QwtPlotGLCanvas(3)

NAME
QwtPlotGLCanvas -

An alternative canvas for a QwtPlot derived from QGLWidget.

SYNOPSIS

#include <qwt_plot_glcanvas.h>

Inherits QGLWidget.

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

  Public Slots
void replot ()
Calls repaint()

  Public Member Functions
QwtPlotGLCanvas (QwtPlot *=NULL)
Constructor.
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) [protected], [virtual]
Draw the background of the canvas

Parameters:
    painter Painter

  void QwtPlotGLCanvas::drawBorder (QPainter *painter) [protected], [virtual]
Draw the border of the canvas

Parameters:
    painter Painter

  void QwtPlotGLCanvas::drawItems (QPainter *painter) [protected], [virtual]
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) [protected], [virtual]
Paint event

Parameters:
    event Paint event

See Also:
    QwtPlot::drawCanvas()

  void QwtPlotGLCanvas::setFrameShadow (Shadowshadow)
Set the frame shadow

Parameters:
    shadow Frame shadow

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

  void QwtPlotGLCanvas::setFrameShape (Shapeshape)
Set the frame shape

Parameters:
    shape Frame shape

See Also:
    frameShape(), setFrameShadow(), QFrame::frameShape()

  void QwtPlotGLCanvas::setFrameStyle (intstyle)
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 (intwidth)
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 (intwidth)
Set the frame mid line width

The default midline width is 0 pixels.

Parameters:
    width Midline width of the frame

See Also:
    midLineWidth(), setLineWidth()

Author

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