private Model FilterModelInBackgroundWorker(
Model model,
int id,
SnapshotPoint caretPosition,
bool recheckCaretPosition,
bool dismissIfEmptyAllowed,
CompletionFilterReason filterReason)
{
if (model == null)
{
return(null);
}
var filterState = model.FilterState;
// If all the filters are on, or all the filters are off then we don't actually
// need to filter.
if (filterState != null)
{
if (filterState.Values.All(b => b) ||
filterState.Values.All(b => !b))
{
filterState = null;
}
}
// We want to dismiss the session if the caret ever moved outside our bounds.
if (recheckCaretPosition && Controller.IsCaretOutsideAllItemBounds(model, caretPosition))
{
return(null);
}
if (id != _filterId)
{
return(model);
}
var textSnapshot = caretPosition.Snapshot;
var allFilteredItems = new List <PresentationItem>();
var textSpanToText = new Dictionary <TextSpan, string>();
var helper = this.Controller.GetCompletionHelper();
// isUnique tracks if there is a single
bool? isUnique = null;
PresentationItem bestFilterMatch = null;
bool filterTextIsPotentialIdentifier = false;
var recentItems = this.Controller.GetRecentItems();
var itemToFilterText = new Dictionary <CompletionItem, string>();
model = model.WithCompletionItemToFilterText(itemToFilterText);
foreach (var currentItem in model.TotalItems)
{
// Check if something new has happened and there's a later on filter operation
// in the chain. If so, there's no need for us to do any more work (as it will
// just be superceded by the later work).
if (id != _filterId)
{
return(model);
}
// We may have wrapped some items in the list in DescriptionModifying items,
// but we should use the actual underlying items when filtering. That way
// our rules can access the underlying item's provider.
if (ItemIsFilteredOut(currentItem.Item, filterState))
{
continue;
}
var filterText = model.GetCurrentTextInSnapshot(currentItem.Item.Span, textSnapshot, textSpanToText);
var matchesFilterText = helper.MatchesFilterText(currentItem.Item, filterText, model.Trigger, filterReason, recentItems);
itemToFilterText[currentItem.Item] = filterText;
if (matchesFilterText)
{
allFilteredItems.Add(currentItem);
// If we have no best match, or this match is better than the last match,
// then the current item is the best filter match.
if (bestFilterMatch == null ||
helper.IsBetterFilterMatch(currentItem.Item, bestFilterMatch.Item, filterText, model.Trigger, filterReason, recentItems))
{
bestFilterMatch = currentItem;
}
// If isUnique is null, then this is the first time we've seen an item that
// matches the filter text. That item is now considered unique. However, if
// isUnique is non-null, then this is the second (or third, or fourth, etc.)
// that a provider said to include. It's no longer unique.
//
// Note: We only want to do this if any filter text was actually provided.
// This is so we can handle the following cases properly:
//
// Console.WriteLi$$
//
// If they try to commit unique item there, we want to commit to
// "WriteLine". However, if they just have:
//
// Console.$$
//
// And they try to commit unique item, we won't commit something just
// because it was in the MRU list.
if (filterText != string.Empty)
{
isUnique = isUnique == null || false;
}
}
else
{
if (filterText.Length <= 1)
{
// Even though the rule provider didn't match this, we'll still include it
// since we want to allow a user typing a single character and seeing all
// possibly completions. However, we don't consider it either unique or a
// filter match, so we won't select it.
allFilteredItems.Add(currentItem);
}
// We want to dismiss the list if the user is typing a # and nothing matches
filterTextIsPotentialIdentifier = filterTextIsPotentialIdentifier ||
filterText.Length == 0 ||
(!char.IsDigit(filterText[0]) && filterText[0] != '-' && filterText[0] != '.');
}
}
if (!filterTextIsPotentialIdentifier && bestFilterMatch == null)
{
// We had no matches, and the user is typing a #, dismiss the list
return(null);
}
if (allFilteredItems.Count == 0)
{
if (dismissIfEmptyAllowed &&
model.DismissIfEmpty &&
filterReason != CompletionFilterReason.BackspaceOrDelete)
{
return(null);
}
if (model.FilterState != null && model.FilterState.Values.Any(b => b))
{
// If the user has turned on some filtering states, and we filtered down to
// nothing, then we do want the UI to show that to them.
return(model.WithFilteredItems(allFilteredItems.ToImmutableArray())
.WithHardSelection(false)
.WithIsUnique(false));
}
else
{
// If we are going to filter everything out, then just preserve the existing
// model, but switch over to soft selection. Also, nothing is unique at that
// point.
return(model.WithHardSelection(false)
.WithIsUnique(false));
}
}
// If we have a best item, then select it. Otherwise just use the first item
// in the list.
var selectedItem = bestFilterMatch ?? allFilteredItems.First();
// If we have a best item, then we want to hard select it. Otherwise we want
// soft selection. However, no hard selection if there's a builder.
var hardSelection = IsHardSelection(model, bestFilterMatch, textSnapshot, helper, model.Trigger, filterReason);
var result = model.WithFilteredItems(allFilteredItems.ToImmutableArray())
.WithSelectedItem(selectedItem)
.WithHardSelection(hardSelection)
.WithIsUnique(isUnique.HasValue && isUnique.Value);
return(result);
}
private Model FilterModelInBackgroundWorker(
Model model,
int id,
SnapshotPoint caretPosition,
bool recheckCaretPosition,
bool dismissIfEmptyAllowed,
CompletionFilterReason filterReason)
{
if (model == null)
{
return null;
}
var filterState = model.FilterState;
// If all the filters are on, or all the filters are off then we don't actually
// need to filter.
if (filterState != null)
{
if (filterState.Values.All(b => b) ||
filterState.Values.All(b => !b))
{
filterState = null;
}
}
// We want to dismiss the session if the caret ever moved outside our bounds.
if (recheckCaretPosition && Controller.IsCaretOutsideAllItemBounds(model, caretPosition))
{
return null;
}
if (id != _filterId)
{
return model;
}
var textSnapshot = caretPosition.Snapshot;
var allFilteredItems = new List<PresentationItem>();
var textSpanToText = new Dictionary<TextSpan, string>();
var helper = this.Controller.GetCompletionHelper();
// isUnique tracks if there is a single
bool? isUnique = null;
PresentationItem bestFilterMatch = null;
bool filterTextIsPotentialIdentifier = false;
var recentItems = this.Controller.GetRecentItems();
var itemToFilterText = new Dictionary<CompletionItem, string>();
model = model.WithCompletionItemToFilterText(itemToFilterText);
foreach (var currentItem in model.TotalItems)
{
// Check if something new has happened and there's a later on filter operation
// in the chain. If so, there's no need for us to do any more work (as it will
// just be superceded by the later work).
if (id != _filterId)
{
return model;
}
// We may have wrapped some items in the list in DescriptionModifying items,
// but we should use the actual underlying items when filtering. That way
// our rules can access the underlying item's provider.
if (ItemIsFilteredOut(currentItem.Item, filterState))
{
continue;
}
var filterText = model.GetCurrentTextInSnapshot(currentItem.Item.Span, textSnapshot, textSpanToText);
var matchesFilterText = MatchesFilterText(helper, currentItem.Item, filterText, model.Trigger, filterReason, recentItems);
itemToFilterText[currentItem.Item] = filterText;
if (matchesFilterText)
{
allFilteredItems.Add(currentItem);
// If we have no best match, or this match is better than the last match,
// then the current item is the best filter match.
if (bestFilterMatch == null ||
IsBetterFilterMatch(helper, currentItem.Item, bestFilterMatch.Item, filterText, model.Trigger, filterReason, recentItems))
{
bestFilterMatch = currentItem;
}
// If isUnique is null, then this is the first time we've seen an item that
// matches the filter text. That item is now considered unique. However, if
// isUnique is non-null, then this is the second (or third, or fourth, etc.)
// that a provider said to include. It's no longer unique.
//
// Note: We only want to do this if any filter text was actually provided.
// This is so we can handle the following cases properly:
//
// Console.WriteLi$$
//
// If they try to commit unique item there, we want to commit to
// "WriteLine". However, if they just have:
//
// Console.$$
//
// And they try to commit unique item, we won't commit something just
// because it was in the MRU list.
if (filterText != string.Empty)
{
isUnique = isUnique == null || false;
}
}
else
{
if (filterText.Length <= 1)
{
// Even though the rule provider didn't match this, we'll still include it
// since we want to allow a user typing a single character and seeing all
// possibly completions. However, we don't consider it either unique or a
// filter match, so we won't select it.
allFilteredItems.Add(currentItem);
}
// We want to dismiss the list if the user is typing a # and nothing matches
filterTextIsPotentialIdentifier = filterTextIsPotentialIdentifier ||
filterText.Length == 0 ||
(!char.IsDigit(filterText[0]) && filterText[0] != '-' && filterText[0] != '.');
}
}
if (!filterTextIsPotentialIdentifier && bestFilterMatch == null)
{
// We had no matches, and the user is typing a #, dismiss the list
return null;
}
if (allFilteredItems.Count == 0)
{
if (dismissIfEmptyAllowed &&
model.DismissIfEmpty &&
filterReason != CompletionFilterReason.BackspaceOrDelete)
{
return null;
}
if (model.FilterState != null && model.FilterState.Values.Any(b => b))
{
// If the user has turned on some filtering states, and we filtered down to
// nothing, then we do want the UI to show that to them.
return model.WithFilteredItems(allFilteredItems.ToImmutableArray())
.WithHardSelection(false)
.WithIsUnique(false);
}
else
{
// If we are going to filter everything out, then just preserve the existing
// model, but switch over to soft selection. Also, nothing is unique at that
// point.
return model.WithHardSelection(false)
.WithIsUnique(false);
}
}
// If we have a best item, then select it. Otherwise just use the first item
// in the list.
var selectedItem = bestFilterMatch ?? allFilteredItems.First();
// If we have a best item, then we want to hard select it. Otherwise we want
// soft selection. However, no hard selection if there's a builder.
var hardSelection = IsHardSelection(model, bestFilterMatch, textSnapshot, helper, model.Trigger, filterReason);
var result = model.WithFilteredItems(allFilteredItems.ToImmutableArray())
.WithSelectedItem(selectedItem)
.WithHardSelection(hardSelection)
.WithIsUnique(isUnique.HasValue && isUnique.Value);
return result;
}