qwttextengine(3)

NAME

QwtTextEngine

SYNOPSIS

Inherited by QwtMathMLTextEngine, QwtPlainTextEngine, and
QwtRichTextEngine.

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.

QwtMathMLTextEngine can be found in Qwt MathML extension,

that needs
the MathML renderer of the Qt solutions package. Unfortu

nately it is
only available with a commercial Qt license.

See also:

QwtText::setTextEngine

Definition at line 38 of file qwt_text_engine.h.

Public Member Functions

virtual ~QwtTextEngine ()
virtual int heightForWidth (const QFont &font, int flags,

const QString

&text, int width) const=0

virtual QSize textSize (const QFont &font, int flags, con

st QString

&text) const=0

virtual bool mightRender (const QString &text) const =0 virtual void textMargins (const QFont &font, const QString

&text, int

&left, int &right, int &top, int &bottom) const =0

virtual void draw (QPainter *painter, const QRect &rect,

int flags,

const QString &text) const=0

Protected Member Functions

QwtTextEngine ()

Constructor & Destructor Documentation

QwtTextEngine::~QwtTextEngine () [virtual]

Destructor.

Definition at line 175 of file qwt_text_engine.cpp.

QwtTextEngine::QwtTextEngine () [protected]

Constructor.

Definition at line 170 of file qwt_text_engine.cpp.

Member Function Documentation

virtual int QwtTextEngine::heightForWidth (const QFont & font,

int flags,

const QString & text, int 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 QSize 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.

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, int & left, int & right, int & top, int & 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 void QwtTextEngine::draw (QPainter * painter, const

QRect & 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.

Author

Generated automatically by Doxygen for Qwt User's Guide

from the source
code.

Version 5.1.1 24 May 2008

QwtTextEngine(3)