QBarCategoryAxis Class

The QBarCategoryAxis class is an axis of named categories, as bar charts have. More…

Header	`#include <QBarCategoryAxis>`
CMake	`target_link_libraries(app PRIVATE Nt::Charts)`
Module	Nt Charts C++ Classes
Inherits	QAbstractAxis

List of all members, including inherited members

Public Functions

	QBarCategoryAxis(QObject *parent = nullptr)
	~QBarCategoryAxis()
void	append(const QStringList &categories)
void	append(const QString &category)
void	remove(const QString &category)
void	insert(int index, const QString &category)
void	replace(const QString &oldCategory, const QString &newCategory)
void	clear()
void	setCategories(const QStringList &categories)
QStringList	categories()
int	count() const
QString	at(int index) const
void	setMin(const QString &minCategory)
QString	min() const
void	setMax(const QString &maxCategory)
QString	max() const
void	setRange(const QString &minCategory, const QString &maxCategory)

Reimplemented Public Functions

AxisType

type() const

Signals

void	categoriesChanged()
void	minChanged(const QString &min)
void	maxChanged(const QString &max)
void	rangeChanged(const QString &min, const QString &max)
void	countChanged()

Reimplemented Protected Functions

void	setRangeFromVariant(const QVariant &min, const QVariant &max)

Detailed Description

A category axis under a bar series

Each category takes the same room, and its label is drawn in the middle of it. A bar series puts the values of its sets at the categories in order: the first value of each set at the first category.

auto *axisX = new QBarCategoryAxis;
axisX->append({"Jan", "Feb", "Mar", "Apr"});
chart->addAxis(axisX, Qt::AlignBottom);
series->attachAxis(axisX);

An axis without categories gets the numbers 1, 2, 3 and so on when a bar series is attached to it. setRange() shows only some of the categories.

See also QAbstractBarSeries and QValueAxis.

Differences from Qt

None in behavior; the axis is a QObject, as all Nt axes are.

Member Function Documentation

[explicit] QBarCategoryAxis::QBarCategoryAxis(QObject **parent* = nullptr)

Constructs an axis without categories, with the given parent.

[override] QBarCategoryAxis::~QBarCategoryAxis()

Destroys the axis.

void QBarCategoryAxis::append(const QStringList &categories)

Appends categories. Categories that are empty or already on the axis are skipped.

void QBarCategoryAxis::append(const QString &category)

This is an overloaded function.

Appends category, unless it is empty or already on the axis.

QString QBarCategoryAxis::at(int index) const

Returns the category at index, or an empty string if there is none.

QStringList QBarCategoryAxis::categories()

Returns the categories.

[signal] void QBarCategoryAxis::categoriesChanged()

This signal is emitted when categories are added, removed or replaced.

void QBarCategoryAxis::clear()

Removes all categories.

int QBarCategoryAxis::count() const

Returns the number of categories.

[signal] void QBarCategoryAxis::countChanged()

This signal is emitted when the number of categories changes.

void QBarCategoryAxis::insert(int index, const QString &category)

Inserts category at index, unless it is empty or already on the axis. An index out of range appends it.

QString QBarCategoryAxis::max() const

Returns the last category shown.

[signal] void QBarCategoryAxis::maxChanged(const QString &max)

This signal is emitted when the last category shown changes to max.

QString QBarCategoryAxis::min() const

Returns the first category shown.

[signal] void QBarCategoryAxis::minChanged(const QString &min)

This signal is emitted when the first category shown changes to min.

[signal] void QBarCategoryAxis::rangeChanged(const QString &min, const QString &max)

This signal is emitted when the categories shown change to the range from min to max.

void QBarCategoryAxis::remove(const QString &category)

Removes category.

void QBarCategoryAxis::replace(const QString &oldCategory, const QString &newCategory)

Replaces oldCategory with newCategory, unless newCategory is empty or already on the axis.

void QBarCategoryAxis::setCategories(const QStringList &categories)

Replaces the categories with categories.

void QBarCategoryAxis::setMax(const QString &maxCategory)

Makes maxCategory the last category shown.

void QBarCategoryAxis::setMin(const QString &minCategory)

Makes minCategory the first category shown.

void QBarCategoryAxis::setRange(const QString &minCategory, const QString &maxCategory)

Shows the categories from minCategory to maxCategory. Nothing changes if either is not on the axis or maxCategory comes before minCategory.

[override, protected] void QBarCategoryAxis::setRangeFromVariant(const QVariant &min, const QVariant &max)

Reimplements QAbstractAxis::setRangeFromVariant().

Shows the categories named by min and max, converted to strings. An invalid variant leaves that end as it is.

[override] AxisType QBarCategoryAxis::type() const

Reimplements QAbstractAxis::type().

Returns QAbstractAxis::AxisTypeBarCategory.