Add tests for the listpreviewwidget.

tests/interfaces/openlp_core_ui/test_listpreviewwidget.py

@@ -0,0 +1,88 @@
+"""
+    Package to test the openlp.core.ui.listpreviewwidget.
+"""
+
+from unittest import TestCase
+from mock import MagicMock, patch
+
+from PyQt4 import QtGui
+
+from openlp.core.lib import Registry, ServiceItem
+from openlp.core.ui import listpreviewwidget
+from tests.utils.osdinteraction import read_service_from_file
+
+class TestServiceManager(TestCase):
+
+    def setUp(self):
+        """
+        Create the UI.
+        """
+        Registry.create()
+        self.app = QtGui.QApplication([])
+        self.main_window = QtGui.QMainWindow()
+        self.image = QtGui.QImage(1, 1, QtGui.QImage.Format_RGB32)
+        self.image_manager = MagicMock()
+        self.image_manager.get_image.return_value = self.image
+        Registry().register(u'image_manager', self.image_manager)
+        self.preview_widget = listpreviewwidget.ListPreviewWidget(self.main_window, 2)
+
+    def tearDown(self):
+        """
+        Delete all the C++ objects at the end so that we don't have a segfault.
+        """
+        del self.preview_widget
+        del self.main_window
+        del self.app
+
+    def initial_slide_count_test(self):
+        """
+        Test the inital slide count.
+        """
+        # GIVEN: A new ListPreviewWidget instance.
+        # WHEN: No SlideItem has been added yet.
+        # THEN: The count of items should be zero.
+        self.assertEqual(self.preview_widget.slide_count(), 0,
+            u'The slide list should be empty.')
+
+    def initial_slide_number_test(self):
+        """
+        Test the inital slide number.
+        """
+        # GIVEN: A new ListPreviewWidget instance.
+        # WHEN: No SlideItem has been added yet.
+        # THEN: The number of the current item should be -1.
+        self.assertEqual(self.preview_widget.current_slide_number(), -1,
+            u'The slide number should be -1.')
+
+    def replace_service_item_test(self):
+        """
+        Test item counts and current number with a service item.
+        """
+        # GIVEN: A ServiceItem with two frames.
+        service_item = ServiceItem(None)
+        service = read_service_from_file(u'serviceitem_image_2.osd')
+        with patch('os.path.exists'):
+            service_item.set_from_service(service[0])
+        # WHEN: Added to the preview widget.
+        self.preview_widget.replace_service_item(service_item, 1, 1)
+        # THEN: The slide count and number should fit.
+        self.assertEqual(self.preview_widget.slide_count(), 2,
+                         u'The slide count should be 2.')
+        self.assertEqual(self.preview_widget.current_slide_number(), 1,
+                         u'The current slide number should  be 1.')
+
+    def change_slide_test(self):
+        """
+        Test the change_slide method.
+        """
+        # GIVEN: A ServiceItem with two frames content.
+        service_item = ServiceItem(None)
+        service = read_service_from_file(u'serviceitem_image_2.osd')
+        with patch('os.path.exists'):
+            service_item.set_from_service(service[0])
+        # WHEN: Added to the preview widget and switched to the second frame.
+        self.preview_widget.replace_service_item(service_item, 1, 0)
+        self.preview_widget.change_slide(1)
+        # THEN: The current_slide_number should reflect the change.
+        self.assertEqual(self.preview_widget.current_slide_number(), 1,
+                         u'The current slide number should  be 1.')