librsvg 2.62.2

A library to render SVG images to Cairo surfaces. GNOME uses this to render SVG icons. Outside of GNOME, other desktop environments use it for similar purposes. Wikimedia uses it for Wikipedia's SVG diagrams.
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

//! Parser for the `viewBox` attribute.

use cssparser::Parser;
use std::ops::Deref;

use crate::error::*;
use crate::parsers::{CommaSeparatedList, Parse};
use crate::rect::Rect;

/// Newtype around a [`Rect`], used to represent the `viewBox` attribute.
///
/// A `ViewBox` is a new user-space coordinate system mapped onto the rectangle defined by
/// the current viewport.  See <https://www.w3.org/TR/SVG2/coords.html#ViewBoxAttribute>
///
/// `ViewBox` derefs to [`Rect`], so you can use [`Rect`]'s methods and fields directly like
/// `vbox.x0` or `vbox.width()`.
#[derive(Debug, Copy, Clone, PartialEq)]
pub struct ViewBox(Rect);

impl Deref for ViewBox {
    type Target = Rect;

    fn deref(&self) -> &Rect {
        &self.0
    }
}

impl From<Rect> for ViewBox {
    fn from(r: Rect) -> ViewBox {
        ViewBox(r)
    }
}

impl Parse for ViewBox {
    // Parse a viewBox attribute
    // https://www.w3.org/TR/SVG/coords.html#ViewBoxAttribute
    //
    // viewBox: double [,] double [,] double [,] double [,]
    //
    // x, y, w, h
    //
    // Where w and h must be nonnegative.
    fn parse<'i>(parser: &mut Parser<'i, '_>) -> Result<ViewBox, ParseError<'i>> {
        let loc = parser.current_source_location();

        let CommaSeparatedList::<f64, 4, 4>(v) = CommaSeparatedList::parse(parser)?;
        let (x, y, width, height) = (v[0], v[1], v[2], v[3]);

        if width >= 0.0 && height >= 0.0 {
            Ok(ViewBox(Rect::new(x, y, x + width, y + height)))
        } else {
            Err(loc.new_custom_error(ValueErrorKind::value_error(
                "width and height must not be negative",
            )))
        }
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn parses_valid_viewboxes() {
        assert_eq!(
            ViewBox::parse_str("  1 2 3 4").unwrap(),
            ViewBox(Rect::new(1.0, 2.0, 4.0, 6.0))
        );

        assert_eq!(
            ViewBox::parse_str(" -1.5 -2.5e1,34,56e2  ").unwrap(),
            ViewBox(Rect::new(-1.5, -25.0, 32.5, 5575.0))
        );
    }

    #[test]
    fn parsing_invalid_viewboxes_yields_error() {
        assert!(ViewBox::parse_str("").is_err());
        assert!(ViewBox::parse_str(" 1,2,-3,-4 ").is_err());
        assert!(ViewBox::parse_str("qwerasdfzxcv").is_err());
        assert!(ViewBox::parse_str(" 1 2 3 4   5").is_err());
        assert!(ViewBox::parse_str(" 1 2 foo 3 4").is_err());

        // https://gitlab.gnome.org/GNOME/librsvg/issues/344
        assert!(ViewBox::parse_str("0 0 9E80.7").is_err());
    }
}