HotPDF Pascal component help

Free Pascal and Lazarus

Build Win64 applications with Free Pascal 3.2.2 and Lazarus 4.6 through Lib/FPC/HotPDFLaz.lpk or the reproducible build-Win64-Lib-FPC.cmd script

Document creation and loading are supported with Flate compression and AES encryption; the TIFF, JPEG 2000, JBIG2, color-management and Zopfli codecs are not linked in Free Pascal builds and report a failure when requested

The whole library compiles under Free Pascal, including XFA form flattening, the XPS, EPUB and CBZ document handlers, the viewer components and HTML import

Why Choose HotPDF

Eight hard-to-match differentiators, the supporting evidence, and the audiences HotPDF is built for — on one page: native source with no DLL, full OpenType shaping, in-process PFX signing, PAdES, three-axis compliance, the multi-gigabyte Direct File API and more

Capability Map

One list of what HotPDF covers: forms, annotations, security and signatures, standards, layers, graphics, images, text, large files and stream output

Core Component

Create documents, configure output, manage metadata, protect files, and finalize generated PDFs

Advanced Workflows

Review loaded-document resolution, direct-file handling, xref-stream parsing, conformance output, and shaping helper workflows

Loaded Document Toolkit

Edit, merge, inspect, compare, sign, search, print, display, and recover existing PDFs through loaded-document APIs with structural object-graph diffs, aligned page changes, perceptual rendered metrics and heatmaps, multi-widget form editing, complete annotation editing, automatic bare-link activation, and cache-aware VCL viewing

Advanced AcroForm Processing

Evaluate bounded typed calculation and validation expressions with conditional, string, date, and array operations, regenerate variable-text appearances, resolve annotation states, and flatten selected fields under signature policies

Bounded JavaScript Runtime

Run application-controlled JavaScript through static or bridge-DLL QuickJS deployments on Win32 and Win64 with strict resource budgets and stable diagnostics

Interactive Document Processing

Inspect and sanitize RichMedia assets, run dynamic XFA widgets without flattening, query and edit lossless XFA packet DOMs, evaluate bounded form scripts, and round-trip every supported XFDF annotation subtype

E-Invoice Business Rules

Validate Factur-X and ZUGFeRD containers plus every profile-specific Schematron check with reviewed XPath 2 compatibility and fail-closed diagnostics

Signing, Accessibility, and Portfolios

Validate signatures and evidence, deeply inspect and transactionally normalize safe PDF/A-4 structures, validate actual painted color, overprint and transparency for PDF/X-6 with versioned rules and bounded content work, generate PDF/UA structure from layout trees, diagnose document, annotation, form, navigation, and tagged semantics for PDF/UA-2, export shared machine-readable compliance findings, and build metadata-rich PDF Portfolios

Font Fallback and Vertical Text

Resolve Unicode scalars through script-specific font chains, inspect actionable missing-glyph diagnostics, and emit CJK text with Identity-V and OpenType vertical metrics

Variable and Color OpenType Fonts

Inspect axes, instantiate and subset CFF2 variation outlines and metrics, and render supported color-glyph formats

Advanced Text and Streaming Layout

Compose Unicode paragraphs with language-aware breaking and bounded shaping caches, then build styled document sections, reusable components, lists, images, tables, bounded page continuations, and automatic logical structure

Progressive Rendering and Cancellation

Render large loaded pages in bounded slices, publish progressive JPEG scans for earlier previews, cancel long operations through one caller-owned token, and record or replay external decisions for repeatable diagnosis

Searchable OCR Text Layers

Connect any synchronous OCR engine to bounded high-resolution page rendering, validate word geometry and Unicode, align invisible text across rotated scans, and publish all selected pages atomically

Loaded-Page Barcode Decoding

Decode full loaded pages or bounded PDF-space regions through application-selected engines, fall back across quarter turns, and receive validated payloads, confidence, orientation, and page-space bounds

Review-First Redaction Detection

Detect bounded PII, named entities, and faces as confidence-scored page-space findings, require explicit reviewer identity before atomic annotation staging, and keep burn-in as a separate decision

Loaded-Page Color Rewrite

Convert selected pages to Gray, RGB, or CMYK, preserve ordinary text and paths as vectors, flatten complex color-managed paint losslessly, and make every spot-plate decision explicit

Structured Loaded-Page Export

Export one accessible reading model as HTML, XHTML, XML, or JSON with tagged order, navigation, page labels, annotations, forms, tables, styles, coordinates, and bounded embedded images

Typed Table Extraction

Merge table fragments across pages, retain repeated headers and merged-cell spans, infer typed values with confidence, and export bounded CSV or JSON

Optional Document Handlers

Recognize XPS, EPUB, and CBZ by inspected content, preserve native XPS paths, gradients, cached package ImageBrush fills, Path opacity masks, isolated Canvas transparency groups and Canvas opacity masks, reusable VisualBrush Forms and patterns, transformed Canvas clips, package fonts, exact glyph IDs, clusters, advances, offsets, RTL origins, Unicode extraction, inherited Canvas navigation with descendant overrides, and clipped external or package-relative links, convert through shared archive and resource budgets, and reuse one immutable PDF cache for output and rendering

Rendering Diagnostics and Telemetry

Cache rendered pages by effective viewer state, report unsupported content, and inspect wall time, CPU, allocations, memory, I/O, cache activity, and decode expansion

Pluggable Render Backends

Run compiled display lists through native or custom rendering engines with explicit capabilities, deterministic fallback, bounded parallel dispatch, and observable execution statistics

Advanced Rendering Semantics

Render isolated and knockout transparency groups, luminosity soft masks, complete Type 3 glyph procedures, reduced-DCT JPEG targets, immutable zero-copy decoded-image handles, and budget-aware parallel JPEG 2000 regions

Bounded JBIG2 Segment Graphs

Validate image and global segment dependencies, page associations, dictionary symbol counts, and allocation budgets before native or external decoding

Display Lists and Print Production

Reuse operator-indexed compiled page commands through one production interpreter, stream tiles and bands, render pages in parallel, flatten transparency without discarding spot colors, inspect ink and trapping, and produce process or spot plates

Resource and Image Optimization

Share repeated content, subset loaded fonts by glyph reachability, remove unused resources, preserve calibrated and spot-color semantics during image optimization, and pack indirect objects under explicit size and locality budgets

Object Graph Editing and Page Assembly

Round-trip versioned object graph snapshots and incremental updates, patch stable graphs, inspect dependency paths and retained-memory dominators, validate linearization, request reproducible output, assemble bounded source sets, compose page ranges, flatten rotation, and manage thumbnails

Copy-on-Write Graph Transactions

Wrap object graph edits in nested savepoints, snapshot only touched indirect roots, spill large stream history to temporary storage, and inspect memory costs

Forms, Containers, and Integration Surfaces

Edit forms transactionally, validate attachments, organize Portfolios, integrate through a versioned zero-copy C ABI, compare named engines through deterministic probes, and continuously minimize malformed-PDF corpus cases

Cross-Reference Recovery

Validate free lists, generation transitions, duplicate definitions, and shadowed revision offsets, then relocate or rebuild damaged xref data under bounded limits with byte-ranged confidence events

Editable Diagnostic Documents

Hand-edit deterministic QDF diagnostic objects or uncompressed streams, then measure stream payloads, rebuild classic xref rows and trailers, reject unsafe structure, and publish only a strictly reloadable PDF

Linearized Output

Write dependency-ordered PDFs with first-page and shared-object hint tables for fast display over byte-range transports

Bounded Stream Processing

Decode strict built-in or application-defined push and pull filters through shared budgets and memory-to-disk spill buffers, isolate custom failures, select high-ratio Flate output through a deterministic zlib baseline and budgeted Zopfli block splitting, run bounded parallel image jobs, and rewrite only when output shrinks

Lossless Content Editing

Parse every content-stream byte into compact lexemes and linked syntax nodes, apply non-overlapping overlays, and serialize untouched ranges without normalization

Scalable Random-Access Loading

Read source-file windows, scan simple objects through immutable spans, bound hostile tokens and containers, retain large page trees as compact placeholders, expose linearized first-page readiness from disjoint HTTP ranges, resolve page objects through indexed random access, and reload decoded object streams through a byte-capped LRU cache

Statistical Performance Regression Gates

Benchmark native Win32 and Win64 load, save, render, and extraction workloads with warmup, raw samples, tail latency, RSS, process I/O, deterministic fixtures, and machine-readable thresholds

Cache Infrastructure

Use bounded weighted object caching, streaming SHA-256 keys, persistent font-subset reuse, and a recoverable rendered-page cache with immediate LRU limit enforcement

Signature Permissions

Verify RSA, RSA-PSS, NIST and Brainpool ECDSA, Ed25519, Ed448, extension-gated ML-DSA, and RFC 3161 signatures, sign directly from RSA, ECDSA, Ed25519, or Ed448 PFX identities, create deterministic CMS containers with independent primary signers, generate and pin PAdES E-EPES signature policies, preflight cumulative PAdES profiles with clause, object, and revision evidence, use callback, CSC remote, Windows CNG, or PKCS#11 signing providers, auto-size CMS placeholders without irreversible estimator calls, and inspect DocMDP and FieldMDP structures

ICC Color Management

Validate and register ICC v2/v4 profiles, render ICCBased vector and image colors through proof and output profiles, honor all PDF rendering intents, apply black-point compensation, and reuse complete transforms through a bounded concurrent cache

Capability Map

Explore the HotPDF overview for forms, annotations, secure signatures, conformance, layers, graphics, images, text, large files, and stream output capabilities

Page Drawing

Draw text, paths, curves, images, metafiles, annotations, and barcode output on the active page

Barcode APIs

Review THPDFBarcode, barcode option enums, simple bar records, and Simple* encoder functions

Images

Review supported bitmap, TIFF, JPEG2000, JBIG2, EMF, and WMF workflows

Compression

Understand FlateDecode, LZW, JBIG2, JPEG, JPEG2000, and bundled native compression paths

Preflight

Generate deterministic XML MRR, extend validation with bounded feature and rule plugins, apply profiles, aggregate batch runs, and review diagnostics

Validation Policies and WTPDF

Apply reusable intake policies, read WTPDF declarations, run bounded validation jobs, and repair metadata independently

Viewer Preferences

Control initial display, print preferences, single-page, column, and two-page cover-spread layouts, page mode, and related PDF viewer settings

Pascal Examples

Open runnable examples for document creation, drawing, encryption, font embedding, paragraphs, and outlines