DXR is a code search and navigation tool aimed at making sense of large projects. It supports full-text and regex searches as well as structural queries.

Mercurial (d8847129d134)

VCS Links

Line Code
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743

/*
 * Copyright 2013 The Android Open Source Project
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

#include "SkFontConfigInterface.h"
#include "SkTypeface_android.h"

#include "SkFontConfigParser_android.h"
#include "SkFontConfigTypeface.h"
#include "SkFontHost_FreeType_common.h"
#include "SkFontMgr.h"
#include "SkGlyphCache.h"
#include "SkPaint.h"
#include "SkString.h"
#include "SkStream.h"
#include "SkThread.h"
#include "SkTypefaceCache.h"
#include "SkTArray.h"
#include "SkTDict.h"
#include "SkTSearch.h"

#include <stdio.h>
#include <string.h>

#ifndef SK_DEBUG_FONTS
    #define SK_DEBUG_FONTS 0
#endif

#if SK_DEBUG_FONTS
    #define DEBUG_FONT(args) SkDebugf args
#else
    #define DEBUG_FONT(args)
#endif

///////////////////////////////////////////////////////////////////////////////

// For test only.
static const char* gTestMainConfigFile = NULL;
static const char* gTestFallbackConfigFile = NULL;
static const char* gTestFontFilePrefix = NULL;

///////////////////////////////////////////////////////////////////////////////

typedef int32_t FontRecID;
#define INVALID_FONT_REC_ID -1

typedef int32_t FamilyRecID;
#define INVALID_FAMILY_REC_ID -1

// used to record our notion of the pre-existing fonts
struct FontRec {
    SkAutoTUnref<SkTypeface> fTypeface;
    SkString fFileName;
    SkTypeface::Style fStyle;
    bool fIsValid;
    FamilyRecID fFamilyRecID;
};

struct FamilyRec {
    FamilyRec() {
        memset(fFontRecID, INVALID_FONT_REC_ID, sizeof(fFontRecID));
    }

    static const int FONT_STYLE_COUNT = 4;
    FontRecID fFontRecID[FONT_STYLE_COUNT];
    bool fIsFallbackFont;
    SkString fFallbackName;
    SkPaintOptionsAndroid fPaintOptions;
};


typedef SkTDArray<FamilyRecID> FallbackFontList;

class SkFontConfigInterfaceAndroid : public SkFontConfigInterface {
public:
    SkFontConfigInterfaceAndroid(SkTDArray<FontFamily*>& fontFamilies);
    virtual ~SkFontConfigInterfaceAndroid();

    virtual bool matchFamilyName(const char familyName[],
                                 SkTypeface::Style requested,
                                 FontIdentity* outFontIdentifier,
                                 SkString* outFamilyName,
                                 SkTypeface::Style* outStyle) SK_OVERRIDE;
    virtual SkStream* openStream(const FontIdentity&) SK_OVERRIDE;

    // new APIs
    virtual SkDataTable* getFamilyNames() SK_OVERRIDE;
    virtual bool matchFamilySet(const char inFamilyName[],
                                SkString* outFamilyName,
                                SkTArray<FontIdentity>*) SK_OVERRIDE;

    /**
     *  Get the family name of the font in the default fallback font list that
     *  contains the specified chararacter. if no font is found, returns false.
     */
    bool getFallbackFamilyNameForChar(SkUnichar uni, const char* lang, SkString* name);
    /**
     *
     */
    SkTypeface* nextLogicalTypeface(SkFontID currFontID, SkFontID origFontID,
                                    const SkPaintOptionsAndroid& options);
    SkTypeface* getTypefaceForGlyphID(uint16_t glyphID, const SkTypeface* origTypeface,
                                      const SkPaintOptionsAndroid& options,
                                      int* lowerBounds, int* upperBounds);

private:
    void addFallbackFamily(FamilyRecID fontRecID);
    SkTypeface* getTypefaceForFontRec(FontRecID fontRecID);
    FallbackFontList* getCurrentLocaleFallbackFontList();
    FallbackFontList* findFallbackFontList(const SkLanguage& lang, bool isOriginal = true);

    SkTArray<FontRec, true> fFonts;
    SkTArray<FamilyRec, true> fFontFamilies;
    SkTDict<FamilyRecID> fFamilyNameDict;
    FamilyRecID fDefaultFamilyRecID;

    // (SkLanguage)<->(fallback chain index) translation
    SkTDict<FallbackFontList*> fFallbackFontDict;
    SkTDict<FallbackFontList*> fFallbackFontAliasDict;
    FallbackFontList fDefaultFallbackList;

    // fallback info for current locale
    SkString fCachedLocale;
    FallbackFontList* fLocaleFallbackFontList;
};

///////////////////////////////////////////////////////////////////////////////

SK_DECLARE_STATIC_MUTEX(gGetSingletonInterfaceMutex);
static SkFontConfigInterfaceAndroid* getSingletonInterface() {
    static SkFontConfigInterfaceAndroid* gFontConfigInterface;

    SkAutoMutexAcquire ac(gGetSingletonInterfaceMutex);
    if (NULL == gFontConfigInterface) {
        // load info from a configuration file that we can use to populate the
        // system/fallback font structures
        SkTDArray<FontFamily*> fontFamilies;
        if (!gTestMainConfigFile) {
            SkFontConfigParser::GetFontFamilies(fontFamilies);
        } else {
            SkFontConfigParser::GetTestFontFamilies(fontFamilies, gTestMainConfigFile,
                                                    gTestFallbackConfigFile);
        }

        gFontConfigInterface = new SkFontConfigInterfaceAndroid(fontFamilies);

        // cleanup the data we received from the parser
        fontFamilies.deleteAll();
    }
    return gFontConfigInterface;
}

SkFontConfigInterface* SkFontConfigInterface::GetSingletonDirectInterface(SkBaseMutex*) {
    // Doesn't need passed-in mutex because getSingletonInterface() uses one
    return getSingletonInterface();
}

///////////////////////////////////////////////////////////////////////////////

static bool has_font(const SkTArray<FontRec, true>& array, const SkString& filename) {
    for (int i = 0; i < array.count(); i++) {
        if (array[i].fFileName == filename) {
            return true;
        }
    }
    return false;
}

#ifndef SK_FONT_FILE_PREFIX
    #define SK_FONT_FILE_PREFIX          "/fonts/"
#endif

static void get_path_for_sys_fonts(SkString* full, const SkString& name) {
    if (gTestFontFilePrefix) {
        full->set(gTestFontFilePrefix);
    } else {
        full->set(getenv("ANDROID_ROOT"));
        full->append(SK_FONT_FILE_PREFIX);
    }
    full->append(name);
}

static void insert_into_name_dict(SkTDict<FamilyRecID>& familyNameDict,
                                  const char* name, FamilyRecID familyRecID) {
    SkAutoAsciiToLC tolc(name);
    if (familyNameDict.find(tolc.lc())) {
        SkDebugf("---- system font attempting to use a the same name [%s] for"
                 "multiple families. skipping subsequent occurrences", tolc.lc());
    } else {
        familyNameDict.set(tolc.lc(), familyRecID);
    }
}

///////////////////////////////////////////////////////////////////////////////

SkFontConfigInterfaceAndroid::SkFontConfigInterfaceAndroid(SkTDArray<FontFamily*>& fontFamilies) :
        fFonts(fontFamilies.count()),
        fFontFamilies(fontFamilies.count() / FamilyRec::FONT_STYLE_COUNT),
        fFamilyNameDict(1024),
        fDefaultFamilyRecID(INVALID_FAMILY_REC_ID),
        fFallbackFontDict(128),
        fFallbackFontAliasDict(128),
        fLocaleFallbackFontList(NULL) {

    for (int i = 0; i < fontFamilies.count(); ++i) {
        FontFamily* family = fontFamilies[i];

        // defer initializing the familyRec until we can be sure that at least
        // one of it's children contains a valid font file
        FamilyRec* familyRec = NULL;
        FamilyRecID familyRecID = INVALID_FAMILY_REC_ID;

        for (int j = 0; j < family->fFontFiles.count(); ++j) {
            SkString filename;
            get_path_for_sys_fonts(&filename, family->fFontFiles[j].fFileName);

            if (has_font(fFonts, filename)) {
                SkDebugf("---- system font and fallback font files specify a duplicate "
                        "font %s, skipping the second occurrence", filename.c_str());
                continue;
            }

            FontRec& fontRec = fFonts.push_back();
            fontRec.fFileName = filename;
            fontRec.fStyle = SkTypeface::kNormal;
            fontRec.fIsValid = false;
            fontRec.fFamilyRecID = familyRecID;

            const FontRecID fontRecID = fFonts.count() - 1;

            SkAutoTUnref<SkStream> stream(SkStream::NewFromFile(filename.c_str()));
            if (stream.get() != NULL) {
                bool isFixedWidth;
                SkString name;
                fontRec.fIsValid = SkTypeface_FreeType::ScanFont(stream.get(), 0,
                                                                 &name, &fontRec.fStyle,
                                                                 &isFixedWidth);
            } else {
                if (!family->fIsFallbackFont) {
                    SkDebugf("---- failed to open <%s> as a font\n", filename.c_str());
                }
            }

            if (fontRec.fIsValid) {
                DEBUG_FONT(("---- SystemFonts[%d][%d] fallback=%d file=%s",
                           i, fFonts.count() - 1, family->fIsFallbackFont, filename.c_str()));
            } else {
                DEBUG_FONT(("---- SystemFonts[%d][%d] fallback=%d file=%s (INVALID)",
                           i, fFonts.count() - 1, family->fIsFallbackFont, filename.c_str()));
                continue;
            }

            // create a familyRec now that we know that at least one font in
            // the family is valid
            if (familyRec == NULL) {
                familyRec = &fFontFamilies.push_back();
                familyRecID = fFontFamilies.count() - 1;
                fontRec.fFamilyRecID = familyRecID;

                familyRec->fIsFallbackFont = family->fIsFallbackFont;
                familyRec->fPaintOptions = family->fFontFiles[j].fPaintOptions;

            } else if (familyRec->fPaintOptions != family->fFontFiles[j].fPaintOptions) {
                SkDebugf("Every font file within a family must have identical"
                         "language and variant attributes");
                sk_throw();
            }

            // add this font to the current familyRec
            if (INVALID_FONT_REC_ID != familyRec->fFontRecID[fontRec.fStyle]) {
                DEBUG_FONT(("Overwriting familyRec for style[%d] old,new:(%d,%d)",
                            fontRec.fStyle, familyRec->fFontRecID[fontRec.fStyle],
                            fontRecID));
            }
            familyRec->fFontRecID[fontRec.fStyle] = fontRecID;
        }

        if (familyRec) {
            if (familyRec->fIsFallbackFont) {
                // add the font to the appropriate fallback chains and also insert a
                // unique name into the familyNameDict for internal usage
                addFallbackFamily(familyRecID);
            } else {
                // add the names that map to this family to the dictionary for easy lookup
                const SkTArray<SkString>& names = family->fNames;
                if (names.empty()) {
                    SkDEBUGFAIL("ERROR: non-fallback font with no name");
                    continue;
                }

                for (int i = 0; i < names.count(); i++) {
                    insert_into_name_dict(fFamilyNameDict, names[i].c_str(), familyRecID);
                }
            }
        }
    }

    DEBUG_FONT(("---- We have %d system fonts", fFonts.count()));

    if (fFontFamilies.count() > 0) {
        fDefaultFamilyRecID = 0;
    }

    // scans the default fallback font chain, adding every entry to every other
    // fallback font chain to which it does not belong. this results in every
    // language-specific fallback font chain having all of its fallback fonts at
    // the front of the chain, and everything else at the end.
    FallbackFontList* fallbackList;
    SkTDict<FallbackFontList*>::Iter iter(fFallbackFontDict);
    const char* fallbackLang = iter.next(&fallbackList);
    while(fallbackLang != NULL) {
        for (int i = 0; i < fDefaultFallbackList.count(); i++) {
            FamilyRecID familyRecID = fDefaultFallbackList[i];
            const SkString& fontLang = fFontFamilies[familyRecID].fPaintOptions.getLanguage().getTag();
            if (strcmp(fallbackLang, fontLang.c_str()) != 0) {
                fallbackList->push(familyRecID);
            }
        }
        // move to the next fallback list in the dictionary
        fallbackLang = iter.next(&fallbackList);
    }
}

SkFontConfigInterfaceAndroid::~SkFontConfigInterfaceAndroid() {
    // iterate through and cleanup fFallbackFontDict
    SkTDict<FallbackFontList*>::Iter iter(fFallbackFontDict);
    FallbackFontList* fallbackList;
    while(iter.next(&fallbackList) != NULL) {
        SkDELETE(fallbackList);
    }
}

void SkFontConfigInterfaceAndroid::addFallbackFamily(FamilyRecID familyRecID) {
    SkASSERT(familyRecID < fFontFamilies.count());
    FamilyRec& familyRec = fFontFamilies[familyRecID];
    SkASSERT(familyRec.fIsFallbackFont);

    // add the fallback family to the name dictionary.  This is
    // needed by getFallbackFamilyNameForChar() so that fallback
    // families can be identified by a unique name. The unique
    // identifier that we've chosen is the familyID in hex (e.g. '0F##fallback').
    familyRec.fFallbackName.printf("%.2x##fallback", familyRecID);
    insert_into_name_dict(fFamilyNameDict, familyRec.fFallbackName.c_str(), familyRecID);

    // add to the default fallback list
    fDefaultFallbackList.push(familyRecID);

    // stop here if it is the default language tag
    const SkString& languageTag = familyRec.fPaintOptions.getLanguage().getTag();
    if (languageTag.isEmpty()) {
        return;
    }

    // add to the appropriate language's custom fallback list
    FallbackFontList* customList = NULL;
    if (!fFallbackFontDict.find(languageTag.c_str(), &customList)) {
        DEBUG_FONT(("----  Created fallback list for \"%s\"", languageTag.c_str()));
        customList = SkNEW(FallbackFontList);
        fFallbackFontDict.set(languageTag.c_str(), customList);
    }
    SkASSERT(customList != NULL);
    customList->push(familyRecID);
}


static FontRecID find_best_style(const FamilyRec& family, SkTypeface::Style style) {

    const FontRecID* fontRecIDs = family.fFontRecID;

    if (fontRecIDs[style] != INVALID_FONT_REC_ID) { // exact match
        return fontRecIDs[style];
    }
    // look for a matching bold
    style = (SkTypeface::Style)(style ^ SkTypeface::kItalic);
    if (fontRecIDs[style] != INVALID_FONT_REC_ID) {
        return fontRecIDs[style];
    }
    // look for the plain
    if (fontRecIDs[SkTypeface::kNormal] != INVALID_FONT_REC_ID) {
        return fontRecIDs[SkTypeface::kNormal];
    }
    // look for anything
    for (int i = 0; i < FamilyRec::FONT_STYLE_COUNT; i++) {
        if (fontRecIDs[i] != INVALID_FONT_REC_ID) {
            return fontRecIDs[i];
        }
    }
    // should never get here, since the fontRecID list should not be empty
    SkDEBUGFAIL("No valid fonts exist for this family");
    return -1;
}

bool SkFontConfigInterfaceAndroid::matchFamilyName(const char familyName[],
                                                   SkTypeface::Style style,
                                                   FontIdentity* outFontIdentifier,
                                                   SkString* outFamilyName,
                                                   SkTypeface::Style* outStyle) {
    // clip to legal style bits
    style = (SkTypeface::Style)(style & SkTypeface::kBoldItalic);

    bool exactNameMatch = false;

    FamilyRecID familyRecID = INVALID_FAMILY_REC_ID;
    if (NULL != familyName) {
        SkAutoAsciiToLC tolc(familyName);
        if (fFamilyNameDict.find(tolc.lc(), &familyRecID)) {
            exactNameMatch = true;
        }
    } else {
        familyRecID = fDefaultFamilyRecID;

    }

    // If no matching family name is found then return false. This allows clients
    // to be able to search for other fonts instead of forcing them to use the
    // default font.
    if (INVALID_FAMILY_REC_ID == familyRecID) {
        return false;
    }

    FontRecID fontRecID = find_best_style(fFontFamilies[familyRecID], style);
    FontRec& fontRec = fFonts[fontRecID];

    if (NULL != outFontIdentifier) {
        outFontIdentifier->fID = fontRecID;
        outFontIdentifier->fTTCIndex = 0;
        outFontIdentifier->fString.set(fontRec.fFileName);
//        outFontIdentifier->fStyle = fontRec.fStyle;
    }

    if (NULL != outFamilyName) {
        if (exactNameMatch) {
            outFamilyName->set(familyName);
        } else {
            // find familyName from list of names
            const char* familyName = NULL;
            SkAssertResult(fFamilyNameDict.findKey(familyRecID, &familyName));
            SkASSERT(familyName);
            outFamilyName->set(familyName);
        }
    }

    if (NULL != outStyle) {
        *outStyle = fontRec.fStyle;
    }

    return true;
}

SkStream* SkFontConfigInterfaceAndroid::openStream(const FontIdentity& identity) {
    return SkStream::NewFromFile(identity.fString.c_str());
}

SkDataTable* SkFontConfigInterfaceAndroid::getFamilyNames() {
    SkTDArray<const char*> names;
    SkTDArray<size_t> sizes;

    SkTDict<FamilyRecID>::Iter iter(fFamilyNameDict);
    const char* familyName = iter.next(NULL);
    while(familyName != NULL) {
        *names.append() = familyName;
        *sizes.append() = strlen(familyName) + 1;

        // move to the next familyName in the dictionary
        familyName = iter.next(NULL);
    }

    return SkDataTable::NewCopyArrays((const void*const*)names.begin(),
                                      sizes.begin(), names.count());
}

bool SkFontConfigInterfaceAndroid::matchFamilySet(const char inFamilyName[],
                                                  SkString* outFamilyName,
                                                  SkTArray<FontIdentity>*) {
    return false;
}

static bool find_proc(SkTypeface* face, SkTypeface::Style style, void* ctx) {
    const FontRecID* fontRecID = (const FontRecID*)ctx;
    FontRecID currFontRecID = ((FontConfigTypeface*)face)->getIdentity().fID;
    return currFontRecID == *fontRecID;
}

SkTypeface* SkFontConfigInterfaceAndroid::getTypefaceForFontRec(FontRecID fontRecID) {
    FontRec& fontRec = fFonts[fontRecID];
    SkTypeface* face = fontRec.fTypeface.get();
    if (!face) {
        // look for it in the typeface cache
        face = SkTypefaceCache::FindByProcAndRef(find_proc, &fontRecID);

        // if it is not in the cache then create it
        if (!face) {
            const char* familyName = NULL;
            SkAssertResult(fFamilyNameDict.findKey(fontRec.fFamilyRecID, &familyName));
            SkASSERT(familyName);
            face = SkTypeface::CreateFromName(familyName, fontRec.fStyle);
        }

        // store the result for subsequent lookups
        fontRec.fTypeface.reset(face);
    }
    SkASSERT(face);
    return face;
}

bool SkFontConfigInterfaceAndroid::getFallbackFamilyNameForChar(SkUnichar uni,
                                                                const char* lang,
                                                                SkString* name) {
    FallbackFontList* fallbackFontList = NULL;
    const SkString langTag(lang);
    if (langTag.isEmpty()) {
        fallbackFontList = this->getCurrentLocaleFallbackFontList();
    } else {
        fallbackFontList = this->findFallbackFontList(langTag);
    }

    for (int i = 0; i < fallbackFontList->count(); i++) {
        FamilyRecID familyRecID = fallbackFontList->getAt(i);

        // if it is not one of the accepted variants then move to the next family
        int32_t acceptedVariants = SkPaintOptionsAndroid::kDefault_Variant |
                                   SkPaintOptionsAndroid::kElegant_Variant;
        if (!(fFontFamilies[familyRecID].fPaintOptions.getFontVariant() & acceptedVariants)) {
            continue;
        }

        FontRecID fontRecID = find_best_style(fFontFamilies[familyRecID], SkTypeface::kNormal);
        SkTypeface* face = this->getTypefaceForFontRec(fontRecID);

        SkPaint paint;
        paint.setTypeface(face);
        paint.setTextEncoding(SkPaint::kUTF32_TextEncoding);

        uint16_t glyphID;
        paint.textToGlyphs(&uni, sizeof(uni), &glyphID);
        if (glyphID != 0) {
            name->set(fFontFamilies[familyRecID].fFallbackName);
            return true;
        }
    }
    return false;
}

FallbackFontList* SkFontConfigInterfaceAndroid::getCurrentLocaleFallbackFontList() {
    SkString locale = SkFontConfigParser::GetLocale();
    if (NULL == fLocaleFallbackFontList || locale != fCachedLocale) {
        fCachedLocale = locale;
        fLocaleFallbackFontList = this->findFallbackFontList(locale);
    }
    return fLocaleFallbackFontList;
}

FallbackFontList* SkFontConfigInterfaceAndroid::findFallbackFontList(const SkLanguage& lang,
                                                                     bool isOriginal) {
    const SkString& langTag = lang.getTag();
    if (langTag.isEmpty()) {
        return &fDefaultFallbackList;
    }

    FallbackFontList* fallbackFontList;
    if (fFallbackFontDict.find(langTag.c_str(), langTag.size(), &fallbackFontList) ||
        fFallbackFontAliasDict.find(langTag.c_str(), langTag.size(), &fallbackFontList)) {
        return fallbackFontList;
    }

    // attempt a recursive fuzzy match
    SkLanguage parent = lang.getParent();
    fallbackFontList = findFallbackFontList(parent, false);

    // cache the original lang so we don't have to do the recursion again.
    if (isOriginal) {
        DEBUG_FONT(("----  Created fallback list alias for \"%s\"", langTag.c_str()));
        fFallbackFontAliasDict.set(langTag.c_str(), fallbackFontList);
    }
    return fallbackFontList;
}

SkTypeface* SkFontConfigInterfaceAndroid::nextLogicalTypeface(SkFontID currFontID,
                                                              SkFontID origFontID,
                                                              const SkPaintOptionsAndroid& opts) {
    // Skia does not support font fallback by default. This enables clients such
    // as WebKit to customize their font selection. In any case, clients can use
    // GetFallbackFamilyNameForChar() to get the fallback font for individual
    // characters.
    if (!opts.isUsingFontFallbacks()) {
        return NULL;
    }

    FallbackFontList* currentFallbackList = findFallbackFontList(opts.getLanguage());
    SkASSERT(currentFallbackList);

    SkTypeface::Style origStyle = SkTypeface::kNormal;
    const SkTypeface* origTypeface = SkTypefaceCache::FindByID(origFontID);
    if (NULL != origTypeface) {
        origStyle = origTypeface->style();
    }

    // we must convert currTypeface into a FontRecID
    FontRecID currFontRecID = INVALID_FONT_REC_ID;
    const SkTypeface* currTypeface = SkTypefaceCache::FindByID(currFontID);
    // non-system fonts are not in the font cache so if we are asked to fallback
    // for a non-system font we will start at the front of the chain.
    if (NULL != currTypeface) {
        currFontRecID = ((FontConfigTypeface*)currTypeface)->getIdentity().fID;
        SkASSERT(INVALID_FONT_REC_ID != currFontRecID);
    }

    FamilyRecID currFamilyRecID = INVALID_FAMILY_REC_ID;
    if (INVALID_FONT_REC_ID != currFontRecID) {
        currFamilyRecID = fFonts[currFontRecID].fFamilyRecID;
    }

    // lookup the index next font in the chain
    int currFallbackFontIndex = currentFallbackList->find(currFamilyRecID);
    // We add 1 to the returned index for 2 reasons: (1) if find succeeds it moves
    // our index to the next entry in the list; (2) if find() fails it returns
    // -1 and incrementing it will set our starting index to 0 (the head of the list)
    int nextFallbackFontIndex = currFallbackFontIndex + 1;

    if(nextFallbackFontIndex >= currentFallbackList->count()) {
        return NULL;
    }

    // If a rec object is set to prefer "kDefault_Variant" it means they have no preference
    // In this case, we set the value to "kCompact_Variant"
    SkPaintOptionsAndroid::FontVariant variant = opts.getFontVariant();
    if (variant == SkPaintOptionsAndroid::kDefault_Variant) {
        variant = SkPaintOptionsAndroid::kCompact_Variant;
    }

    int32_t acceptedVariants = SkPaintOptionsAndroid::kDefault_Variant | variant;

    SkTypeface* nextLogicalTypeface = 0;
    while (nextFallbackFontIndex < currentFallbackList->count()) {
        FamilyRecID familyRecID = currentFallbackList->getAt(nextFallbackFontIndex);
        if ((fFontFamilies[familyRecID].fPaintOptions.getFontVariant() & acceptedVariants) != 0) {
            FontRecID matchedFont = find_best_style(fFontFamilies[familyRecID], origStyle);
            nextLogicalTypeface = this->getTypefaceForFontRec(matchedFont);
            break;
        }
        nextFallbackFontIndex++;
    }

    DEBUG_FONT(("---- nextLogicalFont: currFontID=%d, origFontID=%d, currRecID=%d, "
                "lang=%s, variant=%d, nextFallbackIndex[%d,%d] => nextLogicalTypeface=%d",
                currFontID, origFontID, currFontRecID, opts.getLanguage().getTag().c_str(),
                variant, nextFallbackFontIndex, currentFallbackList->getAt(nextFallbackFontIndex),
                (nextLogicalTypeface) ? nextLogicalTypeface->uniqueID() : 0));
    return SkSafeRef(nextLogicalTypeface);
}

SkTypeface* SkFontConfigInterfaceAndroid::getTypefaceForGlyphID(uint16_t glyphID,
                                                                const SkTypeface* origTypeface,
                                                                const SkPaintOptionsAndroid& opts,
                                                                int* lBounds, int* uBounds) {
    // If we aren't using fallbacks then we shouldn't be calling this
    SkASSERT(opts.isUsingFontFallbacks());
    SkASSERT(origTypeface);

    SkTypeface* currentTypeface = NULL;
    int lowerBounds = 0; //inclusive
    int upperBounds = origTypeface->countGlyphs(); //exclusive

    // check to see if the glyph is in the bounds of the origTypeface
    if (glyphID < upperBounds) {
        currentTypeface = const_cast<SkTypeface*>(origTypeface);
    } else {
        FallbackFontList* currentFallbackList = findFallbackFontList(opts.getLanguage());
        SkASSERT(currentFallbackList);

        // If an object is set to prefer "kDefault_Variant" it means they have no preference
        // In this case, we set the value to "kCompact_Variant"
        SkPaintOptionsAndroid::FontVariant variant = opts.getFontVariant();
        if (variant == SkPaintOptionsAndroid::kDefault_Variant) {
            variant = SkPaintOptionsAndroid::kCompact_Variant;
        }

        int32_t acceptedVariants = SkPaintOptionsAndroid::kDefault_Variant | variant;
        SkTypeface::Style origStyle = origTypeface->style();

        for (int x = 0; x < currentFallbackList->count(); ++x) {
            const FamilyRecID familyRecID = currentFallbackList->getAt(x);
            const SkPaintOptionsAndroid& familyOptions = fFontFamilies[familyRecID].fPaintOptions;
            if ((familyOptions.getFontVariant() & acceptedVariants) != 0) {
                FontRecID matchedFont = find_best_style(fFontFamilies[familyRecID], origStyle);
                currentTypeface = this->getTypefaceForFontRec(matchedFont);
                lowerBounds = upperBounds;
                upperBounds += currentTypeface->countGlyphs();
                if (glyphID < upperBounds) {
                    break;
                }
            }
        }
    }

    if (NULL != currentTypeface) {
        if (lBounds) {
            *lBounds = lowerBounds;
        }
        if (uBounds) {
            *uBounds = upperBounds;
        }
    }
    return currentTypeface;
}

///////////////////////////////////////////////////////////////////////////////

bool SkGetFallbackFamilyNameForChar(SkUnichar uni, const char* lang, SkString* name) {
    SkFontConfigInterfaceAndroid* fontConfig = getSingletonInterface();
    return fontConfig->getFallbackFamilyNameForChar(uni, lang, name);
}

void SkUseTestFontConfigFile(const char* mainconf, const char* fallbackconf,
                             const char* fontsdir) {
    gTestMainConfigFile = mainconf;
    gTestFallbackConfigFile = fallbackconf;
    gTestFontFilePrefix = fontsdir;
    SkASSERT(gTestMainConfigFile);
    SkASSERT(gTestFallbackConfigFile);
    SkASSERT(gTestFontFilePrefix);
    SkDEBUGF(("Use Test Config File Main %s, Fallback %s, Font Dir %s",
              gTestMainConfigFile, gTestFallbackConfigFile, gTestFontFilePrefix));
}

SkTypeface* SkAndroidNextLogicalTypeface(SkFontID currFontID, SkFontID origFontID,
                                         const SkPaintOptionsAndroid& options) {
    SkFontConfigInterfaceAndroid* fontConfig = getSingletonInterface();
    return fontConfig->nextLogicalTypeface(currFontID, origFontID, options);

}

SkTypeface* SkGetTypefaceForGlyphID(uint16_t glyphID, const SkTypeface* origTypeface,
                                    const SkPaintOptionsAndroid& options,
                                    int* lowerBounds, int* upperBounds) {
    SkFontConfigInterfaceAndroid* fontConfig = getSingletonInterface();
    return fontConfig->getTypefaceForGlyphID(glyphID, origTypeface, options,
                                             lowerBounds, upperBounds);
}