public void PresentItems(
ITrackingSpan triggerSpan,
IList <SignatureHelpItem> signatureHelpItems,
SignatureHelpItem selectedItem,
int?selectedParameter)
{
_signatureHelpItems = signatureHelpItems;
_selectedItem = selectedItem;
// Create all the editor signatures for the sig help items we have.
this.CreateSignatures(triggerSpan, selectedParameter);
// It's a new list of items. Either create the editor session if this is the
// first time, or ask the editor session that we already have to recalculate.
if (_editorSessionOpt == null)
{
// We're tracking the caret. Don't have the editor do it.
_editorSessionOpt = _sigHelpBroker.CreateSignatureHelpSession(
_textView,
triggerSpan.GetStartTrackingPoint(PointTrackingMode.Negative),
trackCaret: false);
_editorSessionOpt.Dismissed += (s, e) => OnEditorSessionDismissed();
_editorSessionOpt.SelectedSignatureChanged += OnSelectedSignatureChanged;
}
// So here's the deal. We cannot create the editor session and give it the right
// signatures (even though we know what they are). Instead, the session with
// call back into the ISignatureHelpSourceProvider (which is us) to get those
// values. It will pass itself along with the calls back into
// ISignatureHelpSourceProvider. So, in order to make that connection work, we
// add properties to the session so that we can call back into ourselves, get
// the signatures and add it to the session.
if (!_editorSessionOpt.Properties.ContainsProperty(s_augmentSessionKey))
{
_editorSessionOpt.Properties.AddProperty(s_augmentSessionKey, this);
}
try
{
// Don't want to get any callbacks while we do this.
_ignoreSelectionStatusChangedEvent = true;
_editorSessionOpt.Recalculate();
// Now let the editor know what the currently selected item is.
Contract.Requires(_signatureMap.ContainsKey(selectedItem));
Contract.ThrowIfNull(_signatureMap);
var defaultValue = _signatureMap.GetValueOrDefault(_selectedItem);
if (_editorSessionOpt != null)
{
_editorSessionOpt.SelectedSignature = defaultValue;
}
}
finally
{
_ignoreSelectionStatusChangedEvent = false;
}
}
