michael@0: /*
michael@0:  * Copyright 2013 Google Inc.
michael@0:  *
michael@0:  * Use of this source code is governed by a BSD-style license that can be
michael@0:  * found in the LICENSE file.
michael@0:  */
michael@0: 
michael@0: #include "SkFontMgr.h"
michael@0: #include "SkFontStyle.h"
michael@0: #include "SkFontConfigInterface.h"
michael@0: #include "SkFontConfigTypeface.h"
michael@0: #include "SkMath.h"
michael@0: #include "SkString.h"
michael@0: #include "SkTDArray.h"
michael@0: 
michael@0: // for now we pull these in directly. eventually we will solely rely on the
michael@0: // SkFontConfigInterface instance.
michael@0: #include <fontconfig/fontconfig.h>
michael@0: #include <unistd.h>
michael@0: 
michael@0: // Defined in SkFontHost_FreeType.cpp
michael@0: bool find_name_and_attributes(SkStream* stream, SkString* name,
michael@0:                               SkTypeface::Style* style, bool* isFixedWidth);
michael@0: 
michael@0: // borrow this global from SkFontHost_fontconfig. eventually that file should
michael@0: // go away, and be replaced with this one.
michael@0: extern SkFontConfigInterface* SkFontHost_fontconfig_ref_global();
michael@0: static SkFontConfigInterface* RefFCI() {
michael@0:     return SkFontHost_fontconfig_ref_global();
michael@0: }
michael@0: 
michael@0: // look for the last substring after a '/' and return that, or return null.
michael@0: static const char* find_just_name(const char* str) {
michael@0:     const char* last = strrchr(str, '/');
michael@0:     return last ? last + 1 : NULL;
michael@0: }
michael@0: 
michael@0: static bool is_lower(char c) {
michael@0:     return c >= 'a' && c <= 'z';
michael@0: }
michael@0: 
michael@0: static int get_int(FcPattern* pattern, const char field[]) {
michael@0:     int value;
michael@0:     if (FcPatternGetInteger(pattern, field, 0, &value) != FcResultMatch) {
michael@0:         value = SK_MinS32;
michael@0:     }
michael@0:     return value;
michael@0: }
michael@0: 
michael@0: static const char* get_name(FcPattern* pattern, const char field[]) {
michael@0:     const char* name;
michael@0:     if (FcPatternGetString(pattern, field, 0, (FcChar8**)&name) != FcResultMatch) {
michael@0:         name = "";
michael@0:     }
michael@0:     return name;
michael@0: }
michael@0: 
michael@0: static bool valid_pattern(FcPattern* pattern) {
michael@0:     FcBool is_scalable;
michael@0:     if (FcPatternGetBool(pattern, FC_SCALABLE, 0, &is_scalable) != FcResultMatch || !is_scalable) {
michael@0:         return false;
michael@0:     }
michael@0: 
michael@0:     // fontconfig can also return fonts which are unreadable
michael@0:     const char* c_filename = get_name(pattern, FC_FILE);
michael@0:     if (0 == *c_filename) {
michael@0:         return false;
michael@0:     }
michael@0:     if (access(c_filename, R_OK) != 0) {
michael@0:         return false;
michael@0:     }
michael@0:     return true;
michael@0: }
michael@0: 
michael@0: static bool match_name(FcPattern* pattern, const char family_name[]) {
michael@0:     return !strcasecmp(family_name, get_name(pattern, FC_FAMILY));
michael@0: }
michael@0: 
michael@0: static FcPattern** MatchFont(FcFontSet* font_set,
michael@0:                              const char post_config_family[],
michael@0:                              int* count) {
michael@0:   // Older versions of fontconfig have a bug where they cannot select
michael@0:   // only scalable fonts so we have to manually filter the results.
michael@0: 
michael@0:     FcPattern** iter = font_set->fonts;
michael@0:     FcPattern** stop = iter + font_set->nfont;
michael@0:     // find the first good match
michael@0:     for (; iter < stop; ++iter) {
michael@0:         if (valid_pattern(*iter)) {
michael@0:             break;
michael@0:         }
michael@0:     }
michael@0: 
michael@0:     if (iter == stop || !match_name(*iter, post_config_family)) {
michael@0:         return NULL;
michael@0:     }
michael@0: 
michael@0:     FcPattern** firstIter = iter++;
michael@0:     for (; iter < stop; ++iter) {
michael@0:         if (!valid_pattern(*iter) || !match_name(*iter, post_config_family)) {
michael@0:             break;
michael@0:         }
michael@0:     }
michael@0: 
michael@0:     *count = iter - firstIter;
michael@0:     return firstIter;
michael@0: }
michael@0: 
michael@0: class SkFontStyleSet_FC : public SkFontStyleSet {
michael@0: public:
michael@0:     SkFontStyleSet_FC(FcPattern** matches, int count);
michael@0:     virtual ~SkFontStyleSet_FC();
michael@0: 
michael@0:     virtual int count() SK_OVERRIDE { return fRecCount; }
michael@0:     virtual void getStyle(int index, SkFontStyle*, SkString* style) SK_OVERRIDE;
michael@0:     virtual SkTypeface* createTypeface(int index) SK_OVERRIDE;
michael@0:     virtual SkTypeface* matchStyle(const SkFontStyle& pattern) SK_OVERRIDE;
michael@0: 
michael@0: private:
michael@0:     struct Rec {
michael@0:         SkString    fStyleName;
michael@0:         SkString    fFileName;
michael@0:         SkFontStyle fStyle;
michael@0:     };
michael@0:     Rec* fRecs;
michael@0:     int  fRecCount;
michael@0: };
michael@0: 
michael@0: static int map_range(int value,
michael@0:                      int old_min, int old_max, int new_min, int new_max) {
michael@0:     SkASSERT(old_min < old_max);
michael@0:     SkASSERT(new_min < new_max);
michael@0:     return new_min + SkMulDiv(value - old_min,
michael@0:                               new_max - new_min, old_max - old_min);
michael@0: }
michael@0: 
michael@0: static SkFontStyle make_fontconfig_style(FcPattern* match) {
michael@0:     int weight = get_int(match, FC_WEIGHT);
michael@0:     int width = get_int(match, FC_WIDTH);
michael@0:     int slant = get_int(match, FC_SLANT);
michael@0: //    SkDebugf("old weight %d new weight %d\n", weight, map_range(weight, 0, 80, 0, 400));
michael@0: 
michael@0:     // fontconfig weight seems to be 0..200 or so, so we remap it here
michael@0:     weight = map_range(weight, 0, 80, 0, 400);
michael@0:     width = map_range(width, 0, 200, 0, 9);
michael@0:     return SkFontStyle(weight, width, slant > 0 ? SkFontStyle::kItalic_Slant
michael@0:                                                 : SkFontStyle::kUpright_Slant);
michael@0: }
michael@0: 
michael@0: SkFontStyleSet_FC::SkFontStyleSet_FC(FcPattern** matches, int count) {
michael@0:     fRecCount = count;
michael@0:     fRecs = SkNEW_ARRAY(Rec, count);
michael@0:     for (int i = 0; i < count; ++i) {
michael@0:         fRecs[i].fStyleName.set(get_name(matches[i], FC_STYLE));
michael@0:         fRecs[i].fFileName.set(get_name(matches[i], FC_FILE));
michael@0:         fRecs[i].fStyle = make_fontconfig_style(matches[i]);
michael@0:     }
michael@0: }
michael@0: 
michael@0: SkFontStyleSet_FC::~SkFontStyleSet_FC() {
michael@0:     SkDELETE_ARRAY(fRecs);
michael@0: }
michael@0: 
michael@0: void SkFontStyleSet_FC::getStyle(int index, SkFontStyle* style,
michael@0:                                  SkString* styleName) {
michael@0:     SkASSERT((unsigned)index < (unsigned)fRecCount);
michael@0:     if (style) {
michael@0:         *style = fRecs[index].fStyle;
michael@0:     }
michael@0:     if (styleName) {
michael@0:         *styleName = fRecs[index].fStyleName;
michael@0:     }
michael@0: }
michael@0: 
michael@0: SkTypeface* SkFontStyleSet_FC::createTypeface(int index) {
michael@0:     return NULL;
michael@0: }
michael@0: 
michael@0: SkTypeface* SkFontStyleSet_FC::matchStyle(const SkFontStyle& pattern) {
michael@0:     return NULL;
michael@0: }
michael@0: 
michael@0: class SkFontMgr_fontconfig : public SkFontMgr {
michael@0:     SkAutoTUnref<SkFontConfigInterface> fFCI;
michael@0:     SkDataTable* fFamilyNames;
michael@0: 
michael@0: 
michael@0: public:
michael@0:     SkFontMgr_fontconfig(SkFontConfigInterface* fci)
michael@0:         : fFCI(fci)
michael@0:         , fFamilyNames(fFCI->getFamilyNames()) {}
michael@0: 
michael@0:     virtual ~SkFontMgr_fontconfig() {
michael@0:         SkSafeUnref(fFamilyNames);
michael@0:     }
michael@0: 
michael@0: protected:
michael@0:     virtual int onCountFamilies() const SK_OVERRIDE {
michael@0:         return fFamilyNames->count();
michael@0:     }
michael@0: 
michael@0:     virtual void onGetFamilyName(int index, SkString* familyName) const SK_OVERRIDE {
michael@0:         familyName->set(fFamilyNames->atStr(index));
michael@0:     }
michael@0: 
michael@0:     virtual SkFontStyleSet* onCreateStyleSet(int index) const SK_OVERRIDE {
michael@0:         return this->onMatchFamily(fFamilyNames->atStr(index));
michael@0:     }
michael@0: 
michael@0:     virtual SkFontStyleSet* onMatchFamily(const char familyName[]) const SK_OVERRIDE {
michael@0:         FcPattern* pattern = FcPatternCreate();
michael@0: 
michael@0:         FcPatternAddString(pattern, FC_FAMILY, (FcChar8*)familyName);
michael@0: #if 0
michael@0:         FcPatternAddBool(pattern, FC_SCALABLE, FcTrue);
michael@0: #endif
michael@0:         FcConfigSubstitute(NULL, pattern, FcMatchPattern);
michael@0:         FcDefaultSubstitute(pattern);
michael@0: 
michael@0:         const char* post_config_family = get_name(pattern, FC_FAMILY);
michael@0: 
michael@0:         FcResult result;
michael@0:         FcFontSet* font_set = FcFontSort(0, pattern, 0, 0, &result);
michael@0:         if (!font_set) {
michael@0:             FcPatternDestroy(pattern);
michael@0:             return NULL;
michael@0:         }
michael@0: 
michael@0:         int count;
michael@0:         FcPattern** match = MatchFont(font_set, post_config_family, &count);
michael@0:         if (!match) {
michael@0:             FcPatternDestroy(pattern);
michael@0:             FcFontSetDestroy(font_set);
michael@0:             return NULL;
michael@0:         }
michael@0: 
michael@0:         FcPatternDestroy(pattern);
michael@0: 
michael@0:         SkTDArray<FcPattern*> trimmedMatches;
michael@0:         for (int i = 0; i < count; ++i) {
michael@0:             const char* justName = find_just_name(get_name(match[i], FC_FILE));
michael@0:             if (!is_lower(*justName)) {
michael@0:                 *trimmedMatches.append() = match[i];
michael@0:             }
michael@0:         }
michael@0: 
michael@0:         SkFontStyleSet_FC* sset = SkNEW_ARGS(SkFontStyleSet_FC,
michael@0:                                              (trimmedMatches.begin(),
michael@0:                                               trimmedMatches.count()));
michael@0:         return sset;
michael@0:     }
michael@0: 
michael@0:     virtual SkTypeface* onMatchFamilyStyle(const char familyName[],
michael@0:                                            const SkFontStyle&) const SK_OVERRIDE { return NULL; }
michael@0:     virtual SkTypeface* onMatchFaceStyle(const SkTypeface*,
michael@0:                                          const SkFontStyle&) const SK_OVERRIDE { return NULL; }
michael@0: 
michael@0:     virtual SkTypeface* onCreateFromData(SkData*, int ttcIndex) const SK_OVERRIDE { return NULL; }
michael@0: 
michael@0:     virtual SkTypeface* onCreateFromStream(SkStream* stream, int ttcIndex) const SK_OVERRIDE {
michael@0:         const size_t length = stream->getLength();
michael@0:         if (!length) {
michael@0:             return NULL;
michael@0:         }
michael@0:         if (length >= 1024 * 1024 * 1024) {
michael@0:             return NULL;  // don't accept too large fonts (>= 1GB) for safety.
michael@0:         }
michael@0: 
michael@0:         // TODO should the caller give us the style or should we get it from freetype?
michael@0:         SkTypeface::Style style = SkTypeface::kNormal;
michael@0:         bool isFixedWidth = false;
michael@0:         if (!find_name_and_attributes(stream, NULL, &style, &isFixedWidth)) {
michael@0:             return NULL;
michael@0:         }
michael@0: 
michael@0:         SkTypeface* face = SkNEW_ARGS(FontConfigTypeface, (style, isFixedWidth, stream));
michael@0:         return face;
michael@0:     }
michael@0: 
michael@0:     virtual SkTypeface* onCreateFromFile(const char path[], int ttcIndex) const SK_OVERRIDE {
michael@0:         SkAutoTUnref<SkStream> stream(SkStream::NewFromFile(path));
michael@0:         return stream.get() ? this->createFromStream(stream, ttcIndex) : NULL;
michael@0:     }
michael@0: 
michael@0:     virtual SkTypeface* onLegacyCreateTypeface(const char familyName[],
michael@0:                                                unsigned styleBits) const SK_OVERRIDE {
michael@0:         return FontConfigTypeface::LegacyCreateTypeface(NULL, familyName,
michael@0:                                                   (SkTypeface::Style)styleBits);
michael@0:     }
michael@0: };
michael@0: 
michael@0: SkFontMgr* SkFontMgr::Factory() {
michael@0:     SkFontConfigInterface* fci = RefFCI();
michael@0:     return fci ? SkNEW_ARGS(SkFontMgr_fontconfig, (fci)) : NULL;
michael@0: }