QwtTextEngine Class Reference

Abstract base class for rendering text strings. More...

#include <qwt_text_engine.h>

Inheritance diagram for QwtTextEngine:
Inheritance graph
[legend]

List of all members.

Public Member Functions

virtual ~QwtTextEngine ()
virtual double heightForWidth (const QFont &font, int flags, const QString &text, double width) const =0
virtual QSizeF textSize (const QFont &font, int flags, const QString &text) 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 void draw (QPainter *painter, const QRectF &rect, int flags, const QString &text) const =0

Protected Member Functions

 QwtTextEngine ()

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()

Constructor & Destructor Documentation

QwtTextEngine::~QwtTextEngine (  )  [virtual]

Destructor.

QwtTextEngine::QwtTextEngine (  )  [protected]

Constructor.


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 QwtPlainTextEngine, QwtRichTextEngine, and QwtMathMLTextEngine.

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 QwtPlainTextEngine, QwtRichTextEngine, and QwtMathMLTextEngine.

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 QwtPlainTextEngine, QwtRichTextEngine, and QwtMathMLTextEngine.

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 aligend 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 QwtPlainTextEngine, QwtRichTextEngine, and QwtMathMLTextEngine.

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:
Caluclated size

Implemented in QwtPlainTextEngine, QwtRichTextEngine, and QwtMathMLTextEngine.

Generated on Sun Nov 21 12:01:52 2010 for Qwt User's Guide by  doxygen 1.6.3