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      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 "SkFontMgr.h"
      9 #include "SkFontStyle.h"
     10 #include "SkFontConfigInterface.h"
     11 #include "SkFontConfigTypeface.h"
     12 #include "SkMath.h"
     13 #include "SkString.h"
     14 #include "SkTDArray.h"
     15 
     16 // for now we pull these in directly. eventually we will solely rely on the
     17 // SkFontConfigInterface instance.
     18 #include <fontconfig/fontconfig.h>
     19 #include <unistd.h>
     20 
     21 // Defined in SkFontHost_FreeType.cpp
     22 bool find_name_and_attributes(SkStream* stream, SkString* name,
     23                               SkTypeface::Style* style, bool* isFixedWidth);
     24 
     25 // borrow this global from SkFontHost_fontconfig. eventually that file should
     26 // go away, and be replaced with this one.
     27 extern SkFontConfigInterface* SkFontHost_fontconfig_ref_global();
     28 static SkFontConfigInterface* RefFCI() {
     29     return SkFontHost_fontconfig_ref_global();
     30 }
     31 
     32 // look for the last substring after a '/' and return that, or return null.
     33 static const char* find_just_name(const char* str) {
     34     const char* last = strrchr(str, '/');
     35     return last ? last + 1 : NULL;
     36 }
     37 
     38 static bool is_lower(char c) {
     39     return c >= 'a' && c <= 'z';
     40 }
     41 
     42 static int get_int(FcPattern* pattern, const char field[]) {
     43     int value;
     44     if (FcPatternGetInteger(pattern, field, 0, &value) != FcResultMatch) {
     45         value = SK_MinS32;
     46     }
     47     return value;
     48 }
     49 
     50 static const char* get_name(FcPattern* pattern, const char field[]) {
     51     const char* name;
     52     if (FcPatternGetString(pattern, field, 0, (FcChar8**)&name) != FcResultMatch) {
     53         name = "";
     54     }
     55     return name;
     56 }
     57 
     58 static bool valid_pattern(FcPattern* pattern) {
     59     FcBool is_scalable;
     60     if (FcPatternGetBool(pattern, FC_SCALABLE, 0, &is_scalable) != FcResultMatch || !is_scalable) {
     61         return false;
     62     }
     63 
     64     // fontconfig can also return fonts which are unreadable
     65     const char* c_filename = get_name(pattern, FC_FILE);
     66     if (0 == *c_filename) {
     67         return false;
     68     }
     69     if (access(c_filename, R_OK) != 0) {
     70         return false;
     71     }
     72     return true;
     73 }
     74 
     75 static bool match_name(FcPattern* pattern, const char family_name[]) {
     76     return !strcasecmp(family_name, get_name(pattern, FC_FAMILY));
     77 }
     78 
     79 static FcPattern** MatchFont(FcFontSet* font_set,
     80                              const char post_config_family[],
     81                              int* count) {
     82   // Older versions of fontconfig have a bug where they cannot select
     83   // only scalable fonts so we have to manually filter the results.
     84 
     85     FcPattern** iter = font_set->fonts;
     86     FcPattern** stop = iter + font_set->nfont;
     87     // find the first good match
     88     for (; iter < stop; ++iter) {
     89         if (valid_pattern(*iter)) {
     90             break;
     91         }
     92     }
     93 
     94     if (iter == stop || !match_name(*iter, post_config_family)) {
     95         return NULL;
     96     }
     97 
     98     FcPattern** firstIter = iter++;
     99     for (; iter < stop; ++iter) {
    100         if (!valid_pattern(*iter) || !match_name(*iter, post_config_family)) {
    101             break;
    102         }
    103     }
    104 
    105     *count = iter - firstIter;
    106     return firstIter;
    107 }
    108 
    109 class SkFontStyleSet_FC : public SkFontStyleSet {
    110 public:
    111     SkFontStyleSet_FC(FcPattern** matches, int count);
    112     virtual ~SkFontStyleSet_FC();
    113 
    114     virtual int count() SK_OVERRIDE { return fRecCount; }
    115     virtual void getStyle(int index, SkFontStyle*, SkString* style) SK_OVERRIDE;
    116     virtual SkTypeface* createTypeface(int index) SK_OVERRIDE;
    117     virtual SkTypeface* matchStyle(const SkFontStyle& pattern) SK_OVERRIDE;
    118 
    119 private:
    120     struct Rec {
    121         SkString    fStyleName;
    122         SkString    fFileName;
    123         SkFontStyle fStyle;
    124     };
    125     Rec* fRecs;
    126     int  fRecCount;
    127 };
    128 
    129 static int map_range(int value,
    130                      int old_min, int old_max, int new_min, int new_max) {
    131     SkASSERT(old_min < old_max);
    132     SkASSERT(new_min < new_max);
    133     return new_min + SkMulDiv(value - old_min,
    134                               new_max - new_min, old_max - old_min);
    135 }
    136 
    137 static SkFontStyle make_fontconfig_style(FcPattern* match) {
    138     int weight = get_int(match, FC_WEIGHT);
    139     int width = get_int(match, FC_WIDTH);
    140     int slant = get_int(match, FC_SLANT);
    141 //    SkDebugf("old weight %d new weight %d\n", weight, map_range(weight, 0, 80, 0, 400));
    142 
    143     // fontconfig weight seems to be 0..200 or so, so we remap it here
    144     weight = map_range(weight, 0, 80, 0, 400);
    145     width = map_range(width, 0, 200, 0, 9);
    146     return SkFontStyle(weight, width, slant > 0 ? SkFontStyle::kItalic_Slant
    147                                                 : SkFontStyle::kUpright_Slant);
    148 }
    149 
    150 SkFontStyleSet_FC::SkFontStyleSet_FC(FcPattern** matches, int count) {
    151     fRecCount = count;
    152     fRecs = SkNEW_ARRAY(Rec, count);
    153     for (int i = 0; i < count; ++i) {
    154         fRecs[i].fStyleName.set(get_name(matches[i], FC_STYLE));
    155         fRecs[i].fFileName.set(get_name(matches[i], FC_FILE));
    156         fRecs[i].fStyle = make_fontconfig_style(matches[i]);
    157     }
    158 }
    159 
    160 SkFontStyleSet_FC::~SkFontStyleSet_FC() {
    161     SkDELETE_ARRAY(fRecs);
    162 }
    163 
    164 void SkFontStyleSet_FC::getStyle(int index, SkFontStyle* style,
    165                                  SkString* styleName) {
    166     SkASSERT((unsigned)index < (unsigned)fRecCount);
    167     if (style) {
    168         *style = fRecs[index].fStyle;
    169     }
    170     if (styleName) {
    171         *styleName = fRecs[index].fStyleName;
    172     }
    173 }
    174 
    175 SkTypeface* SkFontStyleSet_FC::createTypeface(int index) {
    176     return NULL;
    177 }
    178 
    179 SkTypeface* SkFontStyleSet_FC::matchStyle(const SkFontStyle& pattern) {
    180     return NULL;
    181 }
    182 
    183 class SkFontMgr_fontconfig : public SkFontMgr {
    184     SkAutoTUnref<SkFontConfigInterface> fFCI;
    185     SkDataTable* fFamilyNames;
    186 
    187     void init() {
    188         if (!fFamilyNames) {
    189             fFamilyNames = fFCI->getFamilyNames();
    190         }
    191     }
    192 
    193 public:
    194     SkFontMgr_fontconfig(SkFontConfigInterface* fci)
    195         : fFCI(fci)
    196         , fFamilyNames(NULL) {}
    197 
    198     virtual ~SkFontMgr_fontconfig() {
    199         SkSafeUnref(fFamilyNames);
    200     }
    201 
    202 protected:
    203     virtual int onCountFamilies() {
    204         this->init();
    205         return fFamilyNames->count();
    206     }
    207 
    208     virtual void onGetFamilyName(int index, SkString* familyName) {
    209         this->init();
    210         familyName->set(fFamilyNames->atStr(index));
    211     }
    212 
    213     virtual SkFontStyleSet* onCreateStyleSet(int index) {
    214         this->init();
    215         return this->onMatchFamily(fFamilyNames->atStr(index));
    216     }
    217 
    218     virtual SkFontStyleSet* onMatchFamily(const char familyName[]) {
    219         this->init();
    220 
    221         FcPattern* pattern = FcPatternCreate();
    222 
    223         FcPatternAddString(pattern, FC_FAMILY, (FcChar8*)familyName);
    224 #if 0
    225         FcPatternAddBool(pattern, FC_SCALABLE, FcTrue);
    226 #endif
    227         FcConfigSubstitute(NULL, pattern, FcMatchPattern);
    228         FcDefaultSubstitute(pattern);
    229 
    230         const char* post_config_family = get_name(pattern, FC_FAMILY);
    231 
    232         FcResult result;
    233         FcFontSet* font_set = FcFontSort(0, pattern, 0, 0, &result);
    234         if (!font_set) {
    235             FcPatternDestroy(pattern);
    236             return NULL;
    237         }
    238 
    239         int count;
    240         FcPattern** match = MatchFont(font_set, post_config_family, &count);
    241         if (!match) {
    242             FcPatternDestroy(pattern);
    243             FcFontSetDestroy(font_set);
    244             return NULL;
    245         }
    246 
    247         FcPatternDestroy(pattern);
    248 
    249         SkTDArray<FcPattern*> trimmedMatches;
    250         for (int i = 0; i < count; ++i) {
    251             const char* justName = find_just_name(get_name(match[i], FC_FILE));
    252             if (!is_lower(*justName)) {
    253                 *trimmedMatches.append() = match[i];
    254             }
    255         }
    256 
    257         SkFontStyleSet_FC* sset = SkNEW_ARGS(SkFontStyleSet_FC,
    258                                              (trimmedMatches.begin(),
    259                                               trimmedMatches.count()));
    260         return sset;
    261     }
    262 
    263     virtual SkTypeface* onMatchFamilyStyle(const char familyName[],
    264                                            const SkFontStyle&) { return NULL; }
    265     virtual SkTypeface* onMatchFaceStyle(const SkTypeface*,
    266                                          const SkFontStyle&) { return NULL; }
    267 
    268     virtual SkTypeface* onCreateFromData(SkData*, int ttcIndex) { return NULL; }
    269 
    270     virtual SkTypeface* onCreateFromStream(SkStream* stream, int ttcIndex) {
    271         const size_t length = stream->getLength();
    272         if (!length) {
    273             return NULL;
    274         }
    275         if (length >= 1024 * 1024 * 1024) {
    276             return NULL;  // don't accept too large fonts (>= 1GB) for safety.
    277         }
    278 
    279         // TODO should the caller give us the style or should we get it from freetype?
    280         SkTypeface::Style style = SkTypeface::kNormal;
    281         bool isFixedWidth = false;
    282         if (!find_name_and_attributes(stream, NULL, &style, &isFixedWidth)) {
    283             return NULL;
    284         }
    285 
    286         SkTypeface* face = SkNEW_ARGS(FontConfigTypeface, (style, isFixedWidth, stream));
    287         return face;
    288     }
    289 
    290     virtual SkTypeface* onCreateFromFile(const char path[], int ttcIndex) {
    291         SkAutoTUnref<SkStream> stream(SkStream::NewFromFile(path));
    292         return stream.get() ? this->createFromStream(stream, ttcIndex) : NULL;
    293     }
    294 
    295     virtual SkTypeface* onLegacyCreateTypeface(const char familyName[],
    296                                                unsigned styleBits) SK_OVERRIDE {
    297         return FontConfigTypeface::LegacyCreateTypeface(NULL, familyName,
    298                                                   (SkTypeface::Style)styleBits);
    299     }
    300 };
    301 
    302 SkFontMgr* SkFontMgr::Factory() {
    303     SkFontConfigInterface* fci = RefFCI();
    304     return fci ? SkNEW_ARGS(SkFontMgr_fontconfig, (fci)) : NULL;
    305 }
    306