private bool IsBetter(SignatureHelpItems bestItems, TextSpan currentTextSpan)
{
// If we have no best text span, then this span is definitely better.
if (bestItems == null)
{
return(true);
}
// Otherwise we want the one that is conceptually the innermost signature. So it's
// only better if the distance from it to the caret position is less than the best
// one so far.
return(currentTextSpan.Start > bestItems.ApplicableSpan.Start);
}
/// <summary>
/// Returns <code>null</code> if our work was preempted and we want to return the
/// previous model we've computed.
/// </summary>
private async Task <(ISignatureHelpProvider provider, SignatureHelpItems items)> ComputeItemsAsync(
ISignatureHelpProvider[] providers,
int caretPosition,
SIGHLP.SignatureHelpTriggerInfo triggerInfo,
Document document,
CancellationToken cancellationToken)
{
ISignatureHelpProvider bestProvider = null;
SignatureHelpItems bestItems = null;
// TODO(cyrusn): We're calling into extensions, we need to make ourselves resilient
// to the extension crashing.
foreach (var provider in providers)
{
// If this is a retrigger command, and another retrigger command has already
// been issued then we can bail out immediately.
//if (IsNonTypeCharRetrigger(triggerInfo) &&
// localRetriggerId != _retriggerId) {
// return null;
//}
cancellationToken.ThrowIfCancellationRequested();
var currentItems = await provider.GetItemsAsync(document, caretPosition, triggerInfo, cancellationToken).ConfigureAwait(false);
if (currentItems != null && currentItems.ApplicableSpan.IntersectsWith(caretPosition))
{
// If another provider provides sig help items, then only take them if they
// start after the last batch of items. i.e. we want the set of items that
// conceptually are closer to where the caret position is. This way if you have:
//
// Goo(new Bar($$
//
// Then invoking sig help will only show the items for "new Bar(" and not also
// the items for "Goo(..."
if (IsBetter(bestItems, currentItems.ApplicableSpan))
{
bestItems = new SignatureHelpItems(currentItems);
bestProvider = provider;
}
}
}
return(bestProvider, bestItems);
}
private static SignatureHelpItem GetSelectedItem(SignatureHelpItems items, ISignatureHelpProvider provider)
{
// Try to find the most appropriate item in the list to select by default.
// If the provider specified one a selected item, then always stick with that one.
if (items.SelectedItemIndex.HasValue)
{
return(items.Items[items.SelectedItemIndex.Value]);
}
// If the provider did not pick a default, and it's the same provider as the previous
// model we have, then try to return the same item that we had before.
//if (currentModel != null && currentModel.Provider == provider) {
// return items.Items.FirstOrDefault(i => DisplayPartsMatch(i, currentModel.SelectedItem)) ?? items.Items.First();
//}
// Otherwise, just pick the first item we have.
return(items.Items.First());
}
private async Task <Tuple <ISignatureHelpProvider, SignatureHelpItems> > ComputeItemsAsync(
IList <ISignatureHelpProvider> providers,
int caretPosition,
SIGHLP.SignatureHelpTriggerInfo triggerInfo,
Document document,
CancellationToken cancellationToken)
{
ISignatureHelpProvider bestProvider = null;
SignatureHelpItems bestItems = null;
// TODO(cyrusn): We're calling into extensions, we need to make ourselves resilient
// to the extension crashing.
foreach (var provider in providers)
{
cancellationToken.ThrowIfCancellationRequested();
var currentItems = await provider.GetItemsAsync(document, caretPosition, triggerInfo, cancellationToken).ConfigureAwait(false);
if (currentItems != null && currentItems.ApplicableSpan.IntersectsWith(caretPosition))
{
// If another provider provides sig help items, then only take them if they
// start after the last batch of items. i.e. we want the set of items that
// conceptually are closer to where the caret position is. This way if you have:
//
// Foo(new Bar($$
//
// Then invoking sig help will only show the items for "new Bar(" and not also
// the items for "Foo(..."
if (IsBetter(bestItems, currentItems.ApplicableSpan))
{
bestItems = new SignatureHelpItems(currentItems);
bestProvider = provider;
}
}
}
return(Tuple.Create(bestProvider, bestItems));
}
public SignatureHelpResult(SignatureHelpItems items, SignatureHelpItem selectedItem, int?selectedParameter)
{
Items = items;
SelectedItem = selectedItem;
SelectedParameter = selectedParameter;
}
