Qwt User's Guide  6.1.1
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Public Types | Public Member Functions | Static Public Member Functions | List of all members
QwtText Class Reference

A class representing a text. More...

#include <qwt_text.h>

Public Types

enum  TextFormat {
  AutoText = 0, PlainText, RichText, MathMLText,
  TeXText, OtherFormat = 100
}
 Text format. More...
 
enum  PaintAttribute { PaintUsingTextFont = 0x01, PaintUsingTextColor = 0x02, PaintBackground = 0x04 }
 Paint Attributes. More...
 
enum  LayoutAttribute { MinimumLayout = 0x01 }
 Layout Attributes The layout attributes affects some aspects of the layout of the text. More...
 
typedef QFlags< PaintAttributePaintAttributes
 Paint attributes.
 
typedef QFlags< LayoutAttributeLayoutAttributes
 Layout attributes.
 

Public Member Functions

 QwtText (const QString &=QString::null, TextFormat textFormat=AutoText)
 
 QwtText (const QwtText &)
 Copy constructor.
 
 ~QwtText ()
 Destructor.
 
QwtTextoperator= (const QwtText &)
 Assignment operator.
 
bool operator== (const QwtText &) const
 Relational operator.
 
bool operator!= (const QwtText &) const
 Relational operator.
 
void setText (const QString &, QwtText::TextFormat textFormat=AutoText)
 
QString text () const
 
bool isNull () const
 
bool isEmpty () const
 
void setFont (const QFont &)
 
QFont font () const
 Return the font.
 
QFont usedFont (const QFont &) const
 
void setRenderFlags (int flags)
 Change the render flags. More...
 
int renderFlags () const
 
void setColor (const QColor &)
 
QColor color () const
 Return the pen color, used for painting the text.
 
QColor usedColor (const QColor &) const
 
void setBorderRadius (double)
 
double borderRadius () const
 
void setBorderPen (const QPen &)
 
QPen borderPen () const
 
void setBackgroundBrush (const QBrush &)
 
QBrush backgroundBrush () const
 
void setPaintAttribute (PaintAttribute, bool on=true)
 
bool testPaintAttribute (PaintAttribute) const
 
void setLayoutAttribute (LayoutAttribute, bool on=true)
 
bool testLayoutAttribute (LayoutAttribute) const
 
double heightForWidth (double width, const QFont &=QFont()) const
 
QSizeF textSize (const QFont &=QFont()) const
 
void draw (QPainter *painter, const QRectF &rect) const
 

Static Public Member Functions

static const QwtTextEnginetextEngine (const QString &text, QwtText::TextFormat=AutoText)
 
static const QwtTextEnginetextEngine (QwtText::TextFormat)
 Find the text engine for a text format. More...
 
static void setTextEngine (QwtText::TextFormat, QwtTextEngine *)
 

Detailed Description

A class representing a text.

A QwtText is a text including a set of attributes how to render it.

See Also
QwtTextEngine, QwtTextLabel

Member Enumeration Documentation

Layout Attributes The layout attributes affects some aspects of the layout of the text.

Enumerator
MinimumLayout 

Layout the text without its margins. This mode is useful if a text needs to be aligned accurately, like the tick labels of a scale. If QwtTextEngine::textMargins is not implemented for the format of the text, MinimumLayout has no effect.

Paint Attributes.

Font and color and background are optional attributes of a QwtText. The paint attributes hold the information, if they are set.

Enumerator
PaintUsingTextFont 

The text has an individual font.

PaintUsingTextColor 

The text has an individual color.

PaintBackground 

The text has an individual background.

Text format.

The text format defines the QwtTextEngine, that is used to render the text.

See Also
QwtTextEngine, setTextEngine()
Enumerator
AutoText 

The text format is determined using QwtTextEngine::mightRender() for all available text engines in increasing order > PlainText. If none of the text engines can render the text is rendered like QwtText::PlainText.

PlainText 

Draw the text as it is, using a QwtPlainTextEngine.

RichText 

Use the Scribe framework (Qt Rich Text) to render the text.

MathMLText 
      Use a MathML (http://en.wikipedia.org/wiki/MathML) render engine
      to display the text. The Qwt MathML extension offers such an engine
      based on the MathML renderer of the Qt solutions package. 
      To enable MathML support the following code needs to be added to the
      application:
QwtText::setTextEngine(QwtText::MathMLText, new QwtMathMLTextEngine()); 
TeXText 

Use a TeX (http://en.wikipedia.org/wiki/TeX) render engine to display the text ( not implemented yet ).

OtherFormat 

The number of text formats can be extended using setTextEngine. Formats >= QwtText::OtherFormat are not used by Qwt.

Constructor & Destructor Documentation

QwtText::QwtText ( const QString &  text = QString::null,
QwtText::TextFormat  textFormat = AutoText 
)

Constructor

Parameters
textText content
textFormatText format

Member Function Documentation

QBrush QwtText::backgroundBrush ( ) const
Returns
Background brush
See Also
setBackgroundBrush(), borderPen()
QPen QwtText::borderPen ( ) const
Returns
Background pen
See Also
setBorderPen(), backgroundBrush()
double QwtText::borderRadius ( ) const
Returns
Radius for the corners of the border frame
See Also
setBorderRadius(), borderPen(), backgroundBrush()
void QwtText::draw ( QPainter *  painter,
const QRectF &  rect 
) const

Draw a text into a rectangle

Parameters
painterPainter
rectRectangle
double QwtText::heightForWidth ( double  width,
const QFont &  defaultFont = QFont() 
) const

Find the height for a given width

Parameters
defaultFontFont, used for the calculation if the text has no font
widthWidth
Returns
Calculated height
bool QwtText::isEmpty ( ) const
inline
Returns
text().isEmpty()
bool QwtText::isNull ( ) const
inline
Returns
text().isNull()
int QwtText::renderFlags ( ) const
Returns
Render flags
See Also
setRenderFlags()
void QwtText::setBackgroundBrush ( const QBrush &  brush)

Set the background brush

Parameters
brushBackground brush
See Also
backgroundBrush(), setBorderPen()
void QwtText::setBorderPen ( const QPen &  pen)

Set the background pen

Parameters
penBackground pen
See Also
borderPen(), setBackgroundBrush()
void QwtText::setBorderRadius ( double  radius)

Set the radius for the corners of the border frame

Parameters
radiusRadius of a rounded corner
See Also
borderRadius(), setBorderPen(), setBackgroundBrush()
void QwtText::setColor ( const QColor &  color)

Set the pen color used for drawing the text.

Parameters
colorColor
Note
Setting the color might have no effect, when the text contains control sequences for setting colors.
void QwtText::setFont ( const QFont &  font)

Set the font.

Parameters
fontFont
Note
Setting the font might have no effect, when the text contains control sequences for setting fonts.
void QwtText::setLayoutAttribute ( LayoutAttribute  attribute,
bool  on = true 
)

Change a layout attribute

Parameters
attributeLayout attribute
onOn/Off
See Also
testLayoutAttribute()
void QwtText::setPaintAttribute ( PaintAttribute  attribute,
bool  on = true 
)

Change a paint attribute

Parameters
attributePaint attribute
onOn/Off
Note
Used by setFont(), setColor(), setBorderPen() and setBackgroundBrush()
See Also
testPaintAttribute()
void QwtText::setRenderFlags ( int  renderFlags)

Change the render flags.

The default setting is Qt::AlignCenter

Parameters
renderFlagsBitwise OR of the flags used like in QPainter::drawText()
See Also
renderFlags(), QwtTextEngine::draw()
Note
Some renderFlags might have no effect, depending on the text format.
void QwtText::setText ( const QString &  text,
QwtText::TextFormat  textFormat = AutoText 
)

Assign a new text content

Parameters
textText content
textFormatText format
See Also
text()
void QwtText::setTextEngine ( QwtText::TextFormat  format,
QwtTextEngine engine 
)
static

Assign/Replace a text engine for a text format

With setTextEngine it is possible to extend Qwt with other types of text formats.

For QwtText::PlainText it is not allowed to assign a engine == NULL.

Parameters
formatText format
engineText engine
See Also
QwtMathMLTextEngine
Warning
Using QwtText::AutoText does nothing.
bool QwtText::testLayoutAttribute ( LayoutAttribute  attribute) const

Test a layout attribute

Parameters
attributeLayout attribute
Returns
true, if attribute is enabled
See Also
setLayoutAttribute()
bool QwtText::testPaintAttribute ( PaintAttribute  attribute) const

Test a paint attribute

Parameters
attributePaint attribute
Returns
true, if attribute is enabled
See Also
setPaintAttribute()
QString QwtText::text ( ) const
Returns
Text as QString.
See Also
setText()
const QwtTextEngine * QwtText::textEngine ( const QString &  text,
QwtText::TextFormat  format = AutoText 
)
static

Find the text engine for a text format

In case of QwtText::AutoText the first text engine (beside QwtPlainTextEngine) is returned, where QwtTextEngine::mightRender returns true. If there is none QwtPlainTextEngine is returned.

If no text engine is registered for the format QwtPlainTextEngine is returnd.

Parameters
textText, needed in case of AutoText
formatText format
Returns
Corresponding text engine
const QwtTextEngine * QwtText::textEngine ( QwtText::TextFormat  format)
static

Find the text engine for a text format.

textEngine can be used to find out if a text format is supported.

Parameters
formatText format
Returns
The text engine, or NULL if no engine is available.
QSizeF QwtText::textSize ( const QFont &  defaultFont = QFont()) const

Find the height for a given width

Parameters
defaultFontFont, used for the calculation if the text has no font
Returns
Calculated height

Returns the size, that is needed to render text

Parameters
defaultFontFont of the text
Returns
Caluclated size
QColor QwtText::usedColor ( const QColor &  defaultColor) const

Return the color of the text, if it has one. Otherwise return defaultColor.

Parameters
defaultColorDefault color
Returns
Color used for drawing the text
See Also
setColor(), color(), PaintAttributes
QFont QwtText::usedFont ( const QFont &  defaultFont) const

Return the font of the text, if it has one. Otherwise return defaultFont.

Parameters
defaultFontDefault font
Returns
Font used for drawing the text
See Also
setFont(), font(), PaintAttributes