CustomScrollPhysics class
A customizable ScrollPhysics which determines Scrollable physics by given CustomScrollPhysicsController. If there is no change on controller, it will default to how ClampingScrollPhysics behaves and always accept user scroll.
Note that you can use DefaultScrollPhysics inherited widget to define a default physics, and use DefaultScrollPhysics.of to get it in children.
- Inheritance
-
- Object
- ScrollPhysics
- CustomScrollPhysics
- Annotations
Constructors
- CustomScrollPhysics({ScrollPhysics? parent = const ClampingScrollPhysics(), CustomScrollPhysicsController? controller})
-
const
Properties
- 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
- controller → CustomScrollPhysicsController?
-
The controller of CustomScrollPhysics, it is mutable and will influence the
physics of Scrollable dynamically.
final
- 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
- hashCode → int
-
The hash code for this object.
no setterinherited
- maxFlingVelocity → double
-
Scroll fling velocity magnitudes will be clamped to this value.
no setterinherited
- 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.
finalinherited
- runtimeType → Type
-
A representation of the runtime type of the object.
no setterinherited
- spring → SpringDescription
-
The spring to use for ballistic simulations.
no setterinherited
- tolerance → Tolerance
-
Deprecated. Call toleranceFor instead.
no setterinherited
Methods
-
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.
inherited
-
applyBoundaryConditions(
ScrollMetrics position, double value) → double -
Determines the overscroll by applying the boundary conditions.
override
-
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.
inherited
-
applyTo(
ScrollPhysics? ancestor) → CustomScrollPhysics -
Combines this ScrollPhysics instance with the given physics.
override
-
buildParent(
ScrollPhysics? ancestor) → ScrollPhysics? -
If parent is null then return ancestor, otherwise recursively build a
ScrollPhysics that has
ancestor
as its parent.inherited -
carriedMomentum(
double existingVelocity) → double -
Returns the velocity carried on repeated flings.
inherited
-
createBallisticSimulation(
ScrollMetrics position, double velocity) → Simulation? -
Returns a simulation for ballistic scrolling starting from the given
position with the given velocity.
inherited
-
noSuchMethod(
Invocation invocation) → dynamic -
Invoked when a nonexistent method or property is accessed.
inherited
-
recommendDeferredLoading(
double velocity, ScrollMetrics metrics, BuildContext context) → bool -
Provides a heuristic to determine if expensive frame-bound tasks should be
deferred.
inherited
-
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.
override
-
toleranceFor(
ScrollMetrics metrics) → Tolerance -
The tolerance to use for ballistic simulations.
inherited
-
toString(
) → String -
A string representation of this object.
inherited
Operators
-
operator ==(
Object other) → bool -
The equality operator.
inherited
Static Methods
-
findInAncestors(
BuildContext context) → CustomScrollPhysics? - Returns the CustomScrollPhysics from Scrollable widget most closely associated with the given context.
-
findInPhysics(
ScrollPhysics? physics) → CustomScrollPhysics? - Finds and returns the CustomScrollPhysics from ScrollPhysics's parents.