com.upokecenter.text.encoders.EncodingBig5 Maven / Gradle / Ivy

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A Java library that implements character encodings used in Web pages and email.

There is a newer version: 0.6.0

package com.upokecenter.text.encoders;

import java.io.*;
import com.upokecenter.util.*;

import com.upokecenter.text.*;

  public class EncodingBig5 implements ICharacterEncoding {
    private static class Decoder implements ICharacterDecoder {
      private final DecoderState state;
      private int lead;

      public Decoder() {
        this.state = new DecoderState(1);
        this.lead = 0;
      }

      public int ReadChar(IByteReader stream) {
        int cc = this.state.GetChar();
        if (cc >= 0) {
          return cc;
        }
        while (true) {
          int b = this.state.ReadInputByte(stream);
          if (b < 0) {
            if (this.lead != 0) {
              this.lead = 0;
              return -2;
            }
            return -1;
          }
          if (this.lead != 0) {
            int c = -1;
            int o = (b < 0x7f) ? 0x40 : 0x62;
            if ((b >= 0x40 && b <= 0x7e) || (b >= 0xa1 && b <= 0xfe)) {
              c = ((this.lead - 0x81) * 157) + (b - o);
              if (c == 1133) {
                this.state.AppendChar(0x304);
                return 0xca;
              }
              if (c == 1135) {
                this.state.AppendChar(0x30c);
                return 0xca;
              }
              if (c == 1164) {
                this.state.AppendChar(0x304);
                return 0xea;
              }
              if (c == 1166) {
                this.state.AppendChar(0x30c);
                return 0xea;
              }
              c = Big5.IndexToCodePoint(c);
            }
            this.lead = 0;
            if (c < 0) {
              if (b < 0x80) {
                this.state.PrependOne(b);
              }
              return -2;
            }
            return c;
          }
          if (b <= 0x7f) {
            return b;
          } else if (b >= 0x81 && b <= 0xfe) {
            this.lead = b;
            continue;
          } else {
            return -2;
          }
        }
      }
    }

    private static class Encoder implements ICharacterEncoder {
      public int Encode(
       int c,
       IWriter output) {
        if (c < 0) {
          return -1;
        }
        if (c < 0x80) {
          output.write((byte)c);
          return 1;
        }
        int cp = Big5.CodePointToIndex(c);
        if (cp < 0) {
          return -2;
        }
        int a = cp / 157;
        int b = cp % 157;
        int o = (b < 0x3f) ? 0x40 : 0x62;
        output.write((byte)(a + 0x81));
        output.write((byte)(b + o));
        return 2;
      }
    }

    public ICharacterDecoder GetDecoder() {
      return new Decoder();
    }

    public ICharacterEncoder GetEncoder() {
      return new Encoder();
    }
  }