1 /*
2  * Copyright 2012 Google Inc.
3  *
4  * Use of this source code is governed by a BSD-style license that can be
5  * found in the LICENSE file.
6  */
7 
8 #ifndef SkOTUtils_DEFINED
9 #define SkOTUtils_DEFINED
10 
11 #include "SkOTTableTypes.h"
12 #include "SkOTTable_OS_2_V4.h"
13 #include "SkOTTable_name.h"
14 #include "SkTypeface.h"
15 
16 class SkData;
17 class SkStream;
18 struct SkAdvancedTypefaceMetrics;
19 
20 struct SkOTUtils {
21     /**
22       *  Calculates the OpenType checksum for data.
23       */
24     static uint32_t CalcTableChecksum(SK_OT_ULONG *data, size_t length);
25 
26     /**
27       *  Renames an sfnt font. On failure (invalid data or not an sfnt font)
28       *  returns nullptr.
29       *
30       *  Essentially, this removes any existing 'name' table and replaces it
31       *  with a new one in which FontFamilyName, FontSubfamilyName,
32       *  UniqueFontIdentifier, FullFontName, and PostscriptName are fontName.
33       *
34       *  The new 'name' table records will be written with the Windows,
35       *  UnicodeBMPUCS2, and English_UnitedStates settings.
36       *
37       *  fontName and fontNameLen must be specified in terms of ASCII chars.
38       *
39       *  Does not affect fontData's ownership.
40       */
41     static SkData* RenameFont(SkStreamAsset* fontData, const char* fontName, int fontNameLen);
42 
43     /** An implementation of LocalizedStrings which obtains it's data from a 'name' table. */
44     class LocalizedStrings_NameTable : public SkTypeface::LocalizedStrings {
45     public:
46         /** Takes ownership of the nameTableData and will free it with SK_DELETE. */
47         LocalizedStrings_NameTable(std::unique_ptr<uint8_t[]> nameTableData, size_t size,
48                                    SK_OT_USHORT types[],
49                                    int typesCount)
50             : fTypes(types), fTypesCount(typesCount), fTypesIndex(0)
51             , fNameTableData(std::move(nameTableData))
52             , fFamilyNameIter(fNameTableData.get(), size, fTypes[fTypesIndex])
53         { }
54 
55         /** Creates an iterator over all data in the 'name' table of a typeface.
56          *  If no valid 'name' table can be found, returns nullptr.
57          */
58         static sk_sp<LocalizedStrings_NameTable> Make(
59             const SkTypeface& typeface,
60             SK_OT_USHORT types[],
61             int typesCount);
62 
63         /** Creates an iterator over all the family names in the 'name' table of a typeface.
64          *  If no valid 'name' table can be found, returns nullptr.
65          */
66         static sk_sp<LocalizedStrings_NameTable> MakeForFamilyNames(const SkTypeface& typeface);
67 
68         bool next(SkTypeface::LocalizedString* localizedString) override;
69     private:
70         static SK_OT_USHORT familyNameTypes[3];
71 
72         SK_OT_USHORT* fTypes;
73         int fTypesCount;
74         int fTypesIndex;
75         std::unique_ptr<uint8_t[]> fNameTableData;
76         SkOTTableName::Iterator fFamilyNameIter;
77     };
78 
79     /** An implementation of LocalizedStrings which has one name. */
80     class LocalizedStrings_SingleName : public SkTypeface::LocalizedStrings {
81     public:
82         LocalizedStrings_SingleName(SkString name, SkString language)
83             : fName(name), fLanguage(language), fHasNext(true)
84         { }
85 
86         bool next(SkTypeface::LocalizedString* localizedString) override {
87             localizedString->fString = fName;
88             localizedString->fLanguage = fLanguage;
89 
90             bool hadNext = fHasNext;
91             fHasNext = false;
92             return hadNext;
93         }
94 
95     private:
96         SkString fName;
97         SkString fLanguage;
98         bool fHasNext;
99     };
100 
101     static void SetAdvancedTypefaceFlags(SkOTTableOS2_V4::Type fsType,
102                                          SkAdvancedTypefaceMetrics* info);
103 };
104 
105 #endif
106