Implement ElementList::childAt()

2 files changed, 29 insertions, 6 deletions

diff --git a/src/QuickStreamer/item.cpp b/src/QuickStreamer/item.cpp
index 53aef4b..ddc986d 100644
--- a/src/QuickStreamer/item.cpp
+++ b/src/QuickStreamer/item.cpp
@@ -12,6 +12,8 @@
 namespace QQuickStreamer {
 namespace Private {
 
+static const GQuark quickStreamItemQuark = g_quark_from_static_string("quick-streamer-item-quark");
+
 class ObjectLocker
 {
 public:
@@ -326,9 +328,17 @@ public:
 
     static Item *childAt(QQmlListProperty<Item> *list, int offset)
     {
-        // FIXME: need to store the wrapper object somewhere
-        qDebug() << Q_FUNC_INFO;
-        return Q_NULLPTR;
+        auto *const parent = static_cast<Item *>(list->object);
+        ObjectLocker locker(parent->target());
+
+        const int n = GST_BIN_NUMCHILDREN(parent->target());
+
+        auto *const child = offset >= 0 && offset < n
+                ? g_list_nth_data(GST_BIN_CHILDREN(parent->target()), n - offset - 1)
+                : Q_NULLPTR;
+
+        return static_cast<Item *>(child ? g_object_get_qdata(G_OBJECT(child), quickStreamItemQuark)
+                                         : Q_NULLPTR);
     }
 
     static void clearChildren(QQmlListProperty<Item> *list)
@@ -641,14 +651,17 @@ QHash<GType, TypeInfo *> TypeInfo::cache;
 
 using Private::TypeInfo;
 using Private::toCamelCase;
+using Private::quickStreamItemQuark;
 
 Item::Item(GstObject *target, QObject *parent)
     : QObject(parent)
     , m_target(target)
 {
     Q_ASSERT(m_target != Q_NULLPTR);
+    Q_ASSERT(g_object_get_qdata(G_OBJECT(m_target), quickStreamItemQuark) == Q_NULLPTR);
 
     g_object_ref_sink(m_target);
+    g_object_set_qdata(G_OBJECT(m_target), quickStreamItemQuark, this);
 
     auto notifyCallback = reinterpret_cast<GCallback>(&Item::emitPropertyChanged);
     g_signal_connect_swapped(target, "notify", notifyCallback, this);
diff --git a/tests/tst_qml/tst_quickstreamer.qml b/tests/tst_qml/tst_quickstreamer.qml
index 7b289a5..6ce8dc5 100644
--- a/tests/tst_qml/tst_quickstreamer.qml
+++ b/tests/tst_qml/tst_quickstreamer.qml
@@ -18,12 +18,22 @@ TestCase {
         }
     }
 
-    function test_properties()
+    function test_nameProperty()
     {
-        console.log([pipeline.name, appSink.name, appSource.name])
-
         compare(pipeline.name, "pipeline0")
         compare(appSink.name, "appsink0")
         compare(appSource.name, "brouhaha")
     }
+
+    function test_children()
+    {
+        console.log(pipeline.children)
+
+        compare(pipeline.children.length, 2)
+        compare(pipeline.children[0], appSource)
+        compare(pipeline.children[1], appSink)
+
+        compare(appSink.children, undefined)
+        compare(appSource.children, undefined)
+    }
 }