<itemvalue="Determines the overscroll by applying the boundary conditions. Called by [ScrollPosition.applyBoundaryConditions], which is called by [ScrollPosition.setPixels] just before the [ScrollPosition.pixels] value is updated, to determine how much of the offset is to be clamped off and sent to [ScrollPosition.didOverscrollBy]. The `value` argument is guaranteed to not equal the [ScrollMetrics.pixels] of the `position` argument when this is called. It is possible for this method to be called when the `position` describes an already-out-of-bounds position. In that case, the boundary conditions should usually only prevent a further increase in the extent to which the position is out of bounds, allowing a decrease to be applied successfully, so that (for instance) an animation can smoothly snap an out of bounds position to the bounds. See [BallisticScrollActivity]. This method must not clamp parts of the offset that are entirely within the bounds described by the given `position`. The given `position` is only valid during this method call. Do not keep a reference to it to use later, as the values may update, may not update, or may update to reflect an entirely unrelated scrollable. Examples [BouncingScrollPhysics] returns zero. In other words, it allows scrolling past the boundary unhindered. [ClampingScrollPhysics] returns the amount by which the value is beyond the position or the boundary, whichever is furthest from the content. In other words, it disallows scrolling past the boundary, but allows scrolling back from being overscrolled, if for some reason the position ends up overscrolled."/>
<itemvalue="allow Implicit Scrolling"/>
<itemvalue="Update the scroll position ([pixels]) to a given pixel value. This should only be called by the current [ScrollActivity], either during the transient callback phase or in response to user input. Returns the overscroll, if any. If the return value is 0.0, that means that [pixels] now returns the given `value`. If the return value is positive, then [pixels] is less than the requested `value` by the given amount (overscroll past the max extent), and if it is negative, it is greater than the requested `value` by the given amount (underscroll past the min extent). The amount of overscroll is computed by [applyBoundaryConditions]. The amount of the change that is applied is reported using [didUpdateScrollPositionBy]. If there is any overscroll, it is reported using [didOverscrollBy]."/>
@ -53,12 +54,11 @@
<itemvalue="repeat"/>
<itemvalue="Creates an animation controller with no upper or lower bound for its value. [value] is the initial value of the animation. [duration] is the length of time this animation should last. [debugLabel] is a string to help identify this animation during debugging (used by [toString]). `vsync` is the [TickerProvider] for the current context. It can be changed by calling [resync]. It is required and must not be null. See [TickerProvider] for advice on obtaining a ticker provider. This constructor is most useful for animations that will be driven using a physics simulation, especially when the physics simulation has no pre-determined bounds."/>
