Loaded Document Toolkit

HotPDF can open an existing PDF, apply page and form operations, inspect typed document state, render or search pages, print with device capabilities, and save the result without moving the workflow to another library

Page operations and merging

• THotPDF.DeletePages accepts the standard one-based page-range syntax, removes duplicate selections once, and preserves a valid page tree
• Deleting loaded pages detaches widget annotations and empty AcroForm field branches that belonged only to the deleted pages
• THotPDF.InsertPagesFromDocument and THotPDF.AppendPagesFromDocument accept THPDFMergeOptions
• Form-name conflicts are checked before page insertion when automatic renaming is disabled, so a rejected merge leaves the destination page count unchanged
• THPDFMergeOption values are moIncludeOutlines, moIncludeFormFields, and moRenameConflictingFormFields
• Outline destinations are remapped through the selected source-to-destination page map, while imported form roots are registered in the destination AcroForm
• THotPDF.InsertLoadedBlankPage inserts a caller-sized blank page at an exact zero-based position
• THPDFWatermarkTemplate.MakeCurve adds a cubic Bezier curve to ordered composite loaded-page watermarks
• THPDFPage.AddCurveWatermark provides the same cubic Bezier primitive during new-document authoring
• Loaded document metadata setters mark the Info dictionary dirty so incremental saves retain edited fields
• BeginIncrementalUpdate 让源文件保持写锁与文件承载状态，只用有界的尾部探测，而不是把完整文件驻留内存
• SaveIncrementalUpdate 只访问被跟踪的更改，把源前缀流式写到新目标；对同一目标使用经验证、带回滚保护的直接追加
• OpenLoadedPageContentStream 把单个或数组 /Contents 值暴露为一个可 seek 的逻辑流，未过滤段保留在源承载存储中，一次最多解码一个过滤段
• 编辑 /Contents 为数组的页面会追加新的间接段，不合并也不清除原始流；渲染与兼容物化使用几何增长的 token 与字节缓冲
• 已加载注释 setter 直接在既有注释对象上更新内容、标题、唯一名称、修改日期、矩形、标志、颜色和边框样式
• 注释矩形端点归一化，虚线边框只保留正的划线长度；视觉变化只使受影响页面的缓存渲染失效
• ActivateLoadedLinks 从定位字形 run 中检测裸网址与电子邮件地址，创建无边框 URI 注释，并跳过与既有链接匹配的候选，无需为每个候选重扫注释列表
• ExtractLoadedPagesTextToStream writes UTF-8 page text directly to a caller-owned stream with range, separator, and BOM controls
• THPDFViewerModel exposes page form-field hit testing and deterministic top-to-bottom keyboard navigation without creating a window
• 已加载签名验证支持 RSA PKCS#1 v1.5、参数校验的 RSA-PSS、ECDSA，以及 RFC 3161 文档与签名时间戳；严格的字节区间检查报告已签名修订长度和未签名的尾随字节，同时保留调用方流位置
• THPDFSignatureInfo.CertificateTimeValidity classifies certificate bounds and signed-time consistency without changing cryptographic svValid semantics
• VerifyLoadedSignatureWithTrust 构建到调用方提供信任锚的签名者路径，验证离线 OCSP 或 CRL 证据，优先每签名 VRI 数据，其次文档级 DSS 与调用方证据
• AnalyzeLoadedSignatureRevisions 遍历传统、流式、混合与压缩对象 xref 历史，把后续更改分类为长期验证、表单填写与签名、注释或其他修改，并独立评估 DocMDP 与 FieldMDP
• SanitiseLoadedDocument 对完整对象图应用仅 JavaScript、活跃内容或严格不可信文档策略，移除不可达载荷对象，并准备有界的紧凑重写
• ScrubLoadedRedactionRemnants 在紧凑完整重写前移除元数据、附件、Redact 注释、不可达资源和保留的增量源字节
• 有界交叉引用恢复 在 startxref 与 xref 数据损坏后重新定位完整的 xref 区段或重建经验证的直接对象偏移，带调用方控制的扫描预算和结构化诊断
• 可扩展加载 让文件流体在修改前保持源承载，惰性解析压缩对象，并接受自定义 THPDFRandomAccessSource 实现
• DecodeLoadedStreamToStream 把有界过滤链运行到调用方持有的流；全文档字节核算、过滤器数量限制、间接引用环检查和管线深度防护可抵御恶意输入
• ExtractLoadedImageToStream 把原生图像载荷或通用解码过滤器输出直接拷贝进调用方持有的流，不物化全尺寸字节数组
• ExportLoadedPagesStructured 把语义阅读顺序、表格、几何、样式与有界图像出现序列化为 HTML、XHTML、XML 或 JSON
• ExtractLoadedTypedTables 构建带置信度评分的规范网格，含合并 span、重复表头、跨页延续、类型化值和原子 CSV 或 JSON 导出
• OptimizeLoadedStreams 在未过滤、Flate、LZW、ASCII85、ASCIIHex 与 RunLength 候选间选择，把大工作缓冲溢写到临时文件，可在四策略 zlib 基线后运行带预算的 Zopfli，只采纳达到正节省阈值的替换
• SubsetLoadedFonts 在追踪页面、Form XObject 与注释外观内容后，从受支持的嵌入 TrueType 与 CFF 字体移除不可达字形程序，同时保留既有的字符、CID、字形、宽度和 ToUnicode 映射
• SetDocumentAttachmentMetadata renames an embedded file and updates its description before the document is saved
• THPDFLoadedFormField 为属性检查器暴露标志、MaxLen、页索引、边界和常见文本字段行为
• THPDFViewerModel creates caller-owned page snapshots and writes the current page directly as BMP while reusing the loaded render cache
• THPDFViewerModel rotates the current view and generated snapshots in 90-degree steps without modifying the loaded PDF page
• THPDFViewerModel 创建旋转感知的增强图元文件，同时保留可缩放的文本与矢量绘图记录
• THPDFViewer.DrawCurrentView 与 PrintCurrentView 把活动矢量视图适配并居中到调用方 canvas 或打印机页面
• THPDFViewerModel.ProcessKeyInput 提供可测试的页面与缩放命令，方向键滚动仍由查看器处理
• THPDFViewerModel.ProcessMouseWheel 提供可测试的 Ctrl+滚轮缩放，垂直与水平滚动仍由查看器直接处理
• THPDFViewerModel.GetNextZoomLevel 与 GetPreviousZoomLevel 暴露确定性的标准缩放导航，范围 5% 到 6400%
• THPDFViewerModel.PagePointToView 与 ViewPointToPage 在页面旋转、视图旋转、MediaBox 偏移与 DPI 之间提供可逆坐标
• THPDFViewerModel.CreatePageRegionSnapshot 只渲染请求的 PDF 矩形，为有界内存的选择快照服务
• THPDFViewer.ResetView restores presentation defaults without unloading the document or changing the current page

Forms and search

• THotPDF.AddLoadedRadioButton creates a parent radio field with child widgets, shared export values, and valid on/off appearance states
• GetLoadedFormFieldNameValuePairs 与 SetLoadedFormFieldNameValuePairs通过 TStrings 交换轻量的name=value 批次（经 TStrings
• ExtractLoadedPagesText 聚合从 1 开始的页面范围，并用调用方选择的分隔符连接
• CMapResourcePath overrides automatic CMap discovery with a caller-selected root containing the standard collection folders
• 赋值 CMapResourcePath 会清除已加载字体解码器，即使路径未变；被替换的外部资源需要一并重载时，请先调用 HPDFClearCMapCaches
• 标准 CMap 映射按解析出的资源根缓存，支持并发表访问，字符表与范围表有序时使用对数查找
• 内嵌完整的 UniJIS、UniGB、UniCNS、UniKS 的 UCS2 与 UTF16 映射，覆盖横排与竖排文本，包括补充标量以及 /DW2 缺席时的标准竖排默认值
• 已加载字体解码器使用文档作用域的 32 MiB 加权 LRU 缓存，供文本提取、SVG 导出、文本替换与显式解码器请求共享
• GetLoadedFontDecoder 返回独立深拷贝；内部只读消费者复用缓存的解析核心
• LoadedFontDecoderCacheMaxBytes、GetLoadedFontDecoderCacheInfo 与 ResetLoadedFontDecoderCacheStatistics 控制并度量缓存复用
• 低分辨率灰度与 RGB JPEG 区域使用降采样逆 DCT 和直接扫描行重采样，不物化全分辨率光栅
• GetLastJPEGReducedDecodeInfo 报告最近一次兼容请求的源、缩放、输出、扫描行与工作内存几何
• AcquireLoadedImageStream 与 AcquireLoadedImageRegionAtResolution 返回不可变共享句柄，热命中不拷贝像素；缓存的 TBitmap 方法保留调用方持有的兼容性
• GetImageDecodeConcurrencyInfo 报告活动飞行、并行 owner 解码峰值、重复等待、完成与失败
• THotPDF.SearchLoadedNext is a stateless page-local search primitive that moves forward from a previous THPDFTextMatch
• THPDFLoadedDocumentFacade groups loaded forms, annotations, outlines, fonts, and images into typed collection objects
• THPDFLoadedFormInfo includes the current and default value, field type, description, read-only flag, and choice options

Outlines and resources

• THotPDF.GetLoadedOutlineEntries returns a complete preorder snapshot as THPDFLoadedOutlineEntryArray
• Each THPDFLoadedOutlineEntry has an index, parent index, level, title, and resolved destination page index
• THPDFLoadedOutlineInfo exposes the same hierarchy through THPDFLoadedOutlineCollection
• THPDFLoadedResourceCollection enumerates fonts and loaded images and can extract supported images as caller-owned bitmaps

System certificate signing

• THotPDF.SignPDFWithSystemCertificate 通过 Windows 证书存储私钥对文件或流输入签名
• THotPDF.GetLoadedSignaturePermissions 把 DocMDP、Catalog 权限关联、SigFieldLock 和 FieldMDP 结构读入 THPDFSignaturePermissionInfo，而不把结构性策略当作加密有效性
• THPDFCertificateStoreSelector selects current-user or local-machine scope, store name, SHA-1 thumbprint, and whether key-provider UI is allowed
• THPDFCMSSignDigestCallback and HPDFCMSSignPDFStreamWithExternalSigner provide the underlying external-digest signer hook
• CNG keys use RSA PKCS#1 SHA-256 signing and legacy CSP keys use the equivalent CryptoAPI path

Printing

• THPDFPrintOptions supports collated copies, paper code, custom paper width and length, orientation, duplex, bin, and quality
• THPDFPrinterCapabilities reports parallel paper codes, names, and physical sizes alongside bins, resolutions, duplex, colour, and maximum copies
• HPDFBuildPrintPageSequence exposes the deterministic physical page sequence used for collated and uncollated jobs

VCL viewer components

• THPDFViewerModel owns navigation, zoom state, text-search results, wrapping, and change notifications without creating a window
• THPDFViewer renders the selected page into a scrollable cached bitmap, supports actual size, fit page, fit width, custom zoom, and view rotation, and draws current search hits over the rendered page
• THPDFSearchPanel connects search text, case sensitivity, whole-word matching, and next or previous navigation to a viewer
• THPDFOutlineViewer displays the full recursive bookmark tree, follows document changes from the linked viewer, and navigates the linked viewer
• THPDFViewerAction descendants provide first, prior, next, last, zoom, fit, rotation, reset, find-next, and clear-search actions

Minimal viewer setup

PDF.LoadFromFile('input.pdf');
PDFViewer.PDFDocument := PDF;
OutlineViewer.Viewer := PDFViewer;
SearchPanel.Viewer := PDFViewer;
PDFViewer.ZoomMode := vzmFitWidth;

Ownership and indexing

• Loaded page indexes and destination page indexes are zero-based
• Page-range strings are one-based and use the same parser as extraction and printing
• Facade records are snapshots and collection mutation methods operate on the current loaded document
• Extracted bitmaps are owned by the caller

Related typed inspection and placement records

• THPDFPageElementKind, THPDFPageElement, and THPDFBaselineRole describe text, image, path, and baseline results returned by loaded page-element inspection
• THPDFWatermarkKind, THPDFWatermarkHorizPos, and THPDFWatermarkVertPos select the content and placement of loaded-document watermarks