QwtPlotScaleItem man page

QwtPlotScaleItem —

A class which draws a scale inside the plot canvas.

Synopsis

#include <qwt_plot_scaleitem.h>

Inherits QwtPlotItem.

Public Types

enum ItemAttribute { Legend = 1, AutoScale = 2 }

enum RenderHint { RenderAntialiased = 1 }

enum RttiValues { Rtti_PlotItem = 0, Rtti_PlotGrid, Rtti_PlotScale, Rtti_PlotMarker, Rtti_PlotCurve, Rtti_PlotHistogram, Rtti_PlotSpectrogram, Rtti_PlotSVG, Rtti_PlotUserItem = 1000 }

Public Member Functions

void attach (QwtPlot *plot)

int borderDistance () const

virtual QwtDoubleRect boundingRect () const

void detach ()

virtual void draw (QPainter *p, const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QRect &rect) const

QFont font () const

void hide ()

QwtDoubleRect invTransform (const QwtScaleMap &, const QwtScaleMap &, const QRect &) const

bool isScaleDivFromAxis () const

bool isVisible () const

virtual void itemChanged ()

virtual QWidget * legendItem () const

QRect paintRect (const QwtScaleMap &, const QwtScaleMap &) const

QPalette palette () const

QwtPlot * plot () const

double position () const

QwtPlotScaleItem (QwtScaleDraw::Alignment=QwtScaleDraw::BottomScale, const double pos=0.0)

virtual int rtti () const

const QwtScaleDiv & scaleDiv () const

const QwtScaleDraw * scaleDraw () const

QwtScaleDraw * scaleDraw ()

QwtDoubleRect scaleRect (const QwtScaleMap &, const QwtScaleMap &) const

void setAlignment (QwtScaleDraw::Alignment)

void setAxis (int xAxis, int yAxis)

void setBorderDistance (int numPixels)

void setFont (const QFont &)

void setItemAttribute (ItemAttribute, bool on=true)

void setPalette (const QPalette &)

void setPosition (double pos)

void setRenderHint (RenderHint, bool on=true)

void setScaleDiv (const QwtScaleDiv &)

void setScaleDivFromAxis (bool on)

void setScaleDraw (QwtScaleDraw *)

void setTitle (const QString &title)

void setTitle (const QwtText &title)

virtual void setVisible (bool)

void setXAxis (int axis)

void setYAxis (int axis)

void setZ (double z)

void show ()

bool testItemAttribute (ItemAttribute) const

bool testRenderHint (RenderHint) const

const QwtText & title () const

QRect transform (const QwtScaleMap &, const QwtScaleMap &, const QwtDoubleRect &) const

virtual void updateLegend (QwtLegend *) const

virtual void updateScaleDiv (const QwtScaleDiv &, const QwtScaleDiv &)

int xAxis () const

int yAxis () const

double z () const

virtual ~QwtPlotScaleItem ()

Detailed Description

A class which draws a scale inside the plot canvas.

QwtPlotScaleItem can be used to draw an axis inside the plot canvas. It might by synchronized to one of the axis of the plot, but can also display its own ticks and labels.

It is allowed to synchronize the scale item with a disabled axis. In plots with vertical and horizontal scale items, it might be necessary to remove ticks at the intersections, by overloading updateScaleDiv().

The scale might be at a specific position (f.e 0.0) or it might be aligned to a canvas border.

Example

The following example shows how to replace the left axis, by a scale item at the x position 0.0.

QwtPlotScaleItem *scaleItem = 
    new QwtPlotScaleItem(QwtScaleDraw::RightScale, 0.0);
scaleItem->setFont(plot->axisWidget(QwtPlot::yLeft)->font());
scaleItem->attach(plot);

plot->enableAxis(QwtPlot::yLeft, false);

Member Enumeration Documentation

enum QwtPlotItem::ItemAttribute [inherited] Plot Item Attributes

·
Legend
The item is represented on the legend.
·
AutoScale
The boundingRect() of the item is included in the autoscaling calculation.

See also:

setItemAttribute(), testItemAttribute()

enum QwtPlotItem::RenderHint [inherited]

Render hints.

enum QwtPlotItem::RttiValues [inherited]

Runtime type information. RttiValues is used to cast plot items, without having to enable runtime type information of the compiler.

Constructor & Destructor Documentation

QwtPlotScaleItem::QwtPlotScaleItem (QwtScaleDraw::Alignmentalignment = QwtScaleDraw::BottomScale, const doublepos = 0.0) [explicit]

Constructor for scale item at the position pos. Parameters:

alignment In case of QwtScaleDraw::BottomScale/QwtScaleDraw::TopScale the scale item is corresponding to the xAxis(), otherwise it corresponds to the yAxis().
pos x or y position, depending on the corresponding axis.

See also:

setPosition(), setAlignment()

QwtPlotScaleItem::~QwtPlotScaleItem () [virtual]

Destructor.

Member Function Documentation

void QwtPlotItem::attach (QwtPlot *plot) [inherited]

Attach the item to a plot. This method will attach a QwtPlotItem to the QwtPlot argument. It will first detach the QwtPlotItem from any plot from a previous call to attach (if necessary). If a NULL argument is passed, it will detach from any QwtPlot it was attached to.

Parameters:

plot Plot widget

See also:

QwtPlotItem::detach()

int QwtPlotScaleItem::borderDistance () const Returns

Distance from a canvas border

See also:

setBorderDistance(), setPosition()

QwtDoubleRect QwtPlotItem::boundingRect () const [virtual, inherited] Returns

An invalid bounding rect: QwtDoubleRect(1.0, 1.0, -2.0, -2.0)

Reimplemented in QwtPlotCurve, QwtPlotMarker, QwtPlotSpectrogram, and QwtPlotSvgItem.

void QwtPlotItem::detach () [inline, inherited]

This method detaches a QwtPlotItem from any QwtPlot it has been associated with. detach() is equivalent to calling attach( NULL )

See also:

attach( QwtPlot* plot )

void QwtPlotScaleItem::draw (QPainter *p, const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QRect &rect) const [virtual]

Draw the scale.

Implements QwtPlotItem.

QFont QwtPlotScaleItem::font () const Returns

tick label font

See also:

setFont()

void QwtPlotItem::hide () [inherited]

Hide the item.

QwtDoubleRect QwtPlotItem::invTransform (const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QRect &rect) const [inherited] Transform a rectangle from paint to scale coordinates

Parameters:

xMap X map
yMap Y map
rect Rectangle in paint coordinates

Returns:

Rectangle in scale coordinates

See also:

transform()

bool QwtPlotScaleItem::isScaleDivFromAxis () const Returns

True, if the synchronization of the scale division with the corresponding axis is enabled.

See also:

setScaleDiv(), setScaleDivFromAxis()

bool QwtPlotItem::isVisible () const [inherited] Returns

true if visible

See also:

setVisible(), show(), hide()

void QwtPlotItem::itemChanged () [virtual, inherited] Update the legend and call QwtPlot::autoRefresh for the parent plot.

See also:

updateLegend()

QWidget * QwtPlotItem::legendItem () const [virtual, inherited]

Allocate the widget that represents the item on the legend. The default implementation is made for QwtPlotCurve and returns a QwtLegendItem(), but an item could be represented by any type of widget, by overloading legendItem() and updateLegend().

Returns:

QwtLegendItem()

See also:

updateLegend() QwtLegend()

Implements QwtLegendItemManager.

QRect QwtPlotItem::paintRect (const QwtScaleMap &xMap, const QwtScaleMap &yMap) const [inherited]

Calculate the bounding paint rect of 2 maps. Parameters:

xMap X map
yMap X map

Returns:

Bounding rect of the scale maps

QPalette QwtPlotScaleItem::palette () const Returns

palette

See also:

setPalette()

QwtPlot * QwtPlotItem::plot () const [inherited]

Return attached plot.

double QwtPlotScaleItem::position () const Returns

Position of the scale

See also:

setPosition(), setAlignment()

int QwtPlotScaleItem::rtti () const [virtual] Returns

QwtPlotItem::Rtti_PlotScale

Reimplemented from QwtPlotItem.

const QwtScaleDiv & QwtPlotScaleItem::scaleDiv () const Returns

Scale division

const QwtScaleDraw * QwtPlotScaleItem::scaleDraw () const Returns

Scale draw

See also:

setScaleDraw()

QwtScaleDraw * QwtPlotScaleItem::scaleDraw () Returns

Scale draw

See also:

setScaleDraw()

QwtDoubleRect QwtPlotItem::scaleRect (const QwtScaleMap &xMap, const QwtScaleMap &yMap) const [inherited]

Calculate the bounding scale rect of 2 maps. Parameters:

xMap X map
yMap X map

Returns:

Bounding rect of the scale maps

void QwtPlotScaleItem::setAlignment (QwtScaleDraw::Alignmentalignment) Change the alignment of the scale

The alignment sets the orientation of the scale and the position of the ticks:

·
QwtScaleDraw::BottomScale: horizontal, ticks below
·
QwtScaleDraw::TopScale: horizontal, ticks above
·
QwtScaleDraw::LeftScale: vertical, ticks left
·
QwtScaleDraw::RightScale: vertical, ticks right

For horizontal scales the position corresponds to QwtPlotItem::yAxis(), otherwise to QwtPlotItem::xAxis().

See also:

scaleDraw(), QwtScaleDraw::alignment(), setPosition()

void QwtPlotItem::setAxis (intxAxis, intyAxis) [inherited] Set X and Y axis

The item will painted according to the coordinates its Axes.

Parameters:

xAxis X Axis
yAxis Y Axis

See also:

setXAxis(), setYAxis(), xAxis(), yAxis()

void QwtPlotScaleItem::setBorderDistance (intdistance)

Align the scale to the canvas. If distance is >= 0 the scale will be aligned to a border of the contents rect of the canvas. If alignment() is QwtScaleDraw::LeftScale, the scale will be aligned to the right border, if it is QwtScaleDraw::TopScale it will be aligned to the bottom (and vice versa),

If distance is < 0 the scale will be at the position().

Parameters:

distance Number of pixels between the canvas border and the backbone of the scale.

See also:

setPosition(), borderDistance()

void QwtPlotScaleItem::setFont (const QFont &font) Change the tick label font

See also:

font()

void QwtPlotItem::setItemAttribute (ItemAttributeattribute, boolon = true) [inherited] Toggle an item attribute

Parameters:

attribute Attribute type
on true/false

See also:

testItemAttribute(), ItemAttribute

void QwtPlotScaleItem::setPalette (const QPalette &palette) Set the palette

See also:

QwtAbstractScaleDraw::draw(), palette()

void QwtPlotScaleItem::setPosition (doublepos) Change the position of the scale

The position is interpreted as y value for horizontal axes and as x value for vertical axes.

The border distance is set to -1.

Parameters:

pos New position

See also:

position(), setAlignment()

void QwtPlotItem::setRenderHint (RenderHinthint, boolon = true) [inherited] Toggle an render hint

Parameters:

hint Render hint
on true/false

See also:

testRenderHint(), RenderHint

void QwtPlotScaleItem::setScaleDiv (const QwtScaleDiv &scaleDiv)

Assign a scale division. When assigning a scaleDiv the scale division won't be synchronized with the corresponding axis anymore.

Parameters:

scaleDiv Scale division

See also:

scaleDiv(), setScaleDivFromAxis(), isScaleDivFromAxis()

void QwtPlotScaleItem::setScaleDivFromAxis (boolon) Enable/Disable the synchronization of the scale division with the corresponding axis.

Parameters:

on true/false

See also:

isScaleDivFromAxis()

void QwtPlotScaleItem::setScaleDraw (QwtScaleDraw *scaleDraw)

Set a scale draw. Parameters:

scaleDraw object responsible for drawing scales.

The main use case for replacing the default QwtScaleDraw is to overload QwtAbstractScaleDraw::label, to replace or swallow tick labels.

See also:

scaleDraw()

void QwtPlotItem::setTitle (const QString &title) [inherited] Set a new title

Parameters:

title Title

See also:

title()

void QwtPlotItem::setTitle (const QwtText &title) [inherited] Set a new title

Parameters:

title Title

See also:

title()

void QwtPlotItem::setVisible (boolon) [virtual, inherited] Show/Hide the item

Parameters:

on Show if true, otherwise hide

See also:

isVisible(), show(), hide()

void QwtPlotItem::setXAxis (intaxis) [inherited] Set the X axis

The item will painted according to the coordinates its Axes.

Parameters:

axis X Axis

See also:

setAxis(), setYAxis(), xAxis()

void QwtPlotItem::setYAxis (intaxis) [inherited] Set the Y axis

The item will painted according to the coordinates its Axes.

Parameters:

axis Y Axis

See also:

setAxis(), setXAxis(), yAxis()

void QwtPlotItem::setZ (doublez) [inherited]

Set the z value. Plot items are painted in increasing z-order.

Parameters:

z Z-value

See also:

z(), QwtPlotDict::itemList()

void QwtPlotItem::show () [inherited]

Show the item.

bool QwtPlotItem::testItemAttribute (ItemAttributeattribute) const [inherited] Test an item attribute

Parameters:

attribute Attribute type

Returns:

true/false

See also:

setItemAttribute(), ItemAttribute

bool QwtPlotItem::testRenderHint (RenderHinthint) const [inherited] Test a render hint

Parameters:

hint Render hint

Returns:

true/false

See also:

setRenderHint(), RenderHint

const QwtText & QwtPlotItem::title () const [inherited] Returns

Title of the item

See also:

setTitle()

QRect QwtPlotItem::transform (const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QwtDoubleRect &rect) const [inherited] Transform a rectangle

Parameters:

xMap X map
yMap Y map
rect Rectangle in scale coordinates

Returns:

Rectangle in paint coordinates

See also:

invTransform()

void QwtPlotItem::updateLegend (QwtLegend *legend) const [virtual, inherited]

Update the widget that represents the item on the legend. updateLegend() is called from itemChanged() to adopt the widget representing the item on the legend to its new configuration.

The default implementation is made for QwtPlotCurve and updates a QwtLegendItem(), but an item could be represented by any type of widget, by overloading legendItem() and updateLegend().

Parameters:

legend Legend

See also:

legendItem(), itemChanged(), QwtLegend()

Implements QwtLegendItemManager.

Reimplemented in QwtPlotCurve.

void QwtPlotScaleItem::updateScaleDiv (const QwtScaleDiv &xScaleDiv, const QwtScaleDiv &yScaleDiv) [virtual]

Update the item to changes of the axes scale division. In case of isScaleDivFromAxis(), the scale draw is synchronized to the correspond axis.

Parameters:

xScaleDiv Scale division of the x-axis
yScaleDiv Scale division of the y-axis

See also:

QwtPlot::updateAxes()

Reimplemented from QwtPlotItem.

int QwtPlotItem::xAxis () const [inherited]

Return xAxis.

int QwtPlotItem::yAxis () const [inherited]

Return yAxis.

double QwtPlotItem::z () const [inherited] Plot items are painted in increasing z-order.

Returns:

setZ(), QwtPlotDict::itemList()

Author

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Info

Mon Aug 1 2011 Version 5.2.2 Qwt User's Guide