QwtPlotGLCanvas Class Reference

An alternative canvas for a QwtPlot derived from QGLWidget. More...

#include <qwt_plot_glcanvas.h>

Inheritance diagram for QwtPlotGLCanvas:

Public Types
enum	Shadow { Plain = QFrame::Plain, Raised = QFrame::Raised, Sunken = QFrame::Sunken }
	Frame shadow. More...
enum	Shape { NoFrame = QFrame::NoFrame, Box = QFrame::Box, Panel = QFrame::Panel }
	Frame shape. More...

Public Slots
void	replot ()
	Calls repaint()

Public Member Functions
	QwtPlotGLCanvas (QwtPlot *=NULL)
	Constructor. More...
virtual	~QwtPlotGLCanvas ()
	Destructor.
void	setFrameStyle (int style)
int	frameStyle () const
void	setFrameShadow (Shadow)
Shadow	frameShadow () const
void	setFrameShape (Shape)
Shape	frameShape () const
void	setLineWidth (int)
int	lineWidth () const
void	setMidLineWidth (int)
int	midLineWidth () const
int	frameWidth () const
QRect	frameRect () const
Q_INVOKABLE QPainterPath	borderPath (const QRect &) const
virtual bool	event (QEvent *)

Protected Member Functions
virtual void	paintEvent (QPaintEvent *)
virtual void	drawBackground (QPainter *)
virtual void	drawBorder (QPainter *)
virtual void	drawItems (QPainter *)

Detailed Description

An alternative canvas for a QwtPlot derived from QGLWidget.

QwtPlotGLCanvas implements the very basics to act as canvas inside of a QwtPlot widget. It might be extended to a full featured alternative to QwtPlotCanvas in a future version of Qwt.

Even if QwtPlotGLCanvas is not derived from QFrame it imitates its API. When using style sheets it supports the box model - beside backgrounds with rounded borders.

See Also

QwtPlot::setCanvas(), QwtPlotCanvas

Note

You might want to use the QPaintEngine::OpenGL paint engine ( see QGL::setPreferredPaintEngine() ). On a Linux test system QPaintEngine::OpenGL2 shows very basic problems ( wrong geometries of rectangles ) but also more advanced stuff like antialiasing doesn't work.

Another way to introduce OpenGL rendering to Qwt is to use QGLPixelBuffer or QGLFramebufferObject. Both type of buffers can be converted into a QImage and used in combination with a regular QwtPlotCanvas.

Member Enumeration Documentation

enum QwtPlotGLCanvas::Shadow

Frame shadow.

Unfortunately it is not possible to use QFrame::Shadow as a property of a widget that is not derived from QFrame. The following enum is made for the designer only. It is safe to use QFrame::Shadow instead.

Enumerator
Plain	QFrame::Plain.
Raised	QFrame::Raised.
Sunken	QFrame::Sunken.

enum QwtPlotGLCanvas::Shape

Frame shape.

Unfortunately it is not possible to use QFrame::Shape as a property of a widget that is not derived from QFrame. The following enum is made for the designer only. It is safe to use QFrame::Shadow instead.

Note

QFrame::StyledPanel and QFrame::WinPanel are unsuported and will be displayed as QFrame::Panel.

Constructor & Destructor Documentation

QwtPlotGLCanvas::QwtPlotGLCanvas ( QwtPlot *  plot = NULL )

explicit

Constructor.

Parameters

plot	Parent plot widget

See Also

QwtPlot::setCanvas()

Member Function Documentation

QPainterPath QwtPlotGLCanvas::borderPath

(

const QRect &

rect

)

const

Returns

Empty path

void QwtPlotGLCanvas::drawBackground ( QPainter *  painter )

protectedvirtual

Draw the background of the canvas

Parameters

painter

Painter

void QwtPlotGLCanvas::drawBorder ( QPainter *  painter )

protectedvirtual

Draw the border of the canvas

Parameters

painter

Painter

void QwtPlotGLCanvas::drawItems ( QPainter *  painter )

protectedvirtual

Draw the plot items

Parameters

painter

Painter

See Also

QwtPlot::drawCanvas()

bool QwtPlotGLCanvas::event ( QEvent *  event )

virtual

Qt event handler for QEvent::PolishRequest and QEvent::StyleChange

Parameters

event

Qt Event

Returns

See QGLWidget::event()

QRect QwtPlotGLCanvas::frameRect

(

)

const

Returns

The rectangle where the frame is drawn in.

QwtPlotGLCanvas::Shadow QwtPlotGLCanvas::frameShadow

(

)

const

Returns

Frame shadow

See Also

setFrameShadow(), QFrame::setFrameShadow()

QwtPlotGLCanvas::Shape QwtPlotGLCanvas::frameShape

(

)

const

Returns

Frame shape

See Also

setFrameShape(), QFrame::frameShape()

int QwtPlotGLCanvas::frameStyle

(

)

const

Returns

The bitwise OR between a frameShape() and a frameShadow()

See Also

setFrameStyle(), QFrame::frameStyle()

int QwtPlotGLCanvas::frameWidth

(

)

const

Returns

Frame width depending on the style, line width and midline width.

int QwtPlotGLCanvas::lineWidth

(

)

const

Returns

Line width of the frame

See Also

setLineWidth(), midLineWidth()

int QwtPlotGLCanvas::midLineWidth

(

)

const

Returns

Midline width of the frame

See Also

setMidLineWidth(), lineWidth()

void QwtPlotGLCanvas::paintEvent ( QPaintEvent *  event )

protectedvirtual

Paint event

Parameters

event

Paint event

See Also

QwtPlot::drawCanvas()

void QwtPlotGLCanvas::setFrameShadow

(

Shadow

shadow

)

Set the frame shadow

Parameters

shadow

Frame shadow

See Also

frameShadow(), setFrameShape(), QFrame::setFrameShadow()

void QwtPlotGLCanvas::setFrameShape

(

Shape

shape

)

Set the frame shape

Parameters

shape

Frame shape

See Also

frameShape(), setFrameShadow(), QFrame::frameShape()

void QwtPlotGLCanvas::setFrameStyle

(

int

style

)

Set the frame style

Parameters

style

The bitwise OR between a shape and a shadow.

See Also

frameStyle(), QFrame::setFrameStyle(), setFrameShadow(), setFrameShape()

void QwtPlotGLCanvas::setLineWidth

(

int

width

)

Set the frame line width

The default line width is 2 pixels.

Parameters

width

Line width of the frame

See Also

lineWidth(), setMidLineWidth()

void QwtPlotGLCanvas::setMidLineWidth

(

int

width

)

Set the frame mid line width

The default midline width is 0 pixels.

Parameters

width

Midline width of the frame

See Also

midLineWidth(), setLineWidth()