1 /*
2  * Copyright 2017 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 #include "SkFontDescriptor.h"
9 #include "SkFontMgr_custom.h"
10 #include "SkMakeUnique.h"
11 #include "SkStream.h"
12 
13 struct SkEmbeddedResource { const uint8_t* data; size_t size; };
14 struct SkEmbeddedResourceHeader { const SkEmbeddedResource* entries; int count; };
15 
16 class EmbeddedSystemFontLoader : public SkFontMgr_Custom::SystemFontLoader {
17 public:
EmbeddedSystemFontLoader(const SkEmbeddedResourceHeader * header)18     EmbeddedSystemFontLoader(const SkEmbeddedResourceHeader* header) : fHeader(header) { }
19 
loadSystemFonts(const SkTypeface_FreeType::Scanner & scanner,SkFontMgr_Custom::Families * families) const20     void loadSystemFonts(const SkTypeface_FreeType::Scanner& scanner,
21                          SkFontMgr_Custom::Families* families) const override
22     {
23         for (int i = 0; i < fHeader->count; ++i) {
24             const SkEmbeddedResource& fontEntry = fHeader->entries[i];
25             load_embedded_font(scanner, fontEntry.data, fontEntry.size, i, families);
26         }
27 
28         if (families->empty()) {
29             SkFontStyleSet_Custom* family = new SkFontStyleSet_Custom(SkString());
30             families->push_back().reset(family);
31             family->appendTypeface(sk_make_sp<SkTypeface_Empty>());
32         }
33     }
34 
35 private:
find_family(SkFontMgr_Custom::Families & families,const char familyName[])36     static SkFontStyleSet_Custom* find_family(SkFontMgr_Custom::Families& families,
37                                               const char familyName[])
38     {
39        for (int i = 0; i < families.count(); ++i) {
40             if (families[i]->getFamilyName().equals(familyName)) {
41                 return families[i].get();
42             }
43         }
44         return nullptr;
45     }
46 
load_embedded_font(const SkTypeface_FreeType::Scanner & scanner,const uint8_t * data,size_t size,int index,SkFontMgr_Custom::Families * families)47     static void load_embedded_font(const SkTypeface_FreeType::Scanner& scanner,
48                                    const uint8_t* data, size_t size, int index,
49                                    SkFontMgr_Custom::Families* families)
50     {
51         auto stream = skstd::make_unique<SkMemoryStream>(data, size, false);
52 
53         int numFaces;
54         if (!scanner.recognizedFont(stream.get(), &numFaces)) {
55             SkDebugf("---- failed to open <%d> as a font\n", index);
56             return;
57         }
58 
59         for (int faceIndex = 0; faceIndex < numFaces; ++faceIndex) {
60             bool isFixedPitch;
61             SkString realname;
62             SkFontStyle style = SkFontStyle(); // avoid uninitialized warning
63             if (!scanner.scanFont(stream.get(), faceIndex,
64                                   &realname, &style, &isFixedPitch, nullptr))
65             {
66                 SkDebugf("---- failed to open <%d> <%d> as a font\n", index, faceIndex);
67                 return;
68             }
69 
70             SkFontStyleSet_Custom* addTo = find_family(*families, realname.c_str());
71             if (nullptr == addTo) {
72                 addTo = new SkFontStyleSet_Custom(realname);
73                 families->push_back().reset(addTo);
74             }
75             auto data = skstd::make_unique<SkFontData>(std::move(stream), faceIndex, nullptr, 0);
76             addTo->appendTypeface(sk_make_sp<SkTypeface_Stream>(std::move(data),
77                                                                 style, isFixedPitch,
78                                                                 true, realname));
79         }
80     }
81 
82     const SkEmbeddedResourceHeader* fHeader;
83 };
84 
SkFontMgr_New_Custom_Embedded(const SkEmbeddedResourceHeader * header)85 sk_sp<SkFontMgr> SkFontMgr_New_Custom_Embedded(const SkEmbeddedResourceHeader* header) {
86     return sk_make_sp<SkFontMgr_Custom>(EmbeddedSystemFontLoader(header));
87 }
88