KQuickCharts

A QtQuick module providing high-performance charts.

Introduction

The Quick Charts module provides a set of charts that can be used from QtQuick applications. They are intended to be used for both simple display of data as well as continuous display of high-volume data (often referred to as plotters). The charts use a system called distance fields for their accelerated rendering, which provides ways of using the GPU for rendering 2D shapes without loss of quality.

Usage Example

The following piece of code will render a simple line chart containing three lines:

import QtQuick
import QtQuick.Controls
 
import org.kde.quickcharts as Charts
 
ApplicationWindow {
    width: 500
    height: 500
 
    Rectangle {
        anchors.centerIn: parent
        width: 300
        height: 200
        border.width: 2
 
        Charts.LineChart {
            anchors.fill: parent
 
            colorSource: Charts.ArraySource { array: ["red", "green", "blue"] }
            nameSource: Charts.ArraySource { array: ["First", "Second", "Third"] }
 
            valueSources: [
                Charts.ArraySource { array: [1, 2, 2, 1] },
                Charts.ArraySource { array: [2, 5, 2, 5] },
                Charts.ArraySource { array: [5, 4, 3, 4] }
            ]
        }
    }
}

Concepts

There are three main concepts to consider when using this module: charts, data sources and decorations.

Charts

These are the main items of the module. They process data and render it in a certain way. Currently there are three main types of charts: pie charts, line charts and bar charts. All charts inherit the Chart class, which provides the most basic chart interface. On top of that is the XYChart base class, which provides an interface for charts that are based on an X/Y grid.

• PieChart
• LineChart
• BarChart

Data Sources

Data sources are objects that provide data to charts. These objects act as adapters to other objects, like Qt's models. All data source objects inherit ChartDataSource, which represents the basic data source interface.

• SingleValueSource
• ArraySource
• ModelSource
• ValueHistorySource
• ModelHistorySource
• ColorGradientSource
• ChartAxisSource

Decorations

Decorations are items that provide extra information about a chart. These are things like a legend or axis labels. They usually work with multiple types of charts, though some may be limited to X/Y charts.

• AxisLabels
• GridLines
• LegendModel

Controls

A submodule is provided that contains pre-made controls that are provided as a convenience layer. These controls may be more restrictive in their data sources or how they display things. They are composed of Charts items along with some QtQuick Controls items. Some of the controls may use style-specific theming.

• Legend
• LegendDelegate
• LineChartControl
• PieChartControl

Supporting Code

There are a number of classes and other pieces of code that are not considered public API and thus not part of the public API documentation. Primarily, these are all the QtQuick Scene Graph related classes located in src/scenegraph/, in addition to the shaders that are used for rendering charts.