def setPlainText(self, p_str):
# FixMe: Keep a reference to old QTextDocuments form previously loaded
# files. This is needed to prevent garbage collection which results in a
# seg fault if the document is discarded while still being highlighted.
self.old_docs.append(self.document())
doc = QTextDocument()
doc.setDocumentLayout(QPlainTextDocumentLayout(doc))
doc.setPlainText(p_str)
self.setDocument(doc)
self.margin.updateWidth()
# start syntax heightening
self.gCodeHighlighter = GcodeSyntaxHighlighter(self)
