Struct QrCode 

pub struct QrCode { /* private fields */ }

The encoded QR code symbol.

Implementations

impl QrCode

pub fn new<D: AsRef<[u8]>>(data: D) -> QrResult<Self>

Constructs a new QR code which automatically encodes the given data.

This method uses the “medium” error correction level and automatically chooses the smallest QR code.

use qrcode_rs::QrCode;

let code = QrCode::new(b"Some data").unwrap();

Errors

Returns error if the QR code cannot be constructed, e.g. when the data is too long.

pub fn with_error_correction_level<D: AsRef<[u8]>>( data: D, ec_level: EcLevel, ) -> QrResult<Self>

Constructs a new QR code which automatically encodes the given data at a specific error correction level.

This method automatically chooses the smallest QR code.

use qrcode_rs::{QrCode, EcLevel};

let code = QrCode::with_error_correction_level(b"Some data", EcLevel::H).unwrap();

Errors

Returns error if the QR code cannot be constructed, e.g. when the data is too long.

pub fn new_micro<D: AsRef<[u8]>>(data: D) -> QrResult<Self>

Constructs a new Micro QR code which automatically encodes the given data.

This method uses the “medium” error correction level and automatically chooses the smallest Micro QR code.

use qrcode_rs::QrCode;

let code = QrCode::new_micro(b"123").unwrap();

Errors

Returns error if the data cannot be encoded as a Micro QR code, e.g. when the data is too long.

pub fn micro_with_error_correction_level<D: AsRef<[u8]>>( data: D, ec_level: EcLevel, ) -> QrResult<Self>

Constructs a new Micro QR code which automatically encodes the given data at a specific error correction level.

This method automatically chooses the smallest Micro QR code.

use qrcode_rs::{QrCode, EcLevel};

let code = QrCode::micro_with_error_correction_level(b"123", EcLevel::L).unwrap();

Errors

Returns error if the data cannot be encoded as a Micro QR code, e.g. when the data is too long, or when the error correction level is not supported by any Micro QR version.

pub fn with_version<D: AsRef<[u8]>>( data: D, version: Version, ec_level: EcLevel, ) -> QrResult<Self>

Constructs a new QR code for the given version and error correction level.

use qrcode_rs::{QrCode, Version, EcLevel};

let code = QrCode::with_version(b"Some data", Version::Normal(5), EcLevel::M).unwrap();

This method can also be used to generate Micro QR code.

use qrcode_rs::{QrCode, Version, EcLevel};

let micro_code = QrCode::with_version(b"123", Version::Micro(1), EcLevel::L).unwrap();

Errors

Returns error if the QR code cannot be constructed, e.g. when the data is too long, or when the version and error correction level are incompatible.

pub fn with_bits(bits: Bits, ec_level: EcLevel) -> QrResult<Self>

Constructs a new QR code with encoded bits.

Use this method only if there are very special need to manipulate the raw bits before encoding. Some examples are:

• Encode data using specific character set with ECI
• Use the FNC1 modes
• Avoid the optimal segmentation algorithm

See the Bits structure for detail.

#![allow(unused_must_use)]

use qrcode_rs::{QrCode, Version, EcLevel};
use qrcode_rs::bits::Bits;

let mut bits = Bits::new(Version::Normal(1));
bits.push_eci_designator(9);
bits.push_byte_data(b"\xca\xfe\xe4\xe9\xea\xe1\xf2 QR");
bits.push_terminator(EcLevel::L);
let qrcode = QrCode::with_bits(bits, EcLevel::L);

Errors

Returns error if the QR code cannot be constructed, e.g. when the bits are too long, or when the version and error correction level are incompatible.

pub const fn version(&self) -> Version

Gets the version of this QR code.

pub const fn error_correction_level(&self) -> EcLevel

Gets the error correction level of this QR code.

pub const fn width(&self) -> usize

Gets the number of modules per side, i.e. the width of this QR code.

The width here does not contain the quiet zone paddings.

pub fn max_allowed_errors(&self) -> usize

Gets the maximum number of allowed erratic modules can be introduced before the data becomes corrupted. Note that errors should not be introduced to functional modules.

pub fn info(&self) -> Info

Returns metadata about this QR code (version, error-correction level, dimensions, module count, error tolerance, and data capacity).

Examples

use qrcode_rs::QrCode;

let code = QrCode::new(b"hello").unwrap();
let info = code.info();
assert_eq!(info.width(), code.width());
assert_eq!(info.module_count(), code.width() * code.width());
assert!(info.data_capacity_bytes() > 0);

pub fn is_functional(&self, x: usize, y: usize) -> bool

Checks whether a module at coordinate (x, y) is a functional module or not.

pub fn to_debug_str(&self, on_char: char, off_char: char) -> String

Converts the QR code into a human-readable string. This is mainly for debugging only.

pub fn to_colors(&self) -> Vec<Color>

Converts the QR code to a vector of colors.

pub fn into_colors(self) -> Vec<Color>

Converts the QR code to a vector of colors.

pub fn render<P: Pixel>(&self) -> Renderer<'_, P>

Renders the QR code into an image. The result is an image builder, which you may do some additional configuration before copying it into a concrete image. Note: theimage crate itself also provides method to rotate the image, or overlay a logo on top of the QR code.

Examples

let image = QrCode::new(b"hello").unwrap()
                   .render()
                   .dark_color(Rgb([0, 0, 128]))
                   .light_color(Rgb([224, 224, 224])) // adjust colors
                   .quiet_zone(false)          // disable quiet zone (white border)
                   .min_dimensions(300, 300)   // sets minimum image size
                   .build();

impl QrCode

pub fn builder<D: AsRef<[u8]>>(data: D) -> QrCodeBuilder<D>

Creates a QrCodeBuilder for configuring and constructing a QR code.

This is an ergonomic alternative to the with_* constructors. The builder uses the same encoding paths, so its output is identical to the equivalent constructor.

Examples

use qrcode_rs::{QrCode, EcLevel};

let code = QrCode::builder(b"https://example.com")
    .ec_level(EcLevel::H)
    .build()
    .unwrap();

pub fn rows(&self) -> Rows<'_>

Returns an iterator yielding one Row of modules at a time.

Each row iterates over the module Colors from left to right. The quiet zone is not included.

Examples

use qrcode_rs::QrCode;

let code = QrCode::new(b"hi").unwrap();
for row in code.rows() {
    for color in row {
    }
}

pub fn dark_modules(&self) -> DarkModules<'_>

Returns an iterator over the (x, y) coordinates of every dark module, convenient for custom rendering. The quiet zone is not included.

Examples

use qrcode_rs::QrCode;

let code = QrCode::new(b"hi").unwrap();
let dark_count = code.dark_modules().count();

pub fn for_url<D: AsRef<[u8]>>(url: D) -> QrResult<Self>

Encodes a URL, using high error correction (robust to print damage).

Errors

Returns an error only if the URL is too long to encode.

pub fn for_text<D: AsRef<[u8]>>(text: D) -> QrResult<Self>

Encodes plain text at the default (medium) error correction level.

Errors

Returns an error only if the text is too long to encode.

pub fn for_wifi(ssid: &str, password: &str, auth: &str) -> QrResult<Self>

Encodes a WiFi configuration that most phone cameras will offer to join.

auth is one of WPA, WEP or nopass. Special characters in the SSID/password are backslash-escaped per the WiFi QR specification.

Errors

Returns an error if the resulting payload is too long to encode.

Examples

use qrcode_rs::QrCode;

let code = QrCode::for_wifi("MyNetwork", "p\\a;ss", "WPA").unwrap();

pub fn for_vcard(name: &str, phone: &str, email: &str) -> QrResult<Self>

Encodes a minimal vCard 3.0 contact card.

Errors

Returns an error if the resulting payload is too long to encode.

Examples

use qrcode_rs::QrCode;

let code = QrCode::for_vcard("John Doe", "+1234567890", "john@example.com").unwrap();

pub fn for_gs1<D: AsRef<[u8]>>(data: D) -> QrResult<Self>

Encodes a GS1 data carrier (FNC1 in first position), e.g. a GTIN / application-identifier payload such as "010491234512345915970331301234561842". Uses medium error correction and the smallest fitting version.

Errors

Returns an error if the data is too long to encode.

Examples

use qrcode_rs::QrCode;

let code = QrCode::for_gs1("010491234512345915970331301234561842").unwrap();

pub fn alt_text<D: AsRef<[u8]>>(data: D) -> String

Generates accessible alt text describing a QR code that encodes data.

URLs are described as “linking to …”; other payloads as “containing: …”. Use the result as the alt of an <img> or the aria-label of an inline SVG so assistive technology can describe the code without decoding it.

This is an associated function (it does not require a constructed QrCode), so the input data does not need to be retained on the code.

Examples

use qrcode_rs::QrCode;

assert_eq!(QrCode::alt_text("https://example.com"), "QR code linking to https://example.com");
assert_eq!(QrCode::alt_text("hello"), "QR code containing: hello");

pub fn alt_text_custom<D: AsRef<[u8]>, F: FnOnce(&[u8]) -> String>( data: D, f: F, ) -> String

Generates alt text with a custom formatter that receives the raw bytes.

Examples

use qrcode_rs::QrCode;

let alt = QrCode::alt_text_custom("hello", |data| {
    format!("A QR code with {} bytes", data.len())
});
assert_eq!(alt, "A QR code with 5 bytes");

Trait Implementations

impl Clone for QrCode

fn clone(&self) -> QrCode

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Index<(usize, usize)> for QrCode

type Output = Color

The returned type after indexing.

fn index(&self, (x, y): (usize, usize)) -> &Color

Performs the indexing (container[index]) operation.