flxzt/rnote · error

PdfImportPagesType try_from

Error message

PdfImportPagesType try_from::<u32>() for value {} failed

What it means

TryFrom<u32> for PdfImportPagesType converts a raw u32 (typically from stored import preferences or a UI combo-box index) into the enum via num_traits::FromPrimitive. When the value does not match any variant, this error is thrown. It guards against corrupted or out-of-range stored settings.

Solutions

1. Validate the u32 against the known variant range before converting, and fall back to a default (e.g. PdfImportPagesType::default()) on failure
2. Fix the stored preference value in the settings/prefs file to a valid discriminant
3. Migrate preferences when upgrading across versions that changed the enum layout

Example fix

// before
let pages_type = PdfImportPagesType::try_from(raw_u32)?;
// after
let pages_type = PdfImportPagesType::try_from(raw_u32)
    .unwrap_or_default(); // or map to a safe default variant

let pages_type = PdfImportPagesType::try_from(raw_u32)
    .unwrap_or_else(|_| PdfImportPagesType::default());

fn valid_pages_type(v: u32) -> bool {
    PdfImportPagesType::from_u32(v).is_some()
}

match PdfImportPagesType::try_from(raw_u32) {
    Ok(t) => t,
    Err(e) => {
        log::warn!("invalid PdfImportPagesType {}, using default", raw_u32);
        PdfImportPagesType::default()
    }
}

When it happens

Trigger: Calling PdfImportPagesType::try_from(v) with a u32 that is not a valid discriminant of the enum — e.g. a value saved by a newer/older app version with different variants, a corrupted prefs file, or an unchecked index from a GUI.

Common situations: Loading PDF import settings from an old or hand-edited config where the pages-type field holds an out-of-range number; schema changes between rnote versions that renumbered variants.

Understand the failure class

Background: Invalid enum value errors: "Unknown type", "Invalid scope", "must be one of" — when a string is not on the library's allowed list — this error's family across 23 libraries.

Related errors

• PdfImportPageSpacing try_from
• SplitOrder try_from:: () for value failed
• PatternStyle try_from
• PredefinedFormat try_from
• MeasureUnit try_from

AI-assisted analysis of flxzt/rnote@bbc5354502 (2026-09-08). Data as JSON: /api/errors/6d8c3ba51994ff26. Report an issue: GitHub.

Appendix: source

Thrown at crates/rnote-engine/src/engine/import.rs:43

pub enum PdfImportPagesType {
    #[serde(rename = "bitmap")]
    Bitmap = 0,
    #[serde(rename = "vector")]
    Vector,
}

impl Default for PdfImportPagesType {
    fn default() -> Self {
        Self::Vector
    }
}

impl TryFrom<u32> for PdfImportPagesType {
    type Error = anyhow::Error;

    fn try_from(value: u32) -> Result<Self, Self::Error> {
        num_traits::FromPrimitive::from_u32(value).ok_or_else(|| {
            anyhow::anyhow!(
                "PdfImportPagesType try_from::<u32>() for value {} failed",
                value
            )
        })
    }
}

#[derive(
    Debug, Clone, Copy, Serialize, Deserialize, num_derive::FromPrimitive, num_derive::ToPrimitive,
)]
#[serde(rename = "pdf_import_page_spacing")]
pub enum PdfImportPageSpacing {
    #[serde(rename = "continuous")]
    Continuous = 0,
    #[serde(rename = "one_per_document_page")]
    OnePerDocumentPage,
}

View on GitHub (pinned to bbc5354502)