src/Tizen.NUI/src/internal/XamlBinding/StyleSheets/CssReader.cs

   1 using System;
   2 using System.Collections.Generic;
   3 using System.IO;
   4
   5 namespace Tizen.NUI.StyleSheets
   6 {
   7         sealed class CssReader : TextReader
   8         {
   9                 readonly TextReader _reader;
  10
  11                 public CssReader(TextReader reader)
  12                 {
  13                         if (reader == null)
  14                                 throw new ArgumentNullException(nameof(reader));
  15
  16                         _reader = reader;
  17                 }
  18
  19                 readonly Queue<char> _cache = new Queue<char>();
  20
  21                 //skip comments
  22                 //TODO unescape escaped sequences
  23                 public override int Peek()
  24                 {
  25                         if (_cache.Count > 0)
  26                                 return _cache.Peek();
  27
  28                         int p = _reader.Peek();
  29                         if (p <= 0)
  30                                 return p;
  31                         if (unchecked((char)p) != '/')
  32                                 return p;
  33
  34                         _cache.Enqueue(unchecked((char)_reader.Read()));
  35                         p = _reader.Peek();
  36                         if (p <= 0)
  37                                 return _cache.Peek();
  38                         if (unchecked((char)p) != '*')
  39                                 return _cache.Peek();
  40
  41                         _cache.Clear();
  42                         _reader.Read(); //consume the '*'
  43
  44                         bool hasStar = false;
  45                         while (true) {
  46                                 var next = _reader.Read();
  47                                 if (next <= 0)
  48                                         return next;
  49                                 if (unchecked((char)next) == '*')
  50                                         hasStar = true;
  51                                 else if (hasStar && unchecked((char)next) == '/')
  52                                         return Peek(); //recursively call self for comments following comments
  53                                 else
  54                                         hasStar = false;
  55                         }
  56                 }
  57
  58                 //skip comments
  59                 //TODO unescape escaped sequences
  60                 public override int Read()
  61                 {
  62                         if (_cache.Count > 0)
  63                                 return _cache.Dequeue();
  64
  65                         int p = _reader.Read();
  66                         if (p <= 0)
  67                                 return p;
  68                         var c = unchecked((char)p);
  69                         if (c != '/')
  70                                 return p;
  71
  72                         _cache.Enqueue(c);
  73                         p = _reader.Read();
  74                         if (p <= 0)
  75                                 return _cache.Dequeue();
  76                         c = unchecked((char)p);
  77                         if (c != '*')
  78                                 return _cache.Dequeue();
  79
  80                         _cache.Clear();
  81                         _reader.Read(); //consume the '*'
  82
  83                         bool hasStar = false;
  84                         while (true) {
  85                                 var next = _reader.Read();
  86                                 if (next <= 0)
  87                                         return next;
  88                                 if (unchecked((char)next) == '*')
  89                                         hasStar = true;
  90                                 else if (hasStar && unchecked((char)next) == '/')
  91                                         return Read(); //recursively call self for comments following comments
  92                                 else
  93                                         hasStar = false;
  94                         }
  95                 }
  96         }
  97 }