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44 #if !defined(QT_NO_RAWFONT)
46 #include "qglyphrun.h"
47 #include "qglyphrun_p.h"
54 \brief The QGlyphRun class provides direct access to the internal glyphs in a font.
60 When Qt displays a string of text encoded in Unicode, it will first convert the Unicode points
61 into a list of glyph indexes and a list of positions based on one or more fonts. The Unicode
62 representation of the text and the QFont object will in this case serve as a convenient
63 abstraction that hides the details of what actually takes place when displaying the text
64 on-screen. For instance, by the time the text actually reaches the screen, it may be represented
65 by a set of fonts in addition to the one specified by the user, e.g. in case the originally
66 selected font did not support all the writing systems contained in the text.
68 Under certain circumstances, it can be useful as an application developer to have more low-level
69 control over which glyphs in a specific font are drawn to the screen. This could for instance
70 be the case in applications that use an external font engine and text shaper together with Qt.
71 QGlyphRun provides an interface to the raw data needed to get text on the screen. It
72 contains a list of glyph indexes, a position for each glyph and a font.
74 It is the user's responsibility to ensure that the selected font actually contains the
75 provided glyph indexes.
77 QTextLayout::glyphRuns() or QTextFragment::glyphRuns() can be used to convert unicode encoded
78 text into a list of QGlyphRun objects, and QPainter::drawGlyphRun() can be used to draw the
81 \note Please note that QRawFont is considered local to the thread in which it is constructed.
82 This in turn means that a new QRawFont will have to be created and set on the QGlyphRun if it is
83 moved to a different thread. If the QGlyphRun contains a reference to a QRawFont from a different
84 thread than the current, it will not be possible to draw the glyphs using a QPainter, as the
85 QRawFont is considered invalid and inaccessible in this case.
90 Constructs an empty QGlyphRun object.
92 QGlyphRun::QGlyphRun() : d(new QGlyphRunPrivate)
97 Constructs a QGlyphRun object which is a copy of \a other.
99 QGlyphRun::QGlyphRun(const QGlyphRun &other)
105 Destroys the QGlyphRun.
107 QGlyphRun::~QGlyphRun()
109 // Required for QExplicitlySharedDataPointer
115 void QGlyphRun::detach()
122 Assigns \a other to this QGlyphRun object.
124 QGlyphRun &QGlyphRun::operator=(const QGlyphRun &other)
131 Compares \a other to this QGlyphRun object. Returns true if the list of glyph indexes,
132 the list of positions and the font are all equal, otherwise returns false.
134 bool QGlyphRun::operator==(const QGlyphRun &other) const
139 if ((d->glyphIndexDataSize != other.d->glyphIndexDataSize)
140 || (d->glyphPositionDataSize != other.d->glyphPositionDataSize)) {
144 for (int i=0; i<qMax(d->glyphIndexDataSize, d->glyphPositionDataSize); ++i) {
145 if (i < d->glyphIndexDataSize && d->glyphIndexData[i] != other.d->glyphIndexData[i])
148 if (i < d->glyphPositionDataSize && d->glyphPositionData[i] != other.d->glyphPositionData[i])
153 return (d->overline == other.d->overline
154 && d->underline == other.d->underline
155 && d->strikeOut == other.d->strikeOut
156 && d->rawFont == other.d->rawFont);
160 Compares \a other to this QGlyphRun object. Returns true if any of the list of glyph
161 indexes, the list of positions or the font are different, otherwise returns false.
163 bool QGlyphRun::operator!=(const QGlyphRun &other) const
165 return !(*this == other);
169 Returns the font selected for this QGlyphRun object.
173 QRawFont QGlyphRun::rawFont() const
179 Sets the font in which to look up the glyph indexes to the \a rawFont
182 \sa rawFont(), setGlyphIndexes()
184 void QGlyphRun::setRawFont(const QRawFont &rawFont)
187 d->rawFont = rawFont;
191 Returns the glyph indexes for this QGlyphRun object.
193 \sa setGlyphIndexes(), setPositions()
195 QVector<quint32> QGlyphRun::glyphIndexes() const
197 if (d->glyphIndexes.constData() == d->glyphIndexData) {
198 return d->glyphIndexes;
200 QVector<quint32> indexes(d->glyphIndexDataSize);
201 qMemCopy(indexes.data(), d->glyphIndexData, d->glyphIndexDataSize * sizeof(quint32));
207 Set the glyph indexes for this QGlyphRun object to \a glyphIndexes. The glyph indexes must
208 be valid for the selected font.
210 void QGlyphRun::setGlyphIndexes(const QVector<quint32> &glyphIndexes)
213 d->glyphIndexes = glyphIndexes; // Keep a reference to the QVector to avoid copying
214 d->glyphIndexData = glyphIndexes.constData();
215 d->glyphIndexDataSize = glyphIndexes.size();
219 Returns the position of the edge of the baseline for each glyph in this set of glyph indexes.
221 QVector<QPointF> QGlyphRun::positions() const
223 if (d->glyphPositions.constData() == d->glyphPositionData) {
224 return d->glyphPositions;
226 QVector<QPointF> glyphPositions(d->glyphPositionDataSize);
227 qMemCopy(glyphPositions.data(), d->glyphPositionData,
228 d->glyphPositionDataSize * sizeof(QPointF));
229 return glyphPositions;
234 Sets the positions of the edge of the baseline for each glyph in this set of glyph indexes to
237 void QGlyphRun::setPositions(const QVector<QPointF> &positions)
240 d->glyphPositions = positions; // Keep a reference to the vector to avoid copying
241 d->glyphPositionData = positions.constData();
242 d->glyphPositionDataSize = positions.size();
246 Clears all data in the QGlyphRun object.
248 void QGlyphRun::clear()
251 d->rawFont = QRawFont();
252 d->strikeOut = false;
254 d->underline = false;
256 setPositions(QVector<QPointF>());
257 setGlyphIndexes(QVector<quint32>());
261 Sets the glyph indexes and positions of this QGlyphRun to use the first \a size
262 elements in the arrays \a glyphIndexArray and \a glyphPositionArray. The data is
263 \e not copied. The caller must guarantee that the arrays are not deleted as long
264 as this QGlyphRun and any copies of it exists.
266 \sa setGlyphIndexes(), setPositions()
268 void QGlyphRun::setRawData(const quint32 *glyphIndexArray, const QPointF *glyphPositionArray,
272 d->glyphIndexes.clear();
273 d->glyphPositions.clear();
275 d->glyphIndexData = glyphIndexArray;
276 d->glyphPositionData = glyphPositionArray;
277 d->glyphIndexDataSize = d->glyphPositionDataSize = size;
281 Returns true if this QGlyphRun should be painted with an overline decoration.
285 bool QGlyphRun::overline() const
291 Indicates that this QGlyphRun should be painted with an overline decoration if \a overline is true.
292 Otherwise the QGlyphRun should be painted with no overline decoration.
296 void QGlyphRun::setOverline(bool overline)
299 d->overline = overline;
303 Returns true if this QGlyphRun should be painted with an underline decoration.
307 bool QGlyphRun::underline() const
313 Indicates that this QGlyphRun should be painted with an underline decoration if \a underline is
314 true. Otherwise the QGlyphRun should be painted with no underline decoration.
318 void QGlyphRun::setUnderline(bool underline)
321 d->underline = underline;
325 Returns true if this QGlyphRun should be painted with a strike out decoration.
329 bool QGlyphRun::strikeOut() const
335 Indicates that this QGlyphRun should be painted with an strike out decoration if \a strikeOut is
336 true. Otherwise the QGlyphRun should be painted with no strike out decoration.
340 void QGlyphRun::setStrikeOut(bool strikeOut)
343 d->strikeOut = strikeOut;
347 Sets the bounding rect of the glyphs in this QGlyphRun to be \a boundingRect. This rectangle
348 will be returned by boundingRect() unless it is empty, in which case the bounding rectangle of the
349 glyphs in the glyph run will be returned instead.
351 \note Unless you are implementing text shaping, you should not have to use this function.
352 It is used specifically when the QGlyphRun should represent an area which is smaller than the
353 area of the glyphs it contains. This could happen e.g. if the glyph run is retrieved by calling
354 QTextLayout::glyphRuns() and the specified range only includes part of a ligature (where two or
355 more characters are combined to a single glyph.) When this is the case, the bounding rect should
356 only include the appropriate part of the ligature glyph, based on a calculation of the average
357 width of the characters in the ligature.
359 In order to support such a case (an example is selections which should be drawn with a different
360 color than the main text color), it is necessary to clip the painting mechanism to the rectangle
361 returned from boundingRect() to avoid drawing the entire ligature glyph.
367 void QGlyphRun::setBoundingRect(const QRectF &boundingRect)
370 d->boundingRect = boundingRect;
374 Returns the smallest rectangle that contains all glyphs in this QGlyphRun. If a bounding rect
375 has been set using setBoundingRect(), then this will be returned. Otherwise the bounding rect
376 will be calculated based on the font metrics of the glyphs in the glyph run.
380 QRectF QGlyphRun::boundingRect() const
382 if (!d->boundingRect.isEmpty())
383 return d->boundingRect;
385 qreal minX, minY, maxX, maxY;
387 for (int i=0; i<qMin(d->glyphPositions.size(), d->glyphIndexes.size()); ++i) {
388 QRectF glyphRect = d->rawFont.boundingRect(d->glyphIndexes.at(i));
389 glyphRect.translate(d->glyphPositions.at(i));
392 minX = glyphRect.left();
393 minY = glyphRect.top();
394 maxX = glyphRect.right();
395 maxY = glyphRect.bottom();
397 minX = qMin(glyphRect.left(), minX);
398 minY = qMin(glyphRect.top(), minY);
399 maxX = qMax(glyphRect.right(),maxX);
400 maxY = qMax(glyphRect.bottom(), maxY);
404 return QRectF(QPointF(minX, minY), QPointF(maxX, maxY));
408 Returns true if the QGlyphRun does not contain any glyphs.
412 bool QGlyphRun::isEmpty() const
414 return d->glyphIndexes.isEmpty();
419 #endif // QT_NO_RAWFONT