Qt 5.9 | Qt Charts | C++ Classes | QChart

Qt 5.9.9 Reference Documentation

# QChart Class

The QChart class manages the graphical representation of the chart's series, legends, and axes. More...

Header: | #include <QChart>
Inherited By: | QPolarChart

- List of all members, including inherited members

## Public Types

enum | AnimationOption { NoAnimation, GridAxisAnimations, SeriesAnimations, AllAnimations }
flags | AnimationOptions
enum | ChartTheme { ChartThemeLight, ChartThemeBlueCerulean, ChartThemeDark, ChartThemeBrownSand, ..., ChartThemeQt }
enum | ChartType { ChartTypeUndefined, ChartTypeCartesian, ChartTypePolar }

## Properties

animationDuration : int animationEasingCurve : QEasingCurve animationOptions : QChart::AnimationOptions backgroundRoundness : qreal backgroundVisible : bool chartType : const QChart::ChartType dropShadowEnabled : bool | locale : QLocale localizeNumbers : bool margins : QMargins plotArea : const QRectF plotAreaBackgroundVisible : bool theme : QChart::ChartTheme title : QString

## Public Functions

| QChart(QGraphicsItem *parent = Q_NULLPTR, Qt::WindowFlags wFlags = Qt::WindowFlags())
| ~QChart()
void | addAxis(QAbstractAxis *axis, Qt::Alignment alignment)
void | addSeries(QAbstractSeries *series)
int | animationDuration() const
QEasingCurve | animationEasingCurve() const
AnimationOptions | animationOptions() const
QList<QAbstractAxis *> | axes(Qt::Orientations orientation = Qt::Horizontal | Qt::Vertical, QAbstractSeries *series = Q_NULLPTR) const
QAbstractAxis * | axisX(QAbstractSeries *series = Q_NULLPTR) const
QAbstractAxis * | axisY(QAbstractSeries *series = Q_NULLPTR) const
QBrush | backgroundBrush() const
QPen | backgroundPen() const
qreal | backgroundRoundness() const
ChartType | chartType() const
void | createDefaultAxes()
bool | isBackgroundVisible() const
bool | isDropShadowEnabled() const
bool | isPlotAreaBackgroundVisible() const
bool | isZoomed()
QLegend * | legend() const
QLocale | locale() const
bool | localizeNumbers() const
QPointF | mapToPosition(const QPointF &value, QAbstractSeries *series = Q_NULLPTR)
QPointF | mapToValue(const QPointF &position, QAbstractSeries *series = Q_NULLPTR)
QMargins | margins() const
QRectF | plotArea() const
QBrush | plotAreaBackgroundBrush() const
QPen | plotAreaBackgroundPen() const
void | removeAllSeries()
void | removeAxis(QAbstractAxis *axis)
void | removeSeries(QAbstractSeries *series)
void | scroll(qreal dx, qreal dy)
QList<QAbstractSeries *> | series() const
void | setAnimationDuration(int msecs)
void | setAnimationEasingCurve(const QEasingCurve &curve)
void | setAnimationOptions(AnimationOptions options)
void | setAxisX(QAbstractAxis *axis, QAbstractSeries *series = Q_NULLPTR)
void | setAxisY(QAbstractAxis *axis, QAbstractSeries *series = Q_NULLPTR)
void | setBackgroundBrush(const QBrush &brush)
void | setBackgroundPen(const QPen &pen)
void | setBackgroundRoundness(qreal diameter)
void | setBackgroundVisible(bool visible = true)
void | setDropShadowEnabled(bool enabled = true)
void | setLocale(const QLocale &locale)
void | setLocalizeNumbers(bool localize)
void | setMargins(const QMargins &margins)
void | setPlotAreaBackgroundBrush(const QBrush &brush)
void | setPlotAreaBackgroundPen(const QPen &pen)
void | setPlotAreaBackgroundVisible(bool visible = true)
void | setTheme(QChart::ChartTheme theme)
void | setTitle(const QString &title)
void | setTitleBrush(const QBrush &brush)
void | setTitleFont(const QFont &font)
QChart::ChartTheme | theme() const
QString | title() const
QBrush | titleBrush() const
QFont | titleFont() const
void | zoom(qreal factor)
void | zoomIn()
void | zoomIn(const QRectF &rect)
void | zoomOut()
void | zoomReset()

## Signals

void | plotAreaChanged(const QRectF &plotArea)

## Detailed Description

The QChart class manages the graphical representation of the chart's series, legends, and axes.

QChart is a QGraphicsWidget that you can show in a QGraphicsScene. It manages the graphical representation of different types of series and other chart related objects like legend and axes. To simply show a chart in a layout, the convenience class QChartView can be used instead of QChart. In addition, line, spline, area, and scatter series can be presented as polar charts by using the QPolarChart class.

See also QChartView and QPolarChart.

## Member Type Documentation

### enum QChart::AnimationOption
flags QChart::AnimationOptions

This enum describes the animations enabled in the chart.

Constant | Value | Description
--- | --- | ---
`QChart::NoAnimation` | `0x0` | Animation is disabled in the chart. This is the default value.
`QChart::GridAxisAnimations` | `0x1` | Grid axis animation is enabled in the chart.
`QChart::SeriesAnimations` | `0x2` | Series animation is enabled in the chart.
`QChart::AllAnimations` | `0x3` | All animation types are enabled in the chart.

The AnimationOptions type is a typedef for QFlags<AnimationOption>. It stores an OR combination of AnimationOption values.

### enum QChart::ChartTheme

This enum describes the theme used by the chart.

A theme is a built-in collection of UI style related settings applied to all the visual elements of a chart, such as colors, pens, brushes, and fonts of series, as well as axes, title, and legend. The Chart themes example illustrates how to use themes.

Note: Changing the theme will overwrite all customizations previously applied to the series.

Constant | Value | Description
--- | --- | ---
`QChart::ChartThemeLight` | `0` | The light theme, which is the default theme.
`QChart::ChartThemeBlueCerulean` | `1` | The cerulean blue theme.
`QChart::ChartThemeDark` | `2` | The dark theme.
`QChart::ChartThemeBrownSand` | `3` | The sand brown theme.
`QChart::ChartThemeBlueNcs` | `4` | The natural color system (NCS) blue theme.
`QChart::ChartThemeHighContrast` | `5` | The high contrast theme.
`QChart::ChartThemeBlueIcy` | `6` | The icy blue theme.
`QChart::ChartThemeQt` | `7` | The Qt theme.

### enum QChart::ChartType

This enum describes the chart type.

Constant | Value | Description
--- | --- | ---
`QChart::ChartTypeUndefined` | `0` | The chart type is not defined.
`QChart::ChartTypeCartesian` | `1` | A cartesian chart.
`QChart::ChartTypePolar` | `2` | A polar chart.

## Property Documentation

### animationDuration : int

This property holds the duration of the animation for the chart.

Access functions:

int | animationDuration() const
void | setAnimationDuration(int msecs)

### animationEasingCurve : QEasingCurve

This property holds the easing curve of the animation for the chart.

Access functions:

QEasingCurve | animationEasingCurve() const
void | setAnimationEasingCurve(const QEasingCurve &curve)

### animationOptions : QChart::AnimationOptions

This property holds the animation options for the chart.

Animations are enabled or disabled based on this setting.

Access functions:

AnimationOptions | animationOptions() const
void | setAnimationOptions(AnimationOptions options)

### backgroundRoundness : qreal

This property holds the diameter of the rounding circle at the corners of the chart background.

Access functions:

qreal | backgroundRoundness() const
void | setBackgroundRoundness(qreal diameter)

### backgroundVisible : bool

This property holds whether the chart background is visible.

Access functions:

bool | isBackgroundVisible() const
void | setBackgroundVisible(bool visible = true)

See also setBackgroundBrush(), setBackgroundPen(), and plotAreaBackgroundVisible.

### chartType : const QChart::ChartType

This property holds whether the chart is a cartesian chart or a polar chart.

This property is set internally and it is read only.

Access functions:

ChartType | chartType() const

See also QPolarChart.

### dropShadowEnabled : bool

This property holds whether the background drop shadow effect is enabled.

If set to `true`, the background drop shadow effect is enabled. If set to `false`, it is disabled.

Note: The drop shadow effect depends on the theme, and therefore the setting may change if the theme is changed.

Access functions:

bool | isDropShadowEnabled() const
void | setDropShadowEnabled(bool enabled = true)

### locale : QLocale

This property holds the locale used to format various chart labels.

Labels are localized only when localizeNumbers is `true`, except for QDateTimeAxis labels, which always use the QLocale set with this property.

Defaults to the application default locale at the time when the chart is constructed.

Access functions:

QLocale | locale() const
void | setLocale(const QLocale &locale)

See also localizeNumbers.

### localizeNumbers : bool

This property holds whether numbers are localized.

When `true`, all generated numbers appearing in various series and axis labels will be localized using the QLocale set with the locale property. When `false`, the C locale is always used. Defaults to `false`.

Note: This property does not affect QDateTimeAxis labels, which always use the QLocale set with the locale property.

Access functions:

bool | localizeNumbers() const
void | setLocalizeNumbers(bool localize)

See also locale.

### margins : QMargins

This property holds the minimum margins allowed between the edge of the chart rectangle and the plot area.

The margins are used for drawing the title, axes, and legend.

Access functions:

QMargins | margins() const
void | setMargins(const QMargins &margins)

### plotArea : const QRectF

This property holds the rectangle within which the chart is drawn.

The plot area does not include the area defined by margins.

Access functions:

QRectF | plotArea() const

Notifier signal:

void | plotAreaChanged(const QRectF &plotArea)

### plotAreaBackgroundVisible : bool

This property holds whether the chart plot area background is visible.

Note: By default, the plot area background is invisible and the plot area uses the general chart background.

Access functions:

bool | isPlotAreaBackgroundVisible() const
void | setPlotAreaBackgroundVisible(bool visible = true)

See also setPlotAreaBackgroundBrush(), setPlotAreaBackgroundPen(), and backgroundVisible.

### theme : QChart::ChartTheme

This property holds the theme used for the chart.

Access functions:

QChart::ChartTheme | theme() const
void | setTheme(QChart::ChartTheme theme)

### title : QString

This property holds the title of the chart.

The title is shown as a headline on top of the chart. Chart titles support HTML formatting.

Access functions:

QString | title() const
void | setTitle(const QString &title)

## Member Function Documentation

### QChart::QChart(QGraphicsItem *parent = Q_NULLPTR, Qt::WindowFlags wFlags = Qt::WindowFlags())

Constructs a chart object that is a child of parent. The properties specified by wFlags are passed to the QGraphicsWidget constructor.

### QChart::~QChart()

Deletes the chart object and its children, such as the series and axis objects added to it.

### void QChart::addAxis(QAbstractAxis *axis, Qt::Alignment alignment)

Adds the axis axis to the chart aligned as specified by alignment. The chart takes the ownership of the axis.

See also removeAxis(), createDefaultAxes(), and QAbstractSeries::attachAxis().

### void QChart::addSeries(QAbstractSeries *series)

Adds the series series to the chart and takes ownership of it.

Note: A newly added series is not attached to any axes by default, not even those that might have been created for the chart using createDefaultAxes() before the series was added to the chart. If no axes are attached to the newly added series before the chart is shown, the series will get drawn as if it had axes with ranges that exactly fit the series to the plot area of the chart. This can be confusing if the same chart also displays other series that have properly attached axes, so always make sure you either call createDefaultAxes() after a series has been added or explicitly attach axes for the series.

See also removeSeries(), removeAllSeries(), createDefaultAxes(), and QAbstractSeries::attachAxis().

### QList<QAbstractAxis *> QChart::axes(Qt::Orientations orientation = Qt::Horizontal | Qt::Vertical, QAbstractSeries *series = Q_NULLPTR) const

Returns the axes attached to the series series with the orientation specified by orientation. If no series is specified, all axes added to the chart with the specified orientation are returned.

See also addAxis() and createDefaultAxes().

### QAbstractAxis *QChart::axisX(QAbstractSeries *series = Q_NULLPTR) const

Returns a pointer to the horizontal axis attached to the specified series. If no series is specified, the first horizontal axis added to the chart is returned.

See also setAxisX(), addAxis(), and QAbstractSeries::attachAxis().

### QAbstractAxis *QChart::axisY(QAbstractSeries *series = Q_NULLPTR) const

Returns a pointer to the vertical axis attached to the specified series. If no series is specified, the first vertical axis added to the chart is returned.

See also setAxisY(), addAxis(), and QAbstractSeries::attachAxis().

### QBrush QChart::backgroundBrush() const

Gets the brush that is used for painting the background of the chart area.

See also setBackgroundBrush().

### QPen QChart::backgroundPen() const

Gets the pen that is used for painting the background of the chart area.

See also setBackgroundPen().

### void QChart::createDefaultAxes()

Creates axes for the chart based on the series that have already been added to the chart. Any axes previously added to the chart will be deleted.

Note: This function has to be called after all series have been added to the chart. The axes created by this function will NOT get automatically attached to any series added to the chart after this function has been called. A series with no axes attached will by default scale to utilize the entire plot area of the chart, which can be confusing if there are other series with properly attached axes also present.

Series type | X-axis | Y-axis
--- | --- | ---
QXYSeries | QValueAxis | QValueAxis
QBarSeries | QBarCategoryAxis | QValueAxis
QPieSeries | None | None

If there are several QXYSeries derived series added to the chart and no series of other types have been added, then only one pair of axes is created. If there are several series of different types added to the chart, then each series gets its own axes pair.

The axes specific to the series can be later obtained from the chart by providing the series as the parameter for the axes() function call. QPieSeries does not create any axes.

See also axisX(), axisY(), axes(), setAxisX(), setAxisY(), and QAbstractSeries::attachAxis().

### bool QChart::isZoomed()

Returns `true` if any series has a zoomed domain.

### QLegend *QChart::legend() const

Returns the legend object of the chart. Ownership stays with the chart.

### QPointF QChart::mapToPosition(const QPointF &value, QAbstractSeries *series = Q_NULLPTR)

Returns the position on the chart that corresponds to the value value in the series specified by series.

### QPointF QChart::mapToValue(const QPointF &position, QAbstractSeries *series = Q_NULLPTR)

Returns the value in the series specified by series at the position specified by position in a chart.

### QBrush QChart::plotAreaBackgroundBrush() const

Returns the brush used to fill the background of the plot area of the chart.

See also plotArea(), plotAreaBackgroundVisible, plotAreaBackgroundPen(), and setPlotAreaBackgroundBrush().

### QPen QChart::plotAreaBackgroundPen() const

Returns the pen used to draw the background of the plot area of the chart.

See also plotArea(), plotAreaBackgroundVisible, plotAreaBackgroundBrush(), and setPlotAreaBackgroundPen().

### void QChart::removeAllSeries()

Removes and deletes all series objects that have been added to the chart.

See also addSeries() and removeSeries().

### void QChart::removeAxis(QAbstractAxis *axis)

Removes the axis axis from the chart. The chart releases the ownership of the specified axis object.

See also addAxis(), createDefaultAxes(), and QAbstractSeries::detachAxis().

### void QChart::removeSeries(QAbstractSeries *series)

Removes the series series from the chart. The chart releases the ownership of the specified series object.

See also addSeries() and removeAllSeries().

### void QChart::scroll(qreal dx, qreal dy)

Scrolls the visible area of the chart by the distance specified by dx and dy.

For polar charts, dx indicates the angle along the angular axis instead of distance.

### QList<QAbstractSeries *> QChart::series() const

Returns all series that are added to the chart.

See also addSeries(), removeSeries(), and removeAllSeries().

### void QChart::setAxisX(QAbstractAxis *axis, QAbstractSeries *series = Q_NULLPTR)

Adds the axis axis to the chart and attaches it to the series series as a bottom-aligned horizontal axis. The chart takes ownership of both the axis and the series. Any horizontal axes previously attached to the series are deleted.

See also axisX(), axisY(), setAxisY(), createDefaultAxes(), and QAbstractSeries::attachAxis().

### void QChart::setAxisY(QAbstractAxis *axis, QAbstractSeries *series = Q_NULLPTR)

Adds the axis axis to the chart and attaches it to the series series as a left-aligned vertical axis. The chart takes ownership of both the axis and the series. Any vertical axes previously attached to the series are deleted.

See also axisX(), axisY(), setAxisX(), createDefaultAxes(), and QAbstractSeries::attachAxis().

### void QChart::setBackgroundBrush(const QBrush &brush)

Sets the brush that is used for painting the background of the chart area to brush.

See also backgroundBrush().

### void QChart::setBackgroundPen(const QPen &pen)

Sets the pen that is used for painting the background of the chart area to pen.

See also backgroundPen().

### void QChart::setPlotAreaBackgroundBrush(const QBrush &brush)

Sets the brush used to fill the background of the plot area of the chart to brush.

See also plotArea(), plotAreaBackgroundVisible, setPlotAreaBackgroundPen(), and plotAreaBackgroundBrush().

### void QChart::setPlotAreaBackgroundPen(const QPen &pen)

Sets the pen used to draw the background of the plot area of the chart to pen.

See also plotArea(), plotAreaBackgroundVisible, setPlotAreaBackgroundBrush(), and plotAreaBackgroundPen().

### void QChart::setTitleBrush(const QBrush &brush)

Sets the brush used for drawing the title text to brush.

See also titleBrush().

### void QChart::setTitleFont(const QFont &font)

Sets the font that is used for drawing the chart title to font.

See also titleFont().

### QBrush QChart::titleBrush() const

Returns the brush used for drawing the title text.

See also setTitleBrush().

### QFont QChart::titleFont() const

Gets the font that is used for drawing the chart title.

See also setTitleFont().

### void QChart::zoom(qreal factor)

Zooms into the view by the custom factor factor.

A factor over 1.0 zooms into the view and a factor between 0.0 and 1.0 zooms out of it.

### void QChart::zoomIn()

Zooms into the view by a factor of two.

### void QChart::zoomIn(const QRectF &rect)

Zooms into the view to a maximum level at which the rectangle rect is still fully visible.

Note: This is not supported for polar charts.

### void QChart::zoomOut()

Zooms out of the view by a factor of two.

### void QChart::zoomReset()

Resets the series domains to what they were before any zoom method was called.

Note: This will also reset scrolling and explicit axis range settings specified between the first zoom operation and calling this method. If no zoom operation has been performed, this method does nothing.