Custom scrolling control on Windows Phone

I want to create a scrollbar like this

This is almost the same as Toggle Switch, but it has 3 states. False, doing nothing, and true. And I want my scrollbar to animate whenever the user releases their finger from the scrollbar. I am using a handled event to detect it. Therefore, when the book image is next to the text "sudah", the book image will slowly move to the right until it reaches the edge. And this animation also works for two different states. Which moves to the center or moves to the left until it reaches the edge. I'm already trying to use the slider class and also make my own control that uses the storyboard but nothing seems to work. This is due to my control.

Custom scroll control

Custom slider control

assets