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. | |
Detailed Description
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.
- See also:
- QwtText::setTextEngine()
Definition at line 35 of file qwt_text_engine.h.
Constructor & Destructor Documentation
| 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.
Member Function Documentation
| virtual void QwtTextEngine::draw | ( | QPainter * | painter, |
| const QRectF & | rect, | ||
| int | flags, | ||
| const QString & | text | ||
| ) | const [pure virtual] |
Draw the text in a clipping rectangle
- Parameters:
-
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
- Parameters:
-
font Font of the text flags Bitwise OR of the flags used like in QPainter::drawText text Text to be rendered width Width
- Returns:
- Calculated height
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
- Parameters:
-
text Text to be tested
- Returns:
- true, if it can be rendered
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.
- Parameters:
-
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
- Parameters:
-
font Font of the text flags Bitwise OR of the flags like in for QPainter::drawText text Text to be rendered
- Returns:
- Calculated size
Implemented in QwtRichTextEngine, and QwtPlainTextEngine.
The documentation for this class was generated from the following files: