Layout and PDF

Pipeline

PagedDocument
    → DocumentPaginator.Paginate(document, ITextMeasurer)
    → PagePlan
    → DocumentPdf paint (Skia)

DocumentPdf.Write / ToBytes call pagination with the same Skia measurer used for painting, so wrap heights match ink.

DocumentPaginator

using Novolis.Documents.Layout;

PagePlan plan = DocumentPaginator.Paginate(document, measurer);

Responsibilities

• Emit First / Toc / Body / Last page slices when configured
• Measure and place blocks in a single content column
• Split overflow across body pages
• Apply H1 / Chapter page breaks
• Resolve header/footer visibility from include flags
• Track ChapterTitle for body pages
• Build TocEntries with resolved page numbers when IncludeToc is set

ITextMeasurer

Layout never references Skia. Tests can fake:

public interface ITextMeasurer
{
    float MeasureHeight(string text, float widthPt, TextStyle style);
    IReadOnlyList<string> WrapLines(string text, float widthPt, TextStyle style);
}

Novolis.Documents.Skia supplies SkiaTextMeasurer (internal to the PDF path; use DocumentPdf.Layout for a plan with real fonts).

PagePlan

PageSlice fields of interest:

• Number — 1-based
• ShowHeader / ShowFooter — resolved for that kind
• ChapterTitle — for chapter-style headers
• Blocks — empty on First (cover is painted from Meta/First, not placed blocks)

DocumentPdf

using Novolis.Documents.Skia;

DocumentPdf.Write(document, @"C:\Users\frank\.novolis\artifacts\out.pdf");
byte[] bytes = DocumentPdf.ToBytes(document);
PagePlan plan = DocumentPdf.Layout(document);

Options

var options = new DocumentPdfOptions
{
    BodyFontPath = @"C:\fonts\MySerif.ttf",
    BoldFontPath = @"C:\fonts\MySerif-Bold.ttf",
};
DocumentPdf.Write(document, path, options);

Default: embedded Latin-subset Liberation Serif (OFL) for compact PDFs. Override paths when you need full Unicode or a house face.

Paint order (per page)

1. Clear white
2. Watermark (if included for that kind)
3. Cover art / placed blocks
4. Header band text
5. Footer band text

What Skia paints that Layout does not invent

• Actual glyphs, table rules, header background fills
• SVG/raster images (ImageBlock)
• Scene-break ornament
• Diagonal watermark

Layout still owns geometry: where blocks sit and which pages exist.

Content box

┌──────────────── trim ────────────────┐
│  margin.top                          │
│  ┌──── header band ────┐             │
│  │                     │             │
│  ├──── content box ────┤             │
│  │  placed blocks      │             │
│  ├──── footer band ────┤             │
│  │                     │             │
│  margin.bottom                       │
└──────────────────────────────────────┘

Content width = Trim.Width − Margin.Horizontal. Content height = Trim.Height − Margin.Vertical − HeaderBand − FooterBand.

Performance notes

• Prefer the embedded subset for short invoices/samples.
• Large images dominate file size — keep logos small.
• Tables with many rows paginate; headers can repeat via RepeatHeaderOnPageBreak.