Qwt User's Guide  6.2.0
QwtPlot Class Reference

A 2-D plotting widget. More...

#include <qwt_plot.h>

Inheritance diagram for QwtPlot:

Public Types

enum  LegendPosition { LeftLegend , RightLegend , BottomLegend , TopLegend }
 
enum  Axis {
  yLeft = QwtAxis::YLeft , yRight = QwtAxis::YRight , xBottom = QwtAxis::XBottom , xTop = QwtAxis::XTop ,
  axisCnt = QwtAxis::AxisPositions
}
 

Public Slots

virtual void replot ()
 Redraw the plot. More...
 
void autoRefresh ()
 Replots the plot if autoReplot() is true.
 

Signals

void itemAttached (QwtPlotItem *plotItem, bool on)
 
void legendDataChanged (const QVariant &itemInfo, const QList< QwtLegendData > &data)
 

Public Member Functions

 QwtPlot (QWidget *=NULL)
 Constructor. More...
 
 QwtPlot (const QwtText &title, QWidget *=NULL)
 Constructor. More...
 
virtual ~QwtPlot ()
 Destructor.
 
void setAutoReplot (bool=true)
 Set or reset the autoReplot option. More...
 
bool autoReplot () const
 
void setPlotLayout (QwtPlotLayout *)
 Assign a new plot layout. More...
 
QwtPlotLayoutplotLayout ()
 
const QwtPlotLayoutplotLayout () const
 
void setTitle (const QString &)
 
void setTitle (const QwtText &)
 
QwtText title () const
 
QwtTextLabeltitleLabel ()
 
const QwtTextLabeltitleLabel () const
 
void setFooter (const QString &)
 
void setFooter (const QwtText &)
 
QwtText footer () const
 
QwtTextLabelfooterLabel ()
 
const QwtTextLabelfooterLabel () const
 
void setCanvas (QWidget *)
 Set the drawing canvas of the plot widget. More...
 
QWidget * canvas ()
 
const QWidget * canvas () const
 
void setCanvasBackground (const QBrush &)
 Change the background of the plotting area. More...
 
QBrush canvasBackground () const
 
virtual QwtScaleMap canvasMap (QwtAxisId) const
 
double invTransform (QwtAxisId, double pos) const
 
double transform (QwtAxisId, double value) const
 Transform a value into a coordinate in the plotting region. More...
 
bool isAxisValid (QwtAxisId) const
 
void setAxisVisible (QwtAxisId, bool on=true)
 Hide or show a specified axis. More...
 
bool isAxisVisible (QwtAxisId) const
 
QwtScaleEngineaxisScaleEngine (QwtAxisId)
 
const QwtScaleEngineaxisScaleEngine (QwtAxisId) const
 
void setAxisScaleEngine (QwtAxisId, QwtScaleEngine *)
 
void setAxisAutoScale (QwtAxisId, bool on=true)
 Enable autoscaling for a specified axis. More...
 
bool axisAutoScale (QwtAxisId) const
 
void setAxisFont (QwtAxisId, const QFont &)
 Change the font of an axis. More...
 
QFont axisFont (QwtAxisId) const
 
void setAxisScale (QwtAxisId, double min, double max, double stepSize=0)
 Disable autoscaling and specify a fixed scale for a selected axis. More...
 
void setAxisScaleDiv (QwtAxisId, const QwtScaleDiv &)
 Disable autoscaling and specify a fixed scale for a selected axis. More...
 
void setAxisScaleDraw (QwtAxisId, QwtScaleDraw *)
 Set a scale draw. More...
 
double axisStepSize (QwtAxisId) const
 Return the step size parameter that has been set in setAxisScale. More...
 
QwtInterval axisInterval (QwtAxisId) const
 Return the current interval of the specified axis. More...
 
const QwtScaleDivaxisScaleDiv (QwtAxisId) const
 Return the scale division of a specified axis. More...
 
const QwtScaleDrawaxisScaleDraw (QwtAxisId) const
 Return the scale draw of a specified axis. More...
 
QwtScaleDrawaxisScaleDraw (QwtAxisId)
 Return the scale draw of a specified axis. More...
 
const QwtScaleWidgetaxisWidget (QwtAxisId) const
 
QwtScaleWidgetaxisWidget (QwtAxisId)
 
void setAxisLabelAlignment (QwtAxisId, Qt::Alignment)
 
void setAxisLabelRotation (QwtAxisId, double rotation)
 
void setAxisTitle (QwtAxisId, const QString &)
 Change the title of a specified axis. More...
 
void setAxisTitle (QwtAxisId, const QwtText &)
 Change the title of a specified axis. More...
 
QwtText axisTitle (QwtAxisId) const
 
void setAxisMaxMinor (QwtAxisId, int maxMinor)
 
int axisMaxMinor (QwtAxisId) const
 
void setAxisMaxMajor (QwtAxisId, int maxMajor)
 
int axisMaxMajor (QwtAxisId) const
 
void insertLegend (QwtAbstractLegend *, LegendPosition=QwtPlot::RightLegend, double ratio=-1.0)
 Insert a legend. More...
 
QwtAbstractLegendlegend ()
 
const QwtAbstractLegendlegend () const
 
void updateLegend ()
 
void updateLegend (const QwtPlotItem *)
 
virtual QSize sizeHint () const override
 
virtual QSize minimumSizeHint () const override
 Return a minimum size hint.
 
virtual void updateLayout ()
 Adjust plot content to its current size. More...
 
virtual void drawCanvas (QPainter *)
 
void updateAxes ()
 Rebuild the axes scales. More...
 
void updateCanvasMargins ()
 Update the canvas margins. More...
 
virtual void getCanvasMarginsHint (const QwtScaleMap maps[], const QRectF &canvasRect, double &left, double &top, double &right, double &bottom) const
 Calculate the canvas margins. More...
 
virtual bool event (QEvent *) override
 Adds handling of layout requests. More...
 
virtual bool eventFilter (QObject *, QEvent *) override
 Event filter. More...
 
virtual void drawItems (QPainter *, const QRectF &, const QwtScaleMap maps[QwtAxis::AxisPositions]) const
 
virtual QVariant itemToInfo (QwtPlotItem *) const
 Build an information, that can be used to identify a plot item on the legend. More...
 
virtual QwtPlotIteminfoToItem (const QVariant &) const
 Identify the plot item according to an item info object, that has bee generated from itemToInfo(). More...
 
void enableAxis (int axisId, bool on=true)
 
bool axisEnabled (int axisId) const
 
- Public Member Functions inherited from QwtPlotDict
 QwtPlotDict ()
 
virtual ~QwtPlotDict ()
 
void setAutoDelete (bool)
 
bool autoDelete () const
 
const QwtPlotItemListitemList () const
 A QwtPlotItemList of all attached plot items. More...
 
QwtPlotItemList itemList (int rtti) const
 
void detachItems (int rtti=QwtPlotItem::Rtti_PlotItem, bool autoDelete=true)
 

Protected Member Functions

virtual void resizeEvent (QResizeEvent *) override
 
- Protected Member Functions inherited from QwtPlotDict
void insertItem (QwtPlotItem *)
 
void removeItem (QwtPlotItem *)
 

Detailed Description

A 2-D plotting widget.

QwtPlot is a widget for plotting two-dimensional graphs. An unlimited number of plot items can be displayed on its canvas. Plot items might be curves (QwtPlotCurve), markers (QwtPlotMarker), the grid (QwtPlotGrid), or anything else derived from QwtPlotItem. A plot can have up to four axes, with each plot item attached to an x- and a y axis. The scales at the axes can be explicitly set (QwtScaleDiv), or are calculated from the plot items, using algorithms (QwtScaleEngine) which can be configured separately for each axis.

The simpleplot example is a good starting point to see how to set up a plot widget.

Example
The following example shows (schematically) the most simple way to use QwtPlot. By default, only the left and bottom axes are visible and their scales are computed automatically.
#include <qwt_plot.h>
#include <qwt_plot_curve.h>
QwtPlot *myPlot = new QwtPlot( "Two Curves", parent );
// add curves
QwtPlotCurve *curve1 = new QwtPlotCurve( "Curve 1" );
QwtPlotCurve *curve2 = new QwtPlotCurve( "Curve 2" );
// connect or copy the data to the curves
curve1->setData( ... );
curve2->setData( ... );
curve1->attach( myPlot );
curve2->attach( myPlot );
// finally, refresh the plot
myPlot->replot();
A plot item, that represents a series of points.
A 2-D plotting widget.
Definition: qwt_plot.h:79
virtual void replot()
Redraw the plot.
Definition: qwt_plot.cpp:545
QwtPlot(QWidget *=NULL)
Constructor.
Definition: qwt_plot.cpp:103
void attach(QwtPlot *plot)
Attach the item to a plot.
void setData(QwtSeriesData< T > *series)

Definition at line 78 of file qwt_plot.h.

Member Enumeration Documentation

◆ LegendPosition

Position of the legend, relative to the canvas.

See also
insertLegend()
Enumerator
LeftLegend 

The legend will be left from the QwtAxis::YLeft axis.

RightLegend 

The legend will be right from the QwtAxis::YRight axis.

BottomLegend 

The legend will be below the footer.

TopLegend 

The legend will be above the title.

Definition at line 93 of file qwt_plot.h.

Constructor & Destructor Documentation

◆ QwtPlot() [1/2]

QwtPlot::QwtPlot ( QWidget *  parent = NULL)
explicit

Constructor.

Parameters
parentParent widget

Definition at line 103 of file qwt_plot.cpp.

◆ QwtPlot() [2/2]

QwtPlot::QwtPlot ( const QwtText title,
QWidget *  parent = NULL 
)
explicit

Constructor.

Parameters
titleTitle text
parentParent widget

Definition at line 114 of file qwt_plot.cpp.

Member Function Documentation

◆ autoReplot()

bool QwtPlot::autoReplot ( ) const
Returns
true if the autoReplot option is set.
See also
setAutoReplot()

Definition at line 319 of file qwt_plot.cpp.

◆ axisAutoScale()

bool QwtPlot::axisAutoScale ( QwtAxisId  axisId) const
Returns
True, if autoscaling is enabled
Parameters
axisIdAxis

Definition at line 213 of file qwt_plot_axis.cpp.

◆ axisFont()

QFont QwtPlot::axisFont ( QwtAxisId  axisId) const
Returns
The font of the scale labels for a specified axis
Parameters
axisIdAxis

Definition at line 237 of file qwt_plot_axis.cpp.

◆ axisInterval()

QwtInterval QwtPlot::axisInterval ( QwtAxisId  axisId) const

Return the current interval of the specified axis.

This is only a convenience function for axisScaleDiv( axisId )->interval();

Parameters
axisIdAxis
Returns
Scale interval
See also
QwtScaleDiv, axisScaleDiv()

Definition at line 344 of file qwt_plot_axis.cpp.

◆ axisMaxMajor()

int QwtPlot::axisMaxMajor ( QwtAxisId  axisId) const
Returns
The maximum number of major ticks for a specified axis
Parameters
axisIdAxis
See also
setAxisMaxMajor(), QwtScaleEngine::divideScale()

Definition at line 251 of file qwt_plot_axis.cpp.

◆ axisMaxMinor()

int QwtPlot::axisMaxMinor ( QwtAxisId  axisId) const
Returns
the maximum number of minor ticks for a specified axis
Parameters
axisIdAxis
See also
setAxisMaxMinor(), QwtScaleEngine::divideScale()

Definition at line 264 of file qwt_plot_axis.cpp.

◆ axisScaleDiv()

const QwtScaleDiv & QwtPlot::axisScaleDiv ( QwtAxisId  axisId) const

Return the scale division of a specified axis.

axisScaleDiv(axisId).lowerBound(), axisScaleDiv(axisId).upperBound() are the current limits of the axis scale.

Parameters
axisIdAxis
Returns
Scale division
See also
QwtScaleDiv, setAxisScaleDiv(), QwtScaleEngine::divideScale()

Definition at line 283 of file qwt_plot_axis.cpp.

◆ axisScaleDraw() [1/2]

QwtScaleDraw * QwtPlot::axisScaleDraw ( QwtAxisId  axisId)

Return the scale draw of a specified axis.

Parameters
axisIdAxis
Returns
Specified scaleDraw for axis, or NULL if axis is invalid.

Definition at line 308 of file qwt_plot_axis.cpp.

◆ axisScaleDraw() [2/2]

const QwtScaleDraw * QwtPlot::axisScaleDraw ( QwtAxisId  axisId) const

Return the scale draw of a specified axis.

Parameters
axisIdAxis
Returns
Specified scaleDraw for axis, or NULL if axis is invalid.

Definition at line 294 of file qwt_plot_axis.cpp.

◆ axisScaleEngine() [1/2]

QwtScaleEngine * QwtPlot::axisScaleEngine ( QwtAxisId  axisId)
Parameters
axisIdAxis
Returns
Scale engine for a specific axis

Definition at line 190 of file qwt_plot_axis.cpp.

◆ axisScaleEngine() [2/2]

const QwtScaleEngine * QwtPlot::axisScaleEngine ( QwtAxisId  axisId) const
Parameters
axisIdAxis
Returns
Scale engine for a specific axis

Definition at line 202 of file qwt_plot_axis.cpp.

◆ axisStepSize()

double QwtPlot::axisStepSize ( QwtAxisId  axisId) const

Return the step size parameter that has been set in setAxisScale.

This doesn't need to be the step size of the current scale.

Parameters
axisIdAxis
Returns
step size parameter value
See also
setAxisScale(), QwtScaleEngine::divideScale()

Definition at line 326 of file qwt_plot_axis.cpp.

◆ axisTitle()

QwtText QwtPlot::axisTitle ( QwtAxisId  axisId) const
Returns
Title of a specified axis
Parameters
axisIdAxis

Definition at line 356 of file qwt_plot_axis.cpp.

◆ axisWidget() [1/2]

QwtScaleWidget * QwtPlot::axisWidget ( QwtAxisId  axisId)
Returns
Scale widget of the specified axis, or NULL if axisId is invalid.
Parameters
axisIdAxis

Definition at line 153 of file qwt_plot_axis.cpp.

◆ axisWidget() [2/2]

const QwtScaleWidget * QwtPlot::axisWidget ( QwtAxisId  axisId) const
Returns
Scale widget of the specified axis, or NULL if axisId is invalid.
Parameters
axisIdAxis

Definition at line 141 of file qwt_plot_axis.cpp.

◆ canvas() [1/2]

QWidget * QwtPlot::canvas ( )
Returns
the plot's canvas

Definition at line 463 of file qwt_plot.cpp.

◆ canvas() [2/2]

const QWidget * QwtPlot::canvas ( ) const
Returns
the plot's canvas

Definition at line 471 of file qwt_plot.cpp.

◆ canvasBackground()

QBrush QwtPlot::canvasBackground ( ) const

Nothing else than: canvas()->palette().brush( QPalette::Normal, QPalette::Window);

Returns
Background brush of the plotting area.
See also
setCanvasBackground()

Definition at line 888 of file qwt_plot.cpp.

◆ canvasMap()

QwtScaleMap QwtPlot::canvasMap ( QwtAxisId  axisId) const
virtual
Parameters
axisIdAxis
Returns
Map for the axis on the canvas. With this map pixel coordinates can translated to plot coordinates and vice versa.
See also
QwtScaleMap, transform(), invTransform()

Definition at line 800 of file qwt_plot.cpp.

◆ drawCanvas()

void QwtPlot::drawCanvas ( QPainter *  painter)
virtual

Redraw the canvas.

Parameters
painterPainter used for drawing
Warning
drawCanvas calls drawItems what is also used for printing. Applications that like to add individual plot items better overload drawItems()
See also
drawItems()

Definition at line 742 of file qwt_plot.cpp.

◆ drawItems()

void QwtPlot::drawItems ( QPainter *  painter,
const QRectF &  canvasRect,
const QwtScaleMap  maps[QwtAxis::AxisPositions] 
) const
virtual

Redraw the canvas items.

Parameters
painterPainter used for drawing
canvasRectBounding rectangle where to paint
mapsQwtAxis::AxisCount maps, mapping between plot and paint device coordinates
Note
Usually canvasRect is contentsRect() of the plot canvas. Due to a bug in Qt this rectangle might be wrong for certain frame styles ( f.e QFrame::Box ) and it might be necessary to fix the margins manually using QWidget::setContentsMargins()

Definition at line 764 of file qwt_plot.cpp.

◆ event()

bool QwtPlot::event ( QEvent *  event)
overridevirtual

Adds handling of layout requests.

Parameters
eventEvent
Returns
See QFrame::event()

Definition at line 237 of file qwt_plot.cpp.

◆ eventFilter()

bool QwtPlot::eventFilter ( QObject *  object,
QEvent *  event 
)
overridevirtual

Event filter.

The plot handles the following events for the canvas:

  • QEvent::Resize The canvas margins might depend on its size
  • QEvent::ContentsRectChange The layout needs to be recalculated
Parameters
objectObject to be filtered
eventEvent
Returns
See QFrame::eventFilter()
See also
updateCanvasMargins(), updateLayout()

Definition at line 271 of file qwt_plot.cpp.

◆ footer()

QwtText QwtPlot::footer ( ) const
Returns
Text of the footer

Definition at line 395 of file qwt_plot.cpp.

◆ footerLabel() [1/2]

QwtTextLabel * QwtPlot::footerLabel ( )
Returns
Footer label widget.

Definition at line 401 of file qwt_plot.cpp.

◆ footerLabel() [2/2]

const QwtTextLabel * QwtPlot::footerLabel ( ) const
Returns
Footer label widget.

Definition at line 407 of file qwt_plot.cpp.

◆ getCanvasMarginsHint()

void QwtPlot::getCanvasMarginsHint ( const QwtScaleMap  maps[],
const QRectF &  canvasRect,
double &  left,
double &  top,
double &  right,
double &  bottom 
) const
virtual

Calculate the canvas margins.

Parameters
mapsQwtAxis::AxisCount maps, mapping between plot and paint device coordinates
canvasRectBounding rectangle where to paint
leftReturn parameter for the left margin
topReturn parameter for the top margin
rightReturn parameter for the right margin
bottomReturn parameter for the bottom margin

Plot items might indicate, that they need some extra space at the borders of the canvas by the QwtPlotItem::Margins flag.

updateCanvasMargins(), QwtPlotItem::getCanvasMarginHint()

Definition at line 670 of file qwt_plot.cpp.

◆ infoToItem()

QwtPlotItem * QwtPlot::infoToItem ( const QVariant &  itemInfo) const
virtual

Identify the plot item according to an item info object, that has bee generated from itemToInfo().

The default implementation simply tries to unwrap a QwtPlotItem pointer:

if ( itemInfo.canConvert<QwtPlotItem *>() )
return qvariant_cast<QwtPlotItem *>( itemInfo );
Base class for items on the plot canvas.
Definition: qwt_plot_item.h:67
Parameters
itemInfoPlot item
Returns
A plot item, when successful, otherwise a NULL pointer.
See also
itemToInfo()

Definition at line 1159 of file qwt_plot.cpp.

◆ insertLegend()

void QwtPlot::insertLegend ( QwtAbstractLegend legend,
QwtPlot::LegendPosition  pos = QwtPlot::RightLegend,
double  ratio = -1.0 
)

Insert a legend.

If the position legend is QwtPlot::LeftLegend or QwtPlot::RightLegend the legend will be organized in one column from top to down. Otherwise the legend items will be placed in a table with a best fit number of columns from left to right.

insertLegend() will set the plot widget as parent for the legend. The legend will be deleted in the destructor of the plot or when another legend is inserted.

Legends, that are not inserted into the layout of the plot widget need to connect to the legendDataChanged() signal. Calling updateLegend() initiates this signal for an initial update. When the application code wants to implement its own layout this also needs to be done for rendering plots to a document ( see QwtPlotRenderer ).

Parameters
legendLegend
posThe legend's position. For top/left position the number of columns will be limited to 1, otherwise it will be set to unlimited.
ratioRatio between legend and the bounding rectangle of title, canvas and axes. The legend will be shrunk if it would need more space than the given ratio. The ratio is limited to ]0.0 .. 1.0]. In case of <= 0.0 it will be reset to the default ratio. The default vertical/horizontal ratio is 0.33/0.5.
See also
legend(), QwtPlotLayout::legendPosition(), QwtPlotLayout::setLegendPosition()

Definition at line 927 of file qwt_plot.cpp.

◆ invTransform()

double QwtPlot::invTransform ( QwtAxisId  axisId,
double  pos 
) const

Transform the x or y coordinate of a position in the drawing region into a value.

Parameters
axisIdAxis
posposition
Returns
Position as axis coordinate
Warning
The position can be an x or a y coordinate, depending on the specified axis.

Definition at line 397 of file qwt_plot_axis.cpp.

◆ isAxisValid()

bool QwtPlot::isAxisValid ( QwtAxisId  axisId) const

Checks if an axis is valid

Parameters
axisIdaxis
Returns
true if the specified axis exists, otherwise false
Note
This method is equivalent to QwtAxis::isValid( axisId ) and simply checks if axisId is one of the values of QwtAxis::Position. It is a placeholder for future releases, where it will be possible to have a customizable number of axes ( multiaxes branch ) at each side.

Definition at line 132 of file qwt_plot_axis.cpp.

◆ isAxisVisible()

bool QwtPlot::isAxisVisible ( QwtAxisId  axisId) const
Returns
True, if a specified axis is visible
Parameters
axisIdAxis

Definition at line 225 of file qwt_plot_axis.cpp.

◆ itemAttached

void QwtPlot::itemAttached ( QwtPlotItem plotItem,
bool  on 
)
signal

A signal indicating, that an item has been attached/detached

Parameters
plotItemPlot item
onAttached/Detached

◆ itemToInfo()

QVariant QwtPlot::itemToInfo ( QwtPlotItem plotItem) const
virtual

Build an information, that can be used to identify a plot item on the legend.

The default implementation simply wraps the plot item into a QVariant object. When overloading itemToInfo() usually infoToItem() needs to reimplemeted too.

Parameters
plotItemPlot item
Returns
Plot item embedded in a QVariant
See also
infoToItem()

Definition at line 1139 of file qwt_plot.cpp.

◆ legend() [1/2]

QwtAbstractLegend * QwtPlot::legend ( )
Returns
the plot's legend
See also
insertLegend()

Definition at line 445 of file qwt_plot.cpp.

◆ legend() [2/2]

const QwtAbstractLegend * QwtPlot::legend ( ) const
Returns
the plot's legend
See also
insertLegend()

Definition at line 454 of file qwt_plot.cpp.

◆ legendDataChanged

void QwtPlot::legendDataChanged ( const QVariant &  itemInfo,
const QList< QwtLegendData > &  data 
)
signal

A signal with the attributes how to update the legend entries for a plot item.

Parameters
itemInfoInfo about a plot item, build from itemToInfo()
dataAttributes of the entries ( usually <= 1 ) for the plot item.
See also
itemToInfo(), infoToItem(), QwtAbstractLegend::updateLegend()

◆ plotLayout() [1/2]

QwtPlotLayout * QwtPlot::plotLayout ( )
Returns
the plot's layout

Definition at line 430 of file qwt_plot.cpp.

◆ plotLayout() [2/2]

const QwtPlotLayout * QwtPlot::plotLayout ( ) const
Returns
the plot's layout

Definition at line 436 of file qwt_plot.cpp.

◆ replot

void QwtPlot::replot ( )
virtualslot

Redraw the plot.

If the autoReplot option is not set (which is the default) or if any curves are attached to raw data, the plot has to be refreshed explicitly in order to make changes visible.

See also
updateAxes(), setAutoReplot()

Definition at line 545 of file qwt_plot.cpp.

◆ resizeEvent()

void QwtPlot::resizeEvent ( QResizeEvent *  e)
overrideprotectedvirtual

Resize and update internal layout

Parameters
eResize event

Definition at line 530 of file qwt_plot.cpp.

◆ setAutoReplot()

void QwtPlot::setAutoReplot ( bool  tf = true)

Set or reset the autoReplot option.

If the autoReplot option is set, the plot will be updated implicitly by manipulating member functions. Since this may be time-consuming, it is recommended to leave this option switched off and call replot() explicitly if necessary.

The autoReplot option is set to false by default, which means that the user has to call replot() in order to make changes visible.

Parameters
tftrue or false. Defaults to true.
See also
replot()

Definition at line 310 of file qwt_plot.cpp.

◆ setAxisAutoScale()

void QwtPlot::setAxisAutoScale ( QwtAxisId  axisId,
bool  on = true 
)

Enable autoscaling for a specified axis.

This member function is used to switch back to autoscaling mode after a fixed scale has been set. Autoscaling is enabled by default.

Parameters
axisIdAxis
onOn/Off
See also
setAxisScale(), setAxisScaleDiv(), updateAxes()
Note
The autoscaling flag has no effect until updateAxes() is executed ( called by replot() ).

Definition at line 449 of file qwt_plot_axis.cpp.

◆ setAxisFont()

void QwtPlot::setAxisFont ( QwtAxisId  axisId,
const QFont &  font 
)

Change the font of an axis.

Parameters
axisIdAxis
fontFont
Warning
This function changes the font of the tick labels, not of the axis title.

Definition at line 430 of file qwt_plot_axis.cpp.

◆ setAxisLabelAlignment()

void QwtPlot::setAxisLabelAlignment ( QwtAxisId  axisId,
Qt::Alignment  alignment 
)

Change the alignment of the tick labels

Parameters
axisIdAxis
alignmentOr'd Qt::AlignmentFlags see <qnamespace.h>
See also
QwtScaleDraw::setLabelAlignment()

Definition at line 549 of file qwt_plot_axis.cpp.

◆ setAxisLabelRotation()

void QwtPlot::setAxisLabelRotation ( QwtAxisId  axisId,
double  rotation 
)

Rotate all tick labels

Parameters
axisIdAxis
rotationAngle in degrees. When changing the label rotation, the label alignment might be adjusted too.
See also
QwtScaleDraw::setLabelRotation(), setAxisLabelAlignment()

Definition at line 564 of file qwt_plot_axis.cpp.

◆ setAxisMaxMajor()

void QwtPlot::setAxisMaxMajor ( QwtAxisId  axisId,
int  maxMajor 
)

Set the maximum number of major scale intervals for a specified axis

Parameters
axisIdAxis
maxMajorMaximum number of major steps
See also
axisMaxMajor()

Definition at line 602 of file qwt_plot_axis.cpp.

◆ setAxisMaxMinor()

void QwtPlot::setAxisMaxMinor ( QwtAxisId  axisId,
int  maxMinor 
)

Set the maximum number of minor scale intervals for a specified axis

Parameters
axisIdAxis
maxMinorMaximum number of minor steps
See also
axisMaxMinor()

Definition at line 578 of file qwt_plot_axis.cpp.

◆ setAxisScale()

void QwtPlot::setAxisScale ( QwtAxisId  axisId,
double  min,
double  max,
double  stepSize = 0 
)

Disable autoscaling and specify a fixed scale for a selected axis.

In updateAxes() the scale engine calculates a scale division from the specified parameters, that will be assigned to the scale widget. So updates of the scale widget usually happen delayed with the next replot.

Parameters
axisIdAxis
minMinimum of the scale
maxMaximum of the scale
stepSizeMajor step size. If step == 0, the step size is calculated automatically using the maxMajor setting.
See also
setAxisMaxMajor(), setAxisAutoScale(), axisStepSize(), QwtScaleEngine::divideScale()

Definition at line 473 of file qwt_plot_axis.cpp.

◆ setAxisScaleDiv()

void QwtPlot::setAxisScaleDiv ( QwtAxisId  axisId,
const QwtScaleDiv scaleDiv 
)

Disable autoscaling and specify a fixed scale for a selected axis.

The scale division will be stored locally only until the next call of updateAxes(). So updates of the scale widget usually happen delayed with the next replot.

Parameters
axisIdAxis
scaleDivScale division
See also
setAxisScale(), setAxisAutoScale()

Definition at line 502 of file qwt_plot_axis.cpp.

◆ setAxisScaleDraw()

void QwtPlot::setAxisScaleDraw ( QwtAxisId  axisId,
QwtScaleDraw scaleDraw 
)

Set a scale draw.

Parameters
axisIdAxis
scaleDrawObject responsible for drawing scales.

By passing scaleDraw it is possible to extend QwtScaleDraw functionality and let it take place in QwtPlot. Please note that scaleDraw has to be created with new and will be deleted by the corresponding QwtScale member ( like a child object ).

See also
QwtScaleDraw, QwtScaleWidget
Warning
The attributes of scaleDraw will be overwritten by those of the previous QwtScaleDraw.

Definition at line 532 of file qwt_plot_axis.cpp.

◆ setAxisScaleEngine()

void QwtPlot::setAxisScaleEngine ( QwtAxisId  axisId,
QwtScaleEngine scaleEngine 
)

Change the scale engine for an axis

Parameters
axisIdAxis
scaleEngineScale engine
See also
axisScaleEngine()

Definition at line 169 of file qwt_plot_axis.cpp.

◆ setAxisTitle() [1/2]

void QwtPlot::setAxisTitle ( QwtAxisId  axisId,
const QString &  title 
)

Change the title of a specified axis.

Parameters
axisIdAxis
titleaxis title

Definition at line 624 of file qwt_plot_axis.cpp.

◆ setAxisTitle() [2/2]

void QwtPlot::setAxisTitle ( QwtAxisId  axisId,
const QwtText title 
)

Change the title of a specified axis.

Parameters
axisIdAxis
titleAxis title

Definition at line 636 of file qwt_plot_axis.cpp.

◆ setAxisVisible()

void QwtPlot::setAxisVisible ( QwtAxisId  axisId,
bool  on = true 
)

Hide or show a specified axis.

Curves, markers and other items can be attached to hidden axes, and transformation of screen coordinates into values works as normal.

Only QwtAxis::XBottom and QwtAxis::YLeft are enabled by default.

Parameters
axisIdAxis
ontrue (visible) or false (hidden)

Definition at line 376 of file qwt_plot_axis.cpp.

◆ setCanvas()

void QwtPlot::setCanvas ( QWidget *  canvas)

Set the drawing canvas of the plot widget.

QwtPlot invokes methods of the canvas as meta methods ( see QMetaObject ). In opposite to using conventional C++ techniques like virtual methods they allow to use canvas implementations that are derived from QWidget or QGLWidget.

The following meta methods could be implemented:

  • replot() When the canvas doesn't offer a replot method, QwtPlot calls update() instead.
  • borderPath() The border path is necessary to clip the content of the canvas When the canvas doesn't have any special border ( f.e rounded corners ) it is o.k. not to implement this method.

The default canvas is a QwtPlotCanvas

Parameters
canvasCanvas Widget
See also
canvas()

Definition at line 213 of file qwt_plot.cpp.

◆ setCanvasBackground()

void QwtPlot::setCanvasBackground ( const QBrush &  brush)

Change the background of the plotting area.

Sets brush to QPalette::Window of all color groups of the palette of the canvas. Using canvas()->setPalette() is a more powerful way to set these colors.

Parameters
brushNew background brush
See also
canvasBackground()

Definition at line 873 of file qwt_plot.cpp.

◆ setFooter() [1/2]

void QwtPlot::setFooter ( const QString &  text)

Change the text the footer

Parameters
textNew text of the footer

Definition at line 372 of file qwt_plot.cpp.

◆ setFooter() [2/2]

void QwtPlot::setFooter ( const QwtText text)

Change the text the footer

Parameters
textNew text of the footer

Definition at line 385 of file qwt_plot.cpp.

◆ setPlotLayout()

void QwtPlot::setPlotLayout ( QwtPlotLayout layout)

Assign a new plot layout.

Parameters
layoutLayout()
See also
plotLayout()

Definition at line 418 of file qwt_plot.cpp.

◆ setTitle() [1/2]

void QwtPlot::setTitle ( const QString &  title)

Change the plot's title

Parameters
titleNew title

Definition at line 328 of file qwt_plot.cpp.

◆ setTitle() [2/2]

void QwtPlot::setTitle ( const QwtText title)

Change the plot's title

Parameters
titleNew title

Definition at line 341 of file qwt_plot.cpp.

◆ sizeHint()

QSize QwtPlot::sizeHint ( ) const
overridevirtual
Returns
Size hint for the plot widget
See also
minimumSizeHint()

Definition at line 480 of file qwt_plot.cpp.

◆ title()

QwtText QwtPlot::title ( ) const
Returns
Title of the plot

Definition at line 351 of file qwt_plot.cpp.

◆ titleLabel() [1/2]

QwtTextLabel * QwtPlot::titleLabel ( )
Returns
Title label widget.

Definition at line 357 of file qwt_plot.cpp.

◆ titleLabel() [2/2]

const QwtTextLabel * QwtPlot::titleLabel ( ) const
Returns
Title label widget.

Definition at line 363 of file qwt_plot.cpp.

◆ transform()

double QwtPlot::transform ( QwtAxisId  axisId,
double  value 
) const

Transform a value into a coordinate in the plotting region.

Parameters
axisIdAxis
valuevalue
Returns
X or Y coordinate in the plotting region corresponding to the value.

Definition at line 414 of file qwt_plot_axis.cpp.

◆ updateAxes()

void QwtPlot::updateAxes ( )

Rebuild the axes scales.

In case of autoscaling the boundaries of a scale are calculated from the bounding rectangles of all plot items, having the QwtPlotItem::AutoScale flag enabled ( QwtScaleEngine::autoScale() ). Then a scale division is calculated ( QwtScaleEngine::didvideScale() ) and assigned to scale widget.

When the scale boundaries have been assigned with setAxisScale() a scale division is calculated ( QwtScaleEngine::didvideScale() ) for this interval and assigned to the scale widget.

When the scale has been set explicitly by setAxisScaleDiv() the locally stored scale division gets assigned to the scale widget.

The scale widget indicates modifications by emitting a QwtScaleWidget::scaleDivChanged() signal.

updateAxes() is usually called by replot().

See also
setAxisAutoScale(), setAxisScale(), setAxisScaleDiv(), replot() QwtPlotItem::boundingRect()

Definition at line 666 of file qwt_plot_axis.cpp.

◆ updateCanvasMargins()

void QwtPlot::updateCanvasMargins ( )

Update the canvas margins.

Plot items might indicate, that they need some extra space at the borders of the canvas by the QwtPlotItem::Margins flag.

getCanvasMarginsHint(), QwtPlotItem::getCanvasMarginHint()

Definition at line 706 of file qwt_plot.cpp.

◆ updateLayout()

void QwtPlot::updateLayout ( )
virtual

Adjust plot content to its current size.

See also
resizeEvent()

Definition at line 577 of file qwt_plot.cpp.

◆ updateLegend() [1/2]

void QwtPlot::updateLegend ( )

Emit legendDataChanged() for all plot item

See also
QwtPlotItem::legendData(), legendDataChanged()

Definition at line 1016 of file qwt_plot.cpp.

◆ updateLegend() [2/2]

void QwtPlot::updateLegend ( const QwtPlotItem plotItem)

Emit legendDataChanged() for a plot item

Parameters
plotItemPlot item
See also
QwtPlotItem::legendData(), legendDataChanged()

Definition at line 1032 of file qwt_plot.cpp.