JFreeChart tooltip unexpected residue

[tomtom79]

Hi all,

I asked the following question on stackexchange but didn't get any solution; hence this post.

My Java Swing application is making use of (the excellent) JFreeChart library but unfortunately there is an unexpected behavior: when hovering the mouse over a chart's datapoint, a customized tooltip is shown (as expected); however, after that there is a constant tooltip residue next to the mouse cursor when it is on the chart but not on a datapoint anymore (i.e. no tooltip should appear anymore).

Hereby a picture that shows the residue (grey dot at to the bottom right of the mouse cursor - it looks like the borders of an empty tooltip):


The residue "follows" the mouse position and if I change application (e.g. alt-tab) and then come back, the residue disappeared. Did someone experience the same problem? Any idea how to solve this?

Technical details:

• I'm using latest JFreeChart version (1.0.19)
• My application is using a specific UI L&F manager but this doesn't seem to be the problem as the residue is also present without it (UI manager set as UIManager.setLookAndFeel(new SubstanceTwilightLookAndFeel())
• The problem is present on XYLineChart and on BarChart
• Tooltips are customized (i.e. implemented XYToolTipGenerator interface where generateToolTip() returns HTML with the tooltip content)
• Tooltip delay is set to minimum (ChartPanel.setInitialDelay(0)) and dismiss delay to maximum (ChartPanel.setDismissDelay(Integer.MAX_VALUE))

Many thanks for any help or hint as I've been stuck on this for hours now!
Thomas

[david.gilbert]

Put a breakpoint in the ChartPanel.getToolTipText() method and see if it is returning a non-null value when the mouse is over the plot background (and not over a data item). If possible, please post a small, self-contained example that reproduces the problem.

[tomtom79]

Thanks for the reply.

I've checked the outcome of both ChartPanel.getToolTipText() and ChartPanel.getToolTipText(MouseEvent evt): only the later one is used and it does return null when not over a data item.

Creating a small example would take quite a bit of time given the amount of customization I'm bringing to my charts. Maybe faster to import JFreeChart source in my project and do a step-by-step debug? Where would you advise to start looking / put a breakpoint?

Thanks,
Thomas