Abstract base class for rendering text strings. More...
#include <qwt_text_engine.h>
Public Member Functions | |
virtual void | draw (QPainter *painter, const QRectF &rect, int flags, const QString &text) const =0 |
virtual double | heightForWidth (const QFont &font, int flags, const QString &text, double width) const =0 |
virtual bool | mightRender (const QString &text) const =0 |
virtual void | textMargins (const QFont &font, const QString &text, double &left, double &right, double &top, double &bottom) const =0 |
virtual QSizeF | textSize (const QFont &font, int flags, const QString &text) const =0 |
virtual | ~QwtTextEngine () |
Destructor. | |
Protected Member Functions | |
QwtTextEngine () | |
Constructor. |
Abstract base class for rendering text strings.
A text engine is responsible for rendering texts for a specific text format. They are used by QwtText to render a text.
QwtPlainTextEngine and QwtRichTextEngine are part of the Qwt library. The implementation of QwtMathMLTextEngine uses code from the Qt solution package. Because of license implications it is built into a separate library.
Definition at line 35 of file qwt_text_engine.h.
QwtTextEngine::~QwtTextEngine | ( | ) | [virtual] |
Destructor.
Definition at line 141 of file qwt_text_engine.cpp.
QwtTextEngine::QwtTextEngine | ( | ) | [protected] |
Constructor.
Definition at line 136 of file qwt_text_engine.cpp.
virtual void QwtTextEngine::draw | ( | QPainter * | painter, |
const QRectF & | rect, | ||
int | flags, | ||
const QString & | text | ||
) | const [pure virtual] |
Draw the text in a clipping rectangle
painter | Painter |
rect | Clipping rectangle |
flags | Bitwise OR of the flags like in for QPainter::drawText() |
text | Text to be rendered |
Implemented in QwtRichTextEngine, and QwtPlainTextEngine.
virtual double QwtTextEngine::heightForWidth | ( | const QFont & | font, |
int | flags, | ||
const QString & | text, | ||
double | width | ||
) | const [pure virtual] |
Find the height for a given width
font | Font of the text |
flags | Bitwise OR of the flags used like in QPainter::drawText |
text | Text to be rendered |
width | Width |
Implemented in QwtRichTextEngine, and QwtPlainTextEngine.
virtual bool QwtTextEngine::mightRender | ( | const QString & | text | ) | const [pure virtual] |
Test if a string can be rendered by this text engine
text | Text to be tested |
Implemented in QwtRichTextEngine, and QwtPlainTextEngine.
virtual void QwtTextEngine::textMargins | ( | const QFont & | font, |
const QString & | text, | ||
double & | left, | ||
double & | right, | ||
double & | top, | ||
double & | bottom | ||
) | const [pure virtual] |
Return margins around the texts
The textSize might include margins around the text, like QFontMetrics::descent(). In situations where texts need to be aligned in detail, knowing these margins might improve the layout calculations.
font | Font of the text |
text | Text to be rendered |
left | Return value for the left margin |
right | Return value for the right margin |
top | Return value for the top margin |
bottom | Return value for the bottom margin |
Implemented in QwtRichTextEngine, and QwtPlainTextEngine.
virtual QSizeF QwtTextEngine::textSize | ( | const QFont & | font, |
int | flags, | ||
const QString & | text | ||
) | const [pure virtual] |
Returns the size, that is needed to render text
font | Font of the text |
flags | Bitwise OR of the flags like in for QPainter::drawText |
text | Text to be rendered |
Implemented in QwtRichTextEngine, and QwtPlainTextEngine.