font_data.h revision 584bf6606b53bda8bf0810e7c0ad57e24cacb4f1 
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_DATA_H_
18#define SFNTLY_CPP_SRC_SFNTLY_DATA_FONT_DATA_H_
19
20#include <vector>
21
22#include "sfntly/port/type.h"
23#include "sfntly/data/byte_array.h"
24#include "sfntly/port/refcount.h"
25
26namespace sfntly {
27
28struct DataSize {
29  enum {
30    kBYTE = 1,
31    kCHAR = 1,
32    kUSHORT = 2,
33    kSHORT = 2,
34    kUINT24 = 3,
35    kULONG = 4,
36    kLONG = 4,
37    kFixed = 4,
38    kFUNIT = 4,
39    kFWORD = 2,
40    kUFWORD = 2,
41    kF2DOT14 = 2,
42    kLONGDATETIME = 8,
43    kTag = 4,
44    kGlyphID = 2,
45    kOffset = 2
46  };
47};
48
49class FontData : virtual public RefCount {
50 public:
51  // Gets the maximum size of the FontData. This is the maximum number of bytes
52  // that the font data can hold and all of it may not be filled with data or
53  // even fully allocated yet.
54  // @return the maximum size of this font data
55  virtual int32_t Size() const;
56
57  // Sets limits on the size of the FontData. The FontData is then only
58  // visible within the bounds set.
59  // @param offset the start of the new bounds
60  // @param length the number of bytes in the bounded array
61  // @return true if the bounding range was successful; false otherwise
62  virtual bool Bound(int32_t offset, int32_t length);
63
64  // Sets limits on the size of the FontData. This is a offset bound only so if
65  // the FontData is writable and growable then there is no limit to that growth
66  // from the bounding operation.
67  // @param offset the start of the new bounds which must be within the current
68  //        size of the FontData
69  // @return true if the bounding range was successful; false otherwise
70  virtual bool Bound(int32_t offset);
71
72  // Makes a slice of this FontData. The returned slice will share the data with
73  // the original <code>FontData</code>.
74  // @param offset the start of the slice
75  // @param length the number of bytes in the slice
76  // @return a slice of the original FontData
77  virtual CALLER_ATTACH FontData* Slice(int32_t offset, int32_t length) = 0;
78
79  // Makes a bottom bound only slice of this array. The returned slice will
80  // share the data with the original <code>FontData</code>.
81  // @param offset the start of the slice
82  // @return a slice of the original FontData
83  virtual CALLER_ATTACH FontData* Slice(int32_t offset) = 0;
84
85  // Gets the length of the data.
86  virtual int32_t Length() const;
87
88 protected:
89  // Constructor.
90  // @param ba the byte array to use for the backing data
91  explicit FontData(ByteArray* ba);
92
93  // Constructor.
94  // @param data the data to wrap
95  // @param offset the offset to start the wrap from
96  // @param length the length of the data wrapped
97  FontData(FontData* data, int32_t offset, int32_t length);
98
99  // Constructor.
100  // @param data the data to wrap
101  // @param offset the offset to start the wrap from
102  FontData(FontData* data, int32_t offset);
103  virtual ~FontData();
104
105  void Init(ByteArray* ba);
106
107  // Gets the offset in the underlying data taking into account any bounds on
108  // the data.
109  // @param offset the offset to get the bound compensated offset for
110  // @return the bound compensated offset
111  int32_t BoundOffset(int32_t offset);
112
113  // Gets the length in the underlying data taking into account any bounds on the data.
114  // @param offset the offset that the length is being used at
115  // @param length the length to get the bound compensated length for
116  // @return the bound compensated length
117  int32_t BoundLength(int32_t offset, int32_t length);
118
119  // TODO(arthurhsu): style guide violation: refactor this protected member
120  ByteArrayPtr array_;
121
122 private:
123  int32_t bound_offset_;
124  int32_t bound_length_;
125};
126typedef Ptr<FontData> FontDataPtr;
127
128}  // namespace sfntly
129
130#endif  // SFNTLY_CPP_SRC_SFNTLY_DATA_FONT_DATA_H_
131