private Model SetModelSelectedItemInBackground(
Model model,
Func<Model, CompletionItem> selector)
{
if (model == null)
{
return null;
}
// Switch to hard selection.
var selectedItem = selector(model);
Contract.ThrowIfFalse(model.TotalItems.Contains(selectedItem) || model.DefaultBuilder == selectedItem);
if (model.FilteredItems.Contains(selectedItem))
{
// Easy case, just set the selected item that's already in the filtered items
// list.
return model.WithSelectedItem(selector(model))
.WithHardSelection(true);
}
else
{
// Item wasn't in the filtered list, so we need to recreate the filtered list
// with that item in it.
var filteredItemsSet = new HashSet<CompletionItem>(model.FilteredItems,
ReferenceEqualityComparer.Instance);
var newFilteredItems = model.TotalItems.Where(
i => filteredItemsSet.Contains(i) || i == selectedItem).ToList();
return model.WithFilteredItems(newFilteredItems)
.WithSelectedItem(selectedItem)
.WithHardSelection(true);
}
}
private bool IsCaretOutsideItemBounds(
Model model,
SnapshotPoint caretPoint,
CompletionItem item,
Dictionary<TextSpan, string> textSpanToText,
Dictionary<TextSpan, ViewTextSpan> textSpanToViewSpan)
{
// Easy first check. See if the caret point is before the start of the item.
if (!textSpanToViewSpan.TryGetValue(item.Span, out var filterSpanInViewBuffer))
{
filterSpanInViewBuffer = model.GetViewBufferSpan(item.Span);
textSpanToViewSpan[item.Span] = filterSpanInViewBuffer;
}
if (caretPoint < filterSpanInViewBuffer.TextSpan.Start)
{
return true;
}
var textSnapshot = caretPoint.Snapshot;
var currentText = model.GetCurrentTextInSnapshot(item.Span, textSnapshot, textSpanToText);
var currentTextSpan = new TextSpan(filterSpanInViewBuffer.TextSpan.Start, currentText.Length);
return !currentTextSpan.IntersectsWith(caretPoint);
}
private Model FilterModelInBackground(
Model model,
int id,
SnapshotPoint caretPosition,
bool recheckCaretPosition,
bool dismissIfEmptyAllowed,
CompletionFilterReason filterReason)
{
using (Logger.LogBlock(FunctionId.Completion_ModelComputation_FilterModelInBackground, CancellationToken.None))
{
return FilterModelInBackgroundWorker(model, id, caretPosition, recheckCaretPosition, dismissIfEmptyAllowed, filterReason);
}
}
internal bool IsCaretOutsideAllItemBounds(Model model, SnapshotPoint caretPoint)
{
var textSpanToTextCache = new Dictionary<TextSpan, string>();
var textSpanToViewSpanCache = new Dictionary<TextSpan, ViewTextSpan>();
foreach (var item in model.TotalItems)
{
if (!IsCaretOutsideItemBounds(model, caretPoint, item, textSpanToTextCache, textSpanToViewSpanCache))
{
return false;
}
}
return true;
}
private void Commit(PresentationItem item, Model model, char? commitChar)
{
AssertIsForeground();
// We could only be called if we had a model at this point.
Contract.ThrowIfNull(model);
// 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();
Commit(item, model, commitChar, CancellationToken.None);
}
private Model SetModelBuilderStateInBackground(
Model model,
bool includeBuilder)
{
if (model == null)
{
return null;
}
// We want to soft select if the user is switching the builder on, or if we were
// already in soft select mode.
var softSelect = includeBuilder || model.IsSoftSelection;
// If the selected item is the builder, select the first filtered item instead.
if (model.SelectedItem == model.DefaultSuggestionModeItem)
{
return model.WithSelectedItem(model.FilteredItems.First())
.WithHardSelection(!softSelect);
}
return model.WithHardSelection(!softSelect).WithUseSuggestionMode(includeBuilder);
}
private Model SetModelBuilderStateInBackground(
Model model,
bool includeBuilder)
{
if (model == null)
{
return null;
}
// We want to soft select if the user is switching the builder on, or if we were
// already in soft select mode.
var softSelect = includeBuilder || model.IsSoftSelection;
if (model.SelectedItem == model.SuggestionModeItem &&
!includeBuilder)
{
// Use had the builder selected, but turned off the builder. Switch to the
// first filtered item.
model = model.WithSelectedItem(model.FilteredItems.First());
}
return model.WithHardSelection(!softSelect)
.WithUseSuggestionMode(includeBuilder);
}
private static ImmutableDictionary<CompletionItemFilter, bool> ComputeEffectiveFilterItemState(Model model)
{
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))
{
return null;
}
}
return filterState;
}
private Model FilterModelInBackgroundWorker(
Model model,
int id,
SnapshotPoint caretPosition,
bool recheckCaretPosition,
bool dismissIfEmptyAllowed,
CompletionFilterReason filterReason)
{
if (model == null)
{
return null;
}
// We want to dismiss the session if the caret ever moved outside our bounds.
// Do this before we check the _filterId. We don't want this work to not happen
// just because the user typed more text and added more filter items.
if (recheckCaretPosition && Controller.IsCaretOutsideAllItemBounds(model, caretPosition))
{
return null;
}
if (id != _filterId)
{
return model;
}
var textSnapshot = caretPosition.Snapshot;
var textSpanToText = new Dictionary<TextSpan, string>();
var document = this.Controller.GetDocument();
var helper = this.Controller.GetCompletionHelper();
var recentItems = this.Controller.GetRecentItems();
var filterResults = new List<FilterResult>();
var filterText = model.GetCurrentTextInSnapshot(
model.OriginalList.Span, textSnapshot, textSpanToText);
// Check if the user is typing a number. If so, only proceed if it's a number
// directly after a <dot>. That's because it is actually reasonable for completion
// to be brought up after a <dot> and for the user to want to filter completion
// items based on a number that exists in the name of the item. However, when
// we are not after a dot (i.e. we're being brought up after <space> is typed)
// then we don't want to filter things. Consider the user writing:
//
// dim i =<space>
//
// We'll bring up the completion list here (as VB has completion on <space>).
// If the user then types '3', we don't want to match against Int32.
var filterTextStartsWithANumber = filterText.Length > 0 && char.IsNumber(filterText[0]);
if (filterTextStartsWithANumber)
{
if (!IsAfterDot(model, textSnapshot, textSpanToText))
{
return null;
}
}
var effectiveFilterItemState = ComputeEffectiveFilterItemState(model);
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;
}
if (ItemIsFilteredOut(currentItem, effectiveFilterItemState))
{
continue;
}
// Check if the item matches the filter text typed so far.
var matchesFilterText = MatchesFilterText(helper, currentItem, filterText, model.Trigger, filterReason, recentItems);
if (matchesFilterText)
{
filterResults.Add(new FilterResult(
currentItem, filterText, matchedFilterText: true));
}
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.
filterResults.Add(new FilterResult(
currentItem, filterText, matchedFilterText: false));
}
}
}
model = model.WithFilterText(filterText);
// If no items matched the filter text then determine what we should do.
if (filterResults.Count == 0)
{
return HandleAllItemsFilteredOut(model, filterReason, dismissIfEmptyAllowed);
}
// If this was deletion, then we control the entire behavior of deletion
// ourselves.
if (model.Trigger.Kind == CompletionTriggerKind.Deletion)
{
return HandleDeletionTrigger(model, filterResults);
}
return HandleNormalFiltering(
model, document, filterReason, caretPosition,
helper, recentItems, filterText, filterResults);
}
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;
}
private bool IsHardSelection(
Model model,
PresentationItem bestFilterMatch,
ITextSnapshot textSnapshot,
CompletionHelper completionHelper,
CompletionTrigger trigger,
CompletionFilterReason reason)
{
if (model.SuggestionModeItem != null)
{
return bestFilterMatch != null && bestFilterMatch.Item.DisplayText == model.SuggestionModeItem.Item.DisplayText;
}
if (bestFilterMatch == null || model.UseSuggestionMode)
{
return false;
}
// We don't have a builder and we have a best match. Normally this will be hard
// selected, except for a few cases. Specifically, if no filter text has been
// provided, and this is not a preselect match then we will soft select it. This
// happens when the completion list comes up implicitly and there is something in
// the MRU list. In this case we do want to select it, but not with a hard
// selection. Otherwise you can end up with the following problem:
//
// dim i as integer =<space>
//
// Completion will comes up after = with 'integer' selected (Because of MRU). We do
// not want 'space' to commit this.
var viewSpan = model.GetViewBufferSpan(bestFilterMatch.Item.Span);
var fullFilterText = model.GetCurrentTextInSnapshot(viewSpan, textSnapshot, endPoint: null);
var shouldSoftSelect = ShouldSoftSelectItem(bestFilterMatch.Item, fullFilterText, trigger);
if (shouldSoftSelect)
{
return false;
}
// If the user moved the caret left after they started typing, the 'best' match may not match at all
// against the full text span that this item would be replacing.
if (!MatchesFilterText(completionHelper, bestFilterMatch.Item, fullFilterText, trigger, reason, this.Controller.GetRecentItems()))
{
return false;
}
// There was either filter text, or this was a preselect match. In either case, we
// can hard select this.
return true;
}
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 textSpanToText = new Dictionary<TextSpan, string>();
var document = this.Controller.GetDocument();
var helper = this.Controller.GetCompletionHelper();
var recentItems = this.Controller.GetRecentItems();
var filterResults = new List<FilterResult>();
var filterText = model.GetCurrentTextInSnapshot(model.OriginalList.Span, textSnapshot, textSpanToText);
// If the user was typing a number, then immediately dismiss completion.
var filterTextStartsWithANumber = filterText.Length > 0 && char.IsNumber(filterText[0]);
if (filterTextStartsWithANumber)
{
return null;
}
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;
}
if (ItemIsFilteredOut(currentItem.Item, filterState))
{
continue;
}
// Check if the item matches the filter text typed so far.
var matchesFilterText = MatchesFilterText(helper, currentItem.Item, filterText, model.Trigger, filterReason, recentItems);
if (matchesFilterText)
{
filterResults.Add(new FilterResult(
currentItem, filterText, matchedFilterText: true));
}
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.
filterResults.Add(new FilterResult(
currentItem, filterText, matchedFilterText: false));
}
}
}
model = model.WithFilterText(filterText);
// If no items matched the filter text then determine what we should do.
if (filterResults.Count == 0)
{
return HandleAllItemsFilteredOut(model, filterReason, dismissIfEmptyAllowed);
}
// If this was deletion, then we control the entire behavior of deletion
// ourselves.
if (model.Trigger.Kind == CompletionTriggerKind.Deletion)
{
return HandleDeletionTrigger(model, filterResults);
}
return HandleNormalFiltering(
model, filterReason, textSnapshot, document,
helper, recentItems, filterText, filterResults);
}
private static Model HandleAllItemsFilteredOut(
Model model,
CompletionFilterReason filterReason,
bool dismissIfEmptyAllowed)
{
if (dismissIfEmptyAllowed &&
model.DismissIfEmpty &&
filterReason == CompletionFilterReason.TypeChar)
{
// If the user was just typing, and the list went to empty *and* this is a
// language that wants to dismiss on empty, then just return a null model
// to stop the completion session.
return null;
}
if (model.FilterState?.Values.Any(b => b) == true)
{
// 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. That way the user
// can turn off filters they don't want and get the right set of items.
return model.WithFilteredItems(ImmutableArray<PresentationItem>.Empty)
.WithFilterText("")
.WithHardSelection(false)
.WithIsUnique(false);
}
else
{
// If we are going to filter everything out, then just preserve the existing
// model (and all the previously filtered items), but switch over to soft
// selection.
return model.WithHardSelection(false)
.WithIsUnique(false);
}
}
private Model HandleDeletionTrigger(Model model, List<FilterResult> filterResults)
{
FilterResult? bestFilterResult = null;
int matchCount = 0;
foreach (var currentFilterResult in filterResults.Where(r => r.MatchedFilterText))
{
if (bestFilterResult == null ||
IsBetterDeletionMatch(currentFilterResult, bestFilterResult.Value))
{
// We had no best result yet, so this is now our best result.
bestFilterResult = currentFilterResult;
matchCount++;
}
}
// If we had a matching item, then pick the best of the matching items and
// choose that one to be hard selected. If we had no actual matching items
// (which can happen if the user deletes down to a single character and we
// include everything), then we just soft select the first item.
var filteredItems = filterResults.Select(r => r.PresentationItem).AsImmutable();
model = model.WithFilteredItems(filteredItems);
if (bestFilterResult != null)
{
return model.WithSelectedItem(bestFilterResult.Value.PresentationItem)
.WithHardSelection(true)
.WithIsUnique(matchCount == 1);
}
else
{
return model.WithHardSelection(false)
.WithIsUnique(false);
}
}
private Model HandleNormalFiltering(
Model model, CompletionFilterReason filterReason,
ITextSnapshot textSnapshot, Document document,
CompletionHelper helper, ImmutableArray<string> recentItems,
string filterText,
List<FilterResult> filterResults)
{
// Not deletion. Defer to the language to decide which item it thinks best
// matches the text typed so far.
// Ask the language to determine which of the *matched* items it wants to select.
var service = this.Controller.GetCompletionService();
var matchingCompletionItems = filterResults.Where(r => r.MatchedFilterText)
.Select(t => t.PresentationItem.Item)
.AsImmutable();
var chosenItems = service.ChooseBestItems(document, matchingCompletionItems, filterText);
// Of the items the service returned, pick the one most recently committed
var bestCompletionItem = GetBestCompletionItemBasedOnMRU(chosenItems, recentItems);
// If we don't have a best completion item yet, then pick the first item from the list.
var bestOrFirstCompletionItem = bestCompletionItem ?? filterResults.First().PresentationItem.Item;
var bestOrFirstPresentationItem = filterResults.Where(
r => r.PresentationItem.Item == bestOrFirstCompletionItem).First().PresentationItem;
var hardSelection = IsHardSelection(
model, bestOrFirstPresentationItem, textSnapshot, helper, filterReason);
// Determine if we should consider this item 'unique' or not. A unique item
// will be automatically committed if the user hits the 'invoke completion'
// without bringing up the completion list. An item is unique if it was the
// only item to match the text typed so far, and there was at least some text
// typed. i.e. if we have "Console.$$" we don't want to commit something
// like "WriteLine" since no filter text has actually been provided. HOwever,
// if "Console.WriteL$$" is typed, then we do want "WriteLine" to be committed.
var matchingItemCount = matchingCompletionItems.Length;
var isUnique = bestCompletionItem != null &&
matchingItemCount == 1 &&
filterText.Length > 0;
var result = model.WithFilteredItems(filterResults.Select(r => r.PresentationItem).AsImmutable())
.WithSelectedItem(bestOrFirstPresentationItem)
.WithHardSelection(hardSelection)
.WithIsUnique(isUnique);
return result;
}
private void Commit(
CompletionItem item, Model model, char? commitChar,
ITextSnapshot initialTextSnapshot, Action nextHandler)
{
AssertIsForeground();
// We could only be called if we had a model at this point.
Contract.ThrowIfNull(model);
// 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.DismissSessionIfActive();
CompletionChange completionChange;
using (var transaction = CaretPreservingEditTransaction.TryCreate(
EditorFeaturesResources.IntelliSense, TextView, _undoHistoryRegistry, _editorOperationsFactoryService))
{
if (transaction == null)
{
// This text buffer has no undo history and has probably been unmapped.
// (Workflow unmaps its projections when losing focus (such as double clicking the completion list)).
// Bail on committing completion because we won't be able to find a Document to update either.
return;
}
// We want to merge with any of our other programmatic edits (e.g. automatic brace completion)
transaction.MergePolicy = AutomaticCodeChangeMergePolicy.Instance;
var provider = GetCompletionProvider(item) as ICustomCommitCompletionProvider;
if (provider != null)
{
provider.Commit(item, this.TextView, this.SubjectBuffer, model.TriggerSnapshot, commitChar);
}
else
{
// Right before calling Commit, we may have passed the commitChar through to the
// editor. That was so that undoing completion will get us back to the state we
// we would be in if completion had done nothing. However, now that we're going
// to actually commit, we want to roll back to where we were before we pushed
// commit character into the buffer. This has multiple benefits:
//
// 1) the buffer is in a state we expect it to be in. i.e. we don't have to
// worry about what might have happened (like brace-completion) when the
// commit char was inserted.
// 2) after we commit the item, we'll pass the commit character again into the
// buffer (unless the items asks us not to). By doing this, we can make sure
// that things like brace-completion or formatting trigger as we expect them
// to.
var characterWasSentIntoBuffer = commitChar != null &&
initialTextSnapshot.Version.VersionNumber != this.SubjectBuffer.CurrentSnapshot.Version.VersionNumber;
if (characterWasSentIntoBuffer)
{
RollbackToBeforeTypeChar(initialTextSnapshot);
}
// Now, get the change the item wants to make. Note that the change will be relative
// to the initial snapshot/document the item was triggered from. We'll map that change
// forward, then apply it to our current snapshot.
var triggerDocument = model.TriggerDocument;
var triggerSnapshot = model.TriggerSnapshot;
var completionService = CompletionService.GetService(triggerDocument);
Contract.ThrowIfNull(completionService, nameof(completionService));
completionChange = completionService.GetChangeAsync(
triggerDocument, item, commitChar, CancellationToken.None).WaitAndGetResult(CancellationToken.None);
var textChange = completionChange.TextChange;
var triggerSnapshotSpan = new SnapshotSpan(triggerSnapshot, textChange.Span.ToSpan());
var mappedSpan = triggerSnapshotSpan.TranslateTo(
this.SubjectBuffer.CurrentSnapshot, SpanTrackingMode.EdgeInclusive);
// Now actually make the text change to the document.
using (var textEdit = this.SubjectBuffer.CreateEdit(EditOptions.None, reiteratedVersionNumber: null, editTag: null))
{
var adjustedNewText = AdjustForVirtualSpace(textChange);
textEdit.Replace(mappedSpan.Span, adjustedNewText);
textEdit.Apply();
}
// adjust the caret position if requested by completion service
if (completionChange.NewPosition != null)
{
TextView.Caret.MoveTo(new SnapshotPoint(
this.SubjectBuffer.CurrentSnapshot, completionChange.NewPosition.Value));
}
// Now, pass along the commit character unless the completion item said not to
if (characterWasSentIntoBuffer && !completionChange.IncludesCommitCharacter)
{
nextHandler();
}
// If the insertion is long enough, the caret will scroll out of the visible area.
// Re-center the view.
this.TextView.Caret.EnsureVisible();
}
transaction.Complete();
}
// Let the completion rules know that this item was committed.
this.MakeMostRecentItem(item.DisplayText);
}
private void CommitOnNonTypeChar(
CompletionItem item, Model model)
{
Commit(item, model, commitChar: null, initialTextSnapshot: null, nextHandler: null);
}
private bool IsHardSelection(
Model model,
CompletionItem bestFilterMatch,
SnapshotPoint caretPosition,
CompletionHelper completionHelper,
CompletionFilterReason reason)
{
if (bestFilterMatch == null || model.UseSuggestionMode)
{
return false;
}
var textSnapshot = caretPosition.Snapshot;
// We don't have a builder and we have a best match. Normally this will be hard
// selected, except for a few cases. Specifically, if no filter text has been
// provided, and this is not a preselect match then we will soft select it. This
// happens when the completion list comes up implicitly and there is something in
// the MRU list. In this case we do want to select it, but not with a hard
// selection. Otherwise you can end up with the following problem:
//
// dim i as integer =<space>
//
// Completion will comes up after = with 'integer' selected (Because of MRU). We do
// not want 'space' to commit this.
var itemViewSpan = model.GetViewBufferSpan(bestFilterMatch.Span);
var fullFilterText = model.GetCurrentTextInSnapshot(itemViewSpan, textSnapshot, endPoint: null);
var trigger = model.Trigger;
var shouldSoftSelect = ShouldSoftSelectItem(bestFilterMatch, fullFilterText, trigger);
if (shouldSoftSelect)
{
return false;
}
// If the user moved the caret left after they started typing, the 'best' match may not match at all
// against the full text span that this item would be replacing.
if (!MatchesFilterText(completionHelper, bestFilterMatch, fullFilterText, trigger, reason, this.Controller.GetRecentItems()))
{
return false;
}
// Switch to soft selection, if user moved caret to the start of a non-empty filter span.
// This prevents commiting if user types a commit character at this position later, but still has the list if user types filter character
// i.e. blah| -> |blah -> !|blah
// We want the filter span non-empty because we still want hard selection in the following case:
//
// A a = new |
if (caretPosition == itemViewSpan.TextSpan.Start && itemViewSpan.TextSpan.Length > 0)
{
return false;
}
// There was either filter text, or this was a preselect match. In either case, we
// can hard select this.
return true;
}
private void Commit(PresentationItem item, Model model, char? commitChar, CancellationToken cancellationToken)
{
var textChanges = ImmutableArray<TextChange>.Empty;
// NOTE(cyrusn): It is intentional that we get the undo history for the
// surface buffer and not the subject buffer.
// There have been some watsons where the ViewBuffer hadn't been registered,
// so use TryGetHistory instead.
ITextUndoHistory undoHistory;
_undoHistoryRegistry.TryGetHistory(this.TextView.TextBuffer, out undoHistory);
using (var transaction = undoHistory?.CreateTransaction(EditorFeaturesResources.IntelliSense))
{
// We want to merge with any of our other programmatic edits (e.g. automatic brace completion)
if (transaction != null)
{
transaction.MergePolicy = AutomaticCodeChangeMergePolicy.Instance;
}
// Check if the provider wants to perform custom commit itself. Otherwise we will
// handle things.
var provider = GetCompletionProvider(item.Item) as ICustomCommitCompletionProvider;
if (provider == null)
{
var viewBuffer = this.TextView.TextBuffer;
var commitDocument = this.SubjectBuffer.CurrentSnapshot.AsText().GetDocumentWithFrozenPartialSemanticsAsync(cancellationToken).WaitAndGetResult(cancellationToken);
// adjust commit item span foward to match current document that is passed to GetChangeAsync below
var commitItem = item.Item;
var currentItemSpan = GetCurrentItemSpan(commitItem, model);
commitItem = commitItem.WithSpan(currentItemSpan);
var completionService = CompletionService.GetService(commitDocument);
var commitChange = completionService.GetChangeAsync(commitDocument, commitItem, commitChar, cancellationToken).WaitAndGetResult(cancellationToken);
textChanges = commitChange.TextChanges;
// 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
});
// edit subject buffer (not view) because text changes are in terms of current document.
using (var textEdit = this.SubjectBuffer.CreateEdit(editOptions, reiteratedVersionNumber: null, editTag: null))
{
for (int iChange = 0; iChange < textChanges.Length; iChange++)
{
var textChange = textChanges[iChange];
var isFirst = iChange == 0;
var isLast = iChange == textChanges.Length - 1;
// add commit char to end of last change if not already included
if (isLast && !commitChange.IncludesCommitCharacter && commitChar.HasValue)
{
textChange = new TextChange(textChange.Span, textChange.NewText + commitChar.Value);
}
var currentSpan = new SnapshotSpan(this.SubjectBuffer.CurrentSnapshot, new Span(textChange.Span.Start, textChange.Span.Length));
// 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;
string newText = textChange.NewText;
if (isFirst)
{
newText = AdjustFirstText(textChange);
}
if (isLast)
{
newText = AdjustLastText(newText, commitChar.GetValueOrDefault(), out textChanged);
currentSpan = AdjustLastSpan(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, newText);
}
textEdit.Apply();
}
// adjust the caret position if requested by completion service
if (commitChange.NewPosition != null)
{
var target = new SnapshotPoint(this.SubjectBuffer.CurrentSnapshot, commitChange.NewPosition.Value);
this.TextView.TryMoveCaretToAndEnsureVisible(target);
}
// 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.Item, this.TextView, this.SubjectBuffer, model.TriggerSnapshot, commitChar);
transaction?.Complete();
}
}
var document = this.SubjectBuffer.CurrentSnapshot.GetOpenDocumentInCurrentContextWithChanges();
var formattingService = document.GetLanguageService<IEditorFormattingService>();
var commitCharTriggersFormatting = commitChar != null &&
(formattingService?.SupportsFormattingOnTypedCharacter(document, commitChar.GetValueOrDefault())
?? false);
if (formattingService != null && (item.Item.Rules.FormatOnCommit || commitCharTriggersFormatting))
{
// 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 caretPoint = this.TextView.GetCaretPoint(this.SubjectBuffer);
IList<TextChange> changes = null;
if (commitCharTriggersFormatting && caretPoint.HasValue)
{
// if the commit character is supported by formatting service, then let the formatting service
// find the appropriate range to format.
changes = formattingService.GetFormattingChangesAsync(document, commitChar.Value, caretPoint.Value.Position, cancellationToken).WaitAndGetResult(cancellationToken);
}
else if (textChanges.Length > 0)
{
// if this is not a supported trigger character for formatting service (space or tab etc.)
// then format the span of the textchange.
var totalSpan = TextSpan.FromBounds(textChanges.Min(c => c.Span.Start), textChanges.Max(c => c.Span.End));
changes = formattingService.GetFormattingChangesAsync(document, totalSpan, cancellationToken).WaitAndGetResult(cancellationToken);
}
if (changes != null && !changes.IsEmpty())
{
document.Project.Solution.Workspace.ApplyTextChanges(document.Id, changes, cancellationToken);
}
formattingTransaction.Complete();
}
}
// Let the completion rules know that this item was committed.
this.MakeMostRecentItem(item.Item.DisplayText);
}
private TextSpan GetCurrentItemSpan(CompletionItem item, Model model)
{
var originalSpanInView = model.GetViewBufferSpan(item.Span);
var currentSpanInView = model.GetCurrentSpanInSnapshot(originalSpanInView, this.TextView.TextBuffer.CurrentSnapshot);
var newStart = item.Span.Start + (currentSpanInView.Span.Start - originalSpanInView.TextSpan.Start);
return new TextSpan(newStart, currentSpanInView.Length);
}
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>();
var commitCharTriggersFormatting = commitChar != null &&
(formattingService?.SupportsFormattingOnTypedCharacter(document, commitChar.GetValueOrDefault())
?? false);
if (formattingService != null && (item.ShouldFormatOnCommit || commitCharTriggersFormatting))
{
// 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 caretPoint = this.TextView.GetCaretPoint(this.SubjectBuffer);
IList<TextChange> changes;
if (commitCharTriggersFormatting && caretPoint.HasValue)
{
// if the commit character is supported by formatting service, then let the formatting service
// find the appropriate range to format.
changes = formattingService.GetFormattingChangesAsync(document, commitChar.Value, caretPoint.Value.Position, CancellationToken.None).WaitAndGetResult(CancellationToken.None);
}
else
{
// if this is not a supported trigger character for formatting service (space or tab etc.)
// then format the span of the textchange.
changes = formattingService.GetFormattingChangesAsync(document, textChange.Span, CancellationToken.None).WaitAndGetResult(CancellationToken.None);
}
if (changes != null && !changes.IsEmpty())
{
document.Project.Solution.Workspace.ApplyTextChanges(document.Id, changes, CancellationToken.None);
}
formattingTransaction.Complete();
}
}
// Let the completion rules know that this item was committed.
GetCompletionRules().CompletionItemCommitted(item);
}
private Boolean IsAfterDot(Model model, ITextSnapshot textSnapshot, Dictionary<TextSpan, string> textSpanToText)
{
var span = model.OriginalList.Span;
// Move the span back one character if possible.
span = TextSpan.FromBounds(Math.Max(0, span.Start - 1), span.End);
var text = model.GetCurrentTextInSnapshot(span, textSnapshot, textSpanToText);
return text.Length > 0 && text[0] == '.';
}
