animation
A value between -1, 0 indicates an animation progress from the current page to the previous page. A value between 0, 1 indicating an animation progress from the current page to the next page.
The animationProgress may be different from the pointer movement. This is because the animation may use an easing curve to look more natural.
A value of zero means no swiping progress, i.e. showing current page/spread. A value of -1 means showing the previous page/spread. A value of 1 means showing the next page/spread.