ScrollbarHandler class abstract

Abstract interface for handling scrollbar interactions and state.

Defines the contract for scrollbar behavior including scroll position tracking, thumb metrics calculation, and user interaction handling (pan, tap).

Implemented types

• Listenable

Constructors

ScrollbarHandler()

Properties

contentSize → double

The total size of the scrollable content.

no setter

hashCode → int

The hash code for this object.

no setter, inherited

maxScroll → double

The maximum scroll offset in pixels.

no setter

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

scroll → double

The current scroll offset in pixels.

no setter

scrollDirection → Axis

The scroll direction (horizontal or vertical).

no setter

scrollProgress ↔ double

The scroll progress as a value between 0.0 and 1.0.

getter/setter pair

shouldShowScrollbar → bool

Whether the scrollbar should be visible (true if content exceeds viewport).

no setter

viewportSize → double

The size of the visible viewport.

no setter

Methods

addListener(VoidCallback listener) → void

Register a closure to be called when the object notifies its listeners.

inherited

computeThumbMetrics(double viewportSize, double minThumbLength) → ({double thumbLength, double thumbOffset})

Computes the thumb length and offset for the scrollbar.

handlePanUpdate(DragUpdateDetails details) → void

Handles pan/drag updates on the scrollbar.

handleTapDown(BuildContext context, TapDownDetails details, Duration jumpDuration, Curve curve) → void

Handles tap events on the scrollbar track.

noSuchMethod(Invocation invocation) → dynamic

Invoked when a nonexistent method or property is accessed.

inherited

removeListener(VoidCallback listener) → void

Remove a previously registered closure from the list of closures that the object notifies.

inherited

setScrollProgress(double value, Duration duration, Curve curve) → void

Animates the scroll progress to value over duration with the given curve.

toString() → String

A string representation of this object.

inherited

Operators

operator ==(Object other) → bool

The equality operator.

inherited

Static Methods

of(BuildContext context) → ScrollbarHandler

Retrieves the ScrollbarHandler from the widget tree.