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QValueAxis Class

The QValueAxis class is used for manipulating chart's axis. More...

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

QCategoryAxis

Properties

Public Functions

QValueAxis(QObject *parent = Q_NULLPTR)
~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 setTickCount(int count)
int tickCount() const

Reimplemented Public Functions

virtual AxisType type() const

Public Slots

void applyNiceNumbers()
  • 1 public slot inherited from QObject

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 tickCountChanged(int tickCount)

Additional Inherited Members

  • 11 static public members inherited from QObject
  • 9 protected functions inherited from QObject

Detailed Description

The QValueAxis class is used for manipulating chart's axis.

ValueAxis can be setup to show axis line with tick marks, grid lines and shades. Values of axis are drawn to position of ticks.

Example code on how to use QValueAxis.

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);

Property Documentation

labelFormat : QString

Defines the label format of the axis. Supported specifiers are: d, i, o, x, X, f, F, e, E, g, G, and c. See QString::sprintf() for additional details.

If the QChart::localizeNumbers is true, the supported specifiers are limited to: d, e, E, f, g, G, and i. Also, only the precision modifier is supported. The rest of the formatting comes from the default QLocale of the application.

Access functions:

QString labelFormat() const
void setLabelFormat(const QString &format)

Notifier signal:

void labelFormatChanged(const QString &format)

max : qreal

Defines the maximum value on the axis. When setting this property the min is adjusted if necessary, to ensure that the range remains valid.

Access functions:

qreal max() const
void setMax(qreal max)

Notifier signal:

void maxChanged(qreal max)

min : qreal

Defines the minimum value on the axis. When setting this property the max is adjusted if necessary, to ensure that the range remains valid.

Access functions:

qreal min() const
void setMin(qreal min)

Notifier signal:

void minChanged(qreal min)

minorTickCount : int

Defines the number of minor ticks on the axis. This indicates how many grid lines are drawn between major ticks on the chart. Labels are not drawn for minor ticks. The default value is 0.

Access functions:

int minorTickCount() const
void setMinorTickCount(int count)

Notifier signal:

void minorTickCountChanged(int minorTickCount)

tickCount : int

Defines the number of ticks on the axis. This indicates how many grid lines are drawn on the chart. The default value is 5, and it can not be below 2.

Access functions:

int tickCount() const
void setTickCount(int count)

Notifier signal:

void tickCountChanged(int tickCount)

Member Function Documentation

QValueAxis::QValueAxis(QObject *parent = Q_NULLPTR)

Constructs an axis object which is a child of parent.

QValueAxis::~QValueAxis()

Destroys the object

[slot] void QValueAxis::applyNiceNumbers()

This method modifies range and number of ticks on the axis to look "nice". Algorithm considers numbers that can be expressed as form of 1*10^n, 2* 10^n or 5*10^n as a nice numbers. These numbers are used for spacing the ticks. This method will modify the current range and number of ticks.

See also setRange() and setTickCount().

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

Axis emits signal when format of axis labels has changed.

Note: Notifier signal for property labelFormat.

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

Axis emits signal when max of axis has changed.

Note: Notifier signal for property max.

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

Axis emits signal when min of axis has changed.

Note: Notifier signal for property min.

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

Axis emits signal when minorTickCount of axis has changed.

Note: Notifier signal for property minorTickCount.

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

Axis emits signal when min or max of axis has changed.

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

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

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

Axis emits signal when tickCount of axis has changed.

Note: Notifier signal for property tickCount.

[virtual] AxisType QValueAxis::type() const

Reimplemented from QAbstractAxis::type().

Returns the type of the axis

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