Provided by: libqwt-doc_6.1.4-2_all 
NAME
QwtPlot - A 2-D plotting widget.
SYNOPSIS
#include <qwt_plot.h>
Inherits QFrame, and QwtPlotDict.
Public Types
enum Axis { yLeft, yRight, xBottom, xTop, axisCnt }
Axis index.
enum LegendPosition { LeftLegend, RightLegend, BottomLegend, TopLegend }
Public Slots
virtual void replot ()
Redraw the plot.
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.
QwtPlot (const QwtText &title, QWidget *=NULL)
Constructor.
virtual ~QwtPlot ()
Destructor.
void applyProperties (const QString &)
QString grabProperties () const
void setAutoReplot (bool=true)
Set or reset the autoReplot option.
bool autoReplot () const
void setPlotLayout (QwtPlotLayout *)
Assign a new plot layout.
QwtPlotLayout * plotLayout ()
const QwtPlotLayout * plotLayout () const
void setTitle (const QString &)
void setTitle (const QwtText &)
QwtText title () const
QwtTextLabel * titleLabel ()
const QwtTextLabel * titleLabel () const
void setFooter (const QString &)
void setFooter (const QwtText &)
QwtText footer () const
QwtTextLabel * footerLabel ()
const QwtTextLabel * footerLabel () const
void setCanvas (QWidget *)
Set the drawing canvas of the plot widget.
QWidget * canvas ()
const QWidget * canvas () const
void setCanvasBackground (const QBrush &)
Change the background of the plotting area.
QBrush canvasBackground () const
virtual QwtScaleMap canvasMap (int axisId) const
double invTransform (int axisId, int pos) const
double transform (int axisId, double value) const
Transform a value into a coordinate in the plotting region.
QwtScaleEngine * axisScaleEngine (int axisId)
const QwtScaleEngine * axisScaleEngine (int axisId) const
void setAxisScaleEngine (int axisId, QwtScaleEngine *)
void setAxisAutoScale (int axisId, bool on=true)
Enable autoscaling for a specified axis.
bool axisAutoScale (int axisId) const
void enableAxis (int axisId, bool tf=true)
Enable or disable a specified axis.
bool axisEnabled (int axisId) const
void setAxisFont (int axisId, const QFont &)
Change the font of an axis.
QFont axisFont (int axisId) const
void setAxisScale (int axisId, double min, double max, double stepSize=0)
Disable autoscaling and specify a fixed scale for a selected axis.
void setAxisScaleDiv (int axisId, const QwtScaleDiv &)
Disable autoscaling and specify a fixed scale for a selected axis.
void setAxisScaleDraw (int axisId, QwtScaleDraw *)
Set a scale draw.
double axisStepSize (int axisId) const
Return the step size parameter that has been set in setAxisScale.
QwtInterval axisInterval (int axisId) const
Return the current interval of the specified axis.
const QwtScaleDiv & axisScaleDiv (int axisId) const
Return the scale division of a specified axis.
const QwtScaleDraw * axisScaleDraw (int axisId) const
Return the scale draw of a specified axis.
QwtScaleDraw * axisScaleDraw (int axisId)
Return the scale draw of a specified axis.
const QwtScaleWidget * axisWidget (int axisId) const
QwtScaleWidget * axisWidget (int axisId)
void setAxisLabelAlignment (int axisId, Qt::Alignment)
void setAxisLabelRotation (int axisId, double rotation)
void setAxisTitle (int axisId, const QString &)
Change the title of a specified axis.
void setAxisTitle (int axisId, const QwtText &)
Change the title of a specified axis.
QwtText axisTitle (int axisId) const
void setAxisMaxMinor (int axisId, int maxMinor)
int axisMaxMinor (int axisId) const
void setAxisMaxMajor (int axisId, int maxMajor)
int axisMaxMajor (int axisId) const
void insertLegend (QwtAbstractLegend *, LegendPosition=QwtPlot::RightLegend, double
ratio=-1.0)
Insert a legend.
QwtAbstractLegend * legend ()
const QwtAbstractLegend * legend () const
void updateLegend ()
void updateLegend (const QwtPlotItem *)
virtual QSize sizeHint () const
virtual QSize minimumSizeHint () const
Return a minimum size hint.
virtual void updateLayout ()
Adjust plot content to its current size.
virtual void drawCanvas (QPainter *)
void updateAxes ()
Rebuild the axes scales.
void updateCanvasMargins ()
Update the canvas margins.
virtual void getCanvasMarginsHint (const QwtScaleMap maps[], const QRectF &canvasRect,
double &left, double &top, double &right, double &bottom) const
Calculate the canvas margins.
virtual bool event (QEvent *)
Adds handling of layout requests.
virtual bool eventFilter (QObject *, QEvent *)
Event filter.
virtual void drawItems (QPainter *, const QRectF &, const QwtScaleMap maps[axisCnt]) const
virtual QVariant itemToInfo (QwtPlotItem *) const
Build an information, that can be used to identify a plot item on the legend.
virtual QwtPlotItem * infoToItem (const QVariant &) const
Identify the plot item according to an item info object, that has bee generated from
itemToInfo().
Protected Member Functions
virtual void resizeEvent (QResizeEvent *e)
Static Protected Member Functions
static bool axisValid (int axisId)
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();
Member Enumeration Documentation
enum QwtPlot::Axis
Axis index.
Enumerator
yLeft Y axis left of the canvas.
yRight Y axis right of the canvas.
xBottom
X axis below the canvas.
xTop X axis above the canvas.
axisCnt
Number of axes.
enum QwtPlot::LegendPosition
Position of the legend, relative to the canvas.
See also:
insertLegend()
Enumerator
LeftLegend
The legend will be left from the QwtPlot::yLeft axis.
RightLegend
The legend will be right from the QwtPlot::yRight axis.
BottomLegend
The legend will be below the footer.
TopLegend
The legend will be above the title.
Constructor & Destructor Documentation
QwtPlot::QwtPlot (QWidget * parent = NULL) [explicit]
Constructor.
Parameters:
parent Parent widget
QwtPlot::QwtPlot (const QwtText & title, QWidget * parent = NULL) [explicit]
Constructor.
Parameters:
title Title text
parent Parent widget
Member Function Documentation
void QwtPlot::applyProperties (const QString &)
This method is intended for manipulating the plot widget from a specific editor in the Qwt
designer plugin.
Warning:
The plot editor has never been implemented.
bool QwtPlot::autoReplot () const
Returns:
true if the autoReplot option is set.
See also:
setAutoReplot()
bool QwtPlot::axisAutoScale (int axisId) const
Returns:
True, if autoscaling is enabled
Parameters:
axisId Axis index
bool QwtPlot::axisEnabled (int axisId) const
Returns:
True, if a specified axis is enabled
Parameters:
axisId Axis index
QFont QwtPlot::axisFont (int axisId) const
Returns:
The font of the scale labels for a specified axis
Parameters:
axisId Axis index
QwtInterval QwtPlot::axisInterval (int axisId) const
Return the current interval of the specified axis. This is only a convenience function for
axisScaleDiv( axisId )->interval();
Parameters:
axisId Axis index
Returns:
Scale interval
See also:
QwtScaleDiv, axisScaleDiv()
int QwtPlot::axisMaxMajor (int axisId) const
Returns:
The maximum number of major ticks for a specified axis
Parameters:
axisId Axis index
See also:
setAxisMaxMajor(), QwtScaleEngine::divideScale()
int QwtPlot::axisMaxMinor (int axisId) const
Returns:
the maximum number of minor ticks for a specified axis
Parameters:
axisId Axis index
See also:
setAxisMaxMinor(), QwtScaleEngine::divideScale()
const QwtScaleDiv & QwtPlot::axisScaleDiv (int 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:
axisId Axis index
Returns:
Scale division
See also:
QwtScaleDiv, setAxisScaleDiv(), QwtScaleEngine::divideScale()
const QwtScaleDraw * QwtPlot::axisScaleDraw (int axisId) const
Return the scale draw of a specified axis.
Parameters:
axisId Axis index
Returns:
Specified scaleDraw for axis, or NULL if axis is invalid.
QwtScaleDraw * QwtPlot::axisScaleDraw (int axisId)
Return the scale draw of a specified axis.
Parameters:
axisId Axis index
Returns:
Specified scaleDraw for axis, or NULL if axis is invalid.
QwtScaleEngine * QwtPlot::axisScaleEngine (int axisId)
Parameters:
axisId Axis index
Returns:
Scale engine for a specific axis
const QwtScaleEngine * QwtPlot::axisScaleEngine (int axisId) const
Parameters:
axisId Axis index
Returns:
Scale engine for a specific axis
double QwtPlot::axisStepSize (int 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:
axisId Axis index
Returns:
step size parameter value
See also:
setAxisScale(), QwtScaleEngine::divideScale()
QwtText QwtPlot::axisTitle (int axisId) const
Returns:
Title of a specified axis
Parameters:
axisId Axis index
bool QwtPlot::axisValid (int axisId) [static], [protected]
Returns:
true if the specified axis exists, otherwise false
Parameters:
axisId axis index
const QwtScaleWidget * QwtPlot::axisWidget (int axisId) const
Returns:
Scale widget of the specified axis, or NULL if axisId is invalid.
Parameters:
axisId Axis index
QwtScaleWidget * QwtPlot::axisWidget (int axisId)
Returns:
Scale widget of the specified axis, or NULL if axisId is invalid.
Parameters:
axisId Axis index
QWidget * QwtPlot::canvas ()
Returns:
the plot's canvas
const QWidget * QwtPlot::canvas () const
Returns:
the plot's canvas
QBrush QwtPlot::canvasBackground () const
Nothing else than: canvas()->palette().brush( QPalette::Normal, QPalette::Window);
Returns:
Background brush of the plotting area.
See also:
setCanvasBackground()
QwtScaleMap QwtPlot::canvasMap (int axisId) const [virtual]
Parameters:
axisId Axis
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()
void QwtPlot::drawCanvas (QPainter * painter) [virtual]
Redraw the canvas.
Parameters:
painter Painter 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()
void QwtPlot::drawItems (QPainter * painter, const QRectF & canvasRect, const QwtScaleMap
maps[axisCnt]) const [virtual]
Redraw the canvas items.
Parameters:
painter Painter used for drawing
canvasRect Bounding rectangle where to paint
maps QwtPlot::axisCnt 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()
void QwtPlot::enableAxis (int axisId, bool tf = true)
Enable or disable a specified axis. When an axis is disabled, this only means that it is
not visible on the screen. Curves, markers and can be attached to disabled axes, and
transformation of screen coordinates into values works as normal.
Only xBottom and yLeft are enabled by default.
Parameters:
axisId Axis index
tf true (enabled) or false (disabled)
bool QwtPlot::event (QEvent * event) [virtual]
Adds handling of layout requests.
Parameters:
event Event
Returns:
See QFrame::event()
bool QwtPlot::eventFilter (QObject * object, QEvent * event) [virtual]
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:
object Object to be filtered
event Event
Returns:
See QFrame::eventFilter()
See also:
updateCanvasMargins(), updateLayout()
QwtText QwtPlot::footer () const
Returns:
Text of the footer
QwtTextLabel * QwtPlot::footerLabel ()
Returns:
Footer label widget.
const QwtTextLabel * QwtPlot::footerLabel () const
Returns:
Footer label widget.
void QwtPlot::getCanvasMarginsHint (const QwtScaleMap maps[], const QRectF & canvasRect,
double & left, double & top, double & right, double & bottom) const [virtual]
Calculate the canvas margins.
Parameters:
maps QwtPlot::axisCnt maps, mapping between plot and paint device coordinates
canvasRect Bounding rectangle where to paint
left Return parameter for the left margin
top Return parameter for the top margin
right Return parameter for the right margin
bottom Return 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()
QString QwtPlot::grabProperties () const
This method is intended for manipulating the plot widget from a specific editor in the Qwt
designer plugin.
Returns:
QString()
Warning:
The plot editor has never been implemented.
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 );
Parameters:
itemInfo Plot item
Returns:
A plot item, when successful, otherwise a NULL pointer.
See also:
itemToInfo()
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:
legend Legend
pos The legend's position. For top/left position the number of columns will be limited
to 1, otherwise it will be set to unlimited.
ratio Ratio 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()
double QwtPlot::invTransform (int axisId, int pos) const
Transform the x or y coordinate of a position in the drawing region into a value.
Parameters:
axisId Axis index
pos position
Returns:
Position as axis coordinate
Warning:
The position can be an x or a y coordinate, depending on the specified axis.
void QwtPlot::itemAttached (QwtPlotItem * plotItem, bool on) [signal]
A signal indicating, that an item has been attached/detached
Parameters:
plotItem Plot item
on Attached/Detached
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.
QVariant itemInfo;
qVariantSetValue( itemInfo, plotItem );
Parameters:
plotItem Plot item
Returns:
Plot item embedded in a QVariant
See also:
infoToItem()
QwtAbstractLegend * QwtPlot::legend ()
Returns:
the plot's legend
See also:
insertLegend()
const QwtAbstractLegend * QwtPlot::legend () const
Returns:
the plot's legend
See also:
insertLegend()
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:
itemInfo Info about a plot item, build from itemToInfo()
data Attributes of the entries ( usually <= 1 ) for the plot item.
See also:
itemToInfo(), infoToItem(), QwtAbstractLegend::updateLegend()
QwtPlotLayout * QwtPlot::plotLayout ()
Returns:
the plot's layout
const QwtPlotLayout * QwtPlot::plotLayout () const
Returns:
the plot's layout
void QwtPlot::replot () [virtual], [slot]
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()
void QwtPlot::resizeEvent (QResizeEvent * e) [protected], [virtual]
Resize and update internal layout
Parameters:
e Resize event
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:
tf true or false. Defaults to true.
See also:
replot()
void QwtPlot::setAxisAutoScale (int 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:
axisId Axis index
on On/Off
See also:
setAxisScale(), setAxisScaleDiv(), updateAxes()
Note:
The autoscaling flag has no effect until updateAxes() is executed ( called by replot()
).
void QwtPlot::setAxisFont (int axisId, const QFont & font)
Change the font of an axis.
Parameters:
axisId Axis index
font Font
Warning:
This function changes the font of the tick labels, not of the axis title.
void QwtPlot::setAxisLabelAlignment (int axisId, Qt::Alignment alignment)
Change the alignment of the tick labels
Parameters:
axisId Axis index
alignment Or'd Qt::AlignmentFlags see <qnamespace.h>
See also:
QwtScaleDraw::setLabelAlignment()
void QwtPlot::setAxisLabelRotation (int axisId, double rotation)
Rotate all tick labels
Parameters:
axisId Axis index
rotation Angle in degrees. When changing the label rotation, the label alignment might
be adjusted too.
See also:
QwtScaleDraw::setLabelRotation(), setAxisLabelAlignment()
void QwtPlot::setAxisMaxMajor (int axisId, int maxMajor)
Set the maximum number of major scale intervals for a specified axis
Parameters:
axisId Axis index
maxMajor Maximum number of major steps
See also:
axisMaxMajor()
void QwtPlot::setAxisMaxMinor (int axisId, int maxMinor)
Set the maximum number of minor scale intervals for a specified axis
Parameters:
axisId Axis index
maxMinor Maximum number of minor steps
See also:
axisMaxMinor()
void QwtPlot::setAxisScale (int 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:
axisId Axis index
min Minimum of the scale
max Maximum of the scale
stepSize Major step size. If step == 0, the step size is calculated automatically
using the maxMajor setting.
See also:
setAxisMaxMajor(), setAxisAutoScale(), axisStepSize(), QwtScaleEngine::divideScale()
void QwtPlot::setAxisScaleDiv (int 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:
axisId Axis index
scaleDiv Scale division
See also:
setAxisScale(), setAxisAutoScale()
void QwtPlot::setAxisScaleDraw (int axisId, QwtScaleDraw * scaleDraw)
Set a scale draw.
Parameters:
axisId Axis index
scaleDraw Object 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.
void QwtPlot::setAxisScaleEngine (int axisId, QwtScaleEngine * scaleEngine)
Change the scale engine for an axis
Parameters:
axisId Axis index
scaleEngine Scale engine
See also:
axisScaleEngine()
void QwtPlot::setAxisTitle (int axisId, const QString & title)
Change the title of a specified axis.
Parameters:
axisId Axis index
title axis title
void QwtPlot::setAxisTitle (int axisId, const QwtText & title)
Change the title of a specified axis.
Parameters:
axisId Axis index
title Axis title
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:
canvas Canvas Widget
See also:
canvas()
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:
brush New background brush
See also:
canvasBackground()
void QwtPlot::setFooter (const QString & text)
Change the text the footer
Parameters:
text New text of the footer
void QwtPlot::setFooter (const QwtText & text)
Change the text the footer
Parameters:
text New text of the footer
void QwtPlot::setPlotLayout (QwtPlotLayout * layout)
Assign a new plot layout.
Parameters:
layout Layout()
See also:
plotLayout()
void QwtPlot::setTitle (const QString & title)
Change the plot's title
Parameters:
title New title
void QwtPlot::setTitle (const QwtText & title)
Change the plot's title
Parameters:
title New title
QSize QwtPlot::sizeHint () const [virtual]
Returns:
Size hint for the plot widget
See also:
minimumSizeHint()
QwtText QwtPlot::title () const
Returns:
Title of the plot
QwtTextLabel * QwtPlot::titleLabel ()
Returns:
Title label widget.
const QwtTextLabel * QwtPlot::titleLabel () const
Returns:
Title label widget.
double QwtPlot::transform (int axisId, double value) const
Transform a value into a coordinate in the plotting region.
Parameters:
axisId Axis index
value value
Returns:
X or Y coordinate in the plotting region corresponding to the value.
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()
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()
void QwtPlot::updateLayout () [virtual]
Adjust plot content to its current size.
See also:
resizeEvent()
void QwtPlot::updateLegend ()
Emit legendDataChanged() for all plot item
See also:
QwtPlotItem::legendData(), legendDataChanged()
void QwtPlot::updateLegend (const QwtPlotItem * plotItem)
Emit legendDataChanged() for a plot item
Parameters:
plotItem Plot item
See also:
QwtPlotItem::legendData(), legendDataChanged()
Author
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