/// <summary>
/// All items that can incrementally parse their children should run their
/// full parse in the same way. This function does that work.
/// </summary>
public static bool FullParseIncrementalItem(
IIncrementalParseItem item,
ItemFactory itemFactory,
ITextProvider text,
TokenStream tokens)
{
ComplexItem complexItem = (ComplexItem)item;
ParseItem prevChild = null;
while (true)
{
ParseItem newChild = item.CreateNextChild(prevChild, itemFactory, text, tokens);
if (newChild != null)
{
complexItem.Children.Add(newChild);
prevChild = newChild;
}
else
{
break;
}
}
item.UpdateCachedChildren();
item.UpdateParseErrors();
return(complexItem.Children.Count > 0);
}
public void OnTextChange(ITextProvider fullNewText, int changeStart, int deletedLength, int insertedLength)
{
Debug.Assert(IsOwnerThread, "CssTree.OnTextChange must be called on the main thread");
if (StyleSheet == null || !IsOwnerThread)
{
return;
}
#if DEBUG_INCREMENTAL_PARSE
DateTime startTime = DateTime.UtcNow;
#endif
// Figure out which tokens changed
ICssParser parser = _parserFactory.CreateParser();
IncrementalTokenizer.Result tokenResult = IncrementalTokenizer.TokenizeChange(
parser.TokenizerFactory, Tokens, TextProvider, fullNewText, changeStart, deletedLength, insertedLength);
// Adjust the input to match what was actually tokenized
changeStart = tokenResult.TokenizationStart;
deletedLength = tokenResult.TextDeletedLength;
insertedLength = tokenResult.TextInsertedLength;
// Figure out where to start incrementally parsing
IIncrementalParseItem parentItem = GetIncrementalParseParent(changeStart, deletedLength);
ComplexItem parentComplexItem = (ComplexItem)parentItem;
int firstReparseChild = FindFirstChildToReparse(parentComplexItem, tokenResult.OldTokenStart);
int firstCleanChild = FindFirstCleanChild(parentComplexItem, tokenResult.OldTokenStart + tokenResult.OldTokenCount);
int firstCleanTokenAfterParent = FindFirstCleanTokenAfterParent(parentComplexItem);
using (CreateWriteLock())
{
// Update the tokens and text
IncrementalTokenizer.ApplyResult(tokenResult);
firstCleanTokenAfterParent += tokenResult.NewTokens.Count - tokenResult.OldTokenCount;
// Init the token stream for parsing
TokenStream tokenStream = new TokenStream(Tokens);
int streamPositionStart = FindTokenToStartParsing(parentComplexItem, firstReparseChild);
tokenStream.Position = streamPositionStart;
Debug.Assert(tokenStream.Position <= tokenResult.OldTokenStart);
// Init parsing
ItemFactory itemFactory = new ItemFactory(parser.ExternalItemFactory, fullNewText, tokenStream);
tokenStream.SkipComments = true; // must be set after extracting comments
// Init the old and new child lists
ParseItemList oldChildren = parentComplexItem.Children;
ParseItemList newChildren = new ParseItemList();
ParseItemList deletedChildren = new ParseItemList();
ParseItemList errorsChangedItems = new ParseItemList();
int deleteChildCount = oldChildren.Count - firstReparseChild;
// CreateNextChild needs to know the previous child for context
ParseItem prevChild = (firstReparseChild > 0) ? oldChildren[firstReparseChild - 1] : null;
while (true)
{
ParseItem newChild = parentItem.CreateNextChild(prevChild, itemFactory, fullNewText, tokenStream);
if (newChild != null)
{
// Are we done parsing yet?
if (newChild.Start >= changeStart + insertedLength)
{
// See if this new child exactly matches an old child
int oldChildIndex = oldChildren.FindInsertIndex(newChild.Start, beforeExisting: true);
ParseItem oldChild = (oldChildIndex < oldChildren.Count) ? oldChildren[oldChildIndex] : null;
if (oldChild != null &&
oldChildIndex >= firstCleanChild &&
oldChild.Start == newChild.Start &&
oldChild.Length == newChild.Length &&
oldChild.GetType() == newChild.GetType())
{
// Found a match, stop parsing
deleteChildCount = oldChildIndex - firstReparseChild;
break;
}
}
newChildren.Add(newChild);
prevChild = newChild;
}
else if (tokenStream.Position != firstCleanTokenAfterParent)
{
// When the parse doesn't stop exactly on the first clean token after the parent,
// then the tree structure changed too much. Just fall back to a full parse:
ParseNewStyleSheet(fullNewText, Tokens);
//Debug.WriteLine("CSS: Full parse:{0}ms", (DateTime.UtcNow - startTime).TotalMilliseconds);
return;
}
else
{
break;
}
}
// Replace items in the parent (saving the deleted items for later)
oldChildren.RemoveRange(firstReparseChild, deleteChildCount, deletedChildren);
oldChildren.AddRange(newChildren);
if (oldChildren.Count == 0)
{
// The parent was deleted, currently can't deal with that as an incremental change
ParseNewStyleSheet(fullNewText, Tokens);
return;
}
// Collect comments over the parsed region
tokenStream.SkipComments = false;
int tokenCount = tokenStream.Position - streamPositionStart;
tokenStream.Position = streamPositionStart;
IList <Comment> comments = parser.ExtractComments(fullNewText, Tokens, tokenStream.Position, tokenCount);
// All done parsing and updating the tree, so now update caches and fire the "on changed" event
StyleSheet.TextProvider = fullNewText;
parentItem.UpdateCachedChildren();
if (parentItem.UpdateParseErrors())
{
errorsChangedItems.Add(parentComplexItem);
}
InsertComments(comments, newChildren);
#if DEBUG_INCREMENTAL_PARSE
Debug.WriteLine("CSS: Inc parse:{0}ms. Deleted:{1}, Inserted:{2}", (DateTime.UtcNow - startTime).TotalMilliseconds, deletedChildren.Count, newChildren.Count);
VerifyTokensAfterIncrementalChange(parser.TokenizerFactory, fullNewText, Tokens);
VerifyTreeAfterIncrementalParse(fullNewText, Tokens, StyleSheet);
#endif
FireOnItemsChanged(deletedChildren, newChildren, errorsChangedItems);
// Clean up the deleted items (must be after the event is fired)
foreach (ParseItem deletedItem in deletedChildren)
{
deletedItem.Parent = null;
}
}
}
