RefreshPhysics class

a scrollPhysics for config refresh scroll effect,enable viewport out of edge whatever physics it is in ClampingScrollPhysics, it doesn't allow to flip out of edge,but in RefreshPhysics,it will allow to do that, by parent physics passing,it also can attach the different of iOS and Android different scroll effect it also handles interception scrolling when refreshed, or when the second floor is open and closed. with SpringDescription passing,you can custom spring back animate,the more paramter can be setting in RefreshConfiguration

see also:

  • RefreshConfiguration, a configuration for Controlling how SmartRefresher widgets behave in a subtree


RefreshPhysics({ScrollPhysics? parent, int? updateFlag, double? maxUnderScrollExtent, SpringDescription? springDescription, RefreshController? controller, double? dragSpeedRatio, double? topHitBoundary, double? bottomHitBoundary, bool? enableScrollWhenRefreshCompleted, bool? enableScrollWhenTwoLevel, double? maxOverScrollExtent})
Creates scroll physics that bounce back from the edge.


allowImplicitScrolling bool
Whether a viewport is allowed to change its scroll position implicitly in response to a call to RenderObject.showOnScreen.
no setterinherited
allowUserScrolling bool
Whether a viewport is allowed to change the scroll position as the result of user input.
no setterinherited
bottomHitBoundary double?
controller RefreshController?
dragSpeedRatio double?
dragStartDistanceMotionThreshold double?
The minimum amount of pixel distance drags must move by to start motion the first time or after each time the drag motion stopped.
no setterinherited
enableScrollWhenRefreshCompleted bool?
enableScrollWhenTwoLevel bool?
hashCode int
The hash code for this object.
no setterinherited
maxFlingVelocity double
Scroll fling velocity magnitudes will be clamped to this value.
no setterinherited
maxOverScrollExtent double?
maxUnderScrollExtent double?
minFlingDistance double
The minimum distance an input pointer drag must have moved to be considered a scroll fling gesture.
no setterinherited
minFlingVelocity double
The minimum velocity for an input pointer drag to be considered a scroll fling.
no setterinherited
parent ScrollPhysics?
If non-null, determines the default behavior for each method.
runtimeType Type
A representation of the runtime type of the object.
no setteroverride
spring SpringDescription
The spring to use for ballistic simulations.
no setterinherited
springDescription SpringDescription?
tolerance Tolerance
Deprecated. Call toleranceFor instead.
no setterinherited
topHitBoundary double?
updateFlag int?
viewportRender RenderViewport?
find out the viewport when bouncing,for compute the layoutExtent in header and footer This does not have any impact on performance. it only execute once
getter/setter pair


adjustPositionForNewDimensions({required ScrollMetrics oldPosition, required ScrollMetrics newPosition, required bool isScrolling, required double velocity}) double
Describes what the scroll position should be given new viewport dimensions.
applyBoundaryConditions(ScrollMetrics position, double value) double
Determines the overscroll by applying the boundary conditions.
applyPhysicsToUserOffset(ScrollMetrics position, double offset) double
Used by DragScrollActivity and other user-driven activities to convert an offset in logical pixels as provided by the DragUpdateDetails into a delta to apply (subtract from the current position) using ScrollActivityDelegate.setPixels.
applyTo(ScrollPhysics? ancestor) RefreshPhysics
Combines this ScrollPhysics instance with the given physics.
buildParent(ScrollPhysics? ancestor) ScrollPhysics?
If parent is null then return ancestor, otherwise recursively build a ScrollPhysics that has ancestor as its parent.
carriedMomentum(double existingVelocity) double
Returns the velocity carried on repeated flings.
createBallisticSimulation(ScrollMetrics position, double velocity) Simulation?
Returns a simulation for ballistic scrolling starting from the given position with the given velocity.
findViewport(BuildContext? context) RenderViewport?
frictionFactor(double overscrollFraction) double
noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent method or property is accessed.
recommendDeferredLoading(double velocity, ScrollMetrics metrics, BuildContext context) bool
Provides a heuristic to determine if expensive frame-bound tasks should be deferred.
shouldAcceptUserOffset(ScrollMetrics position) bool
Whether the scrollable should let the user adjust the scroll offset, for example by dragging. If allowUserScrolling is false, the scrollable will never allow user input to change the scroll position.
toleranceFor(ScrollMetrics metrics) Tolerance
The tolerance to use for ballistic simulations.
toString() String
A string representation of this object.


operator ==(Object other) bool
The equality operator.