Struct TokenUrEncoder 

pub struct TokenUrEncoder { /* private fields */ }

Encodes a Token into UR fragments for display as an animated QR code

Each call to next_part returns one fragment (ur:bytes/…) to be displayed as a single QR frame. The first fragment_count frames cover the whole token; the stream is unbounded and frames beyond that are redundant fountain parts, so a receiver can complete from any sufficiently large subset of frames. The sender typically loops the frames until the receiver signals completion.

If the token fits into a single frame, the single-part form (ur:bytes/<payload>, without fragment indices) is returned, matching the reference implementations.

V3 tokens are normalized to V4 before serialization, so the encoded token payload always uses the cashuB… format.

Implementations

impl TokenUrEncoder

pub fn new( token: &Token, max_fragment_length: usize, ) -> Result<TokenUrEncoder, Error>

Creates a new encoder for token

max_fragment_length is the maximum number of payload bytes per QR frame; DEFAULT_MAX_FRAGMENT_LENGTH is a sane default.

Errors

Returns an error if max_fragment_length is zero or the token cannot be converted to V4 or serialized.

pub fn next_part(&mut self) -> Result<String, Error>

Returns the next UR fragment to display as a QR frame

Errors

Returns an error if the fragment cannot be encoded.

pub fn current_index(&self) -> usize

Returns the number of fragments emitted so far

pub fn fragment_count(&self) -> usize

Returns the number of fragments the token was split into

pub fn is_single_fragment(&self) -> bool

Returns whether the token fits into a single QR frame

Trait Implementations

impl Debug for TokenUrEncoder

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.