protected override async Task ProduceTagsAsync(TaggerContext <KeywordHighlightTag> context, DocumentSnapshotSpan documentSnapshotSpan, int?caretPosition)
{
var cancellationToken = context.CancellationToken;
var document = documentSnapshotSpan.Document;
if (document == null)
{
return;
}
var options = document.Project.Solution.Workspace.Options;
if (!options.GetOption(FeatureOnOffOptions.KeywordHighlighting, document.Project.Language))
{
return;
}
if (!caretPosition.HasValue)
{
return;
}
var snapshotSpan = documentSnapshotSpan.SnapshotSpan;
var position = caretPosition.Value;
var snapshot = snapshotSpan.Snapshot;
var existingTags = context.GetExistingTags(new SnapshotSpan(snapshot, position, 0));
if (!existingTags.IsEmpty())
{
// We already have a tag at this position. So the user is moving from one highlight
// tag to another. In this case we don't want to recompute anything. Let our caller
// know that we should preserve all tags.
context.SetSpansTagged(SpecializedCollections.EmptyEnumerable <DocumentSnapshotSpan>());
return;
}
using (Logger.LogBlock(FunctionId.Tagger_Highlighter_TagProducer_ProduceTags, cancellationToken))
{
var root = await document.GetSyntaxRootAsync(cancellationToken).ConfigureAwait(false);
var spans = _highlightingService.GetHighlights(root, position, cancellationToken);
foreach (var span in spans)
{
context.AddTag(new TagSpan <KeywordHighlightTag>(span.ToSnapshotSpan(snapshot), KeywordHighlightTag.Instance));
}
}
}
protected override Task ProduceTagsAsync(TaggerContext <NavigableHighlightTag> context)
{
// NOTE(cyrusn): Normally we'd limit ourselves to producing tags in the span we were
// asked about. However, we want to produce all tags here so that the user can actually
// navigate between all of them using the appropriate tag navigation commands. If we
// don't generate all the tags then the user will cycle through an incorrect subset.
if (context.CaretPosition == null)
{
return(SpecializedTasks.EmptyTask);
}
var caretPosition = context.CaretPosition.Value;
Workspace workspace;
if (!Workspace.TryGetWorkspace(caretPosition.Snapshot.AsText().Container, out workspace))
{
return(SpecializedTasks.EmptyTask);
}
var document = context.SpansToTag.First(vt => vt.SnapshotSpan.Snapshot == caretPosition.Snapshot).Document;
if (document == null)
{
return(SpecializedTasks.EmptyTask);
}
// Don't produce tags if the feature is not enabled.
if (!workspace.Options.GetOption(FeatureOnOffOptions.ReferenceHighlighting, document.Project.Language))
{
return(SpecializedTasks.EmptyTask);
}
var existingTags = context.GetExistingTags(new SnapshotSpan(caretPosition, 0));
if (!existingTags.IsEmpty())
{
// We already have a tag at this position. So the user is moving from one highlight
// tag to another. In this case we don't want to recompute anything. Let our caller
// know that we should preserve all tags.
context.SetSpansTagged(SpecializedCollections.EmptyEnumerable <DocumentSnapshotSpan>());
return(SpecializedTasks.EmptyTask);
}
// Otherwise, we need to go produce all tags.
return(ProduceTagsAsync(context, caretPosition, workspace, document));
}