QValueAxis Class

The QValueAxis class adds values to a chart's axes. More...

Header:	#include <QValueAxis>
Instantiated By:	ValueAxis
Inherits:	QAbstractAxis
Inherited By:	QCategoryAxis

• List of all members, including inherited members

Public Types

enum	TickType { TicksDynamic, TicksFixed }

Properties

labelFormat : QString max : qreal min : qreal minorTickCount : int

tickAnchor : qreal tickCount : int tickInterval : qreal tickType : TickType

Public Functions

	QValueAxis(QObject *parent = nullptr)
virtual	~QValueAxis()
QString	labelFormat() const
qreal	max() const
qreal	min() const
int	minorTickCount() const
void	setLabelFormat(const QString &format)
void	setMax(qreal max)
void	setMin(qreal min)
void	setMinorTickCount(int count)
void	setRange(qreal min, qreal max)
void	setTickAnchor(qreal anchor)
void	setTickCount(int count)
void	setTickInterval(qreal insterval)
void	setTickType(QValueAxis::TickType type)
qreal	tickAnchor() const
int	tickCount() const
qreal	tickInterval() const
QValueAxis::TickType	tickType() const

Reimplemented Public Functions

virtual QAbstractAxis::AxisType

type() const override

Public Slots

void	applyNiceNumbers()

Signals

void	labelFormatChanged(const QString &format)
void	maxChanged(qreal max)
void	minChanged(qreal min)
void	minorTickCountChanged(int minorTickCount)
void	rangeChanged(qreal min, qreal max)
void	tickAnchorChanged(qreal anchor)
void	tickCountChanged(int tickCount)
void	tickIntervalChanged(qreal interval)
void	tickTypeChanged(QValueAxis::TickType type)

Detailed Description

A value axis can be set up to show an axis line with tick marks, grid lines, and shades. The values on the axis are drawn at the positions of tick marks.

The following example code illustrates how to use the QValueAxis class:

QChartView *chartView = new QChartView;
QLineSeries *series = new QLineSeries;
// ...
chartView->chart()->addSeries(series);

QValueAxis *axisX = new QValueAxis;
axisX->setRange(10, 20.5);
axisX->setTickCount(10);
axisX->setLabelFormat("%.2f");
chartView->chart()->setAxisX(axisX, series);

Member Type Documentation

enum QValueAxis::TickType

This enum describes how the ticks and labels are positioned on the axis.

Constant	Value	Description
QValueAxis::TicksDynamic	0	Ticks are placed according to tickAnchor and tickInterval values.
QValueAxis::TicksFixed	1	Ticks are placed evenly across the axis range. The tickCount value specifies the number of ticks.

Member Function Documentation

QValueAxis::QValueAxis(QObject *parent = nullptr)

Constructs an axis object that is a child of parent.

[slot] void QValueAxis::applyNiceNumbers()

Modifies the current range and number of tick marks on the axis to look nice. The algorithm considers numbers that can be expressed as a form of 1*10^n, 2* 10^n, or 5*10^n to be nice numbers. These numbers are used for setting spacing for the tick marks.

See also setRange() and setTickCount().

[signal] void QValueAxis::labelFormatChanged(const QString &format)

This signal is emitted when the format of axis labels changes.

Note: Notifier signal for property labelFormat.

[signal] void QValueAxis::maxChanged(qreal max)

This signal is emitted when the maximum value of the axis, specified by max, changes.

Note: Notifier signal for property max.

[signal] void QValueAxis::minChanged(qreal min)

This signal is emitted when the minimum value of the axis, specified by min, changes.

Note: Notifier signal for property min.

[signal] void QValueAxis::minorTickCountChanged(int minorTickCount)

This signal is emitted when the number of minor tick marks on the axis, specified by minorTickCount, changes.

Note: Notifier signal for property minorTickCount.

[signal] void QValueAxis::rangeChanged(qreal min, qreal max)

This signal is emitted when the minimum or maximum value of the axis, specified by min and max, changes.

[signal] void QValueAxis::tickCountChanged(int tickCount)

This signal is emitted when the number of tick marks on the axis, specified by tickCount, changes.

Note: Notifier signal for property tickCount.

[virtual] QValueAxis::~QValueAxis()

Destroys the object.

void QValueAxis::setRange(qreal min, qreal max)

Sets the range from min to max on the axis. If min is greater than max, this function returns without making any changes.

[override virtual] QAbstractAxis::AxisType QValueAxis::type() const

Reimplements: QAbstractAxis::type() const.

Returns the type of the axis.