1 /*
2 * Copyright 2013 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 "SkFontConfigInterface.h"
9 #include "SkFontConfigTypeface.h"
10 #include "SkFontMgr.h"
11 #include "SkFontStyle.h"
12 #include "SkMath.h"
13 #include "SkMutex.h"
14 #include "SkString.h"
15 #include "SkTDArray.h"
16
17 // for now we pull these in directly. eventually we will solely rely on the
18 // SkFontConfigInterface instance.
19 #include <fontconfig/fontconfig.h>
20 #include <unistd.h>
21
22 namespace {
23
24 // Fontconfig is not threadsafe before 2.10.91. Before that, we lock with a global mutex.
25 // See skia:1497 for background.
26 SK_DECLARE_STATIC_MUTEX(gFCMutex);
27 static bool gFCSafeToUse;
28
29 struct FCLocker {
FCLocker__anonf61f7c700111::FCLocker30 FCLocker() {
31 if (FcGetVersion() < 21091) { // We assume FcGetVersion() has always been thread safe.
32 gFCMutex.acquire();
33 fUnlock = true;
34 } else {
35 fUnlock = false;
36 }
37 gFCSafeToUse = true;
38 }
39
~FCLocker__anonf61f7c700111::FCLocker40 ~FCLocker() {
41 if (fUnlock) {
42 gFCSafeToUse = false;
43 gFCMutex.release();
44 }
45 }
46
47 private:
48 bool fUnlock;
49 };
50
51 } // namespace
52
53 // borrow this global from SkFontHost_fontconfig. eventually that file should
54 // go away, and be replaced with this one.
55 extern SkFontConfigInterface* SkFontHost_fontconfig_ref_global();
RefFCI()56 static SkFontConfigInterface* RefFCI() {
57 return SkFontHost_fontconfig_ref_global();
58 }
59
60 // look for the last substring after a '/' and return that, or return null.
find_just_name(const char * str)61 static const char* find_just_name(const char* str) {
62 const char* last = strrchr(str, '/');
63 return last ? last + 1 : nullptr;
64 }
65
is_lower(char c)66 static bool is_lower(char c) {
67 return c >= 'a' && c <= 'z';
68 }
69
get_int(FcPattern * pattern,const char field[])70 static int get_int(FcPattern* pattern, const char field[]) {
71 SkASSERT(gFCSafeToUse);
72 int value;
73 if (FcPatternGetInteger(pattern, field, 0, &value) != FcResultMatch) {
74 value = SK_MinS32;
75 }
76 return value;
77 }
78
get_name(FcPattern * pattern,const char field[])79 static const char* get_name(FcPattern* pattern, const char field[]) {
80 SkASSERT(gFCSafeToUse);
81 const char* name;
82 if (FcPatternGetString(pattern, field, 0, (FcChar8**)&name) != FcResultMatch) {
83 name = "";
84 }
85 return name;
86 }
87
valid_pattern(FcPattern * pattern)88 static bool valid_pattern(FcPattern* pattern) {
89 SkASSERT(gFCSafeToUse);
90 FcBool is_scalable;
91 if (FcPatternGetBool(pattern, FC_SCALABLE, 0, &is_scalable) != FcResultMatch || !is_scalable) {
92 return false;
93 }
94
95 // fontconfig can also return fonts which are unreadable
96 const char* c_filename = get_name(pattern, FC_FILE);
97 if (0 == *c_filename) {
98 return false;
99 }
100 if (access(c_filename, R_OK) != 0) {
101 return false;
102 }
103 return true;
104 }
105
match_name(FcPattern * pattern,const char family_name[])106 static bool match_name(FcPattern* pattern, const char family_name[]) {
107 return !strcasecmp(family_name, get_name(pattern, FC_FAMILY));
108 }
109
MatchFont(FcFontSet * font_set,const char post_config_family[],int * count)110 static FcPattern** MatchFont(FcFontSet* font_set,
111 const char post_config_family[],
112 int* count) {
113 // Older versions of fontconfig have a bug where they cannot select
114 // only scalable fonts so we have to manually filter the results.
115
116 FcPattern** iter = font_set->fonts;
117 FcPattern** stop = iter + font_set->nfont;
118 // find the first good match
119 for (; iter < stop; ++iter) {
120 if (valid_pattern(*iter)) {
121 break;
122 }
123 }
124
125 if (iter == stop || !match_name(*iter, post_config_family)) {
126 return nullptr;
127 }
128
129 FcPattern** firstIter = iter++;
130 for (; iter < stop; ++iter) {
131 if (!valid_pattern(*iter) || !match_name(*iter, post_config_family)) {
132 break;
133 }
134 }
135
136 *count = iter - firstIter;
137 return firstIter;
138 }
139
140 class SkFontStyleSet_FC : public SkFontStyleSet {
141 public:
142 SkFontStyleSet_FC(FcPattern** matches, int count);
143 virtual ~SkFontStyleSet_FC();
144
count()145 int count() override { return fRecCount; }
146 void getStyle(int index, SkFontStyle*, SkString* style) override;
147 SkTypeface* createTypeface(int index) override;
148 SkTypeface* matchStyle(const SkFontStyle& pattern) override;
149
150 private:
151 struct Rec {
152 SkString fStyleName;
153 SkString fFileName;
154 SkFontStyle fStyle;
155 };
156 Rec* fRecs;
157 int fRecCount;
158 };
159
map_range(int value,int old_min,int old_max,int new_min,int new_max)160 static int map_range(int value,
161 int old_min, int old_max, int new_min, int new_max) {
162 SkASSERT(old_min < old_max);
163 SkASSERT(new_min < new_max);
164 return new_min + SkMulDiv(value - old_min,
165 new_max - new_min, old_max - old_min);
166 }
167
make_fontconfig_style(FcPattern * match)168 static SkFontStyle make_fontconfig_style(FcPattern* match) {
169 int weight = get_int(match, FC_WEIGHT);
170 int width = get_int(match, FC_WIDTH);
171 int slant = get_int(match, FC_SLANT);
172 // SkDebugf("old weight %d new weight %d\n", weight, map_range(weight, 0, 80, 0, 400));
173
174 // fontconfig weight seems to be 0..200 or so, so we remap it here
175 weight = map_range(weight, 0, 80, 0, 400);
176 width = map_range(width, 0, 200, 0, 9);
177 return SkFontStyle(weight, width, slant > 0 ? SkFontStyle::kItalic_Slant
178 : SkFontStyle::kUpright_Slant);
179 }
180
SkFontStyleSet_FC(FcPattern ** matches,int count)181 SkFontStyleSet_FC::SkFontStyleSet_FC(FcPattern** matches, int count) {
182 fRecCount = count;
183 fRecs = new Rec[count];
184 for (int i = 0; i < count; ++i) {
185 fRecs[i].fStyleName.set(get_name(matches[i], FC_STYLE));
186 fRecs[i].fFileName.set(get_name(matches[i], FC_FILE));
187 fRecs[i].fStyle = make_fontconfig_style(matches[i]);
188 }
189 }
190
~SkFontStyleSet_FC()191 SkFontStyleSet_FC::~SkFontStyleSet_FC() { delete[] fRecs; }
192
getStyle(int index,SkFontStyle * style,SkString * styleName)193 void SkFontStyleSet_FC::getStyle(int index, SkFontStyle* style,
194 SkString* styleName) {
195 SkASSERT((unsigned)index < (unsigned)fRecCount);
196 if (style) {
197 *style = fRecs[index].fStyle;
198 }
199 if (styleName) {
200 *styleName = fRecs[index].fStyleName;
201 }
202 }
203
createTypeface(int index)204 SkTypeface* SkFontStyleSet_FC::createTypeface(int index) {
205 return nullptr;
206 }
207
matchStyle(const SkFontStyle & pattern)208 SkTypeface* SkFontStyleSet_FC::matchStyle(const SkFontStyle& pattern) {
209 return nullptr;
210 }
211
212 class SkFontMgr_fontconfig : public SkFontMgr {
213 SkAutoTUnref<SkFontConfigInterface> fFCI;
214 SkDataTable* fFamilyNames;
215 SkTypeface_FreeType::Scanner fScanner;
216
217 public:
SkFontMgr_fontconfig(SkFontConfigInterface * fci)218 SkFontMgr_fontconfig(SkFontConfigInterface* fci)
219 : fFCI(fci)
220 , fFamilyNames(fFCI->getFamilyNames()) {}
221
~SkFontMgr_fontconfig()222 virtual ~SkFontMgr_fontconfig() {
223 SkSafeUnref(fFamilyNames);
224 }
225
226 protected:
onCountFamilies() const227 int onCountFamilies() const override {
228 return fFamilyNames->count();
229 }
230
onGetFamilyName(int index,SkString * familyName) const231 void onGetFamilyName(int index, SkString* familyName) const override {
232 familyName->set(fFamilyNames->atStr(index));
233 }
234
onCreateStyleSet(int index) const235 SkFontStyleSet* onCreateStyleSet(int index) const override {
236 return this->onMatchFamily(fFamilyNames->atStr(index));
237 }
238
onMatchFamily(const char familyName[]) const239 SkFontStyleSet* onMatchFamily(const char familyName[]) const override {
240 FCLocker lock;
241
242 FcPattern* pattern = FcPatternCreate();
243
244 FcPatternAddString(pattern, FC_FAMILY, (FcChar8*)familyName);
245 #if 0
246 FcPatternAddBool(pattern, FC_SCALABLE, FcTrue);
247 #endif
248 FcConfigSubstitute(nullptr, pattern, FcMatchPattern);
249 FcDefaultSubstitute(pattern);
250
251 const char* post_config_family = get_name(pattern, FC_FAMILY);
252
253 FcResult result;
254 FcFontSet* font_set = FcFontSort(0, pattern, 0, 0, &result);
255 if (!font_set) {
256 FcPatternDestroy(pattern);
257 return nullptr;
258 }
259
260 int count;
261 FcPattern** match = MatchFont(font_set, post_config_family, &count);
262 if (!match) {
263 FcPatternDestroy(pattern);
264 FcFontSetDestroy(font_set);
265 return nullptr;
266 }
267
268 FcPatternDestroy(pattern);
269
270 SkTDArray<FcPattern*> trimmedMatches;
271 for (int i = 0; i < count; ++i) {
272 const char* justName = find_just_name(get_name(match[i], FC_FILE));
273 if (!is_lower(*justName)) {
274 *trimmedMatches.append() = match[i];
275 }
276 }
277
278 SkFontStyleSet_FC* sset =
279 new SkFontStyleSet_FC(trimmedMatches.begin(), trimmedMatches.count());
280 return sset;
281 }
282
onMatchFamilyStyle(const char familyName[],const SkFontStyle &) const283 SkTypeface* onMatchFamilyStyle(const char familyName[],
284 const SkFontStyle&) const override { return nullptr; }
onMatchFamilyStyleCharacter(const char familyName[],const SkFontStyle &,const char * bcp47[],int bcp47Count,SkUnichar character) const285 SkTypeface* onMatchFamilyStyleCharacter(const char familyName[], const SkFontStyle&,
286 const char* bcp47[], int bcp47Count,
287 SkUnichar character) const override {
288 return nullptr;
289 }
onMatchFaceStyle(const SkTypeface *,const SkFontStyle &) const290 SkTypeface* onMatchFaceStyle(const SkTypeface*,
291 const SkFontStyle&) const override { return nullptr; }
292
onCreateFromData(SkData *,int ttcIndex) const293 SkTypeface* onCreateFromData(SkData*, int ttcIndex) const override { return nullptr; }
294
onCreateFromStream(SkStreamAsset * bareStream,int ttcIndex) const295 SkTypeface* onCreateFromStream(SkStreamAsset* bareStream, int ttcIndex) const override {
296 SkAutoTDelete<SkStreamAsset> stream(bareStream);
297 const size_t length = stream->getLength();
298 if (!length) {
299 return nullptr;
300 }
301 if (length >= 1024 * 1024 * 1024) {
302 return nullptr; // don't accept too large fonts (>= 1GB) for safety.
303 }
304
305 // TODO should the caller give us the style or should we get it from freetype?
306 SkFontStyle style;
307 bool isFixedWidth = false;
308 if (!fScanner.scanFont(stream, 0, nullptr, &style, &isFixedWidth, nullptr)) {
309 return nullptr;
310 }
311
312 SkTypeface* face = FontConfigTypeface::Create(style, isFixedWidth, stream.detach());
313 return face;
314 }
315
onCreateFromFile(const char path[],int ttcIndex) const316 SkTypeface* onCreateFromFile(const char path[], int ttcIndex) const override {
317 SkAutoTDelete<SkStreamAsset> stream(SkStream::NewFromFile(path));
318 return stream.get() ? this->createFromStream(stream.detach(), ttcIndex) : nullptr;
319 }
320
onLegacyCreateTypeface(const char familyName[],unsigned styleBits) const321 SkTypeface* onLegacyCreateTypeface(const char familyName[],
322 unsigned styleBits) const override {
323 FCLocker lock;
324 return FontConfigTypeface::LegacyCreateTypeface(familyName, (SkTypeface::Style)styleBits);
325 }
326 };
327
Factory()328 SkFontMgr* SkFontMgr::Factory() {
329 SkFontConfigInterface* fci = RefFCI();
330 return fci ? new SkFontMgr_fontconfig(fci) : nullptr;
331 }
332