QwtThermo Class Reference

Inheritance diagram for QwtThermo:

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Collaboration diagram for QwtThermo:

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List of all members.

Detailed Description

The Thermometer Widget.

QwtThermo is a widget which displays a value in an interval. It supports:

sysinfo.png

By default, the scale and range run over the same interval of values. QwtAbstractScale::setScale() changes the interval of the scale and allows easy conversion between physical units.

The example shows how to make the scale indicate in degrees Fahrenheit and to set the value in degrees Kelvin:

#include <qapplication.h>
#include <qwt_thermo.h>

double Kelvin2Fahrenheit(double kelvin)
{
    // see http://en.wikipedia.org/wiki/Kelvin
    return 1.8*kelvin - 459.67;
}

int main(int argc, char **argv)
{
    const double minKelvin = 0.0;
    const double maxKelvin = 500.0;

    QApplication a(argc, argv);
    QwtThermo t;
    t.setRange(minKelvin, maxKelvin);
    t.setScale(Kelvin2Fahrenheit(minKelvin), Kelvin2Fahrenheit(maxKelvin));
    // set the value in Kelvin but the scale displays in Fahrenheit
    // 273.15 Kelvin = 0 Celsius = 32 Fahrenheit
    t.setValue(273.15);
    a.setMainWidget(&t);
    t.show();
    return a.exec();
}

Todo:
Improve the support for a logarithmic range and/or scale.

Definition at line 69 of file qwt_thermo.h.

Public Types

enum  ScalePos {
  NoScale,
  LeftScale,
  RightScale,
  TopScale,
  BottomScale
}

Public Slots

void setValue (double val)

Public Member Functions

 QwtThermo (QWidget *parent=NULL)
virtual ~QwtThermo ()
void setOrientation (Qt::Orientation o, ScalePos s)
void setScalePosition (ScalePos s)
ScalePos scalePosition () const
void setBorderWidth (int w)
int borderWidth () const
void setFillBrush (const QBrush &b)
const QBrush & fillBrush () const
void setFillColor (const QColor &c)
const QColor & fillColor () const
void setAlarmBrush (const QBrush &b)
const QBrush & alarmBrush () const
void setAlarmColor (const QColor &c)
const QColor & alarmColor () const
void setAlarmLevel (double v)
double alarmLevel () const
void setAlarmEnabled (bool tf)
bool alarmEnabled () const
void setPipeWidth (int w)
int pipeWidth () const
void setMaxValue (double v)
double maxValue () const
void setMinValue (double v)
double minValue () const
double value () const
void setRange (double vmin, double vmax, bool lg=false)
void setMargin (int m)
virtual QSize sizeHint () const
virtual QSize minimumSizeHint () const
void setScaleDraw (QwtScaleDraw *)
const QwtScaleDrawscaleDraw () const

Protected Member Functions

void draw (QPainter *p, const QRect &update_rect)
void drawThermo (QPainter *p)
void layoutThermo (bool update=true)
virtual void scaleChange ()
virtual void fontChange (const QFont &oldFont)
virtual void paintEvent (QPaintEvent *e)
virtual void resizeEvent (QResizeEvent *e)
QwtScaleDrawscaleDraw ()


Constructor & Destructor Documentation

QwtThermo::QwtThermo QWidget *  parent = NULL  )  [explicit]
 

Constructor

Parameters:
parent Parent widget

Definition at line 64 of file qwt_thermo.cpp.

QwtThermo::~QwtThermo  )  [virtual]
 

Destructor.

Definition at line 105 of file qwt_thermo.cpp.


Member Function Documentation

const QBrush & QwtThermo::alarmBrush  )  const
 

Return the liquid brush above the alarm threshold.

Definition at line 694 of file qwt_thermo.cpp.

const QColor & QwtThermo::alarmColor  )  const
 

Return the liquid color above the alarm threshold.

Definition at line 710 of file qwt_thermo.cpp.

bool QwtThermo::alarmEnabled  )  const
 

Return if the alarm threshold is enabled or disabled.

Definition at line 776 of file qwt_thermo.cpp.

double QwtThermo::alarmLevel  )  const
 

Return the alarm threshold.

Definition at line 724 of file qwt_thermo.cpp.

int QwtThermo::borderWidth  )  const
 

Return the border width of the thermometer pipe.

Definition at line 615 of file qwt_thermo.cpp.

void QwtThermo::draw QPainter *  p,
const QRect &  update_rect
[protected]
 

Draw the whole QwtThermo.

Definition at line 183 of file qwt_thermo.cpp.

References QwtAbstractScaleDraw::draw(), and scaleDraw().

Referenced by paintEvent().

void QwtThermo::drawThermo QPainter *  p  )  [protected]
 

Redraw the liquid in thermometer pipe.

Definition at line 440 of file qwt_thermo.cpp.

const QBrush & QwtThermo::fillBrush  )  const
 

Return the liquid brush.

Definition at line 662 of file qwt_thermo.cpp.

const QColor & QwtThermo::fillColor  )  const
 

Return the liquid color.

Definition at line 678 of file qwt_thermo.cpp.

void QwtThermo::fontChange const QFont &  oldFont  )  [protected, virtual]
 

Notify a font change.

Definition at line 426 of file qwt_thermo.cpp.

References layoutThermo().

void QwtThermo::layoutThermo bool  update_geometry = true  )  [protected]
 

Recalculate the QwtThermo geometry and layout based on the QwtThermo::rect() and the fonts.

Parameters:
update_geometry notify the layout system and call update to redraw the scale

Definition at line 223 of file qwt_thermo.cpp.

References QwtScaleDraw::getBorderDistHint(), QwtScaleDraw::move(), scaleDraw(), QwtScaleDraw::setAlignment(), and QwtScaleDraw::setLength().

Referenced by fontChange(), resizeEvent(), scaleChange(), setBorderWidth(), setOrientation(), setPipeWidth(), and setRange().

double QwtThermo::maxValue  )  const
 

Return the maximum value.

Definition at line 117 of file qwt_thermo.cpp.

QSize QwtThermo::minimumSizeHint  )  const [virtual]
 

Return a minimum size hint.

Warning:
The return value depends on the font and the scale.
See also:
QwtThermo::sizeHint

Definition at line 795 of file qwt_thermo.cpp.

References QwtScaleDraw::extent(), QwtScaleDraw::minLength(), and scaleDraw().

Referenced by sizeHint().

double QwtThermo::minValue  )  const
 

Return the minimum value.

Definition at line 129 of file qwt_thermo.cpp.

void QwtThermo::paintEvent QPaintEvent *  e  )  [protected, virtual]
 

Qt paint event.

Definition at line 166 of file qwt_thermo.cpp.

References draw().

int QwtThermo::pipeWidth  )  const
 

Return the width of the pipe.

Definition at line 740 of file qwt_thermo.cpp.

void QwtThermo::resizeEvent QResizeEvent *  e  )  [protected, virtual]
 

Qt resize event handler.

Definition at line 212 of file qwt_thermo.cpp.

References layoutThermo().

void QwtThermo::scaleChange  )  [protected, virtual]
 

Notify a scale change.

Reimplemented from QwtAbstractScale.

Definition at line 433 of file qwt_thermo.cpp.

References layoutThermo().

QwtThermo::ScalePos QwtThermo::scalePosition  )  const
 

Return the scale position.

Definition at line 420 of file qwt_thermo.cpp.

void QwtThermo::setAlarmBrush const QBrush &  brush  ) 
 

Specify the liquid brush above the alarm threshold.

Parameters:
brush New brush. The default is solid white.

Definition at line 687 of file qwt_thermo.cpp.

void QwtThermo::setAlarmColor const QColor &  c  ) 
 

Specify the liquid color above the alarm threshold.

Parameters:
c New color. The default is white.

Definition at line 703 of file qwt_thermo.cpp.

void QwtThermo::setAlarmEnabled bool  tf  ) 
 

Enable or disable the alarm threshold.

Parameters:
tf true (disabled) or false (enabled)

Definition at line 769 of file qwt_thermo.cpp.

void QwtThermo::setAlarmLevel double  v  ) 
 

Specify the alarm threshold.

Definition at line 716 of file qwt_thermo.cpp.

void QwtThermo::setBorderWidth int  w  ) 
 

Set the border width of the pipe.

Definition at line 604 of file qwt_thermo.cpp.

References layoutThermo().

void QwtThermo::setFillBrush const QBrush &  brush  ) 
 

Change the brush of the liquid.

Parameters:
brush New brush. The default brush is solid black.

Definition at line 655 of file qwt_thermo.cpp.

void QwtThermo::setFillColor const QColor &  c  ) 
 

Change the color of the liquid.

Parameters:
c New color. The default color is black.

Definition at line 671 of file qwt_thermo.cpp.

void QwtThermo::setMargin int  m  ) 
 

Specify the distance between the pipe's endpoints and the widget's border.

The margin is used to leave some space for the scale labels. If a large font is used, it is advisable to adjust the margins.

Parameters:
m New Margin. The default values are 10 for horizontal orientation and 20 for vertical orientation.
Warning:
The margin has no effect if the scale is disabled.

This function is a NOOP because margins are determined automatically.

Definition at line 760 of file qwt_thermo.cpp.

void QwtThermo::setMaxValue double  v  ) 
 

Set the maximum value.

Definition at line 111 of file qwt_thermo.cpp.

References setRange().

void QwtThermo::setMinValue double  v  ) 
 

Set the minimum value.

Definition at line 123 of file qwt_thermo.cpp.

References setRange().

void QwtThermo::setOrientation Qt::Orientation  o,
ScalePos  s
 

Set the thermometer orientation and the scale position.

The scale position NoScale disables the scale.

Parameters:
o orientation. Possible values are Qt::Horizontal and Qt::Vertical. The default value is Qt::Vertical.
s Position of the scale. The default value is NoScale.
A valid combination of scale position and orientation is enforced:
  • a horizontal thermometer can have the scale positions TopScale, BottomScale or NoScale;
  • a vertical thermometer can have the scale positions LeftScale, RightScale or NoScale;
  • an invalid scale position will default to NoScale.

See also:
QwtThermo::setScalePosition()

Definition at line 346 of file qwt_thermo.cpp.

References layoutThermo().

Referenced by setScalePosition().

void QwtThermo::setPipeWidth int  w  ) 
 

Change the width of the pipe.

Definition at line 730 of file qwt_thermo.cpp.

References layoutThermo().

void QwtThermo::setRange double  vmin,
double  vmax,
bool  logarithmic = false
 

Set the range.

Parameters:
vmin value corresponding lower or left end of the thermometer
vmax value corresponding to the upper or right end of the thermometer
logarithmic logarithmic mapping, true or false

Definition at line 626 of file qwt_thermo.cpp.

References QwtAbstractScale::autoScale(), layoutThermo(), QwtAbstractScale::rescale(), QwtAbstractScale::scaleEngine(), and QwtAbstractScale::setScaleEngine().

Referenced by setMaxValue(), and setMinValue().

void QwtThermo::setScalePosition ScalePos  s  ) 
 

Change the scale position (and thermometer orientation).

Parameters:
s Position of the scale.
A valid combination of scale position and orientation is enforced:
  • if the new scale position is LeftScale or RightScale, the scale orientation will become Qt::Vertical;
  • if the new scale position is BottomScale or TopScale, the scale orientation will become Qt::Horizontal;
  • if the new scale position is NoScale, the scale orientation will not change.

See also:
QwtThermo::setOrientation()

Definition at line 409 of file qwt_thermo.cpp.

References setOrientation().

void QwtThermo::setValue double  val  )  [slot]
 

Set the current value.

Definition at line 135 of file qwt_thermo.cpp.

QSize QwtThermo::sizeHint  )  const [virtual]
 

Returns:
the minimum size hint
See also:
QwtThermo::minimumSizeHint

Definition at line 785 of file qwt_thermo.cpp.

References minimumSizeHint().

double QwtThermo::value  )  const
 

Return the value.

Definition at line 145 of file qwt_thermo.cpp.


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