THPDFParagraphReflowSession.Preview
Declaration
function Preview(PageIndex: Integer; const Source, Target: THPDFParagraphRectangle;
const Replacement: UnicodeString; const Options: THPDFParagraphReflowOptions;
out Report: THPDFParagraphReflowReport; CancellationToken: THPDFCancellationToken = nil): Boolean;
Swaps the session-owned preview plan without publishing any changes; a pending applied edit has to be committed or rolled back first