ToolTips not shown over JWindows

Tooltips not shown on components placed in JWindows.

The fix/workaround is the following line somewhere in your application startup.

UIManager.getDefaults().put("ToolTipManager.enableToolTipMode", "");

ToolTipManager only requires keyboard focus to show tooltips when the property ToolTipManager.enableToolTipMode is set to “activeApplication”. JWindow widgets do not appear to get keyboard focus in the same way top level JFrames do.