QBarSeries Class

The QBarSeries class presents data in bar graphs. More...

Header: #include <QBarSeries>
CMake: find_package(Qt6 REQUIRED COMPONENTS Graphs)
target_link_libraries(mytarget PRIVATE Qt6::Graphs)
qmake: QT += graphs
Instantiated By: BarSeries
Inherits: QAbstractSeries

Public Types

enum class BarsType { Groups, Stacked, StackedPercent }
enum class LabelsPosition { Center, InsideEnd, InsideBase, OutsideEnd }

Properties

Public Functions

QBarSeries(QObject *parent = nullptr)
bool append(QBarSet *set)
bool append(const QList<QBarSet *> &sets)
QQmlComponent *barComponent() const
QList<QBarSet *> barSets() const
qreal barWidth() const
QBarSeries::BarsType barsType() const
QList<QColor> borderColors() const
void clear()
qsizetype count() const
int find(QBarSet *set) const
bool insert(qsizetype index, QBarSet *set)
bool isLabelsVisible() const
qreal labelsAngle() const
QString labelsFormat() const
qreal labelsMargin() const
QBarSeries::LabelsPosition labelsPosition() const
int labelsPrecision() const
bool remove(QBarSet *set)
QList<QColor> seriesColors() const
void setBarComponent(QQmlComponent *newBarComponent)
void setBarWidth(qreal width)
void setBarsType(QBarSeries::BarsType type)
void setBorderColors(const QList<QColor> &newBorderColors)
void setLabelsAngle(qreal angle)
void setLabelsFormat(const QString &format)
void setLabelsMargin(qreal margin)
void setLabelsPosition(QBarSeries::LabelsPosition position)
void setLabelsPrecision(int precision)
void setLabelsVisible(bool visible = true)
void setSeriesColors(const QList<QColor> &newSeriesColors)
bool take(QBarSet *set)

Reimplemented Public Functions

virtual QAbstractSeries::SeriesType type() const override

Signals

void barComponentChanged()
void barSetsChanged()
void barWidthChanged()
void barsTypeChanged(QBarSeries::BarsType type)
void barsetsAdded(const QList<QBarSet *> &sets)
void barsetsRemoved(const QList<QBarSet *> &sets)
void borderColorsChanged()
void clicked(qsizetype index, QBarSet *barset)
void countChanged()
void doubleClicked(qsizetype index, QBarSet *barset)
void hovered(bool status, qsizetype index, QBarSet *barset)
void labelsAngleChanged(qreal angle)
void labelsFormatChanged(const QString &format)
void labelsMarginChanged(qreal margin)
void labelsPositionChanged(QBarSeries::LabelsPosition position)
void labelsPrecisionChanged(int precision)
void labelsVisibleChanged(bool visible)
void pressed(qsizetype index, QBarSet *barset)
void released(qsizetype index, QBarSet *barset)
void restructuredBars()
void seriesColorsChanged()
void setValueAdded(qsizetype index, qsizetype count, QBarSet *barset)
void setValueChanged(qsizetype index, QBarSet *barset)
void setValueRemoved(qsizetype index, qsizetype count, QBarSet *barset)
void updatedBars()
void updatedLayout()

Detailed Description

This class draws data by default as a series of bars grouped by category, with one bar per category from each bar set added to the series. It also supports horizontal bars and grouping bars as stacked.

A bar series needs the GraphsView x-axis to be set to a BarCategoryAxis and the y-axis set to ValueAxis.

See also QBarSet and QAbstractSeries.

Member Type Documentation

enum class QBarSeries::BarsType

This enum value describes the type of the bar series:

ConstantValueDescription
QBarSeries::BarsType::Groups0Bar sets are grouped by category.
QBarSeries::BarsType::Stacked1Bar sets are stacked after each other by category.
QBarSeries::BarsType::StackedPercent2Bar sets are stacked after each other by category. The segment size corresponds to the percentage of the segment value compared with the total value of all segments in the stack.

enum class QBarSeries::LabelsPosition

This enum value describes the position of the data value labels:

ConstantValueDescription
QBarSeries::LabelsPosition::Center0Label is located in the center of the bar.
QBarSeries::LabelsPosition::InsideEnd1Label is located inside the bar at the top.
QBarSeries::LabelsPosition::InsideBase2Label is located inside the bar at the bottom.
QBarSeries::LabelsPosition::OutsideEnd3Label is located outside the bar at the top.

Property Documentation

barComponent : QQmlComponent*

This property holds a custom QML component used for visualizing each of the bars. Instance of this component is created for each of the bar. When this is not defined, a default rectangle visualization for bars is used.

The dynamic properties available for this component are:

TypeNameDescription
QColorbarColorThe fill color of the bar. This value comes either from the QGraphsTheme or from QBarSet::color if the QBarSet overrides the color.
QColorbarBorderColorThe border color of the bar. This value comes either from the QGraphsTheme or from QBarSet::borderColor if the QBarSet overrides the color.
qrealbarBorderWidthThe width of the bar border. This value comes either from the QGraphsTheme or from QBarSet::borderWidth if the QBarSet overrides the width.
qrealbarValueThe value of the bar. This value comes from the QBarSet::values.
QStringbarLabelThe label of the bar. This value comes from the QBarSet::label.
boolbarSelectedThis value is true when the bar is selected, meaning that the bar index is in QBarSet::selectedBars.

To use any of these, add property with the defined name into your custom component. For example "property color barColor" and "property real barValue".

Access functions:

QQmlComponent *barComponent() const
void setBarComponent(QQmlComponent *newBarComponent)

Notifier signal:

void barComponentChanged()

[read-only] barSets : QList<QBarSet *> const

This property holds a list of sets added to the series.

Access functions:

QList<QBarSet *> barSets() const

Notifier signal:

void barSetsChanged()

barWidth : qreal

This property holds the width of the bars of the series.

The unit of width is the unit of the x-axis. The minimum width for bars is zero, and negative values are treated as zero. Setting the width to zero means that the width of the bar on the screen is one pixel regardless of the scale of the x-axis. Bars wider than zero are scaled using the x-axis scale.

By default, the barWidth is 0.5 (bars will take 50% of the available width). The valid values range from 0.0 (0%) to 1.0 (100%).

Note: When used with QBarSeries, this value specifies the width of a group of bars instead of that of a single bar.

Access functions:

qreal barWidth() const
void setBarWidth(qreal width)

Notifier signal:

See also QBarSeries.

barsType : BarsType

This property holds the type of the bar series.

Access functions:

QBarSeries::BarsType barsType() const
void setBarsType(QBarSeries::BarsType type)

Notifier signal:

void barsTypeChanged(QBarSeries::BarsType type)

borderColors : QList<QColor>

This property holds the list of border colors to be used for all the objects in the series.

If there are more series than colors, the color list wraps and starts again with the first color in the list. If this is not set (default), colors from the QGraphsTheme::borderColors will be used.

Access functions:

QList<QColor> borderColors() const
void setBorderColors(const QList<QColor> &newBorderColors)

Notifier signal:

void borderColorsChanged()

[read-only] count : const qsizetype

This property holds the number of bar sets in a bar series.

Access functions:

qsizetype count() const[see note below]

Note: This function can be invoked via the meta-object system and from QML. See Q_INVOKABLE.

Notifier signal:

void countChanged()

labelsAngle : qreal

This property holds the angle of the value labels in degrees.

Access functions:

qreal labelsAngle() const
void setLabelsAngle(qreal angle)

Notifier signal:

void labelsAngleChanged(qreal angle)

labelsFormat : QString

This property holds the format used for showing labels in a bar series.

QBarSeries supports the following format tag:

@valueThe value of the bar

For example, the following usage of the format tags would produce labels that show the value followed by the unit (u):

series->setLabelsFormat("@value u");

By default, the labels show the value of the bar. For the percent bar series, % is added after the value. The labels are shown on the plot area, if the bars are close to each other, the labels may overlap.

Access functions:

QString labelsFormat() const
void setLabelsFormat(const QString &format)

Notifier signal:

void labelsFormatChanged(const QString &format)

See also labelsVisible, labelsPosition, and labelsPrecision.

labelsMargin : qreal

This property holds the margin of the value labels in pixels.

This margin from side is used when labelsPosition is set to something else than LabelsPosition.Center. The default value is 0.

Access functions:

qreal labelsMargin() const
void setLabelsMargin(qreal margin)

Notifier signal:

void labelsMarginChanged(qreal margin)

labelsPosition : LabelsPosition

This property holds the position of value labels.

Access functions:

QBarSeries::LabelsPosition labelsPosition() const
void setLabelsPosition(QBarSeries::LabelsPosition position)

Notifier signal:

void labelsPositionChanged(QBarSeries::LabelsPosition position)

See also labelsVisible and labelsFormat.

labelsPrecision : int

This property holds the maximum amount of significant digits shown in value labels.

Default value is 6.

Access functions:

int labelsPrecision() const
void setLabelsPrecision(int precision)

Notifier signal:

void labelsPrecisionChanged(int precision)

labelsVisible : bool

This property holds the visibility of the labels in a bar series. The default label visibility is false.

Access functions:

bool isLabelsVisible() const
void setLabelsVisible(bool visible = true)

Notifier signal:

void labelsVisibleChanged(bool visible)

seriesColors : QList<QColor>

This property holds the list of base colors to be used for all the objects in the series.

If there are more series than colors, the color list wraps and starts again with the first color in the list. If this is not set (default), colors from the QGraphsTheme::seriesColors will be used.

Access functions:

QList<QColor> seriesColors() const
void setSeriesColors(const QList<QColor> &newSeriesColors)

Notifier signal:

void seriesColorsChanged()

Member Function Documentation

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

Constructs an empty bar series that is a QObject and a child of parent.

[invokable] bool QBarSeries::append(QBarSet *set)

Adds a set of bars specified by set to the bar series and takes ownership of it. If the set is null or it already belongs to the series, it will not be appended. Returns true if appending succeeded.

Note: This function can be invoked via the meta-object system and from QML. See Q_INVOKABLE.

[invokable] bool QBarSeries::append(const QList<QBarSet *> &sets)

Adds a list of bar sets specified by sets to a bar series and takes ownership of the sets. Returns true if all sets were appended successfully. If any of the sets is null or was previously appended to the series, nothing is appended and this function returns false. If any of the sets appears in the list more than once, nothing is appended and this function returns false.

Note: This function can be invoked via the meta-object system and from QML. See Q_INVOKABLE.

QList<QBarSet *> QBarSeries::barSets() const

Returns a list of bar sets in a bar series. Keeps the ownership of the bar sets.

Note: Getter function for property barSets.

qreal QBarSeries::barWidth() const

Returns the width of the bars of the series.

Note: Getter function for property barWidth.

See also setBarWidth().

[signal] void QBarSeries::barWidthChanged()

This signal is emitted when the bar width changes.

Note: Notifier signal for property barWidth.

[signal] void QBarSeries::barsetsAdded(const QList<QBarSet *> &sets)

This signal is emitted when the bar sets specified by sets are added to the series.

See also append() and insert().

[signal] void QBarSeries::barsetsRemoved(const QList<QBarSet *> &sets)

This signal is emitted when the bar sets specified by sets are removed from the series.

See also remove().

[invokable] void QBarSeries::clear()

Removes all bar sets from the series and permanently deletes them.

Note: This function can be invoked via the meta-object system and from QML. See Q_INVOKABLE.

[signal] void QBarSeries::clicked(qsizetype index, QBarSet *barset)

This signal is emitted when the user clicks the bar specified by index in the bar set specified by barset.

[invokable] qsizetype QBarSeries::count() const

Returns the number of bar sets in a bar series.

Note: This function can be invoked via the meta-object system and from QML. See Q_INVOKABLE.

Note: Getter function for property count.

[signal] void QBarSeries::countChanged()

This signal is emitted when the number of bar sets is changed, for example by append() or remove().

Note: Notifier signal for property count.

[signal] void QBarSeries::doubleClicked(qsizetype index, QBarSet *barset)

This signal is emitted when the user double-clicks the bar specified by index in the bar set specified by barset.

[invokable] int QBarSeries::find(barset.html" translate="no">QBarSet *set) const

Returns the index of the first BarSet found as defined by set. Returns -1 if no BarSet was found.

Note: This function can be invoked via the meta-object system and from QML. See Q_INVOKABLE.

[signal] void QBarSeries::hovered(bool status, qsizetype index, QBarSet *barset)

This signal is emitted when a mouse is hovered over the bar specified by index in the bar set specified by barset. When the mouse moves over the bar, status turns true, and when the mouse moves away again, it turns false.

[invokable] bool QBarSeries::insert(qsizetype index, QBarSet *set)

Inserts a bar set specified by set to a series at the position specified by index and takes ownership of the set. If the set is null or already belongs to the series, it will not be appended. Returns true if inserting succeeds.

Note: This function can be invoked via the meta-object system and from QML. See Q_INVOKABLE.

bool QBarSeries::isLabelsVisible() const

Returns the visibility of labels.

Note: Getter function for property labelsVisible.

[signal] void QBarSeries::labelsAngleChanged(qreal angle)

This signal is emitted when the angle of the value labels changes.

Note: Notifier signal for property labelsAngle.

[signal] void QBarSeries::labelsFormatChanged(const QString &format)

This signal is emitted when the format of data value labels changes.

Note: Notifier signal for property labelsFormat.

[signal] void QBarSeries::labelsMarginChanged(qreal margin)

This signal is emitted when the margin of the value labels changes.

Note: Notifier signal for property labelsMargin.

[signal] void QBarSeries::labelsPositionChanged(QBarSeries::LabelsPosition position)

This signal is emitted when the position of value labels changes.

Note: Notifier signal for property labelsPosition.

[signal] void QBarSeries::labelsPrecisionChanged(int precision)

This signal is emitted when the precision of the value labels changes.

Note: Notifier signal for property labelsPrecision.

[signal] void QBarSeries::labelsVisibleChanged(bool visible)

This signal is emitted when the labels' visibility changes to visible.

Note: Notifier signal for property labelsVisible.

See also isLabelsVisible() and setLabelsVisible().

[signal] void QBarSeries::pressed(qsizetype index, QBarSet *barset)

This signal is emitted when the user clicks the bar specified by index in the bar set specified by barset and holds down the mouse button.

[signal] void QBarSeries::released(qsizetype index, QBarSet *barset)

This signal is emitted when the user releases the mouse press on the bar specified by index in the bar set specified by barset.

[invokable] bool QBarSeries::remove(barset.html" translate="no">QBarSet *set)

Removes the bar set specified by set from the series and permanently deletes it if the removal succeeds. Returns true if the set was removed.

Note: This function can be invoked via the meta-object system and from QML. See Q_INVOKABLE.

[signal] void QBarSeries::restructuredBars()

This signal is emitted when the bars are restructured.

void QBarSeries::setBarWidth(qreal width)

Sets the width of the bars of the series to width.

Note: Setter function for property barWidth.

See also barWidth().

void QBarSeries::setLabelsVisible(bool visible = true)

Sets the visibility of labels in a bar series to visible.

Note: Setter function for property labelsVisible.

See also isLabelsVisible().

[signal] void QBarSeries::setValueAdded(qsizetype index, qsizetype count, QBarSet *barset)

This signal is emitted when a barset's value is changed. index is the index of the barset in the series. The number of the added values is indicated count. The barset is a pointer to the changed set.

[signal] void QBarSeries::setValueChanged(qsizetype index, QBarSet *barset)

This signal is emitted when a barset's value is changed. index is the index of the barset in the series. The barset is a pointer to the changed set.

[signal] void QBarSeries::setValueRemoved(qsizetype index, qsizetype count, QBarSet *barset)

This signal is emitted when a barset's value is changed. index is the index of the barset in the series. The number of the removed values is indicated count. The barset is a pointer to the changed set.

[invokable] bool QBarSeries::take(QBarSet *set)

Takes a single set from the series. Does not delete the bar set object.

Note: The series remains the barset's parent object. You must set the parent object to take full ownership.

Returns true if the take operation succeeds.

Note: This function can be invoked via the meta-object system and from QML. See Q_INVOKABLE.

[override virtual] QAbstractSeries::SeriesType QBarSeries::type() const

Reimplements an access function for property: QAbstractSeries::type.

Returns the bar series.

[signal] void QBarSeries::updatedBars()

This signal is emitted when bars are updated.

[signal] void QBarSeries::updatedLayout()

This signal is emitted when the layout is updated.

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