void IncrementalUpdateBehavior::IncrementalUpdater::OnContainerContentChanging()

in src/BehaviorsSDKNative/Microsoft.Xaml.Interactions/IncrementalUpdateBehavior.cpp [158:204]

39 lines of code
9 McCabe index (conditional complexity)


void IncrementalUpdateBehavior::IncrementalUpdater::OnContainerContentChanging(Windows::UI::Xaml::Controls::ListViewBase^ sender, ContainerContentChangingEventArgs^ e)
{
	UIElement^ contentTemplateRoot = e->ItemContainer->ContentTemplateRoot;

	if (_elementCache.find(contentTemplateRoot) == _elementCache.end())
	{
		return;
	}

	auto& elementCacheRecord = _elementCache[contentTemplateRoot];

	if (!e->InRecycleQueue)
	{
		for (auto& phaseRecordPair : elementCacheRecord)
		{
			for (auto& phaseElementRecord : phaseRecordPair.second)
			{
				phaseElementRecord.FreezeAndHide();
			}
		}

		if (elementCacheRecord.size() > 0)
		{
			e->RegisterUpdateCallback(elementCacheRecord.cbegin()->first, _cccCallbackHandler);
		}

		// set the DataContext manually since we inhibit default operation by setting e.Handled=true
		FrameworkElement^ frameworkElement = dynamic_cast<FrameworkElement^>(contentTemplateRoot);
		if (frameworkElement != nullptr)
		{
			frameworkElement->DataContext = e->Item;
		}
	}
	else
	{
		// clear the DataContext manually since we inhibit default operation by setting e.Handled=true
		contentTemplateRoot->ClearValue(FrameworkElement::DataContextProperty);

		for (auto& phaseRecordPair : elementCacheRecord)
		{
			for (auto& phaseElementRecord : phaseRecordPair.second)
			{
				phaseElementRecord.ThawAndShow();
			}
		}
	}
}