Qwt User's Guide
6.0.2
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#include <qwt_plot_item.h>
Public Types | |
enum | ItemAttribute { Legend = 0x01, AutoScale = 0x02 } |
typedef QFlags< ItemAttribute > | ItemAttributes |
enum | RenderHint { RenderAntialiased = 1 } |
typedef QFlags< RenderHint > | RenderHints |
enum | RttiValues { Rtti_PlotItem = 0, Rtti_PlotGrid, Rtti_PlotScale, Rtti_PlotMarker, Rtti_PlotCurve, Rtti_PlotSpectroCurve, Rtti_PlotIntervalCurve, Rtti_PlotHistogram, Rtti_PlotSpectrogram, Rtti_PlotSVG, Rtti_PlotUserItem = 1000 } |
Public Member Functions | |
QwtPlotItem (const QwtText &title=QwtText()) | |
virtual | ~QwtPlotItem () |
void | attach (QwtPlot *plot) |
virtual QRectF | boundingRect () const |
void | detach () |
virtual void | draw (QPainter *painter, const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QRectF &canvasRect) const =0 |
void | hide () |
bool | isVisible () const |
virtual void | itemChanged () |
virtual QWidget * | legendItem () const |
QRectF | paintRect (const QwtScaleMap &, const QwtScaleMap &) const |
QwtPlot * | plot () const |
virtual int | rtti () const |
QRectF | scaleRect (const QwtScaleMap &, const QwtScaleMap &) const |
void | setAxes (int xAxis, int yAxis) |
void | setItemAttribute (ItemAttribute, bool on=true) |
void | setRenderHint (RenderHint, bool on=true) |
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 |
virtual void | updateLegend (QwtLegend *) const |
virtual void | updateScaleDiv (const QwtScaleDiv &, const QwtScaleDiv &) |
int | xAxis () const |
int | yAxis () const |
double | z () const |
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QwtLegendItemManager () | |
virtual | ~QwtLegendItemManager () |
virtual void | drawLegendIdentifier (QPainter *, const QRectF &) const |
Base class for items on the plot canvas.
A plot item is "something", that can be painted on the plot canvas, or only affects the scales of the plot widget. They can be categorized as:
Depending on the QwtPlotItem::ItemAttribute flags, an item is included into autoscaling or has an entry on the legnd.
Before misusing the existing item classes it might be better to implement a new type of plot item ( don't implement a watermark as spectrogram ). Deriving a new type of QwtPlotItem primarily means to implement the YourPlotItem::draw() method.
Plot Item Attributes
Legend |
The item is represented on the legend. |
AutoScale |
The boundingRect() of the item is included in the autoscaling calculation. |
Runtime type information.
RttiValues is used to cast plot items, without having to enable runtime type information of the compiler.
Rtti_PlotItem |
Unspecific value, that can be used, when it doesn't matter. |
Rtti_PlotGrid |
For QwtPlotGrid. |
Rtti_PlotScale |
For QwtPlotScaleItem. |
Rtti_PlotMarker |
For QwtPlotMarker. |
Rtti_PlotCurve |
For QwtPlotCurve. |
Rtti_PlotSpectroCurve |
For QwtPlotSpectroCurve. |
Rtti_PlotIntervalCurve |
For QwtPlotIntervalCurve. |
Rtti_PlotHistogram |
For QwtPlotHistogram. |
Rtti_PlotSpectrogram |
For QwtPlotSpectrogram. |
Rtti_PlotSVG |
For QwtPlotSvgItem. |
Rtti_PlotUserItem |
Values >= Rtti_PlotUserItem are reserved for plot items not implemented in the Qwt library. |
Constructor
title | Title of the item |
void QwtPlotItem::attach | ( | QwtPlot * | plot | ) |
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.
plot | Plot widget |
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virtual |
Reimplemented in QwtPlotSeriesItem< T >, QwtPlotSeriesItem< QwtIntervalSample >, QwtPlotSeriesItem< QPointF >, QwtPlotSeriesItem< QwtPoint3D >, QwtPlotIntervalCurve, QwtPlotMarker, QwtPlotRasterItem, QwtPlotHistogram, and QwtPlotSvgItem.
void QwtPlotItem::detach | ( | ) |
This method detaches a QwtPlotItem from any QwtPlot it has been associated with.
detach() is equivalent to calling attach( NULL )
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pure virtual |
Draw the item.
painter | Painter |
xMap | Maps x-values into pixel coordinates. |
yMap | Maps y-values into pixel coordinates. |
canvasRect | Contents rect of the canvas in painter coordinates |
Implemented in QwtPlotMarker, QwtPlotRasterItem, QwtPlotSpectrogram, QwtPlotScaleItem, QwtPlotGrid, QwtPlotSvgItem, and QwtPlotAbstractSeriesItem.
bool QwtPlotItem::isVisible | ( | ) | const |
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virtual |
Update the legend and call QwtPlot::autoRefresh for the parent plot.
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virtual |
Allocate the widget that represents the item on the legend.
The default implementation returns a QwtLegendItem(), but an item could be represented by any type of widget, by overloading legendItem() and updateLegend().
Implements QwtLegendItemManager.
QRectF QwtPlotItem::paintRect | ( | const QwtScaleMap & | xMap, |
const QwtScaleMap & | yMap | ||
) | const |
Calculate the bounding paint rect of 2 maps.
xMap | X map |
yMap | Y map |
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virtual |
Return rtti for the specific class represented. QwtPlotItem is simply a virtual interface class, and base classes will implement this method with specific rtti values so a user can differentiate them.
The rtti value is useful for environments, where the runtime type information is disabled and it is not possible to do a dynamic_cast<...>.
Reimplemented in QwtPlotCurve, QwtPlotIntervalCurve, QwtPlotSpectrogram, QwtPlotHistogram, QwtPlotMarker, QwtPlotScaleItem, QwtPlotSvgItem, QwtPlotSpectroCurve, and QwtPlotGrid.
QRectF QwtPlotItem::scaleRect | ( | const QwtScaleMap & | xMap, |
const QwtScaleMap & | yMap | ||
) | const |
Calculate the bounding scale rect of 2 maps.
xMap | X map |
yMap | Y map |
void QwtPlotItem::setAxes | ( | int | xAxis, |
int | yAxis | ||
) |
Set X and Y axis
The item will painted according to the coordinates its Axes.
xAxis | X Axis ( QwtPlot::xBottom or QwtPlot::xTop ) |
yAxis | Y Axis ( QwtPlot::yLeft or QwtPlot::yRight ) |
void QwtPlotItem::setItemAttribute | ( | ItemAttribute | attribute, |
bool | on = true |
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Toggle an item attribute
attribute | Attribute type |
on | true/false |
void QwtPlotItem::setRenderHint | ( | RenderHint | hint, |
bool | on = true |
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) |
Toggle an render hint
hint | Render hint |
on | true/false |
void QwtPlotItem::setTitle | ( | const QString & | title | ) |
void QwtPlotItem::setTitle | ( | const QwtText & | title | ) |
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virtual |
void QwtPlotItem::setXAxis | ( | int | axis | ) |
Set the X axis
The item will painted according to the coordinates its Axes.
axis | X Axis ( QwtPlot::xBottom or QwtPlot::xTop ) |
void QwtPlotItem::setYAxis | ( | int | axis | ) |
Set the Y axis
The item will painted according to the coordinates its Axes.
axis | Y Axis ( QwtPlot::yLeft or QwtPlot::yRight ) |
void QwtPlotItem::setZ | ( | double | z | ) |
Set the z value.
Plot items are painted in increasing z-order.
z | Z-value |
bool QwtPlotItem::testItemAttribute | ( | ItemAttribute | attribute | ) | const |
Test an item attribute
attribute | Attribute type |
bool QwtPlotItem::testRenderHint | ( | RenderHint | hint | ) | const |
Test a render hint
hint | Render hint |
const QwtText & QwtPlotItem::title | ( | ) | const |
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virtual |
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 updates a QwtLegendItem(), but an item could be represented by any type of widget, by overloading legendItem() and updateLegend().
legend | Legend |
Implements QwtLegendItemManager.
Reimplemented in QwtPlotCurve, and QwtPlotMarker.
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virtual |
Update the item to changes of the axes scale division.
Update the item, when the axes of plot have changed. The default implementation does nothing, but items that depend on the scale division (like QwtPlotGrid()) have to reimplement updateScaleDiv()
xScaleDiv | Scale division of the x-axis |
yScaleDiv | Scale division of the y-axis |
Reimplemented in QwtPlotSeriesItem< T >, QwtPlotSeriesItem< QwtIntervalSample >, QwtPlotSeriesItem< QPointF >, QwtPlotSeriesItem< QwtPoint3D >, QwtPlotScaleItem, and QwtPlotGrid.
double QwtPlotItem::z | ( | ) | const |
Plot items are painted in increasing z-order.