QwtPlotItemInfo Class Reference

Utility class for querying QwtPlotItem types and filtering plot items. More...

#include <qwt_plot_item_info.h>

Static Public Member Functions
static bool	isSeriesItem (const QwtPlotItem *item)
	Check whether the item is a QwtPlotSeriesItem subclass.
static bool	isXYSeriesItem (const QwtPlotItem *item)
	Check whether the item stores QPointF data.
static bool	isIntervalSeriesItem (const QwtPlotItem *item)
	Check whether the item stores QwtIntervalSample data.
static bool	isDecoratorItem (const QwtPlotItem *item)
	Check whether the item is a decorator (non-data item)
static bool	isDataItem (const QwtPlotItem *item)
	Check whether the item holds any data series.
static QwtPlotItemList	seriesItems (const QwtPlot *plot)
	Get all QwtPlotSeriesItem instances from a plot.
static QwtPlotItemList	xySeriesItems (const QwtPlot *plot)
	Get all QPointF-based series items from a plot.
static QwtPlotItemList	filterByRtti (const QwtPlot *plot, int rtti)
	Filter items by a single rtti value.
static QwtPlotItemList	filterByRtti (const QwtPlot *plot, const QSet< int > &rttiSet)
	Filter items by a set of rtti values.
static QwtPlotItemList	visibleItems (const QwtPlot *plot)
	Get all currently visible items from a plot.
static int	dataSize (const QwtPlotItem *item)
	Get the number of data samples in a plot item.
static QRectF	dataRect (const QwtPlotItem *item)
	Get the bounding rectangle of the item's data.
static QString	rttiName (int rtti)
	Get a human-readable name for an rtti value.

Detailed Description

Utility class for querying QwtPlotItem types and filtering plot items.

QwtPlotItemInfo provides static methods to determine the runtime type of plot items, filter items by category, and retrieve basic information such as data size and bounding rectangle. This class does not modify any plot or item state.

QwtPlot* plot = ...;
QwtPlotItemList curves = Qwt::QwtPlotItemInfo::xySeriesItems(plot);
for (auto* item : curves) {
    qDebug() << item->title().text()
             << "has" << Qwt::QwtPlotItemInfo::dataSize(item) << "points";
}

See also

QwtPlotDataAccess, QwtPlotStyling

Member Function Documentation

dataRect()

QRectF QwtPlotItemInfo::dataRect ( const QwtPlotItem *  item )

static

Get the bounding rectangle of the item's data.

Parameters

item	Plot item to query

Returns

Bounding rectangle, or an invalid QRectF if the item does not hold data

dataSize()

int QwtPlotItemInfo::dataSize ( const QwtPlotItem *  item )

static

Get the number of data samples in a plot item.

Parameters

item	Plot item to query

Returns

Number of samples, or -1 if the item does not hold a data series

filterByRtti() [1/2]

QwtPlotItemList QwtPlotItemInfo::filterByRtti ( const QwtPlot *  plot, const QSet< int > &  rttiSet  )

static

Filter items by a set of rtti values.

Parameters

plot	Plot to query
rttiSet	Set of rtti values to match

Returns

List of items whose rtti is in the set

filterByRtti() [2/2]

QwtPlotItemList QwtPlotItemInfo::filterByRtti ( const QwtPlot *  plot, int  rtti  )

static

Filter items by a single rtti value.

Parameters

plot	Plot to query
rtti	Runtime type value to match

Returns

List of items matching the rtti

See also

QwtPlotDict::itemList(int)

isDataItem()

bool QwtPlotItemInfo::isDataItem ( const QwtPlotItem *  item )

static

Check whether the item holds any data series.

Parameters

item	Plot item to check

Returns

true for all QwtPlotSeriesItem subclasses

See also

isSeriesItem()

isDecoratorItem()

bool QwtPlotItemInfo::isDecoratorItem ( const QwtPlotItem *  item )

static

Check whether the item is a decorator (non-data item)

Parameters

item	Plot item to check

Returns

true for grid, marker, scale, legend, text label, zone, shape, graphic, arrow marker

isIntervalSeriesItem()

bool QwtPlotItemInfo::isIntervalSeriesItem ( const QwtPlotItem *  item )

static

Check whether the item stores QwtIntervalSample data.

Parameters

item	Plot item to check

Returns

true for QwtPlotIntervalCurve and QwtPlotHistogram

isSeriesItem()

bool QwtPlotItemInfo::isSeriesItem ( const QwtPlotItem *  item )

static

Check whether the item is a QwtPlotSeriesItem subclass.

Parameters

item	Plot item to check, may be nullptr

Returns

true if item is derived from QwtPlotSeriesItem

isXYSeriesItem()

bool QwtPlotItemInfo::isXYSeriesItem ( const QwtPlotItem *  item )

static

Check whether the item stores QPointF data.

Parameters

item	Plot item to check

Returns

true for QwtPlotCurve and QwtPlotBarChart

rttiName()

QString QwtPlotItemInfo::rttiName ( int  rtti )

static

Get a human-readable name for an rtti value.

Parameters

rtti	Runtime type value

Returns

String name such as "PlotCurve", "PlotBarChart", etc.

seriesItems()

QwtPlotItemList QwtPlotItemInfo::seriesItems ( const QwtPlot *  plot )

static

Get all QwtPlotSeriesItem instances from a plot.

Parameters

plot	Plot to query

Returns

List of series items

visibleItems()

QwtPlotItemList QwtPlotItemInfo::visibleItems ( const QwtPlot *  plot )

static

Get all currently visible items from a plot.

Parameters

plot	Plot to query

Returns

List of visible items

xySeriesItems()

QwtPlotItemList QwtPlotItemInfo::xySeriesItems ( const QwtPlot *  plot )

static

Get all QPointF-based series items from a plot.

Parameters

plot	Plot to query

Returns

List of XY series items (curves and bar charts)

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The documentation for this class was generated from the following files:

• /home/runner/work/QWT/QWT/src/plot/qwt_plot_item_info.h
• /home/runner/work/QWT/QWT/src/plot/qwt_plot_item_info.cpp