+ preferences: [
+ {name: "direction", label: "Direction of Travel", kind: "ListSelector", items: [
+ {caption: "right", value: -1},
+ {caption: "left", value: 1}
+ ]},
+ {name: "speed", label: "Speed", kind: "Slider", minimum: 0.1, maximum: 10, snap: 0.1}
+ ],
+ direction: -1,
+ speed: 1.0,