Qwt User's Guide: QwtPlotCanvas Class Reference

Qwt

previous page next page

QwtPlotCanvas Class Reference

Canvas of a QwtPlot. More...

#include <qwt_plot_canvas.h>

List of all members.

Public Types

enum  PaintAttribute {
  PaintCached = 1,
  PaintPacked = 2
}
enum  FocusIndicator {
  NoFocusIndicator,
  CanvasFocusIndicator,
  ItemFocusIndicator
}

Public Member Functions

 QwtPlotCanvas (QwtPlot *)
virtual ~QwtPlotCanvas ()
QwtPlot * plot ()
const QwtPlot * plot () const
void setFocusIndicator (FocusIndicator)
FocusIndicator focusIndicator () const
void setPaintAttribute (PaintAttribute, bool on=true)
bool testPaintAttribute (PaintAttribute) const
QPixmap * paintCache ()
const QPixmap * paintCache () const
void invalidatePaintCache ()
void replot ()

Protected Member Functions

virtual void hideEvent (QHideEvent *)
virtual void paintEvent (QPaintEvent *)
virtual void drawContents (QPainter *)
virtual void drawFocusIndicator (QPainter *)
void drawCanvas (QPainter *painter=NULL)

Detailed Description

Canvas of a QwtPlot.

See also:
QwtPlot

Member Enumeration Documentation

enum QwtPlotCanvas::FocusIndicator

Focus indicator.

  • NoFocusIndicator
    Don't paint a focus indicator
  • CanvasFocusIndicator
    The focus is related to the complete canvas. Paint the focus indicator using paintFocus()
  • ItemFocusIndicator
    The focus is related to an item (curve, point, ...) on the canvas. It is up to the application to display a focus indication using f.e. highlighting.
See also:
setFocusIndicator(), focusIndicator(), paintFocus()
enum QwtPlotCanvas::PaintAttribute

Paint attributes.

  • PaintCached
    Paint double buffered and reuse the content of the pixmap buffer for some spontaneous repaints that happen when a plot gets unhidden, deiconified or changes the focus. Disabling the cache will improve the performance for incremental paints (using QwtPlotCurve::draw).
  • PaintPacked
    Suppress system background repaints and paint it together with the canvas contents. Painting packed might avoid flickering for expensive repaints, when there is a notable gap between painting the background and the plot contents.

The default setting enables PaintCached and PaintPacked

See also:
setPaintAttribute(), testPaintAttribute(), paintCache()

Constructor & Destructor Documentation

QwtPlotCanvas::QwtPlotCanvas ( QwtPlot *  plot  )  [explicit]

Sets a cross cursor, enables QwtPlotCanvas::PaintCached.

QwtPlotCanvas::~QwtPlotCanvas (  )  [virtual]

Destructor.

Member Function Documentation

void QwtPlotCanvas::drawCanvas ( QPainter *  painter = NULL  )  [protected]

Draw the the canvas

Paints all plot items to the contentsRect(), using QwtPlot::drawCanvas and updates the paint cache.

Parameters:
painter Painter
See also:
QwtPlot::drawCanvas(), setPaintAttributes(), testPaintAttributes()
void QwtPlotCanvas::drawContents ( QPainter *  painter  )  [protected, virtual]

Redraw the canvas, and focus rect

Parameters:
painter Painter
void QwtPlotCanvas::drawFocusIndicator ( QPainter *  painter  )  [protected, virtual]

Draw the focus indication

Parameters:
painter Painter
QwtPlotCanvas::FocusIndicator QwtPlotCanvas::focusIndicator (  )  const
Returns:
Focus indicator
See also:
FocusIndicator, setFocusIndicator()
void QwtPlotCanvas::hideEvent ( QHideEvent *  event  )  [protected, virtual]

Hide event

Parameters:
event Hide event
void QwtPlotCanvas::invalidatePaintCache (  ) 

Invalidate the internal paint cache.

const QPixmap * QwtPlotCanvas::paintCache (  )  const

Return the paint cache, might be null.

QPixmap * QwtPlotCanvas::paintCache (  ) 

Return the paint cache, might be null.

void QwtPlotCanvas::paintEvent ( QPaintEvent *  event  )  [protected, virtual]

Paint event

Parameters:
event Paint event
const QwtPlot * QwtPlotCanvas::plot (  )  const

Return parent plot widget.

QwtPlot * QwtPlotCanvas::plot (  ) 

Return parent plot widget.

void QwtPlotCanvas::replot (  ) 

Invalidate the paint cache and repaint the canvas

See also:
invalidatePaintCache()
void QwtPlotCanvas::setFocusIndicator ( FocusIndicator  focusIndicator  ) 

Set the focus indicator

See also:
FocusIndicator, focusIndicator()
void QwtPlotCanvas::setPaintAttribute ( PaintAttribute  attribute,
bool  on = true 
)

Changing the paint attributes.

Parameters:
attribute Paint attribute
on On/Off

The default setting enables PaintCached and PaintPacked

See also:
testPaintAttribute(), drawCanvas(), drawContents(), paintCache()
bool QwtPlotCanvas::testPaintAttribute ( PaintAttribute  attribute  )  const

Test wether a paint attribute is enabled

Parameters:
attribute Paint attribute
Returns:
true if the attribute is enabled
See also:
setPaintAttribute()
Generated on Wed Sep 2 18:37:25 2009 for Qwt User's Guide by  doxygen 1.6.1
previous page start next page