M3EToolbarVisibilityController class

Tracks scroll / manual exit translation for a toolbar.

offset is ≤ 0 and clamped between offsetLimit and 0. Call attach from a TickerProvider (usually the toolbar state) before show / hide.

Inheritance

Constructors

M3EToolbarVisibilityController({M3ESpring motion = M3EMotion.expressiveSpatialDefault, double? exitExtent}): M3EToolbarVisibilityController.

collapsedFraction → double: 0 = fully visible, 1 = fully hidden.
no setter
collapseRequested → bool: Scroll-collapse intent for M3EToolbarScrollAction.collapse, read by the toolbar to flip its own expand state (via its adjacent FAB / expand-trigger spring) the instant a scroll direction changes.
no setter
contentOffset ↔ double: Accumulated scroll delta consumed while dragging.
getter/setter pair
exitExtent ↔ double?: Optional fixed exit distance. When null, the toolbar measures itself and sets offsetLimit to -(extent + screenOffset).
getter/setter pair
hashCode → int: The hash code for this object.
no setterinherited
hasListeners → bool: Whether any listeners are currently registered.
no setterinherited
isAnimating → bool: Whether a settle / show / hide spring is currently running.
no setter
isHidden → bool: Whether the toolbar is fully off-screen.
no setter
motion → M3ESpring: Spring used for show / hide / settle animations.
final
offset ↔ double: Current translation (≤ 0), clamped to [offsetLimit, 0].
getter/setter pair
offsetLimit ↔ double: Maximum negative translation (≤ 0).
getter/setter pair
runtimeType → Type: A representation of the runtime type of the object.
no setterinherited

addListener(VoidCallback listener) → void: Register a closure to be called when the object changes.
inherited
attach(TickerProvider vsync) → void: Binds a ticker for spring show/hide. Safe to call repeatedly.
cancelAnimation() → void: Cancels an in-flight settle / show / hide spring.
detach() → void: Releases settle animation resources. Does not dispose this controller.
dispose() → void: Discards any resources used by the object.
override
hide() → void: Animates to fully hidden (offset == offsetLimit).
noSuchMethod(Invocation invocation) → dynamic: Invoked when a nonexistent method or property is accessed.
inherited
notifyListeners() → void: Call all the registered listeners.
inherited
removeListener(VoidCallback listener) → void: Remove a previously registered closure from the list of closures that are notified when the object changes.
inherited
requestCollapse() → void: Requests the collapse-on-scroll target. No-op if already requested.
requestExpand() → void: Reverses requestCollapse. No-op if not currently requested.
settle({required double velocity}) → void: Settles after a scroll fling using velocity threshold 150.
show() → void: Animates to fully visible (offset == 0).
toggle() → void: Toggles based on collapsedFraction midpoint.
toString() → String: A string representation of this object.
inherited