/// <summary>
/// Adds a root view to the hierarchy.
/// </summary>
/// <param name="tag">The root view tag.</param>
/// <param name="rootView">The root view.</param>
/// <param name="themedRootContext">The React context.</param>
public void AddRootView(
int tag,
SizeMonitoringCanvas rootView,
ThemedReactContext themedRootContext)
{
// This is called on layout manager thread
// Extract dispatcher
var rootViewDispatcher = rootView.Dispatcher;
// _dispatcherToOperationQueueInfo contains a mapping of CoreDispatcher to <UIViewOperationQueueInstance, # of ReactRootView instances>.
// Operation queue instances are created lazily whenever an "unknown" CoreDispatcher is detected. Each operation queue instance
// works together with one dedicated NativeViewHierarchyManager and one ReactChoreographer.
// One operation queue is the "main" one:
// - is coupled with the CoreApplication.MainView dispatcher
// - drives animations in ALL views
QueueInstanceInfo queueInfo;
if (!_dispatcherToOperationQueueInfo.TryGetValue(rootViewDispatcher, out queueInfo))
{
// Queue instance doesn't exist for this dispatcher, we need to create
// Find the CoreApplicationView associated to the new CoreDispatcher
CoreApplicationView foundView = CoreApplication.Views.First(v => v.Dispatcher == rootViewDispatcher);
// Create new ReactChoreographer for this view/dispatcher. It will only be used for its DispatchUICallback services
ReactChoreographer reactChoreographer = ReactChoreographer.CreateSecondaryInstance(foundView);
queueInfo = new QueueInstanceInfo()
{
queueInstance = new UIViewOperationQueueInstance(
_reactContext,
new NativeViewHierarchyManager(_viewManagerRegistry, rootViewDispatcher, OnViewsDropped),
reactChoreographer),
rootViewCount = 1
};
// Add new tuple to map
_dispatcherToOperationQueueInfo.Add(rootViewDispatcher, queueInfo);
if (_active)
{
// Simulate an OnResume from the correct dispatcher thread
// (OnResume/OnSuspend/OnDestroy have this thread affinity, all other methods do enqueuings in a thread safe manner)
DispatcherHelpers.RunOnDispatcher(rootViewDispatcher, queueInfo.queueInstance.OnResume, true); // inlining allowed
}
}
else
{
// Queue instance does exist.
// Increment the count of root views. This is helpful for the case the count reaches 0 so we can cleanup the queue.
queueInfo.rootViewCount++;
}
// Add tag
_reactTagToOperationQueue.Add(tag, queueInfo.queueInstance);
// Send forward
queueInfo.queueInstance.AddRootView(tag, rootView, themedRootContext);
}
/// <summary>
/// Instantiates the <see cref="UIViewOperationQueue"/>.
/// </summary>
/// <param name="reactContext">The React context.</param>
/// <param name="viewManagerRegistry">
/// The view manager registry.
/// </param>
public UIViewOperationQueue(ReactContext reactContext, ViewManagerRegistry viewManagerRegistry)
{
_reactContext = reactContext;
_viewManagerRegistry = viewManagerRegistry;
_active = false;
// Corner case: UWP scenarios that start with no main window.
// We create the UIViewOperationQueueInstance for main dispatcher thread ahead of time so animations
// in secondary windows can work.
var queueInfo = new QueueInstanceInfo()
{
queueInstance = new UIViewOperationQueueInstance(
_reactContext,
new NativeViewHierarchyManager(_viewManagerRegistry, DispatcherHelpers.MainDispatcher, OnViewsDropped),
ReactChoreographer.Instance)
};
_dispatcherToOperationQueueInfo.Add(DispatcherHelpers.MainDispatcher, queueInfo);
_mainUiViewOperationsQueueInstance = queueInfo.queueInstance;
}
