LiveChartItem

The painted item behind LiveChart: a line-and-area chart of the last 60 samples.

LiveChartItem draws the chart, with no theme of its own. Use it through LiveChart, which gives it the theme's colours and font and its accessibility. It is drawn with QPainter, so it renders on Qt Quick's software backend as well as on the GPU.

LiveChartItem is a QQuickPaintedItem; its inherited properties work as usual (Qt documentation).

Example

LiveChart {
    values: cpu.usageHistory
    maximum: 100
    label: qsTr("Load")
    valueText: Math.round(cpu.usage) + "%"
    topText: "100%"
    spanText: qsTr("60 seconds")
}

Series colours should be opaque: the line is drawn as overlapping segments, which show at the joins with a translucent colour.

Properties

Name	Type	Default	Description
`captions`	`bool`	`true`	Draws the caption texts (`label`, `valueText`, `topText`, `spanText` and a 0 at the bottom right). `false` also removes the bands they take at the top and bottom, so the plot grows.
`color2`	`color`	`LiveChart`: `Kirigami.Theme.neutralTextColor` (an amber in Plasma); the item itself `#f67400`	The colour of the second series.
`color`	`color`	`LiveChart`: `AtlasStyle.accent`; the item itself `#3daee9`	The colour of the first series.
`font`	`QFont`	`LiveChart`: the Atlas caption font; the item itself the application font	The font of the captions.
`label`	`string`	`""`	The caption at the top left; also the chart's accessible name in `LiveChart`.
`maximum`	`real`	`0`	The value at the top of the plot. 0 or less scales to the samples: 1.25 times the highest one shown, and at least `minimumScale`.
`minimumScale`	`real`	`1`	The smallest value the automatic scale shows at the top.
`scaleTop`	`real` (read-only)	—	The value the top of the plot stands for now, for a caption.
`spanText`	`string`	`""`	The caption at the bottom left ("60 seconds").
`textColor`	`color`	`LiveChart`: the theme's text colour; the item itself `#232629`	The colour of the captions.
`topText`	`string`	`""`	The caption at the top right ("100%"). Dropped when the chart is too narrow to fit it beside `label` and `valueText`.
`valueText`	`string`	`""`	The caption next to `label` at the top left, e.g. the current value; also the chart's accessible description in `LiveChart`.
`values2`	`QList<real>`	`[]`	An optional second series (upload beside download), drawn over the first. Oldest first; only the last 60 are drawn. Same rules as `values`.
`values`	`QList<real>`	`[]`	The samples, oldest first. Only the last 60 are drawn; the newest sits at the right edge, so fewer than 60 samples fill the right part only. A NaN or infinite sample breaks the line there, and a single sample between breaks draws nothing.