/**
* Sets the document this text area is editing.
*
* @param document The document
*/
public void setDocument(SyntaxDocument document) {
if (this.document == document) return;
if (this.document != null) this.document.removeDocumentListener(documentHandler);
this.document = document;
document.addDocumentListener(documentHandler);
select(0, 0);
updateScrollBars();
painter.repaint();
}
protected void documentChanged(DocumentEvent evt) {
DocumentEvent.ElementChange ch = evt.getChange(document.getDefaultRootElement());
int count;
if (ch == null) count = 0;
else count = ch.getChildrenAdded().length - ch.getChildrenRemoved().length;
int line = getLineOfOffset(evt.getOffset());
if (count == 0) {
painter.invalidateLine(line);
}
// do magic stuff
else if (line < firstLine) {
setFirstLine(firstLine + count);
}
// end of magic stuff
else {
painter.invalidateLineRange(line, firstLine + visibleLines);
updateScrollBars();
}
}