Create PySideWeakRef class.

With this class you can use a c function as a callback on PyObject destruction.

Reviewer: Marcelo Lira <marcelo.lira@openbossa.org>
          Hugo Parente Lima <hugo.pl@gmail.com>

3 files changed, 99 insertions, 0 deletions

diff --git a/libpyside/CMakeLists.txt b/libpyside/CMakeLists.txt
index 6450045de..c3d3f8611 100644
--- a/libpyside/CMakeLists.txt
+++ b/libpyside/CMakeLists.txt
@@ -8,6 +8,7 @@ set(libpyside_SRC
     pysidesignal.cpp
     pysideslot.cpp
     pysideproperty.cpp
+    pysideweakref.cpp
     pyside.cpp
 )
 
@@ -41,6 +42,7 @@ set(libpyside_HEADERS
     pysidemetafunction.h
     pysidesignal.h
     pysideproperty.h
+    pysideweakref.h
 )
 
 if (CMAKE_BUILD_TYPE STREQUAL "Debug")
diff --git a/libpyside/pysideweakref.cpp b/libpyside/pysideweakref.cpp
new file mode 100644
index 000000000..ddb426edf
--- /dev/null
+++ b/libpyside/pysideweakref.cpp
@@ -0,0 +1,80 @@
+#include "pysideweakref.h"
+
+#include <Python.h>
+
+typedef struct {
+    PyObject_HEAD
+    /* Type-specific fields go here. */
+    PySideWeakRefFunction weakref_func;
+    void *user_data;
+} PySideCallableObject;
+
+static PyObject* CallableObject_call(PyObject* callable_object, PyObject* args, PyObject* kw);
+
+static PyTypeObject PySideCallableObjectType = {
+    PyObject_HEAD_INIT(0)
+    0,
+    const_cast<char*>("PySide.Callable"),
+    sizeof(PySideCallableObject),    /*tp_basicsize*/
+    0,                         /*tp_itemsize*/
+    0,                         /*tp_dealloc*/
+    0,                         /*tp_print*/
+    0,                         /*tp_getattr*/
+    0,                         /*tp_setattr*/
+    0,                         /*tp_compare*/
+    0,                         /*tp_repr*/
+    0,                         /*tp_as_number*/
+    0,                         /*tp_as_sequence*/
+    0,                         /*tp_as_mapping*/
+    0,                         /*tp_hash */
+    CallableObject_call,       /*tp_call*/
+    0,                         /*tp_str*/
+    0,                         /*tp_getattro*/
+    0,                         /*tp_setattro*/
+    0,                         /*tp_as_buffer*/
+    Py_TPFLAGS_DEFAULT,        /*tp_flags*/
+    0,                         /* tp_doc */
+};
+
+
+static PyObject* CallableObject_call(PyObject* callable_object, PyObject* args, PyObject* kw)
+{
+    PySideCallableObject* obj = (PySideCallableObject*)(callable_object);
+    obj->weakref_func(obj->user_data);
+
+    Py_XDECREF(PyTuple_GET_ITEM(args, 0)); //kill weak ref
+    Py_RETURN_NONE;
+}
+
+namespace PySide { namespace WeakRef {
+
+PyObject* create(PyObject* obj, PySideWeakRefFunction func, void* userData)
+{
+    if (obj == Py_None)
+        return 0;
+
+    if (PySideCallableObjectType.ob_type == 0)
+    {
+        PySideCallableObjectType.ob_type = &PyType_Type;
+        PyType_Ready(&PySideCallableObjectType);
+    }
+
+    PySideCallableObject* callable = PyObject_New(PySideCallableObject, &PySideCallableObjectType);
+    if (!callable || PyErr_Occurred())
+        return 0;
+
+    PyObject* weak = PyWeakref_NewRef(obj, (PyObject*)callable);
+    if (!weak || PyErr_Occurred())
+        return 0;
+
+    Py_DECREF(callable);
+    if (!weak)
+        return 0;
+
+    callable->weakref_func = func;
+    callable->user_data = userData;
+    return (PyObject*)callable;
+}
+
+} }  //namespace
+
diff --git a/libpyside/pysideweakref.h b/libpyside/pysideweakref.h
new file mode 100644
index 000000000..7bc4ddfc0
--- /dev/null
+++ b/libpyside/pysideweakref.h
@@ -0,0 +1,17 @@
+#ifndef __PYSIDEWEAKREF__
+#define __PYSIDEWEAKREF__
+
+#include <pysidemacros.h>
+#include <Python.h>
+
+typedef void (*PySideWeakRefFunction)(void* userData);
+
+namespace PySide { namespace WeakRef {
+
+PYSIDE_API PyObject* create(PyObject* ob, PySideWeakRefFunction func, void* userData);
+
+} //PySide
+} //WeakRef
+
+
+#endif