public override async Task ProvideCompletionsAsync(CompletionContext context)
{
if (!context.CompletionOptions.ShouldShowNewSnippetExperience())
{
return;
}
var document = context.Document;
var cancellationToken = context.CancellationToken;
var position = context.Position;
var service = document.GetLanguageService <ISnippetService>();
if (service == null)
{
return;
}
var(strippedDocument, newPosition) = await GetDocumentWithoutInvokingTextAsync(document, position, cancellationToken).ConfigureAwait(false);
var snippets = await service.GetSnippetsAsync(strippedDocument, newPosition, cancellationToken).ConfigureAwait(false);
foreach (var snippetData in snippets)
{
var completionItem = SnippetCompletionItem.Create(
displayText: snippetData.DisplayName,
displayTextSuffix: "",
position: position,
snippetIdentifier: snippetData.SnippetIdentifier,
glyph: Glyph.Snippet);
context.AddItem(completionItem);
}
}
public override async Task <CompletionChange> GetChangeAsync(Document document, CompletionItem item, char?commitKey = null, CancellationToken cancellationToken = default)
{
// This retrieves the document without the text used to invoke completion
// as well as the new cursor position after that has been removed.
var(strippedDocument, position) = await GetDocumentWithoutInvokingTextAsync(document, SnippetCompletionItem.GetInvocationPosition(item), cancellationToken).ConfigureAwait(false);
var service = strippedDocument.GetRequiredLanguageService <ISnippetService>();
var snippetIdentifier = SnippetCompletionItem.GetSnippetIdentifier(item);
var snippetProvider = service.GetSnippetProvider(snippetIdentifier);
// This retrieves the generated Snippet
var snippet = await snippetProvider.GetSnippetAsync(strippedDocument, position, cancellationToken).ConfigureAwait(false);
var strippedText = await strippedDocument.GetTextAsync(cancellationToken).ConfigureAwait(false);
// This introduces the text changes of the snippet into the document with the completion invoking text
var allChangesText = strippedText.WithChanges(snippet.TextChanges);
// This retrieves ALL text changes from the original document which includes the TextChanges from the snippet
// as well as the clean up.
var allChangesDocument = document.WithText(allChangesText);
var allTextChanges = await allChangesDocument.GetTextChangesAsync(document, cancellationToken).ConfigureAwait(false);
var change = Utilities.Collapse(allChangesText, allTextChanges.AsImmutable());
// Converts the snippet to an LSP formatted snippet string.
var lspSnippet = await RoslynLSPSnippetConverter.GenerateLSPSnippetAsync(allChangesDocument, snippet.CursorPosition, snippet.Placeholders, change, item.Span.Start, cancellationToken).ConfigureAwait(false);
// If the TextChanges retrieved starts after the trigger point of the CompletionItem,
// then we need to move the bounds backwards and encapsulate the trigger point.
if (change.Span.Start > item.Span.Start)
{
var textSpan = TextSpan.FromBounds(item.Span.Start, change.Span.End);
var snippetText = change.NewText;
Contract.ThrowIfNull(snippetText);
change = new TextChange(textSpan, snippetText);
}
var props = ImmutableDictionary <string, string> .Empty
.Add(SnippetCompletionItem.LSPSnippetKey, lspSnippet);
return(CompletionChange.Create(change, allTextChanges.AsImmutable(), properties: props, snippet.CursorPosition, includesCommitCharacter: true));
}
