lewp_css/domain/at_rules/viewport/
viewport_length.rs

1// This file is part of css. It is subject to the license terms in the COPYRIGHT file found in the top-level directory of this distribution and at https://raw.githubusercontent.com/lemonrock/css/master/COPYRIGHT. No part of predicator, including this file, may be copied, modified, propagated, or distributed except according to the terms contained in the COPYRIGHT file.
2// Copyright © 2017 The developers of css. See the COPYRIGHT file in the top-level directory of this distribution and at https://raw.githubusercontent.com/lemonrock/css/master/COPYRIGHT.
3
4use {
5    crate::{
6        domain::{
7            expressions::CalculablePropertyValue,
8            numbers::CssUnsignedNumber,
9            units::{LengthOrPercentageUnit, Unit},
10        },
11        parsers::ParserContext,
12        CustomParseError,
13    },
14    cssparser::{ParseError, Parser, ToCss},
15    std::fmt,
16    ViewportLength::*,
17};
18
19/// ViewportLength is a length | percentage | auto
20/// See <http://dev.w3.org/csswg/css-device-adapt/#min-max-width-desc>
21/// extend-to-zoom is explicitly not supported as it does not occur in CSS, only when converting from HTML's meta name="viewport" tag (see <http://dev.w3.org/csswg/css-device-adapt/#extend-to-zoom>)
22#[derive(Debug, Clone, Ord, PartialOrd, Eq, PartialEq, Hash)]
23#[allow(missing_docs)]
24pub enum ViewportLength {
25    /// Automatic length
26    auto,
27
28    /// invariant or calculated non-negative length or non-negative percentage
29    value(CalculablePropertyValue<LengthOrPercentageUnit<CssUnsignedNumber>>),
30}
31
32impl ToCss for ViewportLength {
33    fn to_css<W: fmt::Write>(&self, dest: &mut W) -> fmt::Result {
34        match *self {
35            auto => dest.write_str("auto"),
36
37            value(ref numeric_value) => numeric_value.to_css(dest),
38        }
39    }
40}
41
42impl ViewportLength {
43    pub(crate) fn parse<'i, 't>(
44        context: &ParserContext,
45        input: &mut Parser<'i, 't>,
46    ) -> Result<Self, ParseError<'i, CustomParseError<'i>>> {
47        use self::ViewportLength::*;
48
49        if input.r#try(|i| i.expect_ident_matching("auto")).is_ok() {
50            return Ok(auto);
51        }
52
53        Ok(value(
54            LengthOrPercentageUnit::parse_one_outside_calc_function(
55                context, input,
56            )?,
57        ))
58    }
59}
lewp_css/domain/at_rules/viewport/viewport_length.rs

lewp_css/domain/at_rules/viewport/
viewport_length.rs
