- Qt 6.8
- Qt Charts
- QML Types
- PieSeries
- Qt Charts | Commercial or GPLv3

# PieSeries QML Type

Presents data in pie charts. More...

Import Statement: | `import QtCharts 2.8`
Inherits: | AbstractSeries

- List of all members, including inherited members

## Properties

- count : int
- endAngle : real
- holeSize : real
- horizontalPosition : real
- size : real
- startAngle : real
- sum : real
- verticalPosition : real

## Signals

- added(list<PieSlice> slices)
- clicked(PieSlice slice)
- doubleClicked(PieSlice slice)
- hovered(PieSlice slice, bool state)
- pressed(PieSlice slice)
- released(PieSlice slice)
- removed(list<PieSlice> slices)
- sliceAdded(PieSlice slice)
- sliceRemoved(PieSlice slice)

## Methods

- PieSlice append(string label, real value)
- PieSlice at(int index)
- clear()
- PieSlice find(string label)
- bool remove(PieSlice slice)

## Detailed Description

A pie series consists of slices that are defined using the PieSlice type. The slices can have any values as the PieSeries type calculates the percentage of a slice compared with the sum of all slices in the series to determine the actual size of the slice in the chart.

Pie size and position on the chart are controlled by using relative values that range from 0.0 to 1.0. These relate to the actual chart rectangle.

By default, the pie is defined as a full pie. A partial pie can be created by setting a starting angle and angle span for the series. A full pie is 360 degrees, where 0 is at 12 a'clock.

The following QML example shows how to create a simple pie chart.

     ChartView {
         id: chart
         title: "Top-5 car brand shares in Finland"
         anchors.fill: parent
         legend.alignment: Qt.AlignBottom
         antialiasing: true

         property variant othersSlice: 0

         PieSeries {
             id: pieSeries
             PieSlice { label: "Volkswagen"; value: 13.5 }
             PieSlice { label: "Toyota"; value: 10.9 }
             PieSlice { label: "Ford"; value: 8.6 }
             PieSlice { label: "Skoda"; value: 8.2 }
             PieSlice { label: "Volvo"; value: 6.8 }
         }

         Component.onCompleted: {
             // You can also manipulate slices dynamically, like append a slice or set a slice exploded
             othersSlice = pieSeries.append("Others", 52.0);
             pieSeries.find("Volkswagen").exploded = true;
         }
     }

See also PieSlice and ChartView.

## Property Documentation

count : int

The number of slices in the series.

endAngle : real

The ending angle of the pie.

A full pie is 360 degrees, where 0 degrees is at 12 a'clock.

The default value is 360.

holeSize : real

The donut hole size.

The value is relative to the chart rectangle, so that:

- 0.0 is the minimum size (full pie drawn without a hole).
- 1.0 is the maximum size that can fit the chart (the donut has no width).

When setting this property, the size property is adjusted if necessary, to ensure that the hole size is not greater than the pie size.

The default value is 0.0.

horizontalPosition : real

The horizontal position of the pie.

The value is relative to the chart rectangle, so that:

- 0.0 is the absolute left.
- 1.0 is the absolute right.

The default value is 0.5 (center).

See also verticalPosition.

size : real

The pie size.

The value is relative to the chart rectangle, so that:

- 0.0 is the minimum size (pie not drawn).
- 1.0 is the maximum size that can fit the chart.

When setting this property, the holeSize property is adjusted if necessary, to ensure that the hole size is not greater than the pie size.

The default value is 0.7.

startAngle : real

The starting angle of the pie.

A full pie is 360 degrees, where 0 degrees is at 12 a'clock.

The default value is 0.

sum : real

The sum of all slices.

The series keeps track of the sum of all the slices it holds.

verticalPosition : real

The vertical position of the pie.

The value is relative to the chart rectangle, so that:

- 0.0 is the absolute top.
- 1.0 is the absolute bottom.

The default value is 0.5 (center).

See also horizontalPosition.

## Signal Documentation

added(list<PieSlice> slices)

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

The corresponding signal handler is `onAdded`.

Note: The corresponding handler is `onAdded`.

clicked(PieSlice slice)

This signal is emitted when the slice specified by slice is clicked.

The corresponding signal handler is `onClicked`.

Note: The corresponding handler is `onClicked`.

doubleClicked(PieSlice slice)

This signal is emitted when the slice specified by slice is double-clicked.

The corresponding signal handler is `onDoubleClicked`.

Note: The corresponding handler is `onDoubleClicked`.

hovered(PieSlice slice, bool state)

This signal is emitted when a mouse is hovered over the slice specified by slice. When the mouse moves over the slice, state turns `true`, and when the mouse moves away again, it turns `false`.

The corresponding signal handler is `onHovered`.

Note: The corresponding handler is `onHovered`.

pressed(PieSlice slice)

This signal is emitted when the user clicks the slice specified by slice and holds down the mouse button.

The corresponding signal handler is `onPressed`.

Note: The corresponding handler is `onPressed`.

released(PieSlice slice)

This signal is emitted when the user releases the mouse press on the slice specified by slice.

The corresponding signal handler is `onReleased`.

Note: The corresponding handler is `onReleased`.

removed(list<PieSlice> slices)

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

The corresponding signal handler is `onRemoved`.

Note: The corresponding handler is `onRemoved`.

sliceAdded(PieSlice slice)

This signal is emitted when the slice specified by slice is added to the series.

The corresponding signal handler is `onSliceAdded`.

Note: The corresponding handler is `onSliceAdded`.

sliceRemoved(PieSlice slice)

This signal is emitted when the slice specified by slice is removed from the series.

The corresponding signal handler is `onSliceRemoved`.

Note: The corresponding handler is `onSliceRemoved`.

## Method Documentation

PieSlice append(string label, real value)

Adds a new slice with the label label and the value value to the pie.

PieSlice at(int index)

Returns the slice at the position specified by index. Returns null if the index is not valid.

clear()

Removes all slices from the pie.

PieSlice find(string label)

Returns the first slice that has the label label. Returns null if the label is not found.

bool remove(PieSlice slice)

Removes the slice specified by slice from the pie. Returns `true` if the removal was successful, `false` otherwise.