QwtTextEngine Class Reference

Inheritance diagram for QwtTextEngine:

Inheritance graph
[legend]
List of all members.

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, other text engines can be loaded as plugins.

The Qt Solution package includes a renderer for MathML, that could be used successfully for an implementation of a MathML text plugin. Unfortunately the QtMml implementation needs a lot of patches to export interfaces to be usable from Qwt, that can't be published without violation of the Qt Solution license. ( See textengines/mathml, and read the comments in mathml.pro. )

See also:
QwtText

Definition at line 43 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, const 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 126 of file qwt_text_engine.cpp.

QwtTextEngine::QwtTextEngine  )  [protected]
 

Constructor.

Definition at line 121 of file qwt_text_engine.cpp.


Member Function Documentation

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, and QwtRichTextEngine.

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, and QwtRichTextEngine.

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, and QwtRichTextEngine.

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, and QwtRichTextEngine.

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, and QwtRichTextEngine.


Generated on Mon Nov 6 20:34:11 2006 for Qwt User's Guide by  doxygen 1.4.6