Question

Is there a way in JFreeChart to determine from a ChartMouseEvent that x,y coordinates (in plot space) the mouse is over? I’ve tried using the domain crosshair value but that seems inaccurate and lags the actual mouse event.

thanks,

Jeff

Answer 1

Mouse coordinates from getTrigger() are relative to ChartPanel so you need to convert them:

Point2D p = chartPanel.translateScreenToJava2D(mouseChartEvent.getTrigger().getPoint());
Rectangle2D plotArea = chartPanel.getScreenDataArea();
XYPlot plot = (XYPlot) chart.getPlot(); // your plot
double chartX = plot.getDomainAxis().java2DToValue(p.getX(), plotArea, plot.getDomainAxisEdge());
double chartY = plot.getRangeAxis().java2DToValue(p.getY(), plotArea, plot.getRangeAxisEdge());