reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame^] | 1 | /* libs/graphics/ports/SkFontHost_android.cpp |
| 2 | ** |
| 3 | ** Copyright 2006, The Android Open Source Project |
| 4 | ** |
| 5 | ** Licensed under the Apache License, Version 2.0 (the "License"); |
| 6 | ** you may not use this file except in compliance with the License. |
| 7 | ** You may obtain a copy of the License at |
| 8 | ** |
| 9 | ** http://www.apache.org/licenses/LICENSE-2.0 |
| 10 | ** |
| 11 | ** Unless required by applicable law or agreed to in writing, software |
| 12 | ** distributed under the License is distributed on an "AS IS" BASIS, |
| 13 | ** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 14 | ** See the License for the specific language governing permissions and |
| 15 | ** limitations under the License. |
| 16 | */ |
| 17 | |
| 18 | #include "SkFontHost.h" |
| 19 | #include "SkDescriptor.h" |
| 20 | #include "SkMMapStream.h" |
| 21 | #include "SkPaint.h" |
| 22 | #include "SkString.h" |
| 23 | #include "SkStream.h" |
| 24 | #include "SkThread.h" |
| 25 | #include "SkTSearch.h" |
| 26 | #include <stdio.h> |
| 27 | |
| 28 | #define FONT_CACHE_MEMORY_BUDGET (768 * 1024) |
| 29 | |
| 30 | #ifndef SK_FONT_FILE_PREFIX |
| 31 | #define SK_FONT_FILE_PREFIX "/fonts/" |
| 32 | #endif |
| 33 | |
| 34 | SkTypeface::Style find_name_and_style(SkStream* stream, SkString* name); |
| 35 | |
| 36 | static void GetFullPathForSysFonts(SkString* full, const char name[]) |
| 37 | { |
| 38 | full->set(getenv("ANDROID_ROOT")); |
| 39 | full->append(SK_FONT_FILE_PREFIX); |
| 40 | full->append(name); |
| 41 | } |
| 42 | |
| 43 | /////////////////////////////////////////////////////////////////////////////// |
| 44 | |
| 45 | struct FamilyRec; |
| 46 | |
| 47 | /* This guy holds a mapping of a name -> family, used for looking up fonts. |
| 48 | Since it is stored in a stretchy array that doesn't preserve object |
| 49 | semantics, we don't use constructor/destructors, but just have explicit |
| 50 | helpers to manage our internal bookkeeping. |
| 51 | */ |
| 52 | struct NameFamilyPair { |
| 53 | const char* fName; // we own this |
| 54 | FamilyRec* fFamily; // we don't own this, we just reference it |
| 55 | |
| 56 | void construct(const char name[], FamilyRec* family) |
| 57 | { |
| 58 | fName = strdup(name); |
| 59 | fFamily = family; // we don't own this, so just record the referene |
| 60 | } |
| 61 | void destruct() |
| 62 | { |
| 63 | free((char*)fName); |
| 64 | // we don't own family, so just ignore our reference |
| 65 | } |
| 66 | }; |
| 67 | |
| 68 | // we use atomic_inc to grow this for each typeface we create |
| 69 | static int32_t gUniqueFontID; |
| 70 | |
| 71 | // this is the mutex that protects these globals |
| 72 | static SkMutex gFamilyMutex; |
| 73 | static FamilyRec* gFamilyHead; |
| 74 | static SkTDArray<NameFamilyPair> gNameList; |
| 75 | |
| 76 | struct FamilyRec { |
| 77 | FamilyRec* fNext; |
| 78 | SkTypeface* fFaces[4]; |
| 79 | |
| 80 | FamilyRec() |
| 81 | { |
| 82 | fNext = gFamilyHead; |
| 83 | memset(fFaces, 0, sizeof(fFaces)); |
| 84 | gFamilyHead = this; |
| 85 | } |
| 86 | }; |
| 87 | |
| 88 | static SkTypeface* find_best_face(const FamilyRec* family, |
| 89 | SkTypeface::Style style) |
| 90 | { |
| 91 | SkTypeface* const* faces = family->fFaces; |
| 92 | |
| 93 | if (faces[style] != NULL) { // exact match |
| 94 | return faces[style]; |
| 95 | } |
| 96 | // look for a matching bold |
| 97 | style = (SkTypeface::Style)(style ^ SkTypeface::kItalic); |
| 98 | if (faces[style] != NULL) { |
| 99 | return faces[style]; |
| 100 | } |
| 101 | // look for the plain |
| 102 | if (faces[SkTypeface::kNormal] != NULL) { |
| 103 | return faces[SkTypeface::kNormal]; |
| 104 | } |
| 105 | // look for anything |
| 106 | for (int i = 0; i < 4; i++) { |
| 107 | if (faces[i] != NULL) { |
| 108 | return faces[i]; |
| 109 | } |
| 110 | } |
| 111 | // should never get here, since the faces list should not be empty |
| 112 | SkASSERT(!"faces list is empty"); |
| 113 | return NULL; |
| 114 | } |
| 115 | |
| 116 | static FamilyRec* find_family(const SkTypeface* member) |
| 117 | { |
| 118 | FamilyRec* curr = gFamilyHead; |
| 119 | while (curr != NULL) { |
| 120 | for (int i = 0; i < 4; i++) { |
| 121 | if (curr->fFaces[i] == member) { |
| 122 | return curr; |
| 123 | } |
| 124 | } |
| 125 | curr = curr->fNext; |
| 126 | } |
| 127 | return NULL; |
| 128 | } |
| 129 | |
| 130 | static SkTypeface* resolve_uniqueID(uint32_t uniqueID) |
| 131 | { |
| 132 | FamilyRec* curr = gFamilyHead; |
| 133 | while (curr != NULL) { |
| 134 | for (int i = 0; i < 4; i++) { |
| 135 | SkTypeface* face = curr->fFaces[i]; |
| 136 | if (face != NULL && face->uniqueID() == uniqueID) { |
| 137 | return face; |
| 138 | } |
| 139 | } |
| 140 | curr = curr->fNext; |
| 141 | } |
| 142 | return NULL; |
| 143 | } |
| 144 | |
| 145 | /* Remove reference to this face from its family. If the resulting family |
| 146 | is empty (has no faces), return that family, otherwise return NULL |
| 147 | */ |
| 148 | static FamilyRec* remove_from_family(const SkTypeface* face) |
| 149 | { |
| 150 | FamilyRec* family = find_family(face); |
| 151 | SkASSERT(family->fFaces[face->style()] == face); |
| 152 | family->fFaces[face->style()] = NULL; |
| 153 | |
| 154 | for (int i = 0; i < 4; i++) { |
| 155 | if (family->fFaces[i] != NULL) { // family is non-empty |
| 156 | return NULL; |
| 157 | } |
| 158 | } |
| 159 | return family; // return the empty family |
| 160 | } |
| 161 | |
| 162 | // maybe we should make FamilyRec be doubly-linked |
| 163 | static void detach_and_delete_family(FamilyRec* family) |
| 164 | { |
| 165 | FamilyRec* curr = gFamilyHead; |
| 166 | FamilyRec* prev = NULL; |
| 167 | |
| 168 | while (curr != NULL) { |
| 169 | FamilyRec* next = curr->fNext; |
| 170 | if (curr == family) { |
| 171 | if (prev == NULL) { |
| 172 | gFamilyHead = next; |
| 173 | } else { |
| 174 | prev->fNext = next; |
| 175 | } |
| 176 | SkDELETE(family); |
| 177 | return; |
| 178 | } |
| 179 | prev = curr; |
| 180 | curr = next; |
| 181 | } |
| 182 | SkASSERT(!"Yikes, couldn't find family in our list to remove/delete"); |
| 183 | } |
| 184 | |
| 185 | static SkTypeface* find_typeface(const char name[], SkTypeface::Style style) |
| 186 | { |
| 187 | NameFamilyPair* list = gNameList.begin(); |
| 188 | int count = gNameList.count(); |
| 189 | |
| 190 | int index = SkStrLCSearch(&list[0].fName, count, name, sizeof(list[0])); |
| 191 | |
| 192 | if (index >= 0) { |
| 193 | return find_best_face(list[index].fFamily, style); |
| 194 | } |
| 195 | return NULL; |
| 196 | } |
| 197 | |
| 198 | static SkTypeface* find_typeface(const SkTypeface* familyMember, |
| 199 | SkTypeface::Style style) |
| 200 | { |
| 201 | const FamilyRec* family = find_family(familyMember); |
| 202 | return family ? find_best_face(family, style) : NULL; |
| 203 | } |
| 204 | |
| 205 | static void add_name(const char name[], FamilyRec* family) |
| 206 | { |
| 207 | SkAutoAsciiToLC tolc(name); |
| 208 | name = tolc.lc(); |
| 209 | |
| 210 | NameFamilyPair* list = gNameList.begin(); |
| 211 | int count = gNameList.count(); |
| 212 | |
| 213 | int index = SkStrLCSearch(&list[0].fName, count, name, sizeof(list[0])); |
| 214 | |
| 215 | if (index < 0) { |
| 216 | list = gNameList.insert(~index); |
| 217 | list->construct(name, family); |
| 218 | } |
| 219 | } |
| 220 | |
| 221 | static void remove_from_names(FamilyRec* emptyFamily) |
| 222 | { |
| 223 | #ifdef SK_DEBUG |
| 224 | for (int i = 0; i < 4; i++) { |
| 225 | SkASSERT(emptyFamily->fFaces[i] == NULL); |
| 226 | } |
| 227 | #endif |
| 228 | |
| 229 | SkTDArray<NameFamilyPair>& list = gNameList; |
| 230 | |
| 231 | // must go backwards when removing |
| 232 | for (int i = list.count() - 1; i >= 0; --i) { |
| 233 | NameFamilyPair* pair = &list[i]; |
| 234 | if (pair->fFamily == emptyFamily) { |
| 235 | pair->destruct(); |
| 236 | list.remove(i); |
| 237 | } |
| 238 | } |
| 239 | } |
| 240 | |
| 241 | /////////////////////////////////////////////////////////////////////////////// |
| 242 | |
| 243 | class FamilyTypeface : public SkTypeface { |
| 244 | public: |
| 245 | FamilyTypeface(Style style, bool sysFont, SkTypeface* familyMember) |
| 246 | : SkTypeface(style, sk_atomic_inc(&gUniqueFontID) + 1) |
| 247 | { |
| 248 | fIsSysFont = sysFont; |
| 249 | |
| 250 | SkAutoMutexAcquire ac(gFamilyMutex); |
| 251 | |
| 252 | FamilyRec* rec = NULL; |
| 253 | if (familyMember) { |
| 254 | rec = find_family(familyMember); |
| 255 | SkASSERT(rec); |
| 256 | } else { |
| 257 | rec = SkNEW(FamilyRec); |
| 258 | } |
| 259 | rec->fFaces[style] = this; |
| 260 | } |
| 261 | |
| 262 | virtual ~FamilyTypeface() |
| 263 | { |
| 264 | SkAutoMutexAcquire ac(gFamilyMutex); |
| 265 | |
| 266 | // remove us from our family. If the family is now empty, we return |
| 267 | // that and then remove that family from the name list |
| 268 | FamilyRec* family = remove_from_family(this); |
| 269 | if (NULL != family) { |
| 270 | remove_from_names(family); |
| 271 | detach_and_delete_family(family); |
| 272 | } |
| 273 | } |
| 274 | |
| 275 | bool isSysFont() const { return fIsSysFont; } |
| 276 | |
| 277 | virtual SkStream* openStream() = 0; |
| 278 | virtual void closeStream(SkStream*) = 0; |
| 279 | virtual const char* getUniqueString() const = 0; |
| 280 | |
| 281 | private: |
| 282 | bool fIsSysFont; |
| 283 | |
| 284 | typedef SkTypeface INHERITED; |
| 285 | }; |
| 286 | |
| 287 | /////////////////////////////////////////////////////////////////////////////// |
| 288 | |
| 289 | class StreamTypeface : public FamilyTypeface { |
| 290 | public: |
| 291 | StreamTypeface(Style style, bool sysFont, SkTypeface* familyMember, |
| 292 | SkStream* stream) |
| 293 | : INHERITED(style, sysFont, familyMember) |
| 294 | { |
| 295 | fStream = stream; |
| 296 | } |
| 297 | virtual ~StreamTypeface() |
| 298 | { |
| 299 | SkDELETE(fStream); |
| 300 | } |
| 301 | |
| 302 | // overrides |
| 303 | virtual SkStream* openStream() { return fStream; } |
| 304 | virtual void closeStream(SkStream*) {} |
| 305 | virtual const char* getUniqueString() const { return NULL; } |
| 306 | |
| 307 | private: |
| 308 | SkStream* fStream; |
| 309 | |
| 310 | typedef FamilyTypeface INHERITED; |
| 311 | }; |
| 312 | |
| 313 | class FileTypeface : public FamilyTypeface { |
| 314 | public: |
| 315 | FileTypeface(Style style, bool sysFont, SkTypeface* familyMember, |
| 316 | const char path[]) |
| 317 | : INHERITED(style, sysFont, familyMember) |
| 318 | { |
| 319 | SkString fullpath; |
| 320 | |
| 321 | if (sysFont) { |
| 322 | GetFullPathForSysFonts(&fullpath, path); |
| 323 | path = fullpath.c_str(); |
| 324 | } |
| 325 | fPath.set(path); |
| 326 | } |
| 327 | |
| 328 | // overrides |
| 329 | virtual SkStream* openStream() |
| 330 | { |
| 331 | SkStream* stream = SkNEW_ARGS(SkMMAPStream, (fPath.c_str())); |
| 332 | |
| 333 | // check for failure |
| 334 | if (stream->getLength() <= 0) { |
| 335 | SkDELETE(stream); |
| 336 | // maybe MMAP isn't supported. try FILE |
| 337 | stream = SkNEW_ARGS(SkFILEStream, (fPath.c_str())); |
| 338 | if (stream->getLength() <= 0) { |
| 339 | SkDELETE(stream); |
| 340 | stream = NULL; |
| 341 | } |
| 342 | } |
| 343 | return stream; |
| 344 | } |
| 345 | virtual void closeStream(SkStream* stream) |
| 346 | { |
| 347 | SkDELETE(stream); |
| 348 | } |
| 349 | virtual const char* getUniqueString() const { |
| 350 | const char* str = strrchr(fPath.c_str(), '/'); |
| 351 | if (str) { |
| 352 | str += 1; // skip the '/' |
| 353 | } |
| 354 | return str; |
| 355 | } |
| 356 | |
| 357 | private: |
| 358 | SkString fPath; |
| 359 | |
| 360 | typedef FamilyTypeface INHERITED; |
| 361 | }; |
| 362 | |
| 363 | /////////////////////////////////////////////////////////////////////////////// |
| 364 | /////////////////////////////////////////////////////////////////////////////// |
| 365 | |
| 366 | static bool get_name_and_style(const char path[], SkString* name, |
| 367 | SkTypeface::Style* style) |
| 368 | { |
| 369 | SkString fullpath; |
| 370 | GetFullPathForSysFonts(&fullpath, path); |
| 371 | |
| 372 | SkMMAPStream stream(fullpath.c_str()); |
| 373 | if (stream.getLength() > 0) { |
| 374 | *style = find_name_and_style(&stream, name); |
| 375 | return true; |
| 376 | } |
| 377 | else { |
| 378 | SkFILEStream stream(fullpath.c_str()); |
| 379 | if (stream.getLength() > 0) { |
| 380 | *style = find_name_and_style(&stream, name); |
| 381 | return true; |
| 382 | } |
| 383 | } |
| 384 | |
| 385 | SkDebugf("---- failed to open <%s> as a font\n", fullpath.c_str()); |
| 386 | return false; |
| 387 | } |
| 388 | |
| 389 | struct FontInitRec { |
| 390 | const char* fFileName; |
| 391 | const char* const* fNames; // null-terminated list |
| 392 | }; |
| 393 | |
| 394 | static const char* gSansNames[] = { |
| 395 | "sans-serif", "arial", "helvetica", "tahoma", "verdana", NULL |
| 396 | }; |
| 397 | |
| 398 | static const char* gSerifNames[] = { |
| 399 | "serif", "times", "times new roman", "palatino", "georgia", "baskerville", |
| 400 | "goudy", "fantasy", "cursive", "ITC Stone Serif", NULL |
| 401 | }; |
| 402 | |
| 403 | static const char* gMonoNames[] = { |
| 404 | "monospace", "courier", "courier new", "monaco", NULL |
| 405 | }; |
| 406 | |
| 407 | static const char* gFBNames[] = { NULL }; |
| 408 | |
| 409 | /* Fonts must be grouped by family, with the first font in a family having the |
| 410 | list of names (even if that list is empty), and the following members having |
| 411 | null for the list. The names list must be NULL-terminated |
| 412 | */ |
| 413 | static const FontInitRec gSystemFonts[] = { |
| 414 | { "DroidSans.ttf", gSansNames }, |
| 415 | { "DroidSans-Bold.ttf", NULL }, |
| 416 | { "DroidSerif-Regular.ttf", gSerifNames }, |
| 417 | { "DroidSerif-Bold.ttf", NULL }, |
| 418 | { "DroidSerif-Italic.ttf", NULL }, |
| 419 | { "DroidSerif-BoldItalic.ttf", NULL }, |
| 420 | { "DroidSansMono.ttf", gMonoNames }, |
| 421 | #ifdef NO_FALLBACK_FONT |
| 422 | { "DroidSans.ttf", gFBNames } |
| 423 | #else |
| 424 | { "DroidSansFallback.ttf", gFBNames } |
| 425 | #endif |
| 426 | }; |
| 427 | |
| 428 | #define DEFAULT_NAMES gSansNames |
| 429 | |
| 430 | // these globals are assigned (once) by load_system_fonts() |
| 431 | static SkTypeface* gFallBackTypeface; |
| 432 | static FamilyRec* gDefaultFamily; |
| 433 | static SkTypeface* gDefaultNormal; |
| 434 | |
| 435 | static void load_system_fonts() |
| 436 | { |
| 437 | // check if we've already be called |
| 438 | if (NULL != gDefaultNormal) { |
| 439 | return; |
| 440 | } |
| 441 | |
| 442 | const FontInitRec* rec = gSystemFonts; |
| 443 | SkTypeface* firstInFamily = NULL; |
| 444 | |
| 445 | for (size_t i = 0; i < SK_ARRAY_COUNT(gSystemFonts); i++) { |
| 446 | // if we're the first in a new family, clear firstInFamily |
| 447 | if (rec[i].fNames != NULL) { |
| 448 | firstInFamily = NULL; |
| 449 | } |
| 450 | |
| 451 | SkString name; |
| 452 | SkTypeface::Style style; |
| 453 | |
| 454 | if (!get_name_and_style(rec[i].fFileName, &name, &style)) { |
| 455 | SkDebugf("------ can't load <%s> as a font\n", rec[i].fFileName); |
| 456 | continue; |
| 457 | } |
| 458 | |
| 459 | SkTypeface* tf = SkNEW_ARGS(FileTypeface, |
| 460 | (style, |
| 461 | true, // system-font (cannot delete) |
| 462 | firstInFamily, // what family to join |
| 463 | rec[i].fFileName) // filename |
| 464 | ); |
| 465 | |
| 466 | if (rec[i].fNames != NULL) { |
| 467 | firstInFamily = tf; |
| 468 | const char* const* names = rec[i].fNames; |
| 469 | |
| 470 | // record the fallback if this is it |
| 471 | if (names == gFBNames) { |
| 472 | gFallBackTypeface = tf; |
| 473 | } |
| 474 | // record the default family if this is it |
| 475 | if (names == DEFAULT_NAMES) { |
| 476 | gDefaultFamily = find_family(tf); |
| 477 | } |
| 478 | // add the names to map to this family |
| 479 | FamilyRec* family = find_family(tf); |
| 480 | while (*names) { |
| 481 | add_name(*names, family); |
| 482 | names += 1; |
| 483 | } |
| 484 | } |
| 485 | |
| 486 | } |
| 487 | |
| 488 | // do this after all fonts are loaded. This is our default font, and it |
| 489 | // acts as a sentinel so we only execute load_system_fonts() once |
| 490 | gDefaultNormal = find_best_face(gDefaultFamily, SkTypeface::kNormal); |
| 491 | } |
| 492 | |
| 493 | /////////////////////////////////////////////////////////////////////////////// |
| 494 | |
| 495 | void SkFontHost::Serialize(const SkTypeface* face, SkWStream* stream) { |
| 496 | const char* name = ((FamilyTypeface*)face)->getUniqueString(); |
| 497 | |
| 498 | stream->write8((uint8_t)face->getStyle()); |
| 499 | |
| 500 | if (NULL == name || 0 == *name) { |
| 501 | stream->writePackedUInt(0); |
| 502 | // SkDebugf("--- fonthost serialize null\n"); |
| 503 | } else { |
| 504 | uint32_t len = strlen(name); |
| 505 | stream->writePackedUInt(len); |
| 506 | stream->write(name, len); |
| 507 | // SkDebugf("--- fonthost serialize <%s> %d\n", name, face->getStyle()); |
| 508 | } |
| 509 | } |
| 510 | |
| 511 | SkTypeface* SkFontHost::Deserialize(SkStream* stream) { |
| 512 | load_system_fonts(); |
| 513 | |
| 514 | int style = stream->readU8(); |
| 515 | |
| 516 | int len = stream->readPackedUInt(); |
| 517 | if (len > 0) { |
| 518 | SkString str; |
| 519 | str.resize(len); |
| 520 | stream->read(str.writable_str(), len); |
| 521 | |
| 522 | const FontInitRec* rec = gSystemFonts; |
| 523 | for (size_t i = 0; i < SK_ARRAY_COUNT(gSystemFonts); i++) { |
| 524 | if (strcmp(rec[i].fFileName, str.c_str()) == 0) { |
| 525 | // backup until we hit the fNames |
| 526 | for (int j = i; j >= 0; --j) { |
| 527 | if (rec[j].fNames != NULL) { |
| 528 | return SkFontHost::FindTypeface(NULL, rec[j].fNames[0], |
| 529 | (SkTypeface::Style)style); |
| 530 | } |
| 531 | } |
| 532 | } |
| 533 | } |
| 534 | } |
| 535 | return SkFontHost::FindTypeface(NULL, NULL, (SkTypeface::Style)style); |
| 536 | } |
| 537 | |
| 538 | /////////////////////////////////////////////////////////////////////////////// |
| 539 | |
| 540 | SkTypeface* SkFontHost::FindTypeface(const SkTypeface* familyFace, |
| 541 | const char familyName[], |
| 542 | SkTypeface::Style style) |
| 543 | { |
| 544 | load_system_fonts(); |
| 545 | |
| 546 | SkAutoMutexAcquire ac(gFamilyMutex); |
| 547 | |
| 548 | // clip to legal style bits |
| 549 | style = (SkTypeface::Style)(style & SkTypeface::kBoldItalic); |
| 550 | |
| 551 | SkTypeface* tf = NULL; |
| 552 | |
| 553 | if (NULL != familyFace) { |
| 554 | tf = find_typeface(familyFace, style); |
| 555 | } else if (NULL != familyName) { |
| 556 | // SkDebugf("======= familyName <%s>\n", familyName); |
| 557 | tf = find_typeface(familyName, style); |
| 558 | } |
| 559 | |
| 560 | if (NULL == tf) { |
| 561 | tf = find_best_face(gDefaultFamily, style); |
| 562 | } |
| 563 | |
| 564 | return tf; |
| 565 | } |
| 566 | |
| 567 | SkTypeface* SkFontHost::ResolveTypeface(uint32_t fontID) |
| 568 | { |
| 569 | SkAutoMutexAcquire ac(gFamilyMutex); |
| 570 | |
| 571 | return resolve_uniqueID(fontID); |
| 572 | } |
| 573 | |
| 574 | SkStream* SkFontHost::OpenStream(uint32_t fontID) |
| 575 | { |
| 576 | |
| 577 | FamilyTypeface* tf = (FamilyTypeface*)SkFontHost::ResolveTypeface(fontID); |
| 578 | SkStream* stream = tf ? tf->openStream() : NULL; |
| 579 | |
| 580 | if (NULL == stream || stream->getLength() == 0) { |
| 581 | delete stream; |
| 582 | stream = NULL; |
| 583 | } |
| 584 | return stream; |
| 585 | } |
| 586 | |
| 587 | void SkFontHost::CloseStream(uint32_t fontID, SkStream* stream) |
| 588 | { |
| 589 | FamilyTypeface* tf = (FamilyTypeface*)SkFontHost::ResolveTypeface(fontID); |
| 590 | if (NULL != tf) { |
| 591 | tf->closeStream(stream); |
| 592 | } |
| 593 | } |
| 594 | |
| 595 | SkScalerContext* SkFontHost::CreateFallbackScalerContext( |
| 596 | const SkScalerContext::Rec& rec) |
| 597 | { |
| 598 | load_system_fonts(); |
| 599 | |
| 600 | SkAutoDescriptor ad(sizeof(rec) + SkDescriptor::ComputeOverhead(1)); |
| 601 | SkDescriptor* desc = ad.getDesc(); |
| 602 | |
| 603 | desc->init(); |
| 604 | SkScalerContext::Rec* newRec = |
| 605 | (SkScalerContext::Rec*)desc->addEntry(kRec_SkDescriptorTag, |
| 606 | sizeof(rec), &rec); |
| 607 | newRec->fFontID = gFallBackTypeface->uniqueID(); |
| 608 | desc->computeChecksum(); |
| 609 | |
| 610 | return SkFontHost::CreateScalerContext(desc); |
| 611 | } |
| 612 | |
| 613 | /////////////////////////////////////////////////////////////////////////////// |
| 614 | |
| 615 | SkTypeface* SkFontHost::CreateTypeface(SkStream* stream) |
| 616 | { |
| 617 | if (NULL == stream || stream->getLength() <= 0) { |
| 618 | SkDELETE(stream); |
| 619 | return NULL; |
| 620 | } |
| 621 | |
| 622 | SkString name; |
| 623 | SkTypeface::Style style = find_name_and_style(stream, &name); |
| 624 | |
| 625 | return SkNEW_ARGS(StreamTypeface, (style, false, NULL, stream)); |
| 626 | } |
| 627 | |
| 628 | /////////////////////////////////////////////////////////////////////////////// |
| 629 | |
| 630 | size_t SkFontHost::ShouldPurgeFontCache(size_t sizeAllocatedSoFar) |
| 631 | { |
| 632 | if (sizeAllocatedSoFar > FONT_CACHE_MEMORY_BUDGET) |
| 633 | return sizeAllocatedSoFar - FONT_CACHE_MEMORY_BUDGET; |
| 634 | else |
| 635 | return 0; // nothing to do |
| 636 | } |
| 637 | |