+ /** A small 16x16 "+" image with colours */
+ private static String img64add = //
+ ""
+ + "iVBORw0KGgoAAAANSUhEUgAAABAAAAAQCAYAAAAf8/9hAAAABmJLR0QA/wD/AP+gvaeTAAAACXBI"
+ + "WXMAAAsTAAALEwEAmpwYAAAAB3RJTUUH4wUeES0QBFvvnAAAAB1pVFh0Q29tbWVudAAAAAAAQ3Jl"
+ + "YXRlZCB3aXRoIEdJTVBkLmUHAAACH0lEQVQ4y42Tz0sVURTHP+fMmC7CQMpH1EjgIimCsEVBEIg/"
+ + "qIbcBAW2Uai1m/oH2rlJXLQpeRJt2gQhTO0iTTKC1I2JBf5gKCJCRPvhPOed22LmvV70Fn7hwr3c"
+ + "+z3ne+73HCFHEClxaASRHgduA91AW369BkwDI3Foy0GkEofmACQnSxyaCyItAkMClMzYdeCAJgVP"
+ + "tJJrPA7tVoUjNZlngXMAiRmXClfoK/Tjq09x7T6LW+8RxOVJ5+LQzgSRojm5WCEDlMrQVbjIQNtN"
+ + "rh0d5FTzaTLBmWKgM4h0Ig4NzWseohYCJUuqx123Sx0MBpF2+MAdyWUnlqX4lf4bIDHjR+rwJJPR"
+ + "qNCgCjDsA10lM/oKIRcO9lByCYklnG/pqQa4euQ6J5tPoKI0yD6ef33Ku40Z80R7CSJNWyZxT+Ki"
+ + "2ytGP911hyZxQaRp1RtPPPYKD4+sGJwPrDUp7Q9Xxnj9fYrUUnaszEAwQHfrZQAerT/g7cYMiuCp"
+ + "z8LmLI0qBqz6wLQn2v5he57FrXkAtlPH2ZZOuskCzG2+4dnnx3iSuSgCKqLAlAIjmXPiVIRsgYjU"
+ + "usrfO0Gq7cA9jUNbBsZrmiQnac1e6n3FeBzakpf39OSBG9IPHAZwzlFoagVg5edHXn57wZed9dpA"
+ + "C3FoYRDpf8M0AQwKwu9yubxjeA7Y72ENqlp3mOqMcwcwDPQCx8gGchV4BYzGoS1V3gL8AVA5C5/0"
+ + "oRFoAAAAAElFTkSuQmCC";
+
+ /** A small 32x32 "-" image with colours */
+ private static String img64remove = //
+ ""
+ + "iVBORw0KGgoAAAANSUhEUgAAABAAAAAQCAYAAAAf8/9hAAAABmJLR0QA/wD/AP+gvaeTAAAACXBI"
+ + "WXMAAAsTAAALEwEAmpwYAAAAB3RJTUUH4wUeESw5X/JGsQAAAB1pVFh0Q29tbWVudAAAAAAAQ3Jl"
+ + "YXRlZCB3aXRoIEdJTVBkLmUHAAACKUlEQVQ4y5WTO2iTYRSG3+//v/+SJrG5SSABh1JQBHFJNUNR"
+ + "YodCLoMoTkK0YKhQtBmsl01wKVZRBwcrgosg3SwFW9Cippe0VmlpB6uYqYIaNSZtbv/lOKRx0iR9"
+ + "4YOzvOc8vOd8wLbG4nYGAKP9tshKr3Pq0zFXORt0UzbopvUeZ2ml1/niUcIWAYBzwwqr+xgAjCSt"
+ + "wpXjWzx105Ha+1XsMgT8U6IJfPAacyfO50OXJi3VwbtbxMbidtZ3tiClbzi/eAuCmxgai4AfNvNn"
+ + "KJn3X5xWKgwA0lHHYud3MdDUXMcmIOMx0oGJXJCN9tuiJ98p4//DbtTk2cFKhB/OSBcMgQHVMkir"
+ + "AqwJBhGYrIIkCQc2eJK3aewI9Crko2FIh0K1Jo0mcwmV6XFUlmfRXhK7eXuRKaRVIYdiUGKnW8Kn"
+ + "0ia0t6/hKHJVqCcLzncQgLhtIvBfbWbZZahq+cl96AuvQLre2Mw59NUlkCwjZ6USL0uYgSj26B/X"
+ + "oK+vtkYgMAhMRF4x5oWlPdod0UQtfUFo7YEBBKz59BEGAAtRx1xHVgzu5AYyHmMmMJHrZolhhU3t"
+ + "05XJe7s2PJuCq9k1MgKyNjOXiBf8kWW5JDy4XKHBl2ql6+pvX8ZjzDOqrcWsFQAAE/T3H3z2GG/6"
+ + "zhT8sfdKeehWkUQAeJ7WcH23xTz1uPBwf1hclA3mBZjPojFOIOSsVPpmN1OznfpA+Gn+2kCHqg/d"
+ + "LhIA/AFU5d0V6gTjtQAAAABJRU5ErkJggg==";
+
+ /** The code base */
+ private final ConfigItemBase<JComponent, E> base;
+
+ /** The main panel with all the fields in it. */
+ private JPanel main;
+