QGlyphRun class provides direct access to the internal glyphs in a font. 更多...
| 头： | #include <QGlyphRun> |
| qmake: | QT += gui |
| Since: | Qt 4.8 |
| enum | GlyphRunFlag { Overline, Underline, StrikeOut, RightToLeft, SplitLigature } |
| flags | GlyphRunFlags |
| QGlyphRun () | |
| QGlyphRun (const QGlyphRun & other ) | |
| ~QGlyphRun () | |
| QRectF | boundingRect () const |
| void | clear () |
| GlyphRunFlags | flags () const |
| QVector<quint32> | glyphIndexes () const |
| bool | isEmpty () const |
| bool | isRightToLeft () const |
| bool | overline () const |
| QVector<QPointF> | positions () const |
| QRawFont | rawFont () const |
| void | setBoundingRect (const QRectF & boundingRect ) |
| void | setFlag (GlyphRunFlag flag , bool enabled = true) |
| void | setFlags (GlyphRunFlags flags ) |
| void | setGlyphIndexes (const QVector<quint32> & glyphIndexes ) |
| void | setOverline (bool overline ) |
| void | setPositions (const QVector<QPointF> & positions ) |
| void | setRawData (const quint32 * glyphIndexArray , const QPointF * glyphPositionArray , int size ) |
| void | setRawFont (const QRawFont & rawFont ) |
| void | setRightToLeft (bool rightToLeft ) |
| void | setStrikeOut (bool strikeOut ) |
| void | setUnderline (bool underline ) |
| bool | strikeOut () const |
| void | swap (QGlyphRun & other ) |
| bool | underline () const |
| bool | operator!= (const QGlyphRun & other ) const |
| QGlyphRun & | operator= (QGlyphRun && other ) |
| QGlyphRun & | operator= (const QGlyphRun & other ) |
| bool | operator== (const QGlyphRun & other ) const |
QGlyphRun class provides direct access to the internal glyphs in a font.
When Qt displays a string of text encoded in Unicode, it will first convert the Unicode points into a list of glyph indexes and a list of positions based on one or more fonts. The Unicode representation of the text and the QFont object will in this case serve as a convenient abstraction that hides the details of what actually takes place when displaying the text on-screen. For instance, by the time the text actually reaches the screen, it may be represented by a set of fonts in addition to the one specified by the user, e.g. in case the originally selected font did not support all the writing systems contained in the text.
Under certain circumstances, it can be useful as an application developer to have more low-level control over which glyphs in a specific font are drawn to the screen. This could for instance be the case in applications that use an external font engine and text shaper together with Qt. QGlyphRun provides an interface to the raw data needed to get text on the screen. It contains a list of glyph indexes, a position for each glyph and a font.
It is the user's responsibility to ensure that the selected font actually contains the provided glyph indexes.
QTextLayout::glyphRuns () 或 QTextFragment::glyphRuns () can be used to convert unicode encoded text into a list of QGlyphRun objects, and QPainter::drawGlyphRun () can be used to draw the glyphs.
注意： 请注意 QRawFont is considered local to the thread in which it is constructed. This in turn means that a new QRawFont will have to be created and set on the QGlyphRun if it is moved to a different thread. If the QGlyphRun contains a reference to a QRawFont from a different thread than the current, it will not be possible to draw the glyphs using a QPainter , as the QRawFont is considered invalid and inaccessible in this case.
This enum describes flags that alter the way the run of glyphs might be presented or behave in a visual layout. The layout which generates the glyph runs can set these flags based on relevant internal data, to retain information needed to present the text as intended by the user of the layout.
| 常量 | 值 | 描述 |
|---|---|---|
QGlyphRun::Overline
|
0x01
|
Indicates that the glyphs should be visualized together with an overline. |
QGlyphRun::Underline
|
0x02
|
Indicates that the glyphs should be visualized together with an underline. |
QGlyphRun::StrikeOut
|
0x04
|
Indicates that the glyphs should be struck out visually. |
QGlyphRun::RightToLeft
|
0x08
|
Indicates that the glyphs are ordered right to left. This can affect the positioning of other screen elements that are relative to the glyph run, such as an inline text object. |
QGlyphRun::SplitLigature
|
0x10
|
Indicates that the glyph run splits a ligature glyph. This means that a ligature glyph is included in the run, but the characters represented by it corresponds only to part of that ligature. The glyph run's boundingRect () function can in this case be used to retrieve the area covered by glyphs that correspond to the characters represented by the glyph run. When visualizing the glyphs, care needs to be taken to clip to this bounding rect to ensure that only the corresponding part of the ligature is painted. In particular, this can be the case when retrieving a glyph run from a QTextLayout for a specific character range, e.g. when retrieving the selected area of a QTextLayout . |
该枚举在 Qt 5.0 引入或被修改。
The GlyphRunFlags type is a typedef for QFlags <GlyphRunFlag>. It stores an OR combination of GlyphRunFlag values.
构造空的 QGlyphRun 对象。
构造 QGlyphRun object which is a copy of other .
销毁 QGlyphRun .
Returns the smallest rectangle that contains all glyphs in this QGlyphRun . If a bounding rect has been set using setBoundingRect (), then this will be returned. Otherwise the bounding rect will be calculated based on the font metrics of the glyphs in the glyph run.
该函数在 Qt 5.0 引入。
另请参阅 setBoundingRect ().
Clears all data in the QGlyphRun 对象。
Returns the flags set for this QGlyphRun .
该函数在 Qt 5.0 引入。
另请参阅 setFlags (), setFlag ()，和 setFlag ().
Returns the glyph indexes for this QGlyphRun 对象。
另请参阅 setGlyphIndexes () 和 setPositions ().
返回
true
若
QGlyphRun
does not contain any glyphs.
该函数在 Qt 5.0 引入。
返回
true
若此
QGlyphRun
contains glyphs that are painted from the right to the left.
该函数在 Qt 5.0 引入。
另请参阅 setRightToLeft () 和 flags ().
返回
true
若此
QGlyphRun
should be painted with an overline decoration.
另请参阅 setOverline () 和 flags ().
Returns the position of the edge of the baseline for each glyph in this set of glyph indexes.
另请参阅 setPositions ().
Returns the font selected for this QGlyphRun 对象。
另请参阅 setRawFont ().
Sets the bounding rect of the glyphs in this QGlyphRun 到 boundingRect . This rectangle will be returned by boundingRect () unless it is empty, in which case the bounding rectangle of the glyphs in the glyph run will be returned instead.
注意： Unless you are implementing text shaping, you should not have to use this function. It is used specifically when the QGlyphRun should represent an area which is smaller than the area of the glyphs it contains. This could happen e.g. if the glyph run is retrieved by calling QTextLayout::glyphRuns () and the specified range only includes part of a ligature (where two or more characters are combined to a single glyph.) When this is the case, the bounding rect should only include the appropriate part of the ligature glyph, based on a calculation of the average width of the characters in the ligature.
In order to support such a case (an example is selections which should be drawn with a different color than the main text color), it is necessary to clip the painting mechanism to the rectangle returned from boundingRect () to avoid drawing the entire ligature glyph.
该函数在 Qt 5.0 引入。
另请参阅 boundingRect ().
若 enabled is true, then flag 被启用；否则，被禁用。
该函数在 Qt 5.0 引入。
Sets the flags of this QGlyphRun to flags .
该函数在 Qt 5.0 引入。
Set the glyph indexes for this QGlyphRun 对象到 glyphIndexes . The glyph indexes must be valid for the selected font.
另请参阅 glyphIndexes ().
Indicates that this QGlyphRun should be painted with an overline decoration if overline is true. Otherwise the QGlyphRun should be painted with no overline decoration.
另请参阅 overline (), setFlag ()，和 setFlags ().
Sets the positions of the edge of the baseline for each glyph in this set of glyph indexes to positions .
另请参阅 positions ().
Sets the glyph indexes and positions of this QGlyphRun to use the first size elements in the arrays glyphIndexArray and glyphPositionArray . The data is not copied. The caller must guarantee that the arrays are not deleted as long as this QGlyphRun and any copies of it exists.
另请参阅 setGlyphIndexes () 和 setPositions ().
Sets the font in which to look up the glyph indexes to the rawFont 指定。
另请参阅 rawFont () 和 setGlyphIndexes ().
Indicates that this QGlyphRun contains glyphs that should be ordered from the right to left if rightToLeft is true. Otherwise the order of the glyphs is assumed to be left to right.
该函数在 Qt 5.0 引入。
另请参阅 isRightToLeft (), setFlag ()，和 setFlags ().
Indicates that this QGlyphRun should be painted with an strike out decoration if strikeOut is true. Otherwise the QGlyphRun should be painted with no strike out decoration.
另请参阅 strikeOut (), setFlag ()，和 setFlags ().
Indicates that this QGlyphRun should be painted with an underline decoration if underline is true. Otherwise the QGlyphRun should be painted with no underline decoration.
另请参阅 underline (), setFlag ()，和 setFlags ().
返回
true
若此
QGlyphRun
should be painted with a strike out decoration.
另请参阅 setStrikeOut () 和 flags ().
Swaps this glyph run instance with other 。此函数非常快，且从不失败。
该函数在 Qt 5.0 引入。
返回
true
若此
QGlyphRun
should be painted with an underline decoration.
另请参阅 setUnderline () 和 flags ().
比较
other
到此
QGlyphRun
对象。返回
true
if any of the list of glyph indexes, the list of positions or the font are different, otherwise returns
false
.
移动赋值运算符。
赋值 other 到此 QGlyphRun 对象。
比较
other
到此
QGlyphRun
对象。返回
true
if the list of glyph indexes, the list of positions and the font are all equal, otherwise returns
false
.
