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

# CategoryAxis QML Type

CategoryAxis places named ranges on the axis. More...

Import Statement: | import QtCharts 2.8
Instantiates: | QCategoryAxis
Inherits: | AbstractAxis

- List of all members, including inherited members

## Properties

- categoriesLabels : StringList
- count : int
- labelsPosition : enumeration
- startValue : int

## Methods

- append(string label, real endValue)
- remove(string label)
- replace(string oldLabel, string newLabel)

## Detailed Description

This type can be used to explain the underlying data by adding labeled categories. The widths of the category ranges can be specified freely.

For example:

     ChartView {
         title: "Numerical Data for Dummies"
         anchors.fill: parent
         legend.visible: false
         antialiasing: true

         LineSeries {
             axisY: CategoryAxis {
                 min: 0
                 max: 30
                 CategoryRange {
                     label: "critical"
                     endValue: 2
                 }
                 CategoryRange {
                     label: "low"
                     endValue: 4
                 }
                 CategoryRange {
                     label: "normal"
                     endValue: 7
                 }
                 CategoryRange {
                     label: "high"
                     endValue: 15
                 }
                 CategoryRange {
                     label: "extremely high"
                     endValue: 30
                 }
             }

             XYPoint { x: 0; y: 4.3 }
             XYPoint { x: 1; y: 4.1 }
             XYPoint { x: 2; y: 4.7 }
             XYPoint { x: 3; y: 3.9 }
             XYPoint { x: 4; y: 5.2 }
         }
     }

## Property Documentation

categoriesLabels : StringList `[read-only]`

The category labels as a list of strings.

count : int `[read-only]`

The number of categories.

labelsPosition : enumeration

The position of the category labels. The labels in the beginning and in the end of the axes may overlap other axes' labels when positioned on value.

Constant | Description
--- | ---
`CategoryAxis.AxisLabelsPositionCenter` | Labels are centered to category.
`CategoryAxis.AxisLabelsPositionOnValue` | Labels are positioned to the high end limit of the category.

startValue : int

The low end of the first category on the axis.

## Method Documentation

append(string label, real endValue)

Appends a new category to the axis with the label label. A category label has to be unique. endValue specifies the high end limit of the category. It has to be greater than the high end limit of the previous category. Otherwise the method returns without adding a new category.

remove(string label)

Removes a category specified by the label label from the axis.

replace(string oldLabel, string newLabel)

Replaces an existing category label specified by oldLabel with newLabel. If the old label does not exist, the method returns without making any changes.