Emit signals upon property change

2 files changed, 28 insertions, 6 deletions

diff --git a/src/object.cpp b/src/object.cpp
index 31c6504..b722bee 100644
--- a/src/object.cpp
+++ b/src/object.cpp
@@ -16,7 +16,7 @@ struct PropertyInfo
     typedef std::function<void(GstObject *target, QVariant *value)> ReadDelegate;
     typedef std::function<void(GstObject *target, const QVariant &value)> WriteDelegate;
 
-    QByteArray name;
+    const char *name;
     ReadDelegate read;
     WriteDelegate write;
 };
@@ -55,6 +55,20 @@ struct TypeInfo
         return id - properties.size();
     }
 
+    void emitPropertyChanged(Object *object, const GParamSpec *pspec) const
+    {
+        for (int i = 0; i < properties.size(); ++i) {
+            // can compare by pointer because GParamSpec::name is interned
+            if (pspec->name == properties.at(i).name) {
+                QMetaObject::activate(object, metaObject, i, Q_NULLPTR);
+                return;
+            }
+        }
+
+        if (parent)
+            parent->emitPropertyChanged(object, pspec);
+    }
+
     const TypeInfo *parent;
     const QMetaObject *metaObject;
     QVector<PropertyInfo> properties;
@@ -370,11 +384,11 @@ static const TypeInfo *makeTypeInfo(GType gtype)
             continue;
         }
 
-        qDebug("Adding %s::%s", g_type_name(gtype), pSpec->name);
-
         auto notifier = objectBuilder.addSignal(name + QByteArrayLiteral("Changed()"));
         auto property = objectBuilder.addProperty(name, type, notifier.index());
 
+        qDebug("%s %d %d", name.constData(), notifier.index(), property.index());
+
         property.setReadable(pSpec->flags & G_PARAM_READABLE);
         property.setWritable(pSpec->flags & G_PARAM_WRITABLE);
 
@@ -416,8 +430,10 @@ Object::Object(GstObject *target)
     , m_target(target)
 {
     Q_ASSERT(m_target != Q_NULLPTR);
+
     g_object_ref_sink(m_target);
     g_object_set_qdata(G_OBJECT(target), Private::dataKeyQuark(), this);
+    g_signal_connect_swapped(target, "notify", reinterpret_cast<GCallback>(&Object::emitPropertyChanged), this);
 }
 
 Object::~Object()
@@ -446,14 +462,12 @@ void *Object::qt_metacast(const char *className)
 
 int Object::qt_metacall(QMetaObject::Call call, int id, void **args)
 {
-    qDebug("%s: call=%d, id=%d", Q_FUNC_INFO, call, id);
+    qDebug("%s: %d(%d)", Q_FUNC_INFO, call, id);
     id = QObject::qt_metacall(call, id, args);
 
     if (id < 0)
         return id;
 
-    qDebug("-> id=%d", id);
-
     switch(call) {
     case QMetaObject::ReadProperty:
         id = readProperty(id, static_cast<QVariant *>(args[0]));
@@ -492,4 +506,10 @@ int Object::writeProperty(int id, const QVariant &value)
     return typeInfo->writeProperty(m_target, id, value);
 }
 
+void Object::emitPropertyChanged(Object *self, GParamSpec *pspec)
+{
+    const auto *const typeInfo = Private::findTypeInfo(G_OBJECT_TYPE(self->m_target));
+    typeInfo->emitPropertyChanged(self, pspec);
+}
+
 } // namespace QQuickStreamer
diff --git a/src/object.h b/src/object.h
index 43fe227..60b8e0e 100644
--- a/src/object.h
+++ b/src/object.h
@@ -3,6 +3,7 @@
 
 #include <QObject>
 
+typedef struct _GParamSpec GParamSpec;
 typedef struct _GstObject GstObject;
 
 namespace QQuickStreamer {
@@ -28,6 +29,7 @@ public:
 protected:
     int readProperty(int id, QVariant *value);
     int writeProperty(int id, const QVariant &value);
+    static void emitPropertyChanged(Object *self, GParamSpec *pspec);
 
 private:
     GstObject *const m_target;