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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_TRUETYPE_LOCA_TABLE_H_
     18 #define SFNTLY_CPP_SRC_SFNTLY_TABLE_TRUETYPE_LOCA_TABLE_H_
     19 
     20 #include "sfntly/port/java_iterator.h"
     21 #include "sfntly/table/table.h"
     22 #include "sfntly/table/core/font_header_table.h"
     23 
     24 namespace sfntly {
     25 
     26 // A Loca table - 'loca'.
     27 class LocaTable : public Table, public RefCounted<LocaTable> {
     28  public:
     29   class LocaIterator : public PODIterator<int32_t, LocaTable> {
     30    public:
     31     explicit LocaIterator(LocaTable* table);
     32     virtual ~LocaIterator() {}
     33 
     34     virtual bool HasNext();
     35     virtual int32_t Next();
     36 
     37    private:
     38     int32_t index_;
     39   };
     40 
     41   class Builder : public Table::Builder, public RefCounted<Builder> {
     42    public:
     43     // Constructor scope altered to public for base class to instantiate.
     44     Builder(Header* header, WritableFontData* data);
     45     Builder(Header* header, ReadableFontData* data);
     46     virtual ~Builder();
     47 
     48     static CALLER_ATTACH Builder* CreateBuilder(Header* header,
     49                                                 WritableFontData* data);
     50 
     51     // Get the format version that will be used when the loca table is
     52     // generated.
     53     // @return the loca table format version
     54     int32_t format_version() { return format_version_; }
     55     void set_format_version(int32_t value) { format_version_ = value; }
     56 
     57     // Gets the List of locas for loca table builder. These may be manipulated
     58     // in any way by the caller and the changes will be reflected in the final
     59     // loca table produced as long as no subsequent call is made to the
     60     // SetLocaList(List) method.
     61     // If there is no current data for the loca table builder or the loca list
     62     // have not been previously set then this will return an empty List.
     63     IntegerList* LocaList();
     64 
     65     // Set the list of locas to be used for building this table. If any existing
     66     // list was already retrieved with the LocaList() method then the
     67     // connection of that previous list to this builder will be broken.
     68     void SetLocaList(IntegerList* list);
     69 
     70     // Return the offset for the given glyph id. Valid glyph ids are from 0 to
     71     // one less than the number of glyphs. The zero entry is the special entry
     72     // for the notdef glyph. The final entry beyond the last glyph id is used to
     73     // calculate the size of the last glyph.
     74     // @param glyphId the glyph id to get the offset for; must be less than or
     75     //        equal to one more than the number of glyph ids
     76     // @return the offset in the glyph table to the specified glyph id
     77     int32_t GlyphOffset(int32_t glyph_id);
     78 
     79     // Get the length of the data in the glyph table for the specified glyph id.
     80     int32_t GlyphLength(int32_t glyph_id);
     81 
     82     // Set the number of glyphs.
     83     // This method sets the number of glyphs that the builder will attempt to
     84     // parse location data for from the raw binary data. This method only needs
     85     // to be called (and <b>must</b> be) when the raw data for this builder has
     86     // been changed. It does not by itself reset the data or clear any set loca
     87     // list.
     88     void SetNumGlyphs(int32_t num_glyphs);
     89 
     90     // Get the number of glyphs that this builder has support for.
     91     int NumGlyphs();
     92 
     93     // Revert the loca table builder to the state contained in the last raw data
     94     // set on the builder. That raw data may be that read from a font file when
     95     // the font builder was created, that set by a user of the loca table
     96     // builder, or null data if this builder was created as a new empty builder.
     97     void Revert();
     98 
     99     // Get the number of locations or locas. This will be one more than the
    100     // number of glyphs for this table since the last loca position is used to
    101     // indicate the size of the final glyph.
    102     int32_t NumLocas();
    103 
    104     // Get the value from the loca table for the index specified. These are the
    105     // raw values from the table that are used to compute the offset and size of
    106     // a glyph in the glyph table. Valid index values run from 0 to the number
    107     // of glyphs in the font.
    108     int32_t Loca(int32_t index);
    109 
    110     virtual CALLER_ATTACH FontDataTable* SubBuildTable(ReadableFontData* data);
    111     virtual void SubDataSet();
    112     virtual int32_t SubDataSizeToSerialize();
    113     virtual bool SubReadyToSerialize();
    114     virtual int32_t SubSerialize(WritableFontData* new_data);
    115 
    116    private:
    117     // Initialize the internal state from the data. Done lazily since in many
    118     // cases the builder will be just creating a table object with no parsing
    119     // required.
    120     // @param data the data to initialize from
    121     void Initialize(ReadableFontData* data);
    122 
    123     // Checks that the glyph id is within the correct range.
    124     // @return glyph_id if correct, -1 otherwise.
    125     int32_t CheckGlyphRange(int32_t glyph_id);
    126 
    127     int32_t LastGlyphIndex();
    128 
    129     // Internal method to get the loca list if already generated and if not to
    130     // initialize the state of the builder.
    131     // @return the loca list
    132     IntegerList* GetLocaList();
    133 
    134     void ClearLoca(bool nullify);
    135 
    136     int32_t format_version_;  // Note: IndexToLocFormat
    137     int32_t num_glyphs_;
    138     IntegerList loca_;
    139   };
    140 
    141   virtual ~LocaTable();
    142 
    143   int32_t format_version() { return format_version_; }
    144   int32_t num_glyphs() { return num_glyphs_; }
    145 
    146   // Return the offset for the given glyph id. Valid glyph ids are from 0 to the
    147   // one less than the number of glyphs. The zero entry is the special entry for
    148   // the notdef glyph. The final entry beyond the last glyph id is used to
    149   // calculate the size of the last glyph.
    150   // @param glyphId the glyph id to get the offset for; must be less than or
    151   //        equal to one more than the number of glyph ids
    152   // @return the offset in the glyph table to the specified glyph id
    153   int32_t GlyphOffset(int32_t glyph_id);
    154 
    155   // Get the length of the data in the glyph table for the specified glyph id.
    156   int32_t GlyphLength(int32_t glyph_id);
    157 
    158   // Get the number of locations or locas. This will be one more than the number
    159   // of glyphs for this table since the last loca position is used to indicate
    160   // the size of the final glyph.
    161   int32_t NumLocas();
    162 
    163   // Get the value from the loca table for the index specified. Valid index
    164   // values run from 0 to the number of glyphs in the font.
    165   int32_t Loca(int32_t index);
    166 
    167  private:
    168   LocaTable(Header* header,
    169             ReadableFontData* data,
    170             int32_t format_version,
    171             int32_t num_glyphs);
    172 
    173   int32_t format_version_;  // Note: Java's version, renamed to format_version_
    174   int32_t num_glyphs_;
    175 
    176   friend class LocaIterator;
    177 };
    178 typedef Ptr<LocaTable> LocaTablePtr;
    179 typedef Ptr<LocaTable::Builder> LocaTableBuilderPtr;
    180 
    181 }  // namespace sfntly
    182 
    183 #endif  // SFNTLY_CPP_SRC_SFNTLY_TABLE_TRUETYPE_LOCA_TABLE_H_
    184