protected IEnumerator decelerate()
{
if (_isDraggingPastExtents)
{
yield return(_manager.StartCoroutine(springBackToBounds(2f)));
}
else if (_velocities.Count > 0) // bail out if we have no velocities!
{
// get the average velocity by summing all the velocities and dividing by count
float total = 0;
foreach (var v in _velocities)
{
total += v;
}
var avgVelocity = total / _velocities.Count;
var elasticDecelerationModifier = 0.7f;
while (!_isDragging)
{
var deltaMovement = avgVelocity * Time.deltaTime;
var newOffset = _scrollPosition;
if (layoutType == UIAbstractContainer.UILayoutType.Horizontal)
{
newOffset += deltaMovement;
}
else
{
newOffset -= deltaMovement;
}
var absVelocity = Mathf.Abs(avgVelocity);
// if paging is enabled once we slow down we will snap to a page
if (pagingEnabled && absVelocity < 2500)
{
// if we are past the extents let the handler below do the scrolling
if (!_isDraggingPastExtents)
{
scrollToNearestPage();
}
break;
}
// make sure we have some velocity and we are within our bounds
if (absVelocity < 25)
{
break;
}
// use x for horizontal and y for vertical
float lowerBounds;
if (layoutType == UIAbstractContainer.UILayoutType.Horizontal)
{
lowerBounds = _minEdgeInset.x;
}
else
{
lowerBounds = _minEdgeInset.y;
}
if (newOffset < 0 && newOffset > lowerBounds)
{
_scrollPosition = newOffset;
layoutChildren();
avgVelocity *= SCROLL_DECELERATION_MODIFIER;
yield return(null);
}
else
{
_isDraggingPastExtents = true;
_scrollPosition = newOffset;
layoutChildren();
avgVelocity *= elasticDecelerationModifier;
// we up the elasticDecelerationModifier each iteration
elasticDecelerationModifier -= 0.1f;
if (elasticDecelerationModifier <= 0)
{
break;
}
yield return(null);
}
}
if (_isDraggingPastExtents)
{
yield return(_manager.StartCoroutine(springBackToBounds(0.9f)));
}
}
}