Use QObject property to invalidate wrapper before deletion.

Define a getWrapperForQObject function to create / find
wrappers for QObject derived objects.  It sets a property
so that an invalidate function can be called when the QObject
property is cleared in the QObject destructor after all destroyed
signal handlers have been called.  Requires a change to shiboken
to generate calls to the getWrapperForQObject function.

Change-Id: I4ed548af114bf7176e8e8255a3ea70549c35d74c
Reviewed-by: Hugo Parente Lima <hugo.lima@openbossa.org>

2 files changed, 54 insertions, 0 deletions

diff --git a/libpyside/pyside.cpp b/libpyside/pyside.cpp
index 0d96f9530..a71b139a1 100644
--- a/libpyside/pyside.cpp
+++ b/libpyside/pyside.cpp
@@ -36,6 +36,7 @@
 #include <basewrapper.h>
 #include <conversions.h>
 #include <sbkconverter.h>
+#include <gilstate.h>
 #include <typeresolver.h>
 #include <bindingmanager.h>
 #include <algorithm>
@@ -44,6 +45,7 @@
 #include <QStack>
 #include <QCoreApplication>
 #include <QDebug>
+#include <QSharedPointer>
 
 static QStack<PySide::CleanupFunction> cleanupFunctionList;
 static void* qobjectNextAddr;
@@ -293,5 +295,55 @@ void setNextQObjectMemoryAddr(void* addr)
     qobjectNextAddr = addr;
 }
 
+} // namespace PySide
+
+// A QSharedPointer is used with a deletion function to invalidate a pointer
+// when the property value is cleared.  This should be a QSharedPointer with
+// a void* pointer, but that isn't allowed
+typedef char any_t;
+Q_DECLARE_METATYPE(QSharedPointer<any_t>);
+
+namespace PySide
+{
+
+static void invalidatePtr(any_t* object)
+{
+    Shiboken::GilState state;
+
+    SbkObject* wrapper = Shiboken::BindingManager::instance().retrieveWrapper(object);
+    if (wrapper != NULL)
+        Shiboken::BindingManager::instance().releaseWrapper(wrapper);
+}
+
+static const char invalidatePropertyName[] = "_PySideInvalidatePtr";
+
+PyObject* getWrapperForQObject(QObject* cppSelf, SbkObjectType* sbk_type)
+{
+    PyObject* pyOut = (PyObject*)Shiboken::BindingManager::instance().retrieveWrapper(cppSelf);
+    if (pyOut) {
+        Py_INCREF(pyOut);
+        return pyOut;
+    }
+
+    // Setting the property will trigger an QEvent notification, which may call into
+    // code that creates the wrapper so only set the property if it isn't already
+    // set and check if it's created after the set call
+    QVariant existing = cppSelf->property(invalidatePropertyName);
+    if (!existing.isValid()) {
+        QSharedPointer<any_t> shared_with_del((any_t*)cppSelf, invalidatePtr);
+        cppSelf->setProperty(invalidatePropertyName, QVariant::fromValue(shared_with_del));
+        pyOut = (PyObject*)Shiboken::BindingManager::instance().retrieveWrapper(cppSelf);
+        if (pyOut) {
+            Py_INCREF(pyOut);
+            return pyOut;
+        }
+    }
+
+    const char* typeName = typeid(*cppSelf).name();
+    pyOut = Shiboken::Object::newObject(sbk_type, cppSelf, false, false, typeName);
+
+    return pyOut;
+}
+
 } //namespace PySide
 
diff --git a/libpyside/pyside.h b/libpyside/pyside.h
index 779c630a9..35cd36459 100644
--- a/libpyside/pyside.h
+++ b/libpyside/pyside.h
@@ -117,6 +117,8 @@ PYSIDE_API bool inherits(PyTypeObject* self, const char* class_name);
 PYSIDE_API void* nextQObjectMemoryAddr();
 PYSIDE_API void setNextQObjectMemoryAddr(void* addr);
 
+PYSIDE_API PyObject* getWrapperForQObject(QObject* cppSelf, SbkObjectType* sbk_type);
+
 } //namespace PySide