Adds support for Duck Punching (aka Monkey Patching).

The simplest definition of duck punching for our purposes is
the ability to change the definition of a method in an instance of
a class.
To allow this behaviour the SbkBaseWrapper structure had to be
extended with a 'ob_dict' which is a PyObject pointer to the instance
dictionary. It is originally set to NULL until the user tries to access
it. This dictionary could be accessed through the '__dict__' instance
property. For now it is read-only.

The generator was updated to handle the instance dictionary, and an
extensive duck punching test was also added.

Reviewed by Hugo Parente Lima <hugo.lima@openbossa.org>

1 files changed, 139 insertions, 0 deletions

diff --git a/tests/samplebinding/duck_punching_test.py b/tests/samplebinding/duck_punching_test.py
new file mode 100755
index 000000000..cbf48c135
--- /dev/null
+++ b/tests/samplebinding/duck_punching_test.py
@@ -0,0 +1,139 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+#
+# This file is part of the Shiboken Python Bindings Generator project.
+#
+# Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
+#
+# Contact: PySide team <contact@pyside.org>
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU Lesser General Public License
+# version 2.1 as published by the Free Software Foundation. Please
+# review the following information to ensure the GNU Lesser General
+# Public License version 2.1 requirements will be met:
+# http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+# #
+# This program is distributed in the hope that it will be useful, but
+# WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
+# 02110-1301 USA
+
+'''Test cases for virtual methods.'''
+
+import types
+import unittest
+
+from sample import VirtualMethods, SimpleFile, Point
+
+class Duck(VirtualMethods):
+    def __init__(self):
+        VirtualMethods.__init__(self)
+
+class Monkey(SimpleFile):
+    def __init__(self, filename):
+        SimpleFile.__init__(self, filename)
+
+class DuckPunchingTest(unittest.TestCase):
+    '''Test case for duck punching (aka "monkey patching").'''
+
+    def setUp(self):
+        self.multiplier = 2.0
+        self.duck_method_called = False
+
+    def testMonkeyPatchOnVirtualMethod(self):
+        '''Injects new 'virtualMethod0' on a VirtualMethods instance and makes C++ call it.'''
+        vm = VirtualMethods()
+        pt, val, cpx, b = Point(1.1, 2.2), 4, complex(3.3, 4.4), True
+
+        result1 = vm.virtualMethod0(pt, val, cpx, b)
+        result2 = vm.callVirtualMethod0(pt, val, cpx, b)
+        self.assertEqual(result1, result2)
+        self.assertEqual(result1, VirtualMethods.virtualMethod0(vm, pt, val, cpx, b))
+
+        def myVirtualMethod0(obj, pt, val, cpx, b):
+            self.duck_method_called = True
+            return VirtualMethods.virtualMethod0(obj, pt, val, cpx, b) * self.multiplier
+        vm.virtualMethod0 = types.MethodType(myVirtualMethod0, vm, VirtualMethods)
+
+        result1 = vm.callVirtualMethod0(pt, val, cpx, b)
+        self.assert_(self.duck_method_called)
+
+        result2 = vm.virtualMethod0(pt, val, cpx, b)
+        self.assertEqual(result1, result2)
+        self.assertEqual(result1, VirtualMethods.virtualMethod0(vm, pt, val, cpx, b) * self.multiplier)
+
+    def testMonkeyPatchOnVirtualMethodWithInheritance(self):
+        '''Injects new 'virtualMethod0' on an object that inherits from VirtualMethods and makes C++ call it.'''
+        duck = Duck()
+        pt, val, cpx, b = Point(1.1, 2.2), 4, complex(3.3, 4.4), True
+
+        result1 = duck.virtualMethod0(pt, val, cpx, b)
+        result2 = duck.callVirtualMethod0(pt, val, cpx, b)
+        self.assertEqual(result1, result2)
+        self.assertEqual(result1, VirtualMethods.virtualMethod0(duck, pt, val, cpx, b))
+
+        def myVirtualMethod0(obj, pt, val, cpx, b):
+            self.duck_method_called = True
+            return VirtualMethods.virtualMethod0(obj, pt, val, cpx, b) * self.multiplier
+        duck.virtualMethod0 = types.MethodType(myVirtualMethod0, duck, Duck)
+
+        result1 = duck.callVirtualMethod0(pt, val, cpx, b)
+        self.assert_(self.duck_method_called)
+
+        result2 = duck.virtualMethod0(pt, val, cpx, b)
+        self.assertEqual(result1, result2)
+        self.assertEqual(result1, VirtualMethods.virtualMethod0(duck, pt, val, cpx, b) * self.multiplier)
+
+    def testMonkeyPatchOnMethodWithStaticAndNonStaticOverloads(self):
+        '''Injects new 'exists' on a SimpleFile instance and makes C++ call it.'''
+        simplefile = SimpleFile('foobar')
+
+        # Static 'exists'
+        simplefile.exists('sbrubbles')
+        self.assertFalse(self.duck_method_called)
+        # Non-static 'exists'
+        simplefile.exists()
+        self.assertFalse(self.duck_method_called)
+
+        def myExists(obj):
+            self.duck_method_called = True
+            return False
+        simplefile.exists = types.MethodType(myExists, simplefile, SimpleFile)
+
+        # Static 'exists' was overridden by the monkey patch, which accepts 0 arguments
+        self.assertRaises(TypeError, simplefile.exists, 'sbrubbles')
+        # Monkey patched exists
+        simplefile.exists()
+        self.assert_(self.duck_method_called)
+
+    def testMonkeyPatchOnMethodWithStaticAndNonStaticOverloadsWithInheritance(self):
+        '''Injects new 'exists' on an object that inherits from SimpleFile and makes C++ call it.'''
+        monkey = Monkey('foobar')
+
+        # Static 'exists'
+        monkey.exists('sbrubbles')
+        self.assertFalse(self.duck_method_called)
+        # Non-static 'exists'
+        monkey.exists()
+        self.assertFalse(self.duck_method_called)
+
+        def myExists(obj):
+            self.duck_method_called = True
+            return False
+        monkey.exists = types.MethodType(myExists, monkey, SimpleFile)
+
+        # Static 'exists' was overridden by the monkey patch, which accepts 0 arguments
+        self.assertRaises(TypeError, monkey.exists, 'sbrubbles')
+        # Monkey patched exists
+        monkey.exists()
+        self.assert_(self.duck_method_called)
+
+if __name__ == '__main__':
+    unittest.main()
+