Line data    Source code

       1             : /*
       2             :  * Copyright 2011 Google Inc. All Rights Reserved.
       3             :  *
       4             :  * Licensed under the Apache License, Version 2.0 (the "License");
       5             :  * you may not use this file except in compliance with the License.
       6             :  * You may obtain a copy of the License at
       7             :  *
       8             :  *      http://www.apache.org/licenses/LICENSE-2.0
       9             :  *
      10             :  * Unless required by applicable law or agreed to in writing, software
      11             :  * distributed under the License is distributed on an "AS IS" BASIS,
      12             :  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
      13             :  * See the License for the specific language governing permissions and
      14             :  * limitations under the License.
      15             :  */
      16             : 
      17             : #ifndef SFNTLY_CPP_SRC_SFNTLY_DATA_FONT_INPUT_STREAM_H_
      18             : #define SFNTLY_CPP_SRC_SFNTLY_DATA_FONT_INPUT_STREAM_H_
      19             : 
      20             : #include "sfntly/port/type.h"
      21             : #include "sfntly/port/input_stream.h"
      22             : 
      23             : namespace sfntly {
      24             : 
      25             : // An input stream for reading font data.
      26             : // The data types used are as listed:
      27             : // BYTE       8-bit unsigned integer.
      28             : // CHAR       8-bit signed integer.
      29             : // USHORT     16-bit unsigned integer.
      30             : // SHORT      16-bit signed integer.
      31             : // UINT24     24-bit unsigned integer.
      32             : // ULONG      32-bit unsigned integer.
      33             : // LONG       32-bit signed integer.
      34             : // Fixed      32-bit signed fixed-point number (16.16)
      35             : // FUNIT      Smallest measurable distance in the em space.
      36             : // FWORD      16-bit signed integer (SHORT) that describes a quantity in FUnits.
      37             : // UFWORD     16-bit unsigned integer (USHORT) that describes a quantity in
      38             : //            FUnits.
      39             : // F2DOT14    16-bit signed fixed number with the low 14 bits of fraction (2.14)
      40             : // LONGDATETIME  Date represented in number of seconds since 12:00 midnight,
      41             : //               January 1, 1904. The value is represented as a signed 64-bit
      42             : //               integer.
      43             : 
      44             : // Note: Original class inherits from Java's FilterOutputStream, which wraps
      45             : //       an InputStream within.  In C++, we directly do the wrapping without
      46             : //       defining another layer of abstraction.  The wrapped output stream is
      47             : //       *NOT* reference counted (because it's meaningless to ref-count an I/O
      48             : //       stream).
      49             : class FontInputStream : public InputStream {
      50             :  public:
      51             :   // Constructor.
      52             :   // @param is input stream to wrap
      53             :   explicit FontInputStream(InputStream* is);
      54             : 
      55             :   // Constructor for a bounded font input stream.
      56             :   // @param is input stream to wrap
      57             :   // @param length the maximum length of bytes to read
      58             :   FontInputStream(InputStream* is, size_t length);
      59             : 
      60             :   virtual ~FontInputStream();
      61             : 
      62             : 
      63             :   virtual int32_t Available();
      64             :   virtual void Close();
      65             :   virtual void Mark(int32_t readlimit);
      66             :   virtual bool MarkSupported();
      67             :   virtual void Reset();
      68             : 
      69             :   virtual int32_t Read();
      70             :   virtual int32_t Read(ByteVector* buffer);
      71             :   virtual int32_t Read(ByteVector* buffer, int32_t offset, int32_t length);
      72             : 
      73             :   // Get the current position in the stream in bytes.
      74             :   // @return the current position in bytes
      75           0 :   virtual int64_t position() { return position_; }
      76             : 
      77             :   virtual int32_t ReadChar();
      78             :   virtual int32_t ReadUShort();
      79             :   virtual int32_t ReadShort();
      80             :   virtual int32_t ReadUInt24();
      81             :   virtual int64_t ReadULong();
      82             :   virtual int32_t ReadULongAsInt();
      83             :   virtual int32_t ReadLong();
      84             :   virtual int32_t ReadFixed();
      85             :   virtual int64_t ReadDateTimeAsLong();
      86             :   virtual int64_t Skip(int64_t n);  // n can be negative.
      87             : 
      88             :  private:
      89             :   InputStream* stream_;
      90             :   int64_t position_;
      91             :   int64_t length_;  // Bound on length of data to read.
      92             :   bool bounded_;
      93             : };
      94             : 
      95             : }  // namespace sfntly
      96             : 
      97             : #endif  // SFNTLY_CPP_SRC_SFNTLY_DATA_FONT_INPUT_STREAM_H_