ValidatePdfX method

ValidatePdfX walks the open document looking for the file-format markers defined by the ISO 15930 family:

• An XMP metadata stream containing pdfxid:GTS_PDFXVersion (and optionally pdfxid:GTS_PDFXConformance for PDF/X-1a / PDF/X-3).
• The pdfaExtension:schemas description for the pdfxid namespace (XMP extension-schema convention).
• A Document Information Dictionary entry /GTS_PDFXVersion with the same value as the XMP property.
• A catalog /OutputIntents array referencing an OutputIntent dictionary with an embedded ICC profile via /DestOutputProfile.
• An Info-dictionary /Title entry (PDF/X strongly recommends it).
• A trailer /ID array and the absence of /Encrypt (encryption is forbidden by all PDF/X versions).
• xmp:CreateDate and xmp:ModifyDate entries in XMP for Info / XMP parity.

The result is a TPdfXValidationResult record:

• Conformance — the detected level, derived from the XMP version string: pxc1a (matches "PDF/X-1"), pxc3 ("PDF/X-3"), pxc4 ("PDF/X-4"), pxcNone (no PDF/X marker), or pxcUnknown (marker present but unrecognized).
• Issues — a TPdfXValidationIssues set with zero or more of: pvxiMissingXmpMetadata, pvxiMissingPdfXIdentifier, pvxiMissingExtensionSchema, pvxiMissingInfoVersionEntry, pvxiInfoVersionMismatch, pvxiMissingOutputIntent, pvxiMissingIccProfile, pvxiMissingTitle, pvxiMissingTrailerId, pvxiEncryptionPresent, pvxiMissingXmpDates.
• IsCompliant — returns True when Conformance is a real PDF/X level and Issues is empty

ValidatePdfX is a read-only inspection. Use it before pushing a PDF/X payload into a prepress workflow to surface non-conformance to the operator. For the common "what PDF/X level is this?" check that doesn't need the issue list, prefer the lighter-weight PdfXConformance property.

• ValidatePdfX is file-format-level only — it does not enforce content-level PDF/X rules (font embedding completeness, transparency rules for PDF/X-1a / PDF/X-3, OPI / Reference XObjects / PostScript XObjects / JavaScript / visible annotations prohibitions, TrimBox / BleedBox recommendations, TrapNet annotations, etc.). For full validation pair with a preflight tool such as callas pdfaPilot or the Ghent PDF Workgroup Output Suite.
• The validator reports pvxiInfoVersionMismatch only when both Info /GTS_PDFXVersion and XMP pdfxid:GTS_PDFXVersion are present and disagree.
• Calling ValidatePdfX on an inactive document returns a record with Conformance = pxcUnknown and an empty Issues set.
• The level disambiguation (pxc1a / pxc3 / pxc4) is based on substring matching of the XMP version string against "PDF/X-1", "PDF/X-3", "PDF/X-4". Custom version strings outside these patterns fall back to pxcUnknown.