/**
* This method searches ast node that could be reparsed incrementally and returns pair of target
* reparseable node and new replacement node. Returns null if there is no any chance to make
* incremental parsing.
*/
@Nullable
public Couple<ASTNode> findReparseableRoots(
@NotNull PsiFileImpl file,
@NotNull TextRange changedPsiRange,
@NotNull CharSequence newFileText) {
Project project = file.getProject();
final FileElement fileElement = file.getTreeElement();
final CharTable charTable = fileElement.getCharTable();
int lengthShift = newFileText.length() - fileElement.getTextLength();
if (fileElement.getElementType() instanceof ITemplateDataElementType || isTooDeep(file)) {
// unable to perform incremental reparse for template data in JSP, or in exceptionally deep
// trees
return null;
}
final ASTNode leafAtStart =
fileElement.findLeafElementAt(Math.max(0, changedPsiRange.getStartOffset() - 1));
final ASTNode leafAtEnd =
fileElement.findLeafElementAt(
Math.min(changedPsiRange.getEndOffset(), fileElement.getTextLength() - 1));
ASTNode node =
leafAtStart != null && leafAtEnd != null
? TreeUtil.findCommonParent(leafAtStart, leafAtEnd)
: fileElement;
Language baseLanguage = file.getViewProvider().getBaseLanguage();
while (node != null && !(node instanceof FileElement)) {
IElementType elementType = node.getElementType();
if (elementType instanceof IReparseableElementType) {
final TextRange textRange = node.getTextRange();
final IReparseableElementType reparseable = (IReparseableElementType) elementType;
if (baseLanguage.isKindOf(reparseable.getLanguage())
&& textRange.getLength() + lengthShift > 0) {
final int start = textRange.getStartOffset();
final int end = start + textRange.getLength() + lengthShift;
if (end > newFileText.length()) {
reportInconsistentLength(file, newFileText, node, start, end);
break;
}
CharSequence newTextStr = newFileText.subSequence(start, end);
if (reparseable.isParsable(node.getTreeParent(), newTextStr, baseLanguage, project)) {
ASTNode chameleon = reparseable.createNode(newTextStr);
if (chameleon != null) {
DummyHolder holder =
DummyHolderFactory.createHolder(
file.getManager(), null, node.getPsi(), charTable);
holder.getTreeElement().rawAddChildren((TreeElement) chameleon);
if (holder.getTextLength() != newTextStr.length()) {
String details =
ApplicationManager.getApplication().isInternal()
? "text=" + newTextStr + "; treeText=" + holder.getText() + ";"
: "";
LOG.error("Inconsistent reparse: " + details + " type=" + elementType);
}
return Couple.of(node, chameleon);
}
}
}
}
node = node.getTreeParent();
}
return null;
}
