mobile-touch

SKILL.md

Mobile Touch Animation

Apply Disney's 12 animation principles to mobile gestures, haptics, and native app motion.

Quick Reference

Principle
Mobile Implementation

Squash & Stretch
Rubber-banding, bounce on scroll limits

Anticipation
Peek before reveal, long-press preview

Staging
Sheet presentations, focus states

Straight Ahead / Pose to Pose
Gesture-driven vs preset transitions

Follow Through / Overlapping
Momentum scrolling, trailing elements

Slow In / Slow Out
iOS spring animations, Material easing

Arc
Swipe-to-dismiss curves, card throws

Secondary Action
Haptic pulse with visual feedback

Timing
Touch response <100ms, transitions 250-350ms

Exaggeration
Bounce amplitude, haptic intensity

Solid Drawing
Respect safe areas, consistent anchors

Appeal
60fps minimum, gesture continuity

Principle Applications

Squash & Stretch: Implement rubber-band effect at scroll boundaries. Pull-to-refresh should stretch content naturally. Buttons compress on touch.

Anticipation: Long-press shows preview before full action. Drag threshold provides visual hint before item lifts. Swipe shows edge of destination content.

Staging: Use sheet presentations to maintain context. Dim and scale background during modal focus. Hero transitions connect views meaningfully.

Straight Ahead vs Pose to Pose: Gesture-following animations (drag, pinch) are straight ahead—driven by touch input. System transitions (push, present) are pose to pose—predefined keyframes.

Follow Through & Overlapping: Content continues moving after finger lifts (momentum). Navigation bar elements animate slightly after main content. Lists items settle with stagger.

Slow In / Slow Out: iOS uses spring physics—configure mass, stiffness, damping. Android Material uses standard easing: FastOutSlowIn. Never use linear for user-initiated motion.

Arc: Thrown cards follow parabolic arcs. Swipe-to-dismiss curves based on velocity vector. FAB expand/collapse follows natural arc path.

Secondary Action: Pair haptic feedback with visual response. Button ripple accompanies press. Success checkmark triggers light haptic.

Timing: Touch acknowledgment: <100ms. Quick actions: 150-250ms. View transitions: 250-350ms. Complex animations: 350-500ms. Haptic should sync precisely with visual.

Exaggeration: Pull-to-refresh stretches beyond natural—makes feedback clear. Error shake is pronounced. Success animations celebrate appropriately.

Solid Drawing: Respect device safe areas during animation. Maintain consistent transform origins. Account for notch/dynamic island in motion paths.

Appeal: Minimum 60fps, target 120fps on ProMotion displays. Gesture-driven animation must feel connected to finger. Interruptible animations essential.

Platform Patterns

iOS

// Spring animation with follow-through
UIView.animate(withDuration: 0.5,
               delay: 0,
               usingSpringWithDamping: 0.7,
               initialSpringVelocity: 0.5,
               options: .curveEaseOut)

// Haptic pairing
let feedback = UIImpactFeedbackGenerator(style: .medium)
feedback.impactOccurred()

Android

// Material spring animation
SpringAnimation(view, DynamicAnimation.TRANSLATION_Y)
    .setSpring(SpringForce()
        .setStiffness(SpringForce.STIFFNESS_MEDIUM)
        .setDampingRatio(SpringForce.DAMPING_RATIO_MEDIUM_BOUNCY))
    .start()

Haptic Guidelines

Action
iOS
Android

Selection
.selection
EFFECT_TICK

Success
.success
EFFECT_CLICK

Warning
.warning
EFFECT_DOUBLE_CLICK

Error
.error
EFFECT_HEAVY_CLICK

Haptics are secondary action—always pair with visual confirmation.