qglyphrun.cpp

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39 -

40 #include "qglobal.h" -

41 -

42 #if !defined(QT_NO_RAWFONT) -

43 -

44 #include "qglyphrun.h" -

45 #include "qglyphrun_p.h" -

46 #include <qdebug.h> -

47 -

48 QT_BEGIN_NAMESPACE -

49 -

50 /*! -

51 \class QGlyphRun -

52 \brief The QGlyphRun class provides direct access to the internal glyphs in a font. -

53 \since 4.8 -

54 \inmodule QtGui -

55 -

56 \ingroup text -

57 \ingroup shared -

58 -

59 When Qt displays a string of text encoded in Unicode, it will first convert the Unicode points -

60 into a list of glyph indexes and a list of positions based on one or more fonts. The Unicode -

61 representation of the text and the QFont object will in this case serve as a convenient -

62 abstraction that hides the details of what actually takes place when displaying the text -

63 on-screen. For instance, by the time the text actually reaches the screen, it may be represented -

64 by a set of fonts in addition to the one specified by the user, e.g. in case the originally -

65 selected font did not support all the writing systems contained in the text. -

66 -

67 Under certain circumstances, it can be useful as an application developer to have more low-level -

68 control over which glyphs in a specific font are drawn to the screen. This could for instance -

69 be the case in applications that use an external font engine and text shaper together with Qt. -

70 QGlyphRun provides an interface to the raw data needed to get text on the screen. It -

71 contains a list of glyph indexes, a position for each glyph and a font. -

72 -

73 It is the user's responsibility to ensure that the selected font actually contains the -

74 provided glyph indexes. -

75 -

76 QTextLayout::glyphRuns() or QTextFragment::glyphRuns() can be used to convert unicode encoded -

77 text into a list of QGlyphRun objects, and QPainter::drawGlyphRun() can be used to draw the -

78 glyphs. -

79 -

80 \note Please note that QRawFont is considered local to the thread in which it is constructed. -

81 This in turn means that a new QRawFont will have to be created and set on the QGlyphRun if it is -

82 moved to a different thread. If the QGlyphRun contains a reference to a QRawFont from a different -

83 thread than the current, it will not be possible to draw the glyphs using a QPainter, as the -

84 QRawFont is considered invalid and inaccessible in this case. -

85 */ -

86 -

87 /*! -

88 \enum QGlyphRun::GlyphRunFlag -

89 \since 5.0 -

90 -

91 This enum describes flags that alter the way the run of glyphs might be presented or behave in -

92 a visual layout. The layout which generates the glyph runs can set these flags based on relevant -

93 internal data, to retain information needed to present the text as intended by the user of the -

94 layout. -

95 -

96 \value Overline Indicates that the glyphs should be visualized together with an overline. -

97 \value Underline Indicates that the glyphs should be visualized together with an underline. -

98 \value StrikeOut Indicates that the glyphs should be struck out visually. -

99 \value RightToLeft Indicates that the glyphs are ordered right to left. This can affect the -

100 positioning of other screen elements that are relative to the glyph run, such as an inline -

101 text object. -

102 \value SplitLigature Indicates that the glyph run splits a ligature glyph. This means -

103 that a ligature glyph is included in the run, but the characters represented by it corresponds -

104 only to part of that ligature. The glyph run's boundingRect() function can in this case be used -

105 to retrieve the area covered by glyphs that correspond to the characters represented by the -

106 glyph run. When visualizing the glyphs, care needs to be taken to clip to this bounding rect to -

107 ensure that only the corresponding part of the ligature is painted. In particular, this can be -

108 the case when retrieving a glyph run from a QTextLayout for a specific character range, e.g. -

109 when retrieving the selected area of a QTextLayout. -

110 */ -

111 -

112 /*! -

113 Constructs an empty QGlyphRun object. -

114 */ -

115 QGlyphRun::QGlyphRun() : d(new QGlyphRunPrivate) -

116 { -

117 } -

118 -

119 /*! -

120 Constructs a QGlyphRun object which is a copy of \a other. -

121 */ -

122 QGlyphRun::QGlyphRun(const QGlyphRun &other) -

123 { -

124 d = other.d; -

125 } -

126 -

127 /*! -

128 Destroys the QGlyphRun. -

129 */ -

130 QGlyphRun::~QGlyphRun() -

131 { -

132 // Required for QExplicitlySharedDataPointer -

133 } -

134 -

135 /*! -

136 \internal -

137 */ -

138 void QGlyphRun::detach() -

139 { -

140 if (d->ref.load() != 1) -

141 d.detach(); -

142 } -

143 -

144 /*! -

145 Assigns \a other to this QGlyphRun object. -

146 */ -

147 QGlyphRun &QGlyphRun::operator=(const QGlyphRun &other) -

148 { -

149 d = other.d; -

150 return *this; -

151 } -

152 -

153 /*! -

154 \fn void QGlyphRun::swap(QGlyphRun &other) -

155 \since 5.0 -

156 -

157 Swaps this glyph run instance with \a other. This function is very -

158 fast and never fails. -

159 */ -

160 -

161 /*! -

162 Compares \a other to this QGlyphRun object. Returns \c true if the list of glyph indexes, -

163 the list of positions and the font are all equal, otherwise returns \c false. -

164 */ -

165 bool QGlyphRun::operator==(const QGlyphRun &other) const -

166 { -

167 if (d == other.d) -

168 return true; -

169 -

170 if ((d->glyphIndexDataSize != other.d->glyphIndexDataSize) -

171 || (d->glyphPositionDataSize != other.d->glyphPositionDataSize)) { -

172 return false; -

173 } -

174 -

175 if (d->glyphIndexData != other.d->glyphIndexData) { -

176 for (int i = 0; i < d->glyphIndexDataSize; ++i) { -

177 if (d->glyphIndexData[i] != other.d->glyphIndexData[i]) -

178 return false; -

179 } -

180 } -

181 if (d->glyphPositionData != other.d->glyphPositionData) { -

182 for (int i = 0; i < d->glyphPositionDataSize; ++i) { -

183 if (d->glyphPositionData[i] != other.d->glyphPositionData[i]) -

184 return false; -

185 } -

186 } -

187 -

188 return (d->flags == other.d->flags && d->rawFont == other.d->rawFont); -

189 } -

190 -

191 /*! -

192 \fn bool QGlyphRun::operator!=(const QGlyphRun &other) const -

193 -

194 Compares \a other to this QGlyphRun object. Returns \c true if any of the list of glyph -

195 indexes, the list of positions or the font are different, otherwise returns \c false. -

196 */ -

197 -

198 /*! -

199 Returns the font selected for this QGlyphRun object. -

200 -

201 \sa setRawFont() -

202 */ -

203 QRawFont QGlyphRun::rawFont() const -

204 { -

205 return d->rawFont; -

206 } -

207 -

208 /*! -

209 Sets the font in which to look up the glyph indexes to the \a rawFont -

210 specified. -

211 -

212 \sa rawFont(), setGlyphIndexes() -

213 */ -

214 void QGlyphRun::setRawFont(const QRawFont &rawFont) -

215 { -

216 detach(); -

217 d->rawFont = rawFont; -

218 } -

219 -

220 /*! -

221 Returns the glyph indexes for this QGlyphRun object. -

222 -

223 \sa setGlyphIndexes(), setPositions() -

224 */ -

225 QVector<quint32> QGlyphRun::glyphIndexes() const -

226 { -

227 if (d->glyphIndexes.constData() == d->glyphIndexData) { -

228 return d->glyphIndexes; -

229 } else { -

230 QVector<quint32> indexes(d->glyphIndexDataSize); -

231 memcpy(indexes.data(), d->glyphIndexData, d->glyphIndexDataSize * sizeof(quint32)); -

232 return indexes; -

233 } -

234 } -

235 -

236 /*! -

237 Set the glyph indexes for this QGlyphRun object to \a glyphIndexes. The glyph indexes must -

238 be valid for the selected font. -

239 */ -

240 void QGlyphRun::setGlyphIndexes(const QVector<quint32> &glyphIndexes) -

241 { -

242 detach(); -

243 d->glyphIndexes = glyphIndexes; // Keep a reference to the QVector to avoid copying -

244 d->glyphIndexData = glyphIndexes.constData(); -

245 d->glyphIndexDataSize = glyphIndexes.size(); -

246 } -

247 -

248 /*! -

249 Returns the position of the edge of the baseline for each glyph in this set of glyph indexes. -

250 */ -

251 QVector<QPointF> QGlyphRun::positions() const -

252 { -

253 if (d->glyphPositions.constData() == d->glyphPositionData) { -

254 return d->glyphPositions; -

255 } else { -

256 QVector<QPointF> glyphPositions(d->glyphPositionDataSize); -

257 memcpy(glyphPositions.data(), d->glyphPositionData, -

258 d->glyphPositionDataSize * sizeof(QPointF)); -

259 return glyphPositions; -

260 } -

261 } -

262 -

263 /*! -

264 Sets the positions of the edge of the baseline for each glyph in this set of glyph indexes to -

265 \a positions. -

266 */ -

267 void QGlyphRun::setPositions(const QVector<QPointF> &positions) -

268 { -

269 detach(); -

270 d->glyphPositions = positions; // Keep a reference to the vector to avoid copying -

271 d->glyphPositionData = positions.constData(); -

272 d->glyphPositionDataSize = positions.size(); -

273 } -

274 -

275 /*! -

276 Clears all data in the QGlyphRun object. -

277 */ -

278 void QGlyphRun::clear() -

279 { -

280 detach(); -

281 d->rawFont = QRawFont(); -

282 d->flags = 0; -

283 -

284 setPositions(QVector<QPointF>()); -

285 setGlyphIndexes(QVector<quint32>()); -

286 } -

287 -

288 /*! -

289 Sets the glyph indexes and positions of this QGlyphRun to use the first \a size -

290 elements in the arrays \a glyphIndexArray and \a glyphPositionArray. The data is -

291 \e not copied. The caller must guarantee that the arrays are not deleted as long -

292 as this QGlyphRun and any copies of it exists. -

293 -

294 \sa setGlyphIndexes(), setPositions() -

295 */ -

296 void QGlyphRun::setRawData(const quint32 *glyphIndexArray, const QPointF *glyphPositionArray, -

297 int size) -

298 { -

299 detach(); -

300 d->glyphIndexes.clear(); -

301 d->glyphPositions.clear(); -

302 -

303 d->glyphIndexData = glyphIndexArray; -

304 d->glyphPositionData = glyphPositionArray; -

305 d->glyphIndexDataSize = d->glyphPositionDataSize = size; -

306 } -

307 -

308 /*! -

309 Returns \c true if this QGlyphRun should be painted with an overline decoration. -

310 -

311 \sa setOverline(), flags() -

312 */ -

313 bool QGlyphRun::overline() const -

314 { -

315 return d->flags & Overline; -

316 } -

317 -

318 /*! -

319 Indicates that this QGlyphRun should be painted with an overline decoration if \a overline is true. -

320 Otherwise the QGlyphRun should be painted with no overline decoration. -

321 -

322 \sa overline(), setFlag(), setFlags() -

323 */ -

324 void QGlyphRun::setOverline(bool overline) -

325 { -

326 setFlag(Overline, overline); -

327 } -

328 -

329 /*! -

330 Returns \c true if this QGlyphRun should be painted with an underline decoration. -

331 -

332 \sa setUnderline(), flags() -

333 */ -

334 bool QGlyphRun::underline() const -

335 { -

336 return d->flags & Underline; -

337 } -

338 -

339 /*! -

340 Indicates that this QGlyphRun should be painted with an underline decoration if \a underline is -

341 true. Otherwise the QGlyphRun should be painted with no underline decoration. -

342 -

343 \sa underline(), setFlag(), setFlags() -

344 */ -

345 void QGlyphRun::setUnderline(bool underline) -

346 { -

347 setFlag(Underline, underline); -

348 } -

349 -

350 /*! -

351 Returns \c true if this QGlyphRun should be painted with a strike out decoration. -

352 -

353 \sa setStrikeOut(), flags() -

354 */ -

355 bool QGlyphRun::strikeOut() const -

356 { -

357 return d->flags & StrikeOut; -

358 } -

359 -

360 /*! -

361 Indicates that this QGlyphRun should be painted with an strike out decoration if \a strikeOut is -

362 true. Otherwise the QGlyphRun should be painted with no strike out decoration. -

363 -

364 \sa strikeOut(), setFlag(), setFlags() -

365 */ -

366 void QGlyphRun::setStrikeOut(bool strikeOut) -

367 { -

368 setFlag(StrikeOut, strikeOut); -

369 } -

370 -

371 /*! -

372 Returns \c true if this QGlyphRun contains glyphs that are painted from the right to the left. -

373 -

374 \since 5.0 -

375 \sa setRightToLeft(), flags() -

376 */ -

377 bool QGlyphRun::isRightToLeft() const -

378 { -

379 return d->flags & RightToLeft; -

380 } -

381 -

382 /*! -

383 Indicates that this QGlyphRun contains glyphs that should be ordered from the right to left -

384 if \a rightToLeft is true. Otherwise the order of the glyphs is assumed to be left to right. -

385 -

386 \since 5.0 -

387 \sa isRightToLeft(), setFlag(), setFlags() -

388 */ -

389 void QGlyphRun::setRightToLeft(bool rightToLeft) -

390 { -

391 setFlag(RightToLeft, rightToLeft); -

392 } -

393 -

394 /*! -

395 Returns the flags set for this QGlyphRun. -

396 -

397 \since 5.0 -

398 \sa setFlag(), setFlag() -

399 */ -

400 QGlyphRun::GlyphRunFlags QGlyphRun::flags() const -

401 { -

402 return d->flags; -

403 } -

404 -

405 /*! -

406 If \a enabled is true, then \a flag is enabled; otherwise, it is disabled. -

407 -

408 \since 5.0 -

409 \sa flags(), setFlags() -

410 */ -

411 void QGlyphRun::setFlag(GlyphRunFlag flag, bool enabled) -

412 { -

413

if (d->flags.testFlag(flag) == enabled)

d->flags.testF...ag) == enabled	Description
TRUE	never evaluated
FALSE	never evaluated

414

return;

never executed: return;

415 -

416 detach(); -

417 if (enabled) -

d->flags |= flag;

elsed->flags&= ~.setFlag(flag;, enabled);

418

}

never executed: end of block

419 -

420 /*! -

421 Sets the flags of this QGlyphRun to \a flags. -

422 -

423 \since 5.0 -

424 \sa setFlag(), flags() -

425 */ -

426 void QGlyphRun::setFlags(GlyphRunFlags flags) -

427 { -

428 if (d->flags == flags) -

429 return; -

430 -

431 detach(); -

432 d->flags = flags; -

433 } -

434 -

435 /*! -

436 Sets the bounding rect of the glyphs in this QGlyphRun to be \a boundingRect. This rectangle -

437 will be returned by boundingRect() unless it is empty, in which case the bounding rectangle of the -

438 glyphs in the glyph run will be returned instead. -

439 -

440 \note Unless you are implementing text shaping, you should not have to use this function. -

441 It is used specifically when the QGlyphRun should represent an area which is smaller than the -

442 area of the glyphs it contains. This could happen e.g. if the glyph run is retrieved by calling -

443 QTextLayout::glyphRuns() and the specified range only includes part of a ligature (where two or -

444 more characters are combined to a single glyph.) When this is the case, the bounding rect should -

445 only include the appropriate part of the ligature glyph, based on a calculation of the average -

446 width of the characters in the ligature. -

447 -

448 In order to support such a case (an example is selections which should be drawn with a different -

449 color than the main text color), it is necessary to clip the painting mechanism to the rectangle -

450 returned from boundingRect() to avoid drawing the entire ligature glyph. -

451 -

452 \sa boundingRect() -

453 -

454 \since 5.0 -

455 */ -

456 void QGlyphRun::setBoundingRect(const QRectF &boundingRect) -

457 { -

458 detach(); -

459 d->boundingRect = boundingRect; -

460 } -

461 -

462 /*! -

463 Returns the smallest rectangle that contains all glyphs in this QGlyphRun. If a bounding rect -

464 has been set using setBoundingRect(), then this will be returned. Otherwise the bounding rect -

465 will be calculated based on the font metrics of the glyphs in the glyph run. -

466 -

467 \since 5.0 -

468 */ -

469 QRectF QGlyphRun::boundingRect() const -

470 { -

471 if (!d->boundingRect.isEmpty() || !d->rawFont.isValid()) -

472 return d->boundingRect; -

473 -

474 qreal minX, minY, maxX, maxY; -

475 minX = minY = maxX = maxY = 0; -

476 -

477 for (int i = 0, n = qMin(d->glyphIndexDataSize, d->glyphPositionDataSize); i < n; ++i) { -

478 QRectF glyphRect = d->rawFont.boundingRect(d->glyphIndexData[i]); -

479 glyphRect.translate(d->glyphPositionData[i]); -

480 -

481 if (i == 0) { -

482 minX = glyphRect.left(); -

483 minY = glyphRect.top(); -

484 maxX = glyphRect.right(); -

485 maxY = glyphRect.bottom(); -

486 } else { -

487 minX = qMin(glyphRect.left(), minX); -

488 minY = qMin(glyphRect.top(), minY); -

489 maxX = qMax(glyphRect.right(),maxX); -

490 maxY = qMax(glyphRect.bottom(), maxY); -

491 } -

492 } -

493 -

494 return QRectF(QPointF(minX, minY), QPointF(maxX, maxY)); -

495 } -

496 -

497 /*! -

498 Returns \c true if the QGlyphRun does not contain any glyphs. -

499 -

500 \since 5.0 -

501 */ -

502 bool QGlyphRun::isEmpty() const -

503 { -

504 return d->glyphIndexDataSize == 0; -

505 } -

506 -

507 QT_END_NAMESPACE -

508 -

509 #endif // QT_NO_RAWFONT -

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