Fix bug#207, Add initQtMetaType class to libpyside.

Reviewer: Renato Araújo <renato.filho@openbossa.org>
          Luciano Wolf <luciano.wolf@openbossa.org>

1 files changed, 22 insertions, 0 deletions

diff --git a/libpyside/pyside.h b/libpyside/pyside.h
index 3c1c0600c..2048265f4 100644
--- a/libpyside/pyside.h
+++ b/libpyside/pyside.h
@@ -37,12 +37,34 @@
 
 #include <Python.h>
 #include <pysidemacros.h>
+#include <QMetaType>
 
 namespace PySide
 {
 
 PYSIDE_API void init(PyObject *module);
 
+/**
+*   If the type \p T was registered on Qt meta type system with Q_DECLARE_METATYPE macro, this class will initialize
+*   the meta type.
+*
+*   Initialize a meta type means register it on Qt meta type system, Qt itself only do this on the first call of
+*   qMetaTypeId, and this is exactly what we do to init it. If we don't do that, calls to QMetaType::type("QMatrix2x2")
+*   could return zero, causing QVariant to not recognize some C++ types, like QMatrix2x2.
+*/
+template<typename T, bool OK = QMetaTypeId<T>::Defined >
+struct initQtMetaType {
+    initQtMetaType()
+    {
+        qMetaTypeId<T>();
+    }
+};
+
+// Template specialization to do nothing when the type wasn't registered on Qt meta type system.
+template<typename T>
+struct initQtMetaType<T, false> {
+};
+
 } //namespace PySide