Create a DualSlider where clicking and dragging on the background aligns the thumb to the inner edge of the min/max thumbs.
Override the Slider
method setThumbCenterPoint
to support aligning the "center" to an edge of the thumb. Subscribe to the DualSlider's ready
event to realign the thumbs to their respective inner edges.
Caveat: The values of the composite Sliders will still be reported as the offset from the center of the thumbs.