@Override
        public void inputDocumentAboutToBeChanged(IDocument oldInput, IDocument newInput) {
            if (oldInput != null) {
                SQLBackgroundParsingJob.this.cancel();
                oldInput.removeDocumentListener(this);
            }
        }
Prepare completion context for the specified position in the text
plugins/org.jkiss.dbeaver.ui.editors.sql/src/org/jkiss/dbeaver/ui/editors/sql/semantics/SQLBackgroundParsingJob.java