ChartDirector 7.1 (C++ Edition)

QmlChartViewer.setUpdateInterval


Usage

void setUpdateInterval(int interval);

Description

Sets the minimum gap interval between two viewPortChanged signals in milliseconds.

Some GUI designs may generate a lot of QChartViewer.viewPortChanged signals rapidly. For example, an external scroll bar may update the viewport and call QmlChartViewer.updateViewPort rapidly and repeatedly when it is scrolling. As the chart is usually updated in the main GUI thread, updating too rapidly without a gap interval in between may cause other GUI elements to become sluggish.

This method specifies the minimum gap interval between two viewPortChanged signals. The default is 20ms.

If a viewPortChanged signal needs to be emitted during the gap interval, the signal will be delayed and emitted after the gap interval.

If multiple viewPortChanged signals needs to be emitted during the gap interval, they will be merged into one signal, and be emitted after the gap interval.

Arguments

ArgumentDefaultDescription
interval(Mandatory)The minimum gap interval between two viewPortChanged signals in milliseconds.

Return Value

None