AllowUserPageChange property

Allows user input (mouse wheel, scroll bar drag, key bindings) to change the current page

Set to False when you want to fully drive the page index from code

All TPdfView display properties trigger a repaint when assigned; you can change several in sequence without flicker because the redraw is coalesced into a single invalidation

• Set design-time defaults in the Object Inspector or assign at runtime before Active := True.
• Changes propagate to the underlying TPdf only for properties that affect persistent state (e.g. Pdf.PageRotation); pure visual properties stay local to the view
• If you replace PdfView1.Pdf at runtime, re-apply any view-only settings — the new TPdf has its own state