[gjs: 2/3] private: Allow passing type flags to register_type

[Philip Chimento <pchimento src gnome org>]

commit 022b6681f7e8b035581d74d737f083baa40c5f9a
Author: Florian Müllner <fmuellner gnome org>
Date:   Fri Apr 26 21:12:52 2019 +0000

    private: Allow passing type flags to register_type
    
    Unlike Lang.Class, GObject.registerClass currently lacks a way for
    defining abstract classes. Make this possible by allowing for an
    optional GTypeFlags value.
    
    https://gitlab.gnome.org/GNOME/gjs/merge_requests/290

 gi/private.cpp                         | 8 +++++---
 installed-tests/js/testGObjectClass.js | 9 +++++++++
 modules/_legacy.js                     | 3 ++-
 modules/overrides/GObject.js           | 7 ++++++-
 4 files changed, 22 insertions(+), 5 deletions(-)
---
diff --git a/gi/private.cpp b/gi/private.cpp
index 4cc29f74..e53e2871 100644
--- a/gi/private.cpp
+++ b/gi/private.cpp
@@ -252,9 +252,11 @@ static bool gjs_register_type(JSContext* cx, unsigned argc, JS::Value* vp) {
     JSAutoRequest ar(cx);
 
     JS::UniqueChars name;
+    GTypeFlags type_flags;
     JS::RootedObject parent(cx), interfaces(cx), properties(cx);
-    if (!gjs_parse_call_args(cx, "register_type", argv, "osoo", "parent",
-                             &parent, "name", &name, "interfaces", &interfaces,
+    if (!gjs_parse_call_args(cx, "register_type", argv, "osioo", "parent",
+                             &parent, "name", &name, "flags", &type_flags,
+                             "interfaces", &interfaces,
                              "properties", &properties))
         return false;
 
@@ -296,7 +298,7 @@ static bool gjs_register_type(JSContext* cx, unsigned argc, JS::Value* vp) {
     type_info.instance_size = query.instance_size;
 
     GType instance_type = g_type_register_static(
-        parent_priv->gtype(), name.get(), &type_info, GTypeFlags(0));
+        parent_priv->gtype(), name.get(), &type_info, type_flags);
 
     g_type_set_qdata(instance_type, ObjectBase::custom_type_quark(),
                      GINT_TO_POINTER(1));
diff --git a/installed-tests/js/testGObjectClass.js b/installed-tests/js/testGObjectClass.js
index 680c96b1..1bd75285 100644
--- a/installed-tests/js/testGObjectClass.js
+++ b/installed-tests/js/testGObjectClass.js
@@ -114,6 +114,11 @@ const MyObject = GObject.registerClass({
     }
 });
 
+const MyAbstractObject = GObject.registerClass({
+    GTypeFlags: GObject.TypeFlags.ABSTRACT
+}, class MyAbstractObject extends GObject.Object {
+});
+
 const MyApplication = GObject.registerClass({
     Signals: { 'custom': { param_types: [ GObject.TYPE_INT ] } },
 }, class MyApplication extends Gio.Application {
@@ -158,6 +163,10 @@ describe('GObject class with decorator', function () {
         expect (() => GObject.registerClass(class Bar extends Foo {})).toThrow();
     });
 
+    it('throws an error when used with an abstract class', function() {
+        expect (() => new MyAbstractObject()).toThrow();
+    });
+
     it('constructs with default values for properties', function () {
         expect(myInstance.readwrite).toEqual('foo');
         expect(myInstance.readonly).toEqual('bar');
diff --git a/modules/_legacy.js b/modules/_legacy.js
index 8d50c352..8c4b22c3 100644
--- a/modules/_legacy.js
+++ b/modules/_legacy.js
@@ -513,6 +513,7 @@ function defineGObjectLegacyObjects(GObject) {
             let name = params.Name;
 
             let gtypename = _createGTypeName(params);
+            let gflags = params.Abstract ? GObject.TypeFlags.ABSTRACT : 0;
 
             if (!params.Extends)
                 params.Extends = GObject.Object;
@@ -530,7 +531,7 @@ function defineGObjectLegacyObjects(GObject) {
             delete params.Properties;
 
             let newClass = Gi.register_type(parent.prototype, gtypename,
-                gobjectInterfaces, propertiesArray);
+                gflags, gobjectInterfaces, propertiesArray);
 
             // See Class.prototype._construct for the reasoning
             // behind this direct prototype set.
diff --git a/modules/overrides/GObject.js b/modules/overrides/GObject.js
index 8181b815..c6ea6ad9 100644
--- a/modules/overrides/GObject.js
+++ b/modules/overrides/GObject.js
@@ -27,6 +27,7 @@ const Legacy = imports._legacy;
 let GObject;
 
 var GTypeName = Symbol('GType name');
+var GTypeFlags = Symbol('GType flags');
 var interfaces = Symbol('GObject interfaces');
 var properties = Symbol('GObject properties');
 var requires = Symbol('GObject interface requires');
@@ -58,6 +59,8 @@ function registerClass(klass) {
         klass = arguments[1];
         if ('GTypeName' in metaInfo)
             klass[GTypeName] = metaInfo.GTypeName;
+        if ('GTypeFlags' in metaInfo)
+            klass[GTypeFlags] = metaInfo.GTypeFlags;
         if ('Implements' in metaInfo)
             klass[interfaces] = metaInfo.Implements;
         if ('Properties' in metaInfo)
@@ -334,6 +337,8 @@ function _init() {
 
     GObject.Object._classInit = function(klass) {
         let gtypename = _createGTypeName(klass);
+        let gflags = klass.hasOwnProperty(GTypeFlags) ?
+            klass[GTypeFlags] : 0;
         let gobjectInterfaces = klass.hasOwnProperty(interfaces) ?
             klass[interfaces] : [];
         let propertiesArray = _propertiesAsArray(klass);
@@ -341,7 +346,7 @@ function _init() {
         let gobjectSignals = klass.hasOwnProperty(signals) ?
             klass[signals] : [];
 
-        let newClass = Gi.register_type(parent.prototype, gtypename,
+        let newClass = Gi.register_type(parent.prototype, gtypename, gflags,
             gobjectInterfaces, propertiesArray);
         Object.setPrototypeOf(newClass, parent);