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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 if (d->glyphIndexData != other.d->glyphIndexData) {
145 for (int i = 0; i < d->glyphIndexDataSize; ++i) {
146 if (d->glyphIndexData[i] != other.d->glyphIndexData[i])
150 if (d->glyphPositionData != other.d->glyphPositionData) {
151 for (int i = 0; i < d->glyphPositionDataSize; ++i) {
152 if (d->glyphPositionData[i] != other.d->glyphPositionData[i])
157 return (d->overline == other.d->overline
158 && d->underline == other.d->underline
159 && d->strikeOut == other.d->strikeOut
160 && d->rawFont == other.d->rawFont);
164 \fn bool QGlyphRun::operator!=(const QGlyphRun &other) const
166 Compares \a other to this QGlyphRun object. Returns true if any of the list of glyph
167 indexes, the list of positions or the font are different, otherwise returns false.
171 Returns the font selected for this QGlyphRun object.
175 QRawFont QGlyphRun::rawFont() const
181 Sets the font in which to look up the glyph indexes to the \a rawFont
184 \sa rawFont(), setGlyphIndexes()
186 void QGlyphRun::setRawFont(const QRawFont &rawFont)
189 d->rawFont = rawFont;
193 Returns the glyph indexes for this QGlyphRun object.
195 \sa setGlyphIndexes(), setPositions()
197 QVector<quint32> QGlyphRun::glyphIndexes() const
199 if (d->glyphIndexes.constData() == d->glyphIndexData) {
200 return d->glyphIndexes;
202 QVector<quint32> indexes(d->glyphIndexDataSize);
203 qMemCopy(indexes.data(), d->glyphIndexData, d->glyphIndexDataSize * sizeof(quint32));
209 Set the glyph indexes for this QGlyphRun object to \a glyphIndexes. The glyph indexes must
210 be valid for the selected font.
212 void QGlyphRun::setGlyphIndexes(const QVector<quint32> &glyphIndexes)
215 d->glyphIndexes = glyphIndexes; // Keep a reference to the QVector to avoid copying
216 d->glyphIndexData = glyphIndexes.constData();
217 d->glyphIndexDataSize = glyphIndexes.size();
221 Returns the position of the edge of the baseline for each glyph in this set of glyph indexes.
223 QVector<QPointF> QGlyphRun::positions() const
225 if (d->glyphPositions.constData() == d->glyphPositionData) {
226 return d->glyphPositions;
228 QVector<QPointF> glyphPositions(d->glyphPositionDataSize);
229 qMemCopy(glyphPositions.data(), d->glyphPositionData,
230 d->glyphPositionDataSize * sizeof(QPointF));
231 return glyphPositions;
236 Sets the positions of the edge of the baseline for each glyph in this set of glyph indexes to
239 void QGlyphRun::setPositions(const QVector<QPointF> &positions)
242 d->glyphPositions = positions; // Keep a reference to the vector to avoid copying
243 d->glyphPositionData = positions.constData();
244 d->glyphPositionDataSize = positions.size();
248 Clears all data in the QGlyphRun object.
250 void QGlyphRun::clear()
253 d->rawFont = QRawFont();
254 d->strikeOut = false;
256 d->underline = false;
258 setPositions(QVector<QPointF>());
259 setGlyphIndexes(QVector<quint32>());
263 Sets the glyph indexes and positions of this QGlyphRun to use the first \a size
264 elements in the arrays \a glyphIndexArray and \a glyphPositionArray. The data is
265 \e not copied. The caller must guarantee that the arrays are not deleted as long
266 as this QGlyphRun and any copies of it exists.
268 \sa setGlyphIndexes(), setPositions()
270 void QGlyphRun::setRawData(const quint32 *glyphIndexArray, const QPointF *glyphPositionArray,
274 d->glyphIndexes.clear();
275 d->glyphPositions.clear();
277 d->glyphIndexData = glyphIndexArray;
278 d->glyphPositionData = glyphPositionArray;
279 d->glyphIndexDataSize = d->glyphPositionDataSize = size;
283 Returns true if this QGlyphRun should be painted with an overline decoration.
287 bool QGlyphRun::overline() const
293 Indicates that this QGlyphRun should be painted with an overline decoration if \a overline is true.
294 Otherwise the QGlyphRun should be painted with no overline decoration.
298 void QGlyphRun::setOverline(bool overline)
300 if (d->overline == overline)
304 d->overline = overline;
308 Returns true if this QGlyphRun should be painted with an underline decoration.
312 bool QGlyphRun::underline() const
318 Indicates that this QGlyphRun should be painted with an underline decoration if \a underline is
319 true. Otherwise the QGlyphRun should be painted with no underline decoration.
323 void QGlyphRun::setUnderline(bool underline)
325 if (d->underline == underline)
329 d->underline = underline;
333 Returns true if this QGlyphRun should be painted with a strike out decoration.
337 bool QGlyphRun::strikeOut() const
343 Indicates that this QGlyphRun should be painted with an strike out decoration if \a strikeOut is
344 true. Otherwise the QGlyphRun should be painted with no strike out decoration.
348 void QGlyphRun::setStrikeOut(bool strikeOut)
350 if (d->strikeOut == strikeOut)
354 d->strikeOut = strikeOut;
358 Sets the bounding rect of the glyphs in this QGlyphRun to be \a boundingRect. This rectangle
359 will be returned by boundingRect() unless it is empty, in which case the bounding rectangle of the
360 glyphs in the glyph run will be returned instead.
362 \note Unless you are implementing text shaping, you should not have to use this function.
363 It is used specifically when the QGlyphRun should represent an area which is smaller than the
364 area of the glyphs it contains. This could happen e.g. if the glyph run is retrieved by calling
365 QTextLayout::glyphRuns() and the specified range only includes part of a ligature (where two or
366 more characters are combined to a single glyph.) When this is the case, the bounding rect should
367 only include the appropriate part of the ligature glyph, based on a calculation of the average
368 width of the characters in the ligature.
370 In order to support such a case (an example is selections which should be drawn with a different
371 color than the main text color), it is necessary to clip the painting mechanism to the rectangle
372 returned from boundingRect() to avoid drawing the entire ligature glyph.
378 void QGlyphRun::setBoundingRect(const QRectF &boundingRect)
381 d->boundingRect = boundingRect;
385 Returns the smallest rectangle that contains all glyphs in this QGlyphRun. If a bounding rect
386 has been set using setBoundingRect(), then this will be returned. Otherwise the bounding rect
387 will be calculated based on the font metrics of the glyphs in the glyph run.
391 QRectF QGlyphRun::boundingRect() const
393 if (!d->boundingRect.isEmpty())
394 return d->boundingRect;
396 qreal minX, minY, maxX, maxY;
398 for (int i=0; i<qMin(d->glyphPositions.size(), d->glyphIndexes.size()); ++i) {
399 QRectF glyphRect = d->rawFont.boundingRect(d->glyphIndexes.at(i));
400 glyphRect.translate(d->glyphPositions.at(i));
403 minX = glyphRect.left();
404 minY = glyphRect.top();
405 maxX = glyphRect.right();
406 maxY = glyphRect.bottom();
408 minX = qMin(glyphRect.left(), minX);
409 minY = qMin(glyphRect.top(), minY);
410 maxX = qMax(glyphRect.right(),maxX);
411 maxY = qMax(glyphRect.bottom(), maxY);
415 return QRectF(QPointF(minX, minY), QPointF(maxX, maxY));
419 Returns true if the QGlyphRun does not contain any glyphs.
423 bool QGlyphRun::isEmpty() const
425 return d->glyphIndexes.isEmpty();
430 #endif // QT_NO_RAWFONT