fix(list): keep touch panning off the Angular zone and idle items inert

[Copilot]

After HammerJS was replaced with native pointer/touch handling, continuous finger dragging over an igxFor-virtualized igx-list stutters and lags behind the gesture.

Root cause

1. IgxListItemComponent attaches its IgxTouchManager listeners inside the Angular zone, so every pointermove of a drag schedules a full ApplicationRef.tick(). The previous HammerGesturesManager bound listeners via NgZone.runOutsideAngular(). With eager change detection and impure pipes over 100k records, this dominates the frame budget.
2. Items track gestures even when panning is disabled (allowLeftPanning/allowRightPanning both default to false). Tracking takes a pointer capture on the item and calls preventDefault() on every touchmove, so idle items actively interfere with the scroll-inertia touch scrolling.

Changes

• IgxTouchManagerOptions (core/src/core/touch.ts) — two new optional, @internal options:
  • ngZone — listeners are attached with runOutsideAngular(); only the discrete callbacks (pointerDown, panStart, panEnd, panCancel, tap, swipe) re-enter via ngZone.run(). The high-frequency panMove deliberately stays outside.
  • canStart — predicate evaluated on pointerdown; returning false skips the gesture entirely (no pointer capture, no touchmove preventDefault).
  • Consumers that pass neither (carousel, navigation drawer, time picker) are unaffected — both paths fall back to a direct call.
• IgxListItemComponent — opts into both. panMove only writes DOM (transform, visibility), so it needs no change detection; the emitting callbacks still run in the zone.
• Tests — idle items must not capture the pointer or prevent touchmove defaults; panMove must run outside the zone while panStart/panEnd run inside.
• CHANGELOG — noted under 22.1.0.

// list-item.component.ts
this._gestures = new IgxTouchManager(this.elementRef.nativeElement, {
    panStart: () => this.panStart(),
    panMove: (event) => this.panMove(event),
    panEnd: () => this.panEnd(),
    panCancel: () => this.panCancel()
}, {
    ngZone: this._zone,
    // Do not track the gesture at all when the item cannot be panned. Otherwise every
    // pressed item captures the pointer and suppresses the touch scrolling of the list.
    canStart: () => this.panningAllowed
});

canStart is evaluated lazily per gesture, so runtime changes to the list's panning inputs are picked up without recreating the manager; headers never track.

• Fixes IgxList with IgxFor virtualization lags during continuous touch scrolling #17470

[Copilot]

Copilot was unable to review this pull request because there is no eligible user to bill. To allow Copilot reviews on bot-authored pull requests, enable direct organization billing in your organization's Copilot settings.

[Copilot]

Copilot was unable to review this pull request because there is no eligible user to bill. To allow Copilot reviews on bot-authored pull requests, enable direct organization billing in your organization's Copilot settings.

[Copilot]

Pull request overview

Copilot reviewed 4 out of 4 changed files in this pull request and generated no new comments.

[Copilot]

Pull request overview

Copilot reviewed 4 out of 4 changed files in this pull request and generated no new comments.