I've looked at JChart2D source code (version 3.2.2) and it seems that it's impossible to generate the legends you're trying to get (both the left and the right ones): this because in JChart2D a legend is a simple string drawn via g.drawString(str,x,y);
; hence, there can't be any possible rectangle containing the legend nor images near the strings to improve legend readability.
If you're in a hurry, you might try to change the source code itself by adding a line stroke just before the strings itself. You can do it in Chart2D.paintTraceLabels(Graphics)
method, near the end of the method itself, via the method g2d.drawLine(x1,y1,x2,y2);
: you can get the stroke via trace.getStroke()
.
Alternatively, you can contact the main developer to safely perform the needed change. Hope it helps