Method get_nested_interface_object

gi/boxed.cpp:523–561

template <class Base, class Prototype, class Instance>
template <class FieldInstance>
bool BoxedInstance<Base, Prototype, Instance>::get_nested_interface_object(
    JSContext* cx, JSObject* parent_obj, const GI::FieldInfo& field_info,
    const GI::UnownedInfo<FieldInstance::TAG>& struct_info,
    JS::MutableHandleValue value) const {
    if (!GI::struct_is_simple(struct_info)) {
        gjs_throw(cx, "Reading field %s.%s is not supported",
                  format_name().c_str(), field_info.name());

        return false;
    }

    // If we have already set the field from a JS object which we have stashed
    // because it owns pointers, return that JS object instead of creating one.
    auto entry = m_nested_objects.lookup(field_info.name());
    if (entry.found()) {
        value.setObject(*entry->value().get());
        return true;
    }

    JS::RootedObject obj{
        cx, gjs_new_object_with_generic_prototype(cx, struct_info)};
    if (!obj)
        return false;

    FieldInstance* priv = FieldInstance::new_for_js_object(cx, obj);

    // A structure nested inside a parent object; doesn't have an independent
    // allocation
    adopt_nested_ptr(priv, raw_ptr() + field_info.offset());

    /* We never actually read the reserved slot, but we put the parent object
     * into it to hold onto the parent object.
     */
    JS::SetReservedSlot(obj, BoxedInstance::PARENT_OBJECT,
                        JS::ObjectValue(*parent_obj));

    value.setObject(*obj);
    return true;
}

/**
 * BoxedBase::field_getter: