iconwriter 2.0.1

A simple solution for encoding common icon file formats.
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106

//! Structs for encoding `.ico` files.

extern crate ico;

use crate::{AsSize, IconError, Icon, Image};
use image::DynamicImage;
use std::{
    convert::TryFrom,
    fmt::{self, Debug, Formatter},
    io::{self, Write},
    result,
};

/// An ecoder for the `.ico` file format.
#[derive(Clone)]
pub struct Ico {
    icon_dir: ico::IconDir,
    keys: Vec<u32>,
}

/// The _key-type_ for `Ico`. Note that `Key(0)` represents
/// a _256x256_ entry.
#[derive(Copy, Clone, Debug, PartialEq, Eq, Hash)]
pub struct Key(pub u8);

impl Icon for Ico {
    type Key = Key;

    fn with_capacity(capacity: usize) -> Self {
        Ico {
            icon_dir: ico::IconDir::new(ico::ResourceType::Icon),
            keys: Vec::with_capacity(capacity),
        }
    }

    fn len(&self) -> usize {
        self.icon_dir.entries().len()
    }

    fn add_entry<F: FnMut(&DynamicImage, u32) -> io::Result<DynamicImage>>(
        &mut self,
        filter: F,
        source: &Image,
        key: Self::Key,
    ) -> Result<(), IconError<Self::Key>> {
        let size = key.as_size();

        if self.keys.contains(&size) {
            return Err(IconError::AlreadyIncluded(key));
        }

        let icon = source.rasterize(filter, size)?;
        let data = icon.to_rgba().into_vec();
        let image = ico::IconImage::from_rgba_data(size, size, data);

        let entry = ico::IconDirEntry::encode(&image)?;
        self.icon_dir.add_entry(entry);

        Ok(())
    }

    fn write<W: Write>(&mut self, w: &mut W) -> io::Result<()> {
        self.icon_dir.write(w)
    }
}

impl Debug for Ico {
    fn fmt(&self, f: &mut Formatter) -> result::Result<(), fmt::Error> {
        let n_entries = self.icon_dir.entries().len();
        let mut entries_str = String::with_capacity(42 * n_entries);

        for _ in 0..n_entries {
            entries_str.push_str("ico::IconDirEntry {{ /* fields omitted */ }}, ");
        }

        let icon_dir = format!(
            "ico::IconDir {{ restype: ico::ResourceType::Icon, entries: [{:?}] }}",
            entries_str
        );

        write!(f, "iconwriter::Ico {{ icon_dir: {} }} ", icon_dir)
    }
}

impl AsSize for Key {
    fn as_size(&self) -> u32 {
        if self.0 == 0 {
            256
        } else {
            self.0 as u32
        }
    }
}

impl TryFrom<u32> for Key {
    type Error = io::Error;

    fn try_from(val: u32) -> io::Result<Self> {
        match val {
            256 => Ok(Key(0)),
            0 => Err(io::Error::from(io::ErrorKind::InvalidInput)),
            n if n < 256 => Ok(Key(n as u8)),
            _ => Err(io::Error::from(io::ErrorKind::InvalidInput))
        }
    }
}