Public Types¶

enum Style { NoSymbol = -1, Ellipse, Rect, Diamond, Triangle, DTriangle, UTriangle, LTriangle, RTriangle, Cross, XCross, HLine, VLine, Star1, Star2, Hexagon, Path, Pixmap, Graphic, SvgDocument, UserStyle = 1000 }
enum CachePolicy { NoCache, Cache, AutoCache }

Public Member Functions¶

QwtSymbol (Style=NoSymbol)
QwtSymbol (Style, const QBrush &, const QPen &, const QSize &)
Constructor. QwtSymbol (const QPainterPath &, const QBrush &, const QPen &)
Constructor. virtual ~QwtSymbol ()
Destructor. void setCachePolicy (CachePolicy)
CachePolicy cachePolicy () const
void setSize (const QSize &)
void setSize (int width, int height=-1)
Specify the symbol's size. const QSize & size () const
void setPinPoint (const QPointF &pos, bool enable=true)
Set and enable a pin point. QPointF pinPoint () const
void setPinPointEnabled (bool)
bool isPinPointEnabled () const
virtual void setColor (const QColor &)
Set the color of the symbol. void setBrush (const QBrush &)
Assign a brush. const QBrush & brush () const
void setPen (const QColor &, qreal width=0.0, Qt::PenStyle=Qt::SolidLine)
void setPen (const QPen &)
const QPen & pen () const
void setStyle (Style)
Style style () const
void setPath (const QPainterPath &)
Set a painter path as symbol. const QPainterPath & path () const
void setPixmap (const QPixmap &)
const QPixmap & pixmap () const
void setGraphic (const QwtGraphic &)
const QwtGraphic & graphic () const
void setSvgDocument (const QByteArray &)
void drawSymbol (QPainter *, const QRectF &) const
Draw the symbol into a rectangle. void drawSymbol (QPainter *, const QPointF &) const
Draw the symbol at a specified position. void drawSymbols (QPainter *, const QPolygonF &) const
Draw symbols at the specified points. void drawSymbols (QPainter *, const QPointF *, int numPoints) const
virtual QRect boundingRect () const
void invalidateCache ()

Protected Member Functions¶

virtual void renderSymbols (QPainter *, const QPointF *, int numPoints) const

enum QwtSymbol::CachePolicy¶

Depending on the render engine and the complexity of the symbol shape it might be faster to render the symbol to a pixmap and to paint this pixmap.

F.e. the raster paint engine is a pure software renderer where in cache mode a draw operation usually ends in raster operation with the the backing store, that are usually faster, than the algorithms for rendering polygons. But the opposite can be expected for graphic pipelines that can make use of hardware acceleration.

The default setting is AutoCache

See also:

Note:

Warning:

Enumerator

NoCache

Don't use a pixmap cache.

Cache

Always use a pixmap cache.

AutoCache

Use a cache when one of the following conditions is true:

•

The symbol is rendered with the software renderer ( QPaintEngine::Raster )

enum QwtSymbol::Style¶

Symbol Style

See also:

Enumerator

NoSymbol

No Style. The symbol cannot be drawn.

Ellipse

Ellipse or circle.

Rect

Rectangle.

Diamond

Diamond.

Triangle

Triangle pointing upwards.

DTriangle

Triangle pointing downwards.

UTriangle

Triangle pointing upwards.

LTriangle

Triangle pointing left.

RTriangle

Triangle pointing right.

Cross

Cross (+)

XCross

Diagonal cross (X)

HLine

Horizontal line.

VLine

Vertical line.

Star1

X combined with +.

Star2

Six-pointed star.

Hexagon

Hexagon.

Path

The symbol is represented by a painter path, where the origin ( 0, 0 ) of the path coordinate system is mapped to the position of the symbol.

See also:

Pixmap

The symbol is represented by a pixmap. The pixmap is centered or aligned to its pin point.

See also:

Graphic

The symbol is represented by a graphic. The graphic is centered or aligned to its pin point.

See also:

SvgDocument

The symbol is represented by a SVG graphic. The graphic is centered or aligned to its pin point.

See also:

UserStyle

Styles >= QwtSymbol::UserSymbol are reserved for derived classes of QwtSymbol that overload drawSymbols() with additional application specific symbol types.

QwtSymbol::QwtSymbol (Style style = NoSymbol)¶

Default Constructor

Parameters:

The symbol is constructed with gray interior, black outline with zero width, no size and style 'NoSymbol'.

QwtSymbol::QwtSymbol (QwtSymbol::Style style, const QBrush & brush, const QPen & pen, const QSize & size)¶

Constructor.

Parameters:

See also:

QwtSymbol::QwtSymbol (const QPainterPath & path, const QBrush & brush, const QPen & pen)¶

Constructor. The symbol gets initialized by a painter path. The style is set to QwtSymbol::Path, the size is set to empty ( the path is displayed unscaled ).

Parameters:

See also:

QRect QwtSymbol::boundingRect () const [virtual]¶

Calculate the bounding rectangle for a symbol at position (0,0).

Returns:

const QBrush & QwtSymbol::brush () const¶

Returns:

See also:

QwtSymbol::CachePolicy QwtSymbol::cachePolicy () const¶

Returns:

See also:

void QwtSymbol::drawSymbol (QPainter * painter, const QRectF & rect) const¶

Draw the symbol into a rectangle. The symbol is painted centered and scaled into the target rectangle. It is always painted uncached and the pin point is ignored.

This method is primarily intended for drawing a symbol to the legend.

Parameters:

void QwtSymbol::drawSymbol (QPainter * painter, const QPointF & pos) const [inline]¶

Draw the symbol at a specified position.

Parameters:

void QwtSymbol::drawSymbols (QPainter * painter, const QPolygonF & points) const [inline]¶

Draw symbols at the specified points.

Parameters:

void QwtSymbol::drawSymbols (QPainter * painter, const QPointF * points, int numPoints) const¶

Render an array of symbols

Painting several symbols is more effective than drawing symbols one by one, as a couple of layout calculations and setting of pen/brush can be done once for the complete array.

Parameters:

const QwtGraphic & QwtSymbol::graphic () const¶

Returns:

See also:

void QwtSymbol::invalidateCache ()¶

Invalidate the cached symbol pixmap

The symbol invalidates its cache, whenever an attribute is changed that has an effect ob how to display a symbol. In case of derived classes with individual styles ( >= QwtSymbol::UserStyle ) it might be necessary to call invalidateCache() for attributes that are relevant for this style.

See also:

bool QwtSymbol::isPinPointEnabled () const¶

Returns:

See also:

const QPainterPath & QwtSymbol::path () const¶

Returns:

See also:

const QPen & QwtSymbol::pen () const¶

Returns:

See also:

QPointF QwtSymbol::pinPoint () const¶

Returns:

See also:

const QPixmap & QwtSymbol::pixmap () const¶

Returns:

See also:

void QwtSymbol::renderSymbols (QPainter * painter, const QPointF * points, int numPoints) const [protected], [virtual]¶

Render the symbol to series of points

Parameters:

void QwtSymbol::setBrush (const QBrush & brush)¶

Assign a brush. The brush is used to draw the interior of the symbol.

Parameters:

See also:

void QwtSymbol::setCachePolicy (QwtSymbol::CachePolicy policy)¶

Change the cache policy

The default policy is AutoCache

Parameters:

See also:

void QwtSymbol::setColor (const QColor & color) [virtual]¶

Set the color of the symbol. Change the color of the brush for symbol types with a filled area. For all other symbol types the color will be assigned to the pen.

Parameters:

See also:

void QwtSymbol::setGraphic (const QwtGraphic & graphic)¶

Set a graphic as symbol

Parameters:

See also:

Note:

void QwtSymbol::setPath (const QPainterPath & path)¶

Set a painter path as symbol. The symbol is represented by a painter path, where the origin ( 0, 0 ) of the path coordinate system is mapped to the position of the symbol.

When the symbol has valid size the painter path gets scaled to fit into the size. Otherwise the symbol size depends on the bounding rectangle of the path.

Example

#include <qwt_symbol.h>
QwtSymbol *symbol = new QwtSymbol();
QPen pen( Qt::black, 2 );
pen.setJoinStyle( Qt::MiterJoin );
symbol->setPen( pen );
symbol->setBrush( Qt::red );
QPainterPath path;
path.moveTo( 0, 8 );
path.lineTo( 0, 5 );
path.lineTo( -3, 5 );
path.lineTo( 0, 0 );
path.lineTo( 3, 5 );
path.lineTo( 0, 5 );
QTransform transform;
transform.rotate( -30.0 );
path = transform.map( path );
symbol->setPath( path );
symbol->setPinPoint( QPointF( 0.0, 0.0 ) );
setSize( 10, 14 );

Parameters:

Note:

See also:

void QwtSymbol::setPen (const QColor & color, qreal width = 0.0, Qt::PenStyle style = Qt::SolidLine)¶

Build and assign a pen

In Qt5 the default pen width is 1.0 ( 0.0 in Qt4 ) what makes it non cosmetic ( see QPen::isCosmetic() ). This method has been introduced to hide this incompatibility.

Parameters:

See also:

void QwtSymbol::setPen (const QPen & pen)¶

Assign a pen

The pen is used to draw the symbol's outline.

Parameters:

See also:

void QwtSymbol::setPinPoint (const QPointF & pos, bool enable = true)¶

Set and enable a pin point. The position of a complex symbol is not always aligned to its center ( f.e an arrow, where the peak points to a position ). The pin point defines the position inside of a Pixmap, Graphic, SvgDocument or PainterPath symbol where the represented point has to be aligned to.

Parameters:

See also:

void QwtSymbol::setPinPointEnabled (bool on)¶

En/Disable the pin point alignment

Parameters:

See also:

void QwtSymbol::setPixmap (const QPixmap & pixmap)¶

Set a pixmap as symbol

Parameters:

See also:

Note:

void QwtSymbol::setSize (const QSize & size)¶

Set the symbol's size

Parameters:

See also:

void QwtSymbol::setSize (int width, int height = -1)¶

Specify the symbol's size. If the 'h' parameter is left out or less than 0, and the 'w' parameter is greater than or equal to 0, the symbol size will be set to (w,w).

Parameters:

See also:

void QwtSymbol::setStyle (QwtSymbol::Style style)¶

Specify the symbol style

Parameters:

See also:

void QwtSymbol::setSvgDocument (const QByteArray & svgDocument)¶

Set a SVG icon as symbol

Parameters:

See also:

Note:

const QSize & QwtSymbol::size () const¶

Returns:

See also:

QwtSymbol::Style QwtSymbol::style () const¶

Returns:

See also: