public async Task <IAsyncQuickInfoSession> TriggerQuickInfoAsync(
ITextView textView,
ITrackingPoint triggerPoint,
QuickInfoSessionOptions options,
CancellationToken cancellationToken)
{
cancellationToken.ThrowIfCancellationRequested();
// Caret element requires UI thread.
await this.joinableTaskContext.Factory.SwitchToMainThreadAsync();
// We switched threads and there is some latency, so ensure that we're still not canceled.
cancellationToken.ThrowIfCancellationRequested();
// Dismiss any currently open session.
var currentSession = this.GetSession(textView);
if (currentSession != null)
{
await currentSession.DismissAsync();
}
// Get the trigger point from the caret if none is provided.
triggerPoint = triggerPoint ?? textView.TextSnapshot.CreateTrackingPoint(
textView.Caret.Position.BufferPosition,
PointTrackingMode.Negative);
var newSession = new AsyncQuickInfoSession(
this.OrderedSourceProviders,
this.guardedOperations,
this.joinableTaskContext,
this.toolTipService,
textView,
triggerPoint,
options,
null);
// StartAsync() is responsible for dispatching a StateChange
// event if canceled so no need to clean these up on cancellation.
newSession.StateChanged += this.OnStateChanged;
textView.Properties.AddProperty(typeof(AsyncQuickInfoSession), newSession);
try
{
await newSession.StartAsync(cancellationToken);
}
catch (OperationCanceledException) when(!cancellationToken.IsCancellationRequested)
{
// Don't throw OperationCanceledException unless the caller canceled us.
// This can happen if computation was canceled by a quick info source
// dismissing the session during computation, which we want to consider
// more of a 'N/A' than an error.
return(null);
}
return(newSession);
}
