#!/usr/bin/env python
# -*- coding: utf-8 -*-
#
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## Copyright (C) 2016 The Qt Company Ltd.
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## This file is part of the test suite of Qt for Python.
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'''Test case for objects that keep references to other object without owning them (e.g. model/view relationships).'''

import unittest
from sys import getrefcount

from sample import ObjectModel, ObjectView

class TestKeepReference(unittest.TestCase):
    '''Test case for objects that keep references to other object without owning them (e.g. model/view relationships).'''

    def testReferenceCounting(self):
        '''Tests reference count of model-like object referred by view-like objects.'''
        model1 = ObjectModel()
        refcount1 = getrefcount(model1)
        view1 = ObjectView()
        view1.setModel(model1)
        self.assertEqual(getrefcount(view1.model()), refcount1 + 1)

        view2 = ObjectView()
        view2.setModel(model1)
        self.assertEqual(getrefcount(view2.model()), refcount1 + 2)

        model2 = ObjectModel()
        view2.setModel(model2)
        self.assertEqual(getrefcount(view1.model()), refcount1 + 1)

    def testReferenceCountingWhenDeletingReferrer(self):
        '''Tests reference count of model-like object referred by deceased view-like object.'''
        model = ObjectModel()
        refcount1 = getrefcount(model)
        view = ObjectView()
        view.setModel(model)
        self.assertEqual(getrefcount(view.model()), refcount1 + 1)

        del view
        self.assertEqual(getrefcount(model), refcount1)

    def testReferreedObjectSurvivalAfterContextEnd(self):
        '''Model-like object assigned to a view-like object must survive after get out of context.'''
        def createModelAndSetToView(view):
            model = ObjectModel()
            model.setObjectName('created model')
            view.setModel(model)
        view = ObjectView()
        createModelAndSetToView(view)
        model = view.model()

if __name__ == '__main__':
    unittest.main()