SlideAnimationEngine<TKey> class

Paint-only FLIP slide engine. See the library doc for the timing model.

Two protocols here are load-bearing and easy to break. The SETTLE protocol in _onSlideTick notifies with deltas at exactly 0 BEFORE removing completed entries, then notifies once more after cleanup so listeners can observe the active-to-idle transition. And COMPOSITION retargets an entry in place, which is why completion cleanup checks SlideAnimation.installStamp as well as identity: a listener may have composed onto the very entry that just completed.

Constructors

SlideAnimationEngine({required TickerProvider vsync, required NodeIdRegistry<TKey> nids, required VoidCallback onTick})

Properties

hasActive → bool

Whether any slide is currently installed, animating or settled but not yet cleaned up. Composed into TreeController.hasActiveSlides.

no setter

hasActiveX → bool

Whether any active slide entry is animating horizontally (startDeltaX != 0). Lets render-layer hot paths skip per-row X-delta reads when no X-axis work is in flight.

no setter

hashCode → int

The hash code for this object.

no setter, inherited

maxAbsDelta → double

Maximum |currentDelta| across every active slide entry, or 0.0 when no slides are active.

no setter

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

Methods

animateFromOffsets(Map<TKey, ({double x, double y})> priorOffsets, Map<TKey, ({double x, double y})> currentOffsets, {required Duration duration, required Curve curve, required bool structuralAnimationsDisabled, double maxSlideDistance = double.infinity}) → void

Installs FLIP slides for every node whose offset changed between priorOffsets and currentOffsets. See TreeController.animateSlideFromOffsets for the full contract.

cancelForKey(TKey key) → void

Cancels the slide for key, if any. Tolerant of unregistered keys. Used by _cancelAnimationStateForSubtree during reparenting.

clearAll() → void

Resets every slide-related field back to its initial state and disposes the ticker. Called from TreeController._clear (and indirectly from dispose). The next animateFromOffsets call recreates the ticker via the existing _ticker ??= ... pattern. NOT safe mid-lifecycle, since it drops _slideByNid capacity; use purgeActive for that.

clearForNid(int nid) → void

Defensive slot reset for the nid adopt and release paths. Bounds-checked because those can run before resizeForCapacity has grown this engine's array to cover nid.

debugAssertConsistent() → void

Verifies _activeSlideNids mirrors _slideByNid exactly. Throws StateError on inconsistency. Wrapped in assert at call sites so release builds skip it.

deltaForKey(TKey key) → double

Slide delta for key, or 0.0 if not currently sliding (or not registered).

deltaForNid(int nid) → double

Slide delta for the live nid, or 0.0 if not currently sliding. Caller must guarantee nid is within range.

deltaXForKey(TKey key) → double

X-axis slide delta for key, or 0.0 if not currently sliding (or not registered).

deltaXForNid(int nid) → double

X-axis (cross-axis indent) slide delta for the live nid, or 0.0 if not currently sliding. Caller must guarantee nid is within range.

dispose() → void

Terminal teardown. Identical to clearAll, which already disposes the ticker, and kept as its own entry point so every engine tears down through the same name.

markPreserveProgress(TKey key) → void

Sets SlideAnimation.preserveProgressOnRebatch = true on the slide entry for key. Tolerant of unregistered keys and inactive slides (no-op).

noSuchMethod(Invocation invocation) → dynamic

Invoked when a nonexistent method or property is accessed.

inherited

purgeActive() → void

Capacity-preserving purge of every active slide: entries cleared and the ticker STOPPED, not disposed, so the next install restarts it.

resizeForCapacity(int nidCapacity) → void

Grows the per-nid slide array to match nidCapacity. Called by TreeController._onStoreCapacityGrew in lockstep with every other per-nid array. New slots default to null (not sliding).

toString() → String

A string representation of this object.

inherited

Operators

operator ==(Object other) → bool

The equality operator.

inherited