationBar(@NonNull Dialog dialog) {
    Window window = dialog.getWindow();
    if (window != null) {
        DisplayMetrics metrics = new DisplayMetrics();
        window.getWindowManager().getDefaultDisplay().getMetrics(metrics);

        GradientDrawable dimDrawable = new GradientDrawable();
        // ...customize your dim effect here

        GradientDrawable navigationBarDrawable = new GradientDrawable();
        navigationBarDrawable.setShape(GradientDrawable.RECTANGLE);
        navigationBarDrawable.setColor(Color.WHITE);

        Drawable[] layers = {dimDrawable, navigationBarDrawable};

        LayerDrawable windowBackground = new LayerDrawable(layers);
        windowBackground.setLayerInsetTop(1, metrics.heightPixels);

        window.setBackgroundDrawable(windowBackground);
    }
}

The method “setLayerInsetTop” requires the API 23 but that’s fine because dark navigation bar icons were introduced in Android O (API 26).

So the last part of the solution is to call this method from your bottom sheets onCreate method like this.

@NonNull
@Override
public Dialog onCreateDialog(Bundle savedInstanceState) {
    Dialog dialog = super.onCreateDialog(savedInstanceState);

    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O_MR1) {
        setWhiteNavigationBar(dialog);
    }

    return dialog;
}

I hope it helps and please let me know if you find a device or case in which this solution does not work.