Struct RngCaptcha

pub struct RngCaptcha<T> { /* private fields */ }

A CAPTCHA.

Implementations

impl<T: Rng + RngCore> RngCaptcha<T>

pub fn from_rng(rng: T) -> RngCaptcha<T>

pub fn new() -> Captcha

Returns an empty CAPTCHA.

pub fn apply_filter<F: Filter>(&mut self, f: F) -> &mut Self

Applies the filter f to the CAPTCHA.

This method is used to add noise, grids, etc or to transform the shape of the CAPTCHA.

pub fn set_font<F: Font + 'static>(&mut self, f: F) -> &mut Self

Sets another font that is used for the characters.

Calling this method does not have an effect on the font of the characters which have already been added to the CAPTCHA. The new font is only applied to the characters which are written to the CAPTCHA after this method is called.

If characters have been set via set_chars(), this method will overwrite the setting.

pub fn set_color(&mut self, color: [u8; 3]) -> &mut Self

pub fn save(&self, p: &Path) -> Result<()>

Saves the CAPTCHA to a image file.

The format that is written is determined from the filename’s extension. On error Err is returned.

pub fn set_chars(&mut self, c: &[char]) -> &mut Self

Sets the characters that should be used when generating a CAPTCHA.

Important: The characters have to exist for the current font. You can get all characters which are supported by the current font by calling supported_chars().

pub fn add_char(&mut self) -> &mut Self

Adds a random character using the current font.

pub fn add_text_area(&mut self) -> &mut Self

Adds a red box to the CAPTCHA representing the area which contains text.

pub fn text_area(&self) -> Geometry

Returns the geometry of the area which contains text in the CAPTCHA.

pub fn extract(&mut self, area: Geometry) -> &mut Self

Crops the CAPTCHA to the given geometry.

pub fn view(&mut self, w: u32, h: u32) -> &mut Self

Crops the CAPTCHA to the given width and height with the text centered withing this box.

pub fn chars(&self) -> Vec<char>

Returns the characters that have been added to this CAPTCHA.

pub fn chars_as_string(&self) -> String

Returns the characters that have been added to this CAPTCHA collected into a string.

pub fn add_chars(&mut self, n: u32) -> &mut Self

Adds the given number of random characters to the CAPTCHA using the current font.

pub fn as_wav(&self) -> Vec<Option<Vec<u8>>>

Returns for each letter in the CAPTCHA an audio in WAV format.

Warning: Currently this feature is rather limited. The same audio data is returned for the same letter, i.e. no noise is added. Someone could solve the CAPTCHA by simply having the audio for each letter and comparing them with the current challenge.

pub fn as_png(&self) -> Option<Vec<u8>>

Returns the CAPTCHA as a png image.

Returns None on error.

pub fn as_base64(&self) -> Option<String>

pub fn as_tuple(&self) -> Option<(String, Vec<u8>)>

Returns a tuple which contains the characters that have been added to this CAPTCHA as a string and the image encoded as a PNG.

Returns None on error.

pub fn supported_chars(&self) -> Vec<char>

Returns the supported characters of the current font.