IconWriter

A simple solution for encoding common icon file-formats, such as .ico, .icns and favicon.

This crate is mostly a wrapper for other libraries, unifying existing APIs into a single, cohesive interface.

Overview

An icon consists of a map between entries and images. An entry is simply the key type of an icon.

IconWriter simply automates the process of re-scaling images, creating entries and combining them into an icon.

Keys

Each icon format is associated with a particular key type, which determines how entries are labeled. Each key can only be associated with a single image.

For example, icon formats that only differentiate entries by the dimensions of their associated images are labeled by positive integers, such as the .ico and .icns file-formats.

On the other hand, icon formats that distinguish their entries by path, such as png sequeces and FreeDesktop icon themes , are labeled by path.

Note that, since the dimensions of the images contained in an entry are dictated by their associated entries, every key must be convertible to a positive integers. Therefore, all key types are required to implement AsRef<u32>.

Resampling

Pictures are scaled using resampling filters, which are represented by functions that take a source image and a size and return a re-scaled image.

This allows the users of this crate to provide their custom resampling filters. Common resampling filters are provided in the resample module.

Examples

IconWriter simply automates the process of re-scaling pictures and combining them into an icon.

Pictures are scaled using resampling filters, which are represented by functions that take a source image and a size and return a re-scaled image.

Resampling filters are represented by functions that take a source image and a size and return a rescaled raw RGBA buffer. This allows the users of this crate to provide their custom resampling filters. Common resampling filters are provided by the resample module.

Examples

General Usage

The Icon::add_entry can be used to automatically resample source images and converts them to entries in an icon.

use iconwriter::{Ico, Image, Icon, IconError};

fn example() -> Result<(), IconError> {
    let icon = Ico::new();
    let src = Image::open("image.svg")?;
    icon.add_entry(resample::linear, &img, 32)
}

Writing to Disk

Implementors of the Icon trait can be written to any object that implements io::Write with the Icon::write method.

use iconwriter::favicon::Favicon;
use std::{io, fs::File};
 
fn example() -> io::Result<()> {
    let icon = Favicon::new();

    // Process the icon ...

    let file = File::create("out.icns")?;
    icon.write(file)
}

Alternatively, icons can be directly written to a file on disk with Icon::save method.

use iconwriter::favicon::Favicon;
use std::{io, fs::File};
 
fn example() -> io::Result<()> {
    let icon = Favicon::new();

    /* Process the icon */

    icon.save("./output/")
}

Support

Icon Formats

This are the output formats IconWriter nativally supports. Be aware that custum output types can be created using the Icon trait.

• ico
• icns
• favicon

Icns Support

IconWriter uses the icns crate for generating .icns files. The supported icon types are specified by the creators of such crate as follows:

Image Formats

IconWriter uses image for raster graphics manipulations and resvg with the raqote backend for svg rasterization. Note that raqote requires cmake to build.