objectbox: Support native JSObject GType for signal parameters and properties

Define a new boxed 'JSObject' GType and use it to wrap native JSObjects.

To do this, create an ObjectBox class that automatically roots and unroots
a JSObject persistently.
This class uses a private constructor and a pimpl idiom to force the
allocation of the wrapper in the stack, that is doable using a 'boxed'
static method that returns a unique_ptr.
Internally the boxed wrapper uses a ref-counting system that allows us to
avoid copies and re-rooting.

Define GObject.TYPE_JSOBJECT as 'JSObject' GType and add an alias for the
JS Objects using the $gtype property.

Add a ParamSpec jsobject alias.

1 files changed, 31 insertions, 0 deletions

diff --git a/gjs/objectbox.h b/gjs/objectbox.h
new file mode 100644
index 00000000..62179fc2
--- /dev/null
+++ b/gjs/objectbox.h
@@ -0,0 +1,31 @@
+/* -*- mode: C++; c-basic-offset: 4; indent-tabs-mode: nil; -*- */
+// SPDX-License-Identifier: MIT OR LGPL-2.0-or-later
+// SPDX-FileCopyrightText: 2019 Marco Trevisan <marco.trevisan@canonical.com>
+
+#pragma once
+
+#include <config.h>
+
+#include <memory>
+
+#include <glib-object.h>
+
+#include <js/TypeDecls.h>
+
+#include "gjs/macros.h"
+
+struct ObjectBox {
+    using Ptr = std::unique_ptr<ObjectBox, void (*)(ObjectBox*)>;
+
+    [[nodiscard]] static GType gtype();
+    [[nodiscard]] static ObjectBox::Ptr boxed(JSContext*, JSObject*);
+
+    GJS_JSAPI_RETURN_CONVENTION
+    static JSObject* object_for_c_ptr(JSContext*, ObjectBox*);
+
+ private:
+    ObjectBox(JSContext*, JSObject*);
+
+    struct impl;
+    std::unique_ptr<impl> m_impl;
+};