css 0.0.22

// 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.
// 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.


/// A resolution.
#[derive(Clone, Debug, PartialEq)]
pub enum MediaResolution
{
	infinite,
	
	finite(CalculablePropertyValue<ResolutionUnit<CssSignedNumber>>),
}

impl ToCss for MediaResolution
{
	fn to_css<W: fmt::Write>(&self, dest: &mut W) -> fmt::Result
	{
		use self::MediaResolution::*;
		
		match *self
		{
			infinite => dest.write_str("infinite"),
			finite(ref value) => value.to_css(dest),
		}
	}
}

impl MediaResolution
{
	// WebKit only supports integer values of 1 and 2, but we more liberally support floating point values of any value, positive or negative or zero
	fn parseWebKit<'i, 't>(input: &mut Parser<'i, 't>) -> Result<Self, ParseError<'i, CustomParseError<'i>>>
	{
		use self::MediaResolution::*;
		
		let value = match *input.next()?
		{
			Token::Number { value, .. } => CssSignedNumber::new(value).map_err(|cssNumberConversionError| ParseError::Custom(CustomParseError::CouldNotParseCssSignedNumber(cssNumberConversionError, value))),
			
			ref unexpectedToken @ _ => CustomParseError::unexpectedToken(unexpectedToken),
		}?;
		
		Ok(finite(CalculablePropertyValue::Constant(ResolutionUnit::dppx(value))))
	}
	
	fn parse<'i, 't>(context: &ParserContext, input: &mut Parser<'i, 't>) -> Result<Self, ParseError<'i, CustomParseError<'i>>>
	{
		use self::MediaResolution::*;
		
		if input.try(|i| i.expect_ident_matching("auto")).is_ok()
		{
			return Ok(infinite);
		}
		
		Ok(finite(ResolutionUnit::parse_one_outside_calc_function(context, input)?))
	}
}