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      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_TABLE_HEADER_H_
     18 #define SFNTLY_CPP_SRC_SFNTLY_TABLE_HEADER_H_
     19 
     20 #include "sfntly/port/refcount.h"
     21 
     22 namespace sfntly {
     23 
     24 class Header : public RefCounted<Header> {
     25  public:
     26   // Make a partial header with only the basic info for an empty new table.
     27   explicit Header(int32_t tag);
     28 
     29   // Make a partial header with only the basic info for a new table.
     30   Header(int32_t tag, int32_t length);
     31 
     32   // Make a full header as read from an existing font.
     33   Header(int32_t tag, int64_t checksum, int32_t offset, int32_t length);
     34   virtual ~Header();
     35 
     36   // Get the table tag.
     37   int32_t tag() { return tag_; }
     38 
     39   // Get the table offset. The offset is from the start of the font file.  This
     40   // offset value is what was read from the font file during construction of the
     41   // font. It may not be meaningful if the font was maninpulated through the
     42   // builders.
     43   int32_t offset() { return offset_; }
     44 
     45   // Is the offset in the header valid. The offset will not be valid if the
     46   // table was constructed during building and has no physical location in a
     47   // font file.
     48   bool offset_valid() { return offset_valid_; }
     49 
     50   // Get the length of the table as recorded in the table record header.  During
     51   // building the header length will reflect the length that was initially read
     52   // from the font file. This may not be consistent with the current state of
     53   // the data.
     54   int32_t length() { return length_; }
     55 
     56   // Is the length in the header valid. The length will not be valid if the
     57   // table was constructed during building and has no physical location in a
     58   // font file until the table is built from the builder.
     59   bool length_valid() { return length_valid_; }
     60 
     61   // Get the checksum for the table as recorded in the table record header.
     62   int64_t checksum() { return checksum_; }
     63 
     64   // Is the checksum valid. The checksum will not be valid if the table was
     65   // constructed during building and has no physical location in a font file.
     66   // Note that this does *NOT* check the validity of the checksum against
     67   // the calculated checksum for the table data.
     68   bool checksum_valid() { return checksum_valid_; }
     69 
     70   // UNIMPLEMENTED: boolean equals(Object obj)
     71   //                int hashCode()
     72   //                string toString()
     73 
     74  private:
     75   int32_t tag_;
     76   int32_t offset_;
     77   bool offset_valid_;
     78   int32_t length_;
     79   bool length_valid_;
     80   int64_t checksum_;
     81   bool checksum_valid_;
     82 
     83   friend class HeaderComparatorByOffset;
     84   friend class HeaderComparatorByTag;
     85 };
     86 typedef Ptr<Header> HeaderPtr;
     87 
     88 class HeaderComparator {
     89  public:
     90   virtual ~HeaderComparator() {}
     91   virtual bool operator()(const HeaderPtr h1,
     92                           const HeaderPtr h2) = 0;
     93 };
     94 
     95 class HeaderComparatorByOffset : public HeaderComparator {
     96  public:
     97   virtual ~HeaderComparatorByOffset() {}
     98   virtual bool operator()(const HeaderPtr h1,
     99                           const HeaderPtr h2);
    100 };
    101 
    102 class HeaderComparatorByTag : public HeaderComparator {
    103  public:
    104   virtual ~HeaderComparatorByTag() {}
    105   virtual bool operator()(const HeaderPtr h1,
    106                           const HeaderPtr h2);
    107 };
    108 
    109 typedef std::set<HeaderPtr, HeaderComparatorByOffset> HeaderOffsetSortedSet;
    110 typedef std::set<HeaderPtr, HeaderComparatorByTag> HeaderTagSortedSet;
    111 
    112 }  // namespace sfntly
    113 
    114 #endif  // SFNTLY_CPP_SRC_SFNTLY_TABLE_HEADER_H_
    115