Method set_nested_interface_object

gi/boxed.cpp:659–724

template <class Base, class Prototype, class Instance>
template <class FieldBase>
bool BoxedInstance<Base, Prototype, Instance>::set_nested_interface_object(
    JSContext* cx, const GI::FieldInfo& field_info,
    const GI::UnownedInfo<FieldBase::TAG>& boxed_info, JS::HandleValue value) {
    if (!GI::struct_is_simple(boxed_info)) {
        gjs_throw(cx, "Writing field %s.%s is not supported",
                  format_name().c_str(), field_info.name());

        return false;
    }

    /* If we can't directly copy from the source object we need to construct a
     * new temporary object. */
    FieldBase* source_priv = nullptr;
    JS::RootedObject source_object{cx};
    bool field_has_same_info = false;

    if constexpr (std::is_same_v<FieldBase, Base>) {
        field_has_same_info = info() == boxed_info;
        if (field_has_same_info) {
            source_object = &value.toObject();
            source_priv = FieldBase::for_js(cx, source_object);
        }
    }

    if (!source_priv && !field_has_same_info) {
        source_object = &value.toObject();
        source_priv = FieldBase::for_js(cx, source_object);

        if (source_priv && source_priv->info() != boxed_info) {
            std::string source_name{source_priv->format_name()};
            gjs_throw(cx, "Impossible to associate a %s to a %s.%s field",
                      source_name.c_str(), name(), field_info.name());
            return false;
        }
    }

    if (!source_priv) {
        JS::RootedObject proto{cx,
                               gjs_lookup_generic_prototype(cx, boxed_info)};
        if (!proto)
            return false;

        JS::RootedValueArray<1> args{cx};
        args[0].set(value);
        source_object = gjs_construct_object_dynamic(cx, proto, args);
        if (!source_object ||
            !FieldBase::for_js_typecheck(cx, source_object, &source_priv))
            return false;
    }

    if (!source_priv->check_is_instance(cx, "copy"))
        return false;

    // Any pointers in the copied memory are still owned by the source struct.
    // So we need to tie the lifetime of the source JS object to this one.
    if (GI::simple_struct_has_pointers(boxed_info) &&
        !m_nested_objects.put(field_info.name(), source_object)) {
        JS_ReportOutOfMemory(cx);