`pdfDeleteOCGFromAppEvent`

Remove event/category flags from a layer's automatic-state

Category	Optional content

Purpose — Remove event/category flags from a layer's automatic-state application rules (/AS array entries).

Description — Clears Categories unconditionally from the OCG's application-category bitmask. Events is cleared only when DelCategoryOnly=FALSE; when DelCategoryOnly=TRUE, only the category bits are cleared and the event bits are left untouched. The bits being cleared here are the ones set by the companion call pdfAddOCGToAppEvent (not itself part of this chapter's cluster — it lives in the same per-OCG /AS event/category bitmask, serialized to /OCProperties/D/AS). If no bits were ever added for this OCG, the call still succeeds as a no-op once the handle itself is valid.

Declarations

BOOL32 __stdcall pdfDeleteOCGFromAppEvent(PPDF IPDF, uint32_t Handle, TOCAppEvent Events, TOCGUsageCategory Categories, BOOL32 DelCategoryOnly);

Delphi

function pdfDeleteOCGFromAppEvent(const IPDF: PPDF; Handle: Cardinal; Events: TOCAppEvent; Categories: TOCGUsageCategory; DelCategoryOnly: LongBool): LongBool; stdcall; external 'LumasPdf.dll';

TOCAppEvent / TOCGUsageCategory (bit flags):

Delphi

TOCAppEvent = Cardinal;
const aeExport = 1; aePrint = 2; aeView = 4;

TOCGUsageCategory = Cardinal;
const oucNone = 0; oucExport = 1; oucLanguage = 2; oucPrint = 4;
      oucUser = 8; oucView = 16; oucZoom = 32;

Parameters

Parameter	Type	Description
`IPDF`	`PPDF`	Instance handle.
`Handle`	`Cardinal`	OCG handle.
`Events`	`TOCAppEvent`	Event bits to clear (ignored when `DelCategoryOnly=TRUE`).
`Categories`	`TOCGUsageCategory`	Category bits to clear — always applied.
`DelCategoryOnly`	`BOOL32`	`TRUE` = clear only `Categories`, leave `Events` untouched.

Return value — TRUE if Handle is a valid OCG; FALSE otherwise.

See also — pdfAddOCGToAppEvent (adds the bits this call removes; not yet enriched in this chapter)

C# (P/Invoke)

wrappers/dotnet/LumasPdf.cs

[return: MarshalAs(UnmanagedType.Bool)]

Area

Core SDK