BeginPageObjectEditTransaction method

Component: TPdf · Unit: PDFium

Starts a reproducible page-object edit transaction on the active document

Syntax

procedure BeginPageObjectEditTransaction(AllowSignedDocument: Boolean = False);

Description

BeginPageObjectEditTransaction captures a bounded, reproducible snapshot of the active document and enters the transaction state in which page-object edits are journalled instead of being applied directly

By default the call refuses a document that carries signatures; pass AllowSignedDocument = True to open the transaction anyway when the caller accepts responsibility for invalidating existing signatures

Remarks

Track progress through PageObjectEditTransactionStatus while the transaction is open
Call CommitPageObjectEditTransaction to apply the journalled edits or RollbackPageObjectEditTransaction to restore the snapshot
Nested transactions are not supported; begin the next one only after committing or rolling back

Example

Wrap a group of object edits so they can be undone as one unit

Pdf1.BeginPageObjectEditTransaction;
try
  Pdf1.SetTextObjectFontSize(3, 14);
  if not Pdf1.CommitPageObjectEditTransaction then Pdf1.RollbackPageObjectEditTransaction;
finally
  Pdf1.UpdatePage(1);
end;