public bool TryGetController(ITextView textView, ITextBuffer subjectBuffer, out Controller controller)
{
AssertIsForeground();
// check whether this feature is on.
if (!subjectBuffer.GetOption(InternalFeatureOnOffOptions.CompletionSet))
{
controller = null;
return false;
}
// If we don't have a presenter, then there's no point in us even being involved. Just
// defer to the next handler in the chain.
// Also, if there's an inline rename session then we do not want completion.
if (_completionPresenter == null || _inlineRenameService.ActiveSession != null)
{
controller = null;
return false;
}
var autobraceCompletionCharSet = GetAllAutoBraceCompletionChars(subjectBuffer.ContentType);
controller = Controller.GetInstance(
textView, subjectBuffer,
_editorOperationsFactoryService, _undoHistoryRegistry, _completionPresenter,
new AggregateAsynchronousOperationListener(_asyncListeners, FeatureAttribute.CompletionSet),
_allCompletionProviders, autobraceCompletionCharSet);
return true;
}
private void Commit(CompletionItem item, TextChange textChange, Model model, char?commitChar)
{
AssertIsForeground();
// We could only be called if we had a model at this point.
Contract.ThrowIfNull(model);
item = Controller.GetExternallyUsableCompletionItem(item);
// Now that we've captured the model at this point, we can stop ourselves entirely.
// This is also desirable as we may have reentrancy problems when we call into
// custom commit completion providers. I.e. if the custom provider moves the caret,
// then we do not want to process that move as it may put us into an unexpected state.
//
// TODO(cyrusn): We still have a general reentrancy problem where calling into a custom
// commit provider (or just calling into the editor) may cause something to call back
// into us. However, for now, we just hope that no such craziness will occur.
this.StopModelComputation();
// NOTE(cyrusn): It is intentional that we get the undo history for the
// surface buffer and not the subject buffer.
using (var transaction = _undoHistoryRegistry.GetHistory(this.TextView.TextBuffer).CreateTransaction(EditorFeaturesResources.IntelliSense))
{
// We want to merge with any of our other programmatic edits (e.g. automatic brace completion)
transaction.MergePolicy = AutomaticCodeChangeMergePolicy.Instance;
// Check if the provider wants to perform custom commit itself. Otherwise we will
// handle things.
var provider = item.CompletionProvider as ICustomCommitCompletionProvider;
if (provider == null)
{
var viewBuffer = this.TextView.TextBuffer;
// Use character based diffing here to avoid overwriting the commit character placed into the editor.
var editOptions = new EditOptions(new StringDifferenceOptions
{
DifferenceType = StringDifferenceTypes.Character,
IgnoreTrimWhiteSpace = EditOptions.DefaultMinimalChange.DifferenceOptions.IgnoreTrimWhiteSpace
});
using (var textEdit = viewBuffer.CreateEdit(editOptions, reiteratedVersionNumber: null, editTag: null))
{
var viewSpan = model.GetSubjectBufferFilterSpanInViewBuffer(textChange.Span);
var currentSpan = model.GetCurrentSpanInSnapshot(viewSpan, viewBuffer.CurrentSnapshot);
// In order to play nicely with automatic brace completion, we need to
// not touch the opening paren. We'll check our span and textchange
// for ( and adjust them accordingly if we find them.
// all this is needed since we don't use completion set mechanism provided by VS but we implement everything ourselves.
// due to that, existing brace completion engine in editor that should take care of interaction between brace completion
// and intellisense doesn't work for us. so we need this kind of workaround to support it nicely.
bool textChanged;
var finalText = GetFinalText(textChange, commitChar.GetValueOrDefault(), out textChanged);
currentSpan = GetFinalSpan(currentSpan, commitChar.GetValueOrDefault(), textChanged);
var caretPoint = this.TextView.GetCaretPoint(this.SubjectBuffer);
var virtualCaretPoint = this.TextView.GetVirtualCaretPoint(this.SubjectBuffer);
if (caretPoint.HasValue && virtualCaretPoint.HasValue)
{
// TODO(dustinca): We need to call a different API here. TryMoveCaretToAndEnsureVisible might center within the view.
this.TextView.TryMoveCaretToAndEnsureVisible(new VirtualSnapshotPoint(caretPoint.Value));
}
caretPoint = this.TextView.GetCaretPoint(this.SubjectBuffer);
// Now that we're doing character level diffing, we need to move the caret to the end of
// the span being replaced. Otherwise, we can replace M|ai with Main and wind up with
// M|ain, since character based diffing makes that quite legit.
if (caretPoint.HasValue)
{
var endInSubjectBuffer = this.TextView.BufferGraph.MapDownToBuffer(currentSpan.End, PointTrackingMode.Positive, caretPoint.Value.Snapshot.TextBuffer, PositionAffinity.Predecessor);
if (caretPoint.Value < endInSubjectBuffer)
{
this.TextView.TryMoveCaretToAndEnsureVisible(new SnapshotPoint(currentSpan.Snapshot.TextBuffer.CurrentSnapshot, currentSpan.End.Position));
}
}
textEdit.Replace(currentSpan, finalText);
textEdit.Apply();
}
// We've manipulated the caret position in order to generate the correct edit. However,
// if the insertion is long enough, the caret will scroll out of the visible area.
// Re-center the view.
using (var textEdit = viewBuffer.CreateEdit(editOptions, reiteratedVersionNumber: null, editTag: null))
{
var caretPoint = this.TextView.GetCaretPoint(this.SubjectBuffer);
if (caretPoint.HasValue)
{
this.TextView.Caret.EnsureVisible();
}
}
transaction.Complete();
}
else
{
// Let the provider handle this.
provider.Commit(item, this.TextView, this.SubjectBuffer, model.TriggerSnapshot, commitChar);
transaction.Complete();
}
}
var document = this.SubjectBuffer.CurrentSnapshot.GetOpenDocumentInCurrentContextWithChanges();
var formattingService = document.GetLanguageService <IEditorFormattingService>();
if (formattingService != null &&
(item.ShouldFormatOnCommit || (commitChar != null && formattingService.SupportsFormattingOnTypedCharacter(document, commitChar.GetValueOrDefault()))))
{
// Formatting the completion item affected span is done as a separate transaction because this gives the user
// the flexibility to undo the formatting but retain the changes associated with the completion item
using (var formattingTransaction = _undoHistoryRegistry.GetHistory(this.TextView.TextBuffer).CreateTransaction(EditorFeaturesResources.IntelliSenseCommitFormatting))
{
var changes = formattingService.GetFormattingChangesAsync(document, textChange.Span, CancellationToken.None).WaitAndGetResult(CancellationToken.None);
document.Project.Solution.Workspace.ApplyTextChanges(document.Id, changes, CancellationToken.None);
formattingTransaction.Complete();
}
}
// Let the rules factories know that this item was committed.
foreach (var rules in GetCompletionRules())
{
rules.CompletionItemComitted(item);
}
}