This event occurs when a Javascript touch start event occurs on the extended plot area.

Use JsChartViewer.attachHandler with the event id "TouchStartPlotArea" to attach a handler to this event.

The JsChartViewer.getChartMouseX, JsChartViewer.getChartMouseY, JsChartViewer.getPlotAreaMouseX and JsChartViewer.getPlotAreaMouseY can be used to obtain the mouse or touch coordinates relative to the chart.

See JsChartViewer.setPlotAreaMouseMargin on what is the extended plot area.