/**
* Determine the area of the document whose syntax highlighting is impacted by the change of
* source content
*
* @param offset The initial offset of the change
* @param length The length of the change
* @throws BadLocationException If the change processing fails
*/
public void processChangedLines(int offset, int length) throws BadLocationException {
Element line;
int startOffset = offset;
int changeOffset = offset;
int changeLength = length;
MutableAttributeSet highlight = getStyle(InformSyntax.Normal.getName());
MutableAttributeSet tokenCheck = getStyle(InformSyntax.Normal.getName());
// Locate start of first highlight token at insert/remove offset
if (changeOffset > 0) {
// Check for the element before the insertion/removal point (offset-1) so if the
// insertion/removal point is at the boundary of two elements we get the previous
// highlight token not the following highlight token
Element token = getCharacterElement(offset - 1);
startOffset = token.getStartOffset();
highlight = (MutableAttributeSet) token.getAttributes();
tokenCheck = getStyle((String) highlight.getAttribute(AttributeSet.NameAttribute));
while (highlight.containsAttributes(tokenCheck) && changeOffset > 0) {
changeOffset = startOffset;
token = getCharacterElement(changeOffset - 1);
startOffset = token.getStartOffset();
highlight = (MutableAttributeSet) token.getAttributes();
}
}
// Find the length of the text in the document impacted by the insert/remove.
// The length of the text between the start of the first highlight token at the insert point
// to the end of the current line plus the length of the text being inserted into the document.
if (length > 0) {
line = getParagraphElement(offset + length);
} else {
line = getParagraphElement(offset);
}
changeLength = line.getEndOffset() - changeOffset;
applyHighlighting(changeOffset, changeLength);
}
/**
* Apply inform syntax highlighting to the specified portion of the document
*
* @param offset The initial offset at which to apply syntax highlighting
* @param length The length of the document text to be highlighted
* @throws BadLocationException If applying highlighting fails
*/
public void applyHighlighting(int offset, int length) throws BadLocationException {
int startOffset;
int endOffset;
int tokenLength;
MutableAttributeSet syntax;
String source = getText(offset, length);
ResourceLexer lexer = new ResourceLexer(source, offset);
ResourceToken token = lexer.nextElement();
while (token.getType() != ResourceToken.EOS) {
startOffset = token.getStartPosition();
endOffset = token.getEndPosition();
tokenLength = endOffset - startOffset;
if (token.getType() == ResourceToken.COMMENT) {
syntax = getStyle(InformSyntax.Comment.getName());
} else if (token.getType() == ResourceToken.STRING) {
syntax = getStyle(InformSyntax.String.getName());
} else if (token.getType() == ResourceToken.SYMBOL) {
if (Resource.isKeyword(token.getContent())) {
syntax = getStyle(InformSyntax.Keyword.getName());
} else {
syntax = getStyle(InformSyntax.Normal.getName());
}
} else if (token.getType() == ResourceToken.WHITESPACE) {
syntax = getStyle(InformSyntax.White.getName());
} else {
syntax = getStyle(InformSyntax.Normal.getName());
}
setCharacterAttributes(startOffset, tokenLength, syntax, true);
token = lexer.nextElement();
}
}
/**
* Insert a string with syntax highlighting
*
* @param offset The offset to insert the string
* @param str The String to be inserted in the document
* @param a The AttributeSet for the String
* @throws BadLocationException If the insert action fails
*/
@Override
public void insertString(int offset, String str, AttributeSet a) throws BadLocationException {
super.insertString(offset, str, getStyle(InformSyntax.Normal.getName()));
processChangedLines(offset, str.length());
}