PlusMinusSlider #

A plus minus slider allows the user to continuously fire an event carrying a value between -1 and +1 by moving a thumb from its center position to the left or right (or top and bottom) edge of the control. The thumb will automatically center itself again on the zero position when the user lets go of the mouse button.

Scrolling through a large list of items at different speeds is one possible use case for a control like this. You may be familiar with Google Picasa, which has a similar control for scrolling through the image list.