public override Task <ImmutableArray <SymbolDisplayPart> > GetDescriptionAsync(CancellationToken cancellationToken = default(CancellationToken))
{
var descriptionTask = CompletionItem.GetDescriptionAsync(cancellationToken);
var updatedDescriptionTask = descriptionTask.SafeContinueWithFromAsync(async task =>
{
var parts = task.Result;
var note = await _completionService.GetSnippetExpansionNoteForCompletionItemAsync(CompletionItem, _workspace).ConfigureAwait(false);
if (!string.IsNullOrEmpty(note))
{
if (parts.Any())
{
parts = parts.Add(new SymbolDisplayPart(SymbolDisplayPartKind.LineBreak, null, Environment.NewLine));
}
parts = parts.Add(new SymbolDisplayPart(SymbolDisplayPartKind.Text, null, note));
}
return(parts);
},
cancellationToken,
TaskContinuationOptions.OnlyOnRanToCompletion,
TaskScheduler.Default);
return(updatedDescriptionTask);
}
public CancellableContentControl(ToolTipProvider toolTipProvider, CompletionItem completionItem)
{
Debug.Assert(_foregroundObject.IsForeground());
_toolTipProvider = toolTipProvider;
// Set our content to be "..." initially.
this.Content = toolTipProvider._defaultTextBlock;
// Kick off the task to produce the new content. When it completes, call back on
// the UI thread to update the display.
var scheduler = TaskScheduler.FromCurrentSynchronizationContext();
completionItem.GetDescriptionAsync(_cancellationTokenSource.Token)
.ContinueWith(ProcessDescription, _cancellationTokenSource.Token,
TaskContinuationOptions.OnlyOnRanToCompletion, scheduler);
// If we get unloaded (i.e. the user scrolls down in the completion list and VS
// dismisses the existing tooltip), then cancel the work we're doing
this.Unloaded += (s, e) => _cancellationTokenSource.Cancel();
}
