Format Configs

Every document opens with a BaseConfig implementation. Pass one to OpenDocumentAsync or let the format catalog create its default. All classes below live in the Doconut namespace.

var token = await viewer.OpenDocumentAsync(path, new PdfConfig
{
    AllowSearch = true,
    AllowCopy   = true,
    ImageResolution = 150
});

Inheritance and nested PDF settings

Every format inherits the five BaseConfig properties. Formats that can redirect through PDF expose a nested PdfConfig. In WordConfig, ExcelConfig, and PptConfig, AllowSearch and AllowCopy are convenience properties that read and write the nested PdfConfig.

DefaultRender = true selects the native format renderer. On formats with a PDF redirect, false converts to an in-memory PDF first and then uses the PDF viewer. That path is often useful for text-coordinate search, but costs an extra conversion.

Unless stated otherwise, the tables show constructor/property defaults. The automatic format catalog deliberately overrides two of them: it creates ExcelConfig with SplitWorksheets = true, and MhtConfig with DefaultRender = false.

BaseConfig

PdfConfig

Formats: PDF. Default DPI: 200.

showHyperlinks in ViewerConfig controls the client overlay, while ExtractHyperlinks controls server extraction. Enable both.

WordConfig

Formats: DOC, DOCX, DOCM, DOT, DOTX, DOTM, RTF, ODT, OTT, XML. Default DPI: 200.

ExcelConfig

Formats: XLS, XLSX, XLSM, XLSB, XLTX, XLTM, ODS, CSV. Default DPI: 200.

CustomStyleCell exposes CustomStyleDateTime, CustomStyleNumberDecimal, and CustomStyleNumberInteger, all nullable strings.

new ExcelConfig() sets SplitWorksheets to false; opening an Excel file without an explicit config uses the format catalog, which sets it to true.

PptConfig

Formats: PPT, PPTX, PPTM, PPSX, PPSM, POT, POTX, POTM, ODP. Default DPI: 200.

On Linux and macOS, presentation rendering with the current engine requires libgdiplus and System.Drawing.EnableUnixSupport=true. Install the fonts used by the presentation or provide FontFolders.

CadConfig

Formats: DWG, DXF, DGN. Default DPI: 200.

EmailConfig

Formats: EML, EMLX, MSG. Default DPI: 200.

ImageConfig, TiffConfig, and PsdConfig

ImageConfig covers JPG, JPEG, JPE, PNG, BMP, GIF, ICO, EPS, TGA, WEBP, CDR, CMX, DNG, EMF, WMF, AVIF, and SVG. Its default DPI is 100.

DicomConfig

Formats: DCM, IMA. Default effective DPI: 100. Requires the DICOM plugin.

TxtConfig

Format: TXT. Default DPI: 200.

Use WordConfig when plain text needs richer page-layout behavior.

ProjectConfig

Formats: MPP, MPPX, MPX. Default DPI: 200.

For exact text-coordinate search, use DefaultRender = false.

VisioConfig

Formats: VSD, VSDX, VSS, VSSX, VST, VSTX, VDX, VSX, VSDM. Default DPI: 200.

HtmlConfig, EpubConfig, MhtConfig, and XpsConfig

All four default to 200 DPI and expose a nested PdfConfig.

Configuration examples by family

BaseConfig[] configs =
[
    new PdfConfig
    {
        AllowSearch = true,
        ExtractHyperlinks = true,
        HyperlinksPageCount = 0
    },
    new WordConfig
    {
        PaperSize = DocPaperSize.A4,
        RemovePaperMargin = false,
        FontFolders = ["/usr/share/fonts/truetype"],
        AllowSearch = true
    },
    new ExcelConfig
    {
        PaperLandscape = true,
        AutoFitContents = true,
        CalculateFormula = true,
        SplitWorksheets = false,
        PrintGridlines = false
    },
    new PptConfig
    {
        FastLoad = true,
        FontFolders = ["/usr/share/fonts/truetype"],
        AllowSearch = true
    },
    new CadConfig
    {
        ShowColor = true,
        WhiteBackground = true,
        ShowModel = true,
        ShowLayouts = false,
        QualityText = CadConfig.RenderQuality.High
    },
    new EmailConfig
    {
        SkipExternalImages = true,
        RemoveLastWhitePage = true,
        TimeZoneOffset = TimeSpan.Zero
    },
    new ImageConfig
    {
        MaxImagePixelSize = 3000,
        TransparentPng = true
    },
    new DicomConfig
    {
        DisplayMode = DicomDisplayMode.AnimationAndFrames,
        AnimationFrameDelayMs = 100,
        LoopCount = 0
    }
];

Per-extension selection

static BaseConfig? ConfigForExtension(string extUpper) => extUpper switch
{
    ".DOC" or ".DOCX" or ".DOT" or ".DOTX" or ".ODT" => new WordConfig
    {
        AutoFitAllTables = WordConfig.TableAutoFitBehavior.AutoFitToWindow,
        PaperSize = DocPaperSize.Tabloid,
        PdfConfig = new PdfConfig { ExtractHyperlinks = true, HyperlinksPageCount = 5, AllowCopy = true }
    },
    ".PDF" => new PdfConfig { AllowSearch = true, AllowCopy = true },
    ".XLS" or ".XLSX" or ".ODS" or ".CSV" => new ExcelConfig { AllowSearch = true, AllowCopy = true },
    ".DCM" or ".IMA" => new DicomConfig { DisplayMode = DicomDisplayMode.AnimationAndFrames },
    // DefaultRender = false → PDF redirect → pixel-accurate native text search
    ".HTML" or ".HTM" => new HtmlConfig { DefaultRender = false },
    ".EML" or ".EMLX" or ".MSG" => new EmailConfig { DefaultRender = false },
    _ => null // fall back to the format's default config
};