tests/test_gobject.py

   1 # -*- Mode: Python -*-
   2
   3 import sys
   4 import gc
   5 import unittest
   6 import warnings
   7
   8 from gi.repository import GObject, GLib
   9 from gi import PyGIDeprecationWarning
  10 from gi.module import get_introspection_module
  11
  12 import gi
  13 _gobject = gi._gi._gobject
  14
  15 import testhelper
  16
  17
  18 class TestGObjectAPI(unittest.TestCase):
  19     def test_gobject_inheritance(self):
  20         # GObject.Object is a class hierarchy as follows:
  21         # overrides.Object -> introspection.Object -> static.GObject
  22         GIObjectModule = get_introspection_module('GObject')
  23         self.assertTrue(issubclass(GObject.Object, GIObjectModule.Object))
  24         self.assertTrue(issubclass(GIObjectModule.Object, _gobject.GObject))
  25
  26         self.assertEqual(_gobject.GObject.__gtype__, GObject.TYPE_OBJECT)
  27         self.assertEqual(GIObjectModule.Object.__gtype__, GObject.TYPE_OBJECT)
  28         self.assertEqual(GObject.Object.__gtype__, GObject.TYPE_OBJECT)
  29
  30         # The pytype wrapper should hold the outer most Object class from overrides.
  31         self.assertEqual(GObject.TYPE_OBJECT.pytype, GObject.Object)
  32
  33     def test_gobject_unsupported_overrides(self):
  34         obj = GObject.Object()
  35
  36         with self.assertRaisesRegex(RuntimeError, 'Data access methods are unsupported.*'):
  37             obj.get_data()
  38
  39         with self.assertRaisesRegex(RuntimeError, 'This method is currently unsupported.*'):
  40             obj.force_floating()
  41
  42     def test_compat_api(self):
  43         with warnings.catch_warnings(record=True) as w:
  44             warnings.simplefilter('always')
  45             # GObject formerly exposed a lot of GLib's functions
  46             self.assertEqual(GObject.markup_escape_text('foo'), 'foo')
  47
  48             ml = GObject.MainLoop()
  49             self.assertFalse(ml.is_running())
  50
  51             context = GObject.main_context_default()
  52             self.assertTrue(context.pending() in [False, True])
  53
  54             context = GObject.MainContext()
  55             self.assertFalse(context.pending())
  56
  57             self.assertTrue(issubclass(w[0].category, PyGIDeprecationWarning))
  58             self.assertTrue('GLib.markup_escape_text' in str(w[0]), str(w[0]))
  59
  60             self.assertLess(GObject.PRIORITY_HIGH, GObject.PRIORITY_DEFAULT)
  61
  62     def test_min_max_int(self):
  63         with warnings.catch_warnings():
  64             warnings.simplefilter('ignore', PyGIDeprecationWarning)
  65
  66             self.assertEqual(GObject.G_MAXINT16, 2 ** 15 - 1)
  67             self.assertEqual(GObject.G_MININT16, -2 ** 15)
  68             self.assertEqual(GObject.G_MAXUINT16, 2 ** 16 - 1)
  69
  70             self.assertEqual(GObject.G_MAXINT32, 2 ** 31 - 1)
  71             self.assertEqual(GObject.G_MININT32, -2 ** 31)
  72             self.assertEqual(GObject.G_MAXUINT32, 2 ** 32 - 1)
  73
  74             self.assertEqual(GObject.G_MAXINT64, 2 ** 63 - 1)
  75             self.assertEqual(GObject.G_MININT64, -2 ** 63)
  76             self.assertEqual(GObject.G_MAXUINT64, 2 ** 64 - 1)
  77
  78
  79 class TestReferenceCounting(unittest.TestCase):
  80     def test_regular_object(self):
  81         obj = GObject.GObject()
  82         self.assertEqual(obj.__grefcount__, 1)
  83
  84         obj = GObject.new(GObject.GObject)
  85         self.assertEqual(obj.__grefcount__, 1)
  86
  87     def test_floating(self):
  88         obj = testhelper.Floating()
  89         self.assertEqual(obj.__grefcount__, 1)
  90
  91         obj = GObject.new(testhelper.Floating)
  92         self.assertEqual(obj.__grefcount__, 1)
  93
  94     def test_owned_by_library(self):
  95         # Upon creation, the refcount of the object should be 2:
  96         # - someone already has a reference on the new object.
  97         # - the python wrapper should hold its own reference.
  98         obj = testhelper.OwnedByLibrary()
  99         self.assertEqual(obj.__grefcount__, 2)
 100
 101         # We ask the library to release its reference, so the only
 102         # remaining ref should be our wrapper's. Once the wrapper
 103         # will run out of scope, the object will get finalized.
 104         obj.release()
 105         self.assertEqual(obj.__grefcount__, 1)
 106
 107     def test_owned_by_library_out_of_scope(self):
 108         obj = testhelper.OwnedByLibrary()
 109         self.assertEqual(obj.__grefcount__, 2)
 110
 111         # We are manually taking the object out of scope. This means
 112         # that our wrapper has been freed, and its reference dropped. We
 113         # cannot check it but the refcount should now be 1 (the ref held
 114         # by the library is still there, we didn't call release()
 115         obj = None
 116
 117         # When we get the object back from the lib, the wrapper is
 118         # re-created, so our refcount will be 2 once again.
 119         obj = testhelper.owned_by_library_get_instance_list()[0]
 120         self.assertEqual(obj.__grefcount__, 2)
 121
 122         obj.release()
 123         self.assertEqual(obj.__grefcount__, 1)
 124
 125     def test_owned_by_library_using_gobject_new(self):
 126         # Upon creation, the refcount of the object should be 2:
 127         # - someone already has a reference on the new object.
 128         # - the python wrapper should hold its own reference.
 129         obj = GObject.new(testhelper.OwnedByLibrary)
 130         self.assertEqual(obj.__grefcount__, 2)
 131
 132         # We ask the library to release its reference, so the only
 133         # remaining ref should be our wrapper's. Once the wrapper
 134         # will run out of scope, the object will get finalized.
 135         obj.release()
 136         self.assertEqual(obj.__grefcount__, 1)
 137
 138     def test_owned_by_library_out_of_scope_using_gobject_new(self):
 139         obj = GObject.new(testhelper.OwnedByLibrary)
 140         self.assertEqual(obj.__grefcount__, 2)
 141
 142         # We are manually taking the object out of scope. This means
 143         # that our wrapper has been freed, and its reference dropped. We
 144         # cannot check it but the refcount should now be 1 (the ref held
 145         # by the library is still there, we didn't call release()
 146         obj = None
 147
 148         # When we get the object back from the lib, the wrapper is
 149         # re-created, so our refcount will be 2 once again.
 150         obj = testhelper.owned_by_library_get_instance_list()[0]
 151         self.assertEqual(obj.__grefcount__, 2)
 152
 153         obj.release()
 154         self.assertEqual(obj.__grefcount__, 1)
 155
 156     def test_floating_and_sunk(self):
 157         # Upon creation, the refcount of the object should be 2:
 158         # - someone already has a reference on the new object.
 159         # - the python wrapper should hold its own reference.
 160         obj = testhelper.FloatingAndSunk()
 161         self.assertEqual(obj.__grefcount__, 2)
 162
 163         # We ask the library to release its reference, so the only
 164         # remaining ref should be our wrapper's. Once the wrapper
 165         # will run out of scope, the object will get finalized.
 166         obj.release()
 167         self.assertEqual(obj.__grefcount__, 1)
 168
 169     def test_floating_and_sunk_out_of_scope(self):
 170         obj = testhelper.FloatingAndSunk()
 171         self.assertEqual(obj.__grefcount__, 2)
 172
 173         # We are manually taking the object out of scope. This means
 174         # that our wrapper has been freed, and its reference dropped. We
 175         # cannot check it but the refcount should now be 1 (the ref held
 176         # by the library is still there, we didn't call release()
 177         obj = None
 178
 179         # When we get the object back from the lib, the wrapper is
 180         # re-created, so our refcount will be 2 once again.
 181         obj = testhelper.floating_and_sunk_get_instance_list()[0]
 182         self.assertEqual(obj.__grefcount__, 2)
 183
 184         obj.release()
 185         self.assertEqual(obj.__grefcount__, 1)
 186
 187     def test_floating_and_sunk_using_gobject_new(self):
 188         # Upon creation, the refcount of the object should be 2:
 189         # - someone already has a reference on the new object.
 190         # - the python wrapper should hold its own reference.
 191         obj = GObject.new(testhelper.FloatingAndSunk)
 192         self.assertEqual(obj.__grefcount__, 2)
 193
 194         # We ask the library to release its reference, so the only
 195         # remaining ref should be our wrapper's. Once the wrapper
 196         # will run out of scope, the object will get finalized.
 197         obj.release()
 198         self.assertEqual(obj.__grefcount__, 1)
 199
 200     def test_floating_and_sunk_out_of_scope_using_gobject_new(self):
 201         obj = GObject.new(testhelper.FloatingAndSunk)
 202         self.assertEqual(obj.__grefcount__, 2)
 203
 204         # We are manually taking the object out of scope. This means
 205         # that our wrapper has been freed, and its reference dropped. We
 206         # cannot check it but the refcount should now be 1 (the ref held
 207         # by the library is still there, we didn't call release()
 208         obj = None
 209
 210         # When we get the object back from the lib, the wrapper is
 211         # re-created, so our refcount will be 2 once again.
 212         obj = testhelper.floating_and_sunk_get_instance_list()[0]
 213         self.assertEqual(obj.__grefcount__, 2)
 214
 215         obj.release()
 216         self.assertEqual(obj.__grefcount__, 1)
 217
 218     def test_uninitialized_object(self):
 219         class Obj(GObject.GObject):
 220             def __init__(self):
 221                 x = self.__grefcount__
 222                 super(Obj, self).__init__()
 223                 assert x >= 0  # quiesce pyflakes
 224
 225         # Accessing __grefcount__ before the object is initialized is wrong.
 226         # Ensure we get a proper exception instead of a crash.
 227         self.assertRaises(TypeError, Obj)
 228
 229
 230 class A(GObject.GObject):
 231     def __init__(self):
 232         super(A, self).__init__()
 233
 234
 235 class TestPythonReferenceCounting(unittest.TestCase):
 236     # Newly created instances should alwayshave two references: one for
 237     # the GC, and one for the bound variable in the local scope.
 238
 239     def test_new_instance_has_two_refs(self):
 240         obj = GObject.GObject()
 241         self.assertEqual(sys.getrefcount(obj), 2)
 242
 243     def test_new_instance_has_two_refs_using_gobject_new(self):
 244         obj = GObject.new(GObject.GObject)
 245         self.assertEqual(sys.getrefcount(obj), 2)
 246
 247     def test_new_subclass_instance_has_two_refs(self):
 248         obj = A()
 249         self.assertEqual(sys.getrefcount(obj), 2)
 250
 251     def test_new_subclass_instance_has_two_refs_using_gobject_new(self):
 252         obj = GObject.new(A)
 253         self.assertEqual(sys.getrefcount(obj), 2)
 254
 255
 256 class TestContextManagers(unittest.TestCase):
 257     class ContextTestObject(GObject.GObject):
 258         prop = GObject.Property(default=0, type=int)
 259
 260     def on_prop_set(self, obj, prop):
 261         # Handler which tracks property changed notifications.
 262         self.tracking.append(obj.get_property(prop.name))
 263
 264     def setUp(self):
 265         self.tracking = []
 266         self.obj = self.ContextTestObject()
 267         self.handler = self.obj.connect('notify::prop', self.on_prop_set)
 268
 269     def test_freeze_notify_context(self):
 270         # Verify prop tracking list
 271         self.assertEqual(self.tracking, [])
 272         self.obj.props.prop = 1
 273         self.assertEqual(self.tracking, [1])
 274         self.obj.props.prop = 2
 275         self.assertEqual(self.tracking, [1, 2])
 276         self.assertEqual(self.obj.__grefcount__, 1)
 277
 278         pyref_count = sys.getrefcount(self.obj)
 279
 280         # Using the context manager the tracking list should not be affected.
 281         # The GObject reference count should stay the same and the python
 282         # object ref-count should go up.
 283         with self.obj.freeze_notify():
 284             self.assertEqual(self.obj.__grefcount__, 1)
 285             self.assertEqual(sys.getrefcount(self.obj), pyref_count + 1)
 286             self.obj.props.prop = 3
 287             self.assertEqual(self.obj.props.prop, 3)
 288             self.assertEqual(self.tracking, [1, 2])
 289
 290         # After the context manager, the prop should have been modified,
 291         # the tracking list will be modified, and the python object ref
 292         # count goes back down.
 293         gc.collect()
 294         self.assertEqual(self.obj.props.prop, 3)
 295         self.assertEqual(self.tracking, [1, 2, 3])
 296         self.assertEqual(self.obj.__grefcount__, 1)
 297         self.assertEqual(sys.getrefcount(self.obj), pyref_count)
 298
 299     def test_handler_block_context(self):
 300         # Verify prop tracking list
 301         self.assertEqual(self.tracking, [])
 302         self.obj.props.prop = 1
 303         self.assertEqual(self.tracking, [1])
 304         self.obj.props.prop = 2
 305         self.assertEqual(self.tracking, [1, 2])
 306         self.assertEqual(self.obj.__grefcount__, 1)
 307
 308         pyref_count = sys.getrefcount(self.obj)
 309
 310         # Using the context manager the tracking list should not be affected.
 311         # The GObject reference count should stay the same and the python
 312         # object ref-count should go up.
 313         with self.obj.handler_block(self.handler):
 314             self.assertEqual(self.obj.__grefcount__, 1)
 315             self.assertEqual(sys.getrefcount(self.obj), pyref_count + 1)
 316             self.obj.props.prop = 3
 317             self.assertEqual(self.obj.props.prop, 3)
 318             self.assertEqual(self.tracking, [1, 2])
 319
 320         # After the context manager, the prop should have been modified
 321         # the tracking list should have stayed the same and the GObject ref
 322         # count goes back down.
 323         gc.collect()
 324         self.assertEqual(self.obj.props.prop, 3)
 325         self.assertEqual(self.tracking, [1, 2])
 326         self.assertEqual(self.obj.__grefcount__, 1)
 327         self.assertEqual(sys.getrefcount(self.obj), pyref_count)
 328
 329     def test_freeze_notify_context_nested(self):
 330         self.assertEqual(self.tracking, [])
 331         with self.obj.freeze_notify():
 332             self.obj.props.prop = 1
 333             self.assertEqual(self.tracking, [])
 334
 335             with self.obj.freeze_notify():
 336                 self.obj.props.prop = 2
 337                 self.assertEqual(self.tracking, [])
 338
 339                 with self.obj.freeze_notify():
 340                     self.obj.props.prop = 3
 341                     self.assertEqual(self.tracking, [])
 342                 self.assertEqual(self.tracking, [])
 343             self.assertEqual(self.tracking, [])
 344
 345         # Finally after last context, the notifications should have collapsed
 346         # and the last one sent.
 347         self.assertEqual(self.tracking, [3])
 348
 349     def test_handler_block_context_nested(self):
 350         self.assertEqual(self.tracking, [])
 351         with self.obj.handler_block(self.handler):
 352             self.obj.props.prop = 1
 353             self.assertEqual(self.tracking, [])
 354
 355             with self.obj.handler_block(self.handler):
 356                 self.obj.props.prop = 2
 357                 self.assertEqual(self.tracking, [])
 358
 359                 with self.obj.handler_block(self.handler):
 360                     self.obj.props.prop = 3
 361                     self.assertEqual(self.tracking, [])
 362                 self.assertEqual(self.tracking, [])
 363             self.assertEqual(self.tracking, [])
 364
 365         # Finally after last context, the notifications should have collapsed
 366         # and the last one sent.
 367         self.assertEqual(self.obj.props.prop, 3)
 368         self.assertEqual(self.tracking, [])
 369
 370     def test_freeze_notify_normal_usage_ref_counts(self):
 371         # Ensure ref counts without using methods as context managers
 372         # maintain the same count.
 373         self.assertEqual(self.obj.__grefcount__, 1)
 374         self.obj.freeze_notify()
 375         self.assertEqual(self.obj.__grefcount__, 1)
 376         self.obj.thaw_notify()
 377         self.assertEqual(self.obj.__grefcount__, 1)
 378
 379     def test_handler_block_normal_usage_ref_counts(self):
 380         self.assertEqual(self.obj.__grefcount__, 1)
 381         self.obj.handler_block(self.handler)
 382         self.assertEqual(self.obj.__grefcount__, 1)
 383         self.obj.handler_unblock(self.handler)
 384         self.assertEqual(self.obj.__grefcount__, 1)
 385
 386     def test_freeze_notify_context_error(self):
 387         # Test an exception occurring within a freeze context exits the context
 388         try:
 389             with self.obj.freeze_notify():
 390                 self.obj.props.prop = 1
 391                 self.assertEqual(self.tracking, [])
 392                 raise ValueError('Simulation')
 393         except ValueError:
 394             pass
 395
 396         # Verify the property set within the context called notify.
 397         self.assertEqual(self.obj.props.prop, 1)
 398         self.assertEqual(self.tracking, [1])
 399
 400         # Verify we are still not in a frozen context.
 401         self.obj.props.prop = 2
 402         self.assertEqual(self.tracking, [1, 2])
 403
 404     def test_handler_block_context_error(self):
 405         # Test an exception occurring within a handler block exits the context
 406         try:
 407             with self.obj.handler_block(self.handler):
 408                 self.obj.props.prop = 1
 409                 self.assertEqual(self.tracking, [])
 410                 raise ValueError('Simulation')
 411         except ValueError:
 412             pass
 413
 414         # Verify the property set within the context didn't call notify.
 415         self.assertEqual(self.obj.props.prop, 1)
 416         self.assertEqual(self.tracking, [])
 417
 418         # Verify we are still not in a handler block context.
 419         self.obj.props.prop = 2
 420         self.assertEqual(self.tracking, [2])
 421
 422
 423 @unittest.skipUnless(hasattr(GObject.Binding, 'unbind'),
 424                      'Requires newer GLib which has g_binding_unbind')
 425 class TestPropertyBindings(unittest.TestCase):
 426     class TestObject(GObject.GObject):
 427         int_prop = GObject.Property(default=0, type=int)
 428
 429     def setUp(self):
 430         self.source = self.TestObject()
 431         self.target = self.TestObject()
 432
 433     def test_default_binding(self):
 434         binding = self.source.bind_property('int_prop', self.target, 'int_prop',
 435                                             GObject.BindingFlags.DEFAULT)
 436         binding = binding  # PyFlakes
 437
 438         # Test setting value on source gets pushed to target
 439         self.source.int_prop = 1
 440         self.assertEqual(self.source.int_prop, 1)
 441         self.assertEqual(self.target.int_prop, 1)
 442
 443         # Test setting value on target does not change source
 444         self.target.props.int_prop = 2
 445         self.assertEqual(self.source.int_prop, 1)
 446         self.assertEqual(self.target.int_prop, 2)
 447
 448     def test_bidirectional_binding(self):
 449         binding = self.source.bind_property('int_prop', self.target, 'int_prop',
 450                                             GObject.BindingFlags.BIDIRECTIONAL)
 451         binding = binding  # PyFlakes
 452
 453         # Test setting value on source gets pushed to target
 454         self.source.int_prop = 1
 455         self.assertEqual(self.source.int_prop, 1)
 456         self.assertEqual(self.target.int_prop, 1)
 457
 458         # Test setting value on target also changes source
 459         self.target.props.int_prop = 2
 460         self.assertEqual(self.source.int_prop, 2)
 461         self.assertEqual(self.target.int_prop, 2)
 462
 463     def test_transform_to_only(self):
 464         def transform_to(binding, value, user_data=None):
 465             self.assertEqual(user_data, 'test-data')
 466             return value * 2
 467
 468         binding = self.source.bind_property('int_prop', self.target, 'int_prop',
 469                                             GObject.BindingFlags.DEFAULT,
 470                                             transform_to, None, 'test-data')
 471         binding = binding  # PyFlakes
 472
 473         self.source.int_prop = 1
 474         self.assertEqual(self.source.int_prop, 1)
 475         self.assertEqual(self.target.int_prop, 2)
 476
 477         self.target.props.int_prop = 1
 478         self.assertEqual(self.source.int_prop, 1)
 479         self.assertEqual(self.target.int_prop, 1)
 480
 481     def test_transform_from_only(self):
 482         def transform_from(binding, value, user_data=None):
 483             self.assertEqual(user_data, None)
 484             return value * 2
 485
 486         binding = self.source.bind_property('int_prop', self.target, 'int_prop',
 487                                             GObject.BindingFlags.BIDIRECTIONAL,
 488                                             None, transform_from)
 489         binding = binding  # PyFlakes
 490
 491         self.source.int_prop = 1
 492         self.assertEqual(self.source.int_prop, 1)
 493         self.assertEqual(self.target.int_prop, 1)
 494
 495         self.target.props.int_prop = 1
 496         self.assertEqual(self.source.int_prop, 2)
 497         self.assertEqual(self.target.int_prop, 1)
 498
 499     def test_transform_bidirectional(self):
 500         test_data = object()
 501
 502         def transform_to(binding, value, user_data=None):
 503             self.assertEqual(user_data, test_data)
 504             return value * 2
 505
 506         def transform_from(binding, value, user_data=None):
 507             self.assertEqual(user_data, test_data)
 508             return value // 2
 509
 510         test_data_ref_count = sys.getrefcount(test_data)
 511         transform_to_ref_count = sys.getrefcount(transform_to)
 512         transform_from_ref_count = sys.getrefcount(transform_from)
 513
 514         # bidirectional bindings
 515         binding = self.source.bind_property('int_prop', self.target, 'int_prop',
 516                                             GObject.BindingFlags.BIDIRECTIONAL,
 517                                             transform_to, transform_from, test_data)
 518         binding = binding  # PyFlakes
 519         binding_ref_count = sys.getrefcount(binding)
 520         binding_gref_count = binding.__grefcount__
 521
 522         self.source.int_prop = 1
 523         self.assertEqual(self.source.int_prop, 1)
 524         self.assertEqual(self.target.int_prop, 2)
 525
 526         self.target.props.int_prop = 4
 527         self.assertEqual(self.source.int_prop, 2)
 528         self.assertEqual(self.target.int_prop, 4)
 529
 530         self.assertEqual(sys.getrefcount(binding), binding_ref_count)
 531         self.assertEqual(binding.__grefcount__, binding_gref_count)
 532
 533         # test_data ref count increases by 2, once for each callback.
 534         self.assertEqual(sys.getrefcount(test_data), test_data_ref_count + 2)
 535         self.assertEqual(sys.getrefcount(transform_to), transform_to_ref_count + 1)
 536         self.assertEqual(sys.getrefcount(transform_from), transform_from_ref_count + 1)
 537
 538         # Unbind should clear out the binding and its transforms
 539         binding.unbind()
 540
 541         # Setting source or target should not change the other.
 542         self.target.int_prop = 3
 543         self.source.int_prop = 5
 544         self.assertEqual(self.target.int_prop, 3)
 545         self.assertEqual(self.source.int_prop, 5)
 546
 547         self.assertEqual(sys.getrefcount(test_data), test_data_ref_count)
 548         self.assertEqual(sys.getrefcount(transform_to), transform_to_ref_count)
 549         self.assertEqual(sys.getrefcount(transform_from), transform_from_ref_count)
 550
 551     def test_explicit_unbind_clears_connection(self):
 552         self.assertEqual(self.source.int_prop, 0)
 553         self.assertEqual(self.target.int_prop, 0)
 554
 555         # Test deleting binding reference removes binding.
 556         binding = self.source.bind_property('int_prop', self.target, 'int_prop')
 557         self.source.int_prop = 1
 558         self.assertEqual(self.source.int_prop, 1)
 559         self.assertEqual(self.target.int_prop, 1)
 560
 561         # unbind should clear out the bindings self reference
 562         binding.unbind()
 563         self.assertEqual(binding.__grefcount__, 1)
 564
 565         self.source.int_prop = 10
 566         self.assertEqual(self.source.int_prop, 10)
 567         self.assertEqual(self.target.int_prop, 1)
 568
 569         # An already unbound BindingWeakRef will raise if unbind is attempted a second time.
 570         self.assertRaises(ValueError, binding.unbind)
 571
 572     def test_reference_counts(self):
 573         self.assertEqual(self.source.__grefcount__, 1)
 574         self.assertEqual(self.target.__grefcount__, 1)
 575
 576         # Binding ref count will be 2 do to the initial ref implicitly held by
 577         # the act of binding and the ref incurred by using __call__ to generate
 578         # a wrapper from the weak binding ref within python.
 579         binding = self.source.bind_property('int_prop', self.target, 'int_prop')
 580         self.assertEqual(binding.__grefcount__, 2)
 581
 582         # Creating a binding does not inc refs on source and target (they are weak
 583         # on the binding object itself)
 584         self.assertEqual(self.source.__grefcount__, 1)
 585         self.assertEqual(self.target.__grefcount__, 1)
 586
 587         # Use GObject.get_property because the "props" accessor leaks.
 588         # Note property names are canonicalized.
 589         self.assertEqual(binding.get_property('source'), self.source)
 590         self.assertEqual(binding.get_property('source_property'), 'int-prop')
 591         self.assertEqual(binding.get_property('target'), self.target)
 592         self.assertEqual(binding.get_property('target_property'), 'int-prop')
 593         self.assertEqual(binding.get_property('flags'), GObject.BindingFlags.DEFAULT)
 594
 595         # Delete reference to source or target and the binding will remove its own
 596         # "self reference".
 597         ref = self.source.weak_ref()
 598         del self.source
 599         gc.collect()
 600         self.assertEqual(ref(), None)
 601         self.assertEqual(binding.__grefcount__, 1)
 602
 603         # Finally clear out the last ref held by the python wrapper
 604         ref = binding.weak_ref()
 605         del binding
 606         gc.collect()
 607         self.assertEqual(ref(), None)
 608
 609
 610 class TestGValue(unittest.TestCase):
 611     def test_type_constant(self):
 612         self.assertEqual(GObject.TYPE_VALUE, GObject.Value.__gtype__)
 613         self.assertEqual(GObject.type_name(GObject.TYPE_VALUE), 'GValue')
 614
 615     def test_no_type(self):
 616         value = GObject.Value()
 617         self.assertEqual(value.g_type, GObject.TYPE_INVALID)
 618         self.assertRaises(TypeError, value.set_value, 23)
 619         self.assertEqual(value.get_value(), None)
 620
 621     def test_int(self):
 622         value = GObject.Value(GObject.TYPE_UINT)
 623         self.assertEqual(value.g_type, GObject.TYPE_UINT)
 624         value.set_value(23)
 625         self.assertEqual(value.get_value(), 23)
 626         value.set_value(42.0)
 627         self.assertEqual(value.get_value(), 42)
 628
 629     def test_string(self):
 630         value = GObject.Value(str, 'foo_bar')
 631         self.assertEqual(value.g_type, GObject.TYPE_STRING)
 632         self.assertEqual(value.get_value(), 'foo_bar')
 633
 634     def test_float(self):
 635         # python float is G_TYPE_DOUBLE
 636         value = GObject.Value(float, 23.4)
 637         self.assertEqual(value.g_type, GObject.TYPE_DOUBLE)
 638         value.set_value(1e50)
 639         self.assertAlmostEqual(value.get_value(), 1e50)
 640
 641         value = GObject.Value(GObject.TYPE_FLOAT, 23.4)
 642         self.assertEqual(value.g_type, GObject.TYPE_FLOAT)
 643         self.assertRaises(TypeError, value.set_value, 'string')
 644         self.assertRaises(OverflowError, value.set_value, 1e50)
 645
 646     def test_float_inf_nan(self):
 647         nan = float('nan')
 648         for type_ in [GObject.TYPE_FLOAT, GObject.TYPE_DOUBLE]:
 649             for x in [float('inf'), float('-inf'), nan]:
 650                 value = GObject.Value(type_, x)
 651                 # assertEqual() is False for (nan, nan)
 652                 if x is nan:
 653                     self.assertEqual(str(value.get_value()), 'nan')
 654                 else:
 655                     self.assertEqual(value.get_value(), x)
 656
 657     def test_enum(self):
 658         value = GObject.Value(GLib.FileError, GLib.FileError.FAILED)
 659         self.assertEqual(value.get_value(), GLib.FileError.FAILED)
 660
 661     def test_flags(self):
 662         value = GObject.Value(GLib.IOFlags, GLib.IOFlags.IS_READABLE)
 663         self.assertEqual(value.get_value(), GLib.IOFlags.IS_READABLE)
 664
 665     def test_object(self):
 666         class TestObject(GObject.Object):
 667             pass
 668         obj = TestObject()
 669         value = GObject.Value(GObject.TYPE_OBJECT, obj)
 670         self.assertEqual(value.get_value(), obj)
 671
 672 if __name__ == '__main__':
 673     unittest.main()