def test_ok_button(self):
"""Test behaviour of Ok button."""
# Test Ok button without any input in the combo box
dialog = NeedsCalculatorDialog(PARENT)
ok_button = dialog.button_box.button(QtWidgets.QDialogButtonBox.Ok)
self.assertFalse(ok_button.isEnabled())
# Close because this is a modal dialog
dialog.reject()
input_layer = load_test_vector_layer('other', 'minimum_needs.shp')
QgsProject.instance().addMapLayers([input_layer])
# Open the dialog again
dialog = NeedsCalculatorDialog(PARENT)
ok_button = dialog.button_box.button(QtWidgets.QDialogButtonBox.Ok)
# Test Ok button with layer and displaced field
# selected in the combo box
dialog.layer.setLayer(input_layer)
dialog.displaced.setField('displaced')
self.assertTrue(ok_button.isEnabled())
