maui-linux/Xamarin.Forms.Core/StyleSheets/CssReader.cs

97 строки
2.0 KiB
C#

using System;
using System.Collections.Generic;
using System.IO;
namespace Xamarin.Forms.StyleSheets
{
sealed class CssReader : TextReader
{
readonly TextReader _reader;
public CssReader(TextReader reader)
{
if (reader == null)
throw new ArgumentNullException(nameof(reader));
_reader = reader;
}
readonly Queue<char> _cache = new Queue<char>();
//skip comments
//TODO unescape escaped sequences
public override int Peek()
{
if (_cache.Count > 0)
return _cache.Peek();
int p = _reader.Peek();
if (p <= 0)
return p;
if (unchecked((char)p) != '/')
return p;
_cache.Enqueue(unchecked((char)_reader.Read()));
p = _reader.Peek();
if (p <= 0)
return _cache.Peek();
if (unchecked((char)p) != '*')
return _cache.Peek();
_cache.Clear();
_reader.Read(); //consume the '*'
bool hasStar = false;
while (true) {
var next = _reader.Read();
if (next <= 0)
return next;
if (unchecked((char)next) == '*')
hasStar = true;
else if (hasStar && unchecked((char)next) == '/')
return Peek(); //recursively call self for comments following comments
else
hasStar = false;
}
}
//skip comments
//TODO unescape escaped sequences
public override int Read()
{
if (_cache.Count > 0)
return _cache.Dequeue();
int p = _reader.Read();
if (p <= 0)
return p;
var c = unchecked((char)p);
if (c != '/')
return p;
_cache.Enqueue(c);
p = _reader.Read();
if (p <= 0)
return _cache.Dequeue();
c = unchecked((char)p);
if (c != '*')
return _cache.Dequeue();
_cache.Clear();
_reader.Read(); //consume the '*'
bool hasStar = false;
while (true) {
var next = _reader.Read();
if (next <= 0)
return next;
if (unchecked((char)next) == '*')
hasStar = true;
else if (hasStar && unchecked((char)next) == '/')
return Read(); //recursively call self for comments following comments
else
hasStar = false;
}
}
}
}