if (fSourceViewer instanceof ITextViewerExtension5) {
ITextViewerExtension5 extension= (ITextViewerExtension5) fSourceViewer;
fReusableRegion.setOffset(modelOffset);
fReusableRegion.setLength(modelLength);
return extension.modelRange2WidgetRange(fReusableRegion);
}
IRegion region= fSourceViewer.getVisibleRegion();
int offset= region.getOffset();
int length= region.getLength();