How to apply a custom font to all elements in QML

I want to know if there is a way to apply a custom font to all elements in QML like we can easily do in HTML, setting the font on the tag body. I already have the font accessible in QML with:

FontLoader { id: robotoRegular; source: "fonts/Roboto-Regular.ttf" }

But now if I do something like:

ApplicationWindow {
    font.family: robotoRegular.name

It doesn't seem to work, and probably isn't supposed to. Or is there a way?

I'm using Qt 5.11.2, QtQuick 2.2.

Try this code:

#include <QFontDatabase>

void InstallDefaultFont()
{
    qint32 fontId = QFontDatabase::addApplicationFont(":/font.otf");
    QStringList fontList = QFontDatabase::applicationFontFamilies(fontId);

    QString family = fontList.first();
    QGuiApplication::setFont(QFont(family));
}

This will setup the default font for QML and Widgets as well.