08 — Interaction & Motion (Shared)

Global interaction conventions and motion language. Module docs 10_Interaction_Specification.md specialize per module.

1. Touch gestures (phone/tablet)

Gesture	Behaviour	Where
Tap	Primary action, ripple `m-fast`	Everywhere
Long-press	Context menu (`AppMenu`), reorder, multi-select entry	List rows, cards, attachments
Double-tap	Zoom on images/PDF; nothing else	Media previews
Swipe left/right	Row actions (mark read, delete draft, archive)	Lists with `Dismissible`-style actions (keep ≤ 2)
Pull down	Refresh	All scrollables
Pinch	Zoom	Media, charts (tablet)
Drag	Reorder (timetable slots, dashboard widgets), image preview dismiss	Module-specific
Hardware back / back gesture	Pop; on root tab → exit app (Android) or previous shell branch	All
Edge swipe	Drawer on phone	App shell

Input	Behaviour
Hover	`m-fast` surface tint, tooltip after 500 ms
Click	Tap equivalent
Right-click	Context menu (same as long-press)
Wheel	Scroll; Ctrl+wheel zoom on media
ESC	Close dialog/sheet/menu/search; cancel selection
Tab / Shift+Tab	Focus traversal (logical order), visible focus ring `primary`
Enter	Submit focused form; Space toggles focused control
Ctrl+K	Global search
Ctrl/Cmd+Enter	Submit from text areas
Arrows	List navigation in menus/dropdowns

Event	Haptic
Success	`HapticFeedback.lightImpact()`
Error	`HapticFeedback.mediumImpact()`
Long-press menu	`HapticFeedback.selectionClick()`
Pull-to-refresh completion	`lightImpact()`
Destructive confirm	`heavyImpact()`
Rule	Haptics off when system setting disabled; no haptics on web/desktop

Enter: new screen slides forward (m-base); content fades + slight rise (m-slow).
Exit: reverse slide; dialogs/sheets scale+fade in, slide down on dismiss.
Hero: shared-element flight for list→detail (avatar→profile header, thumbnail→ attachment preview) m-slow.
State change: color/size transitions m-fast; icon morph via AnimatedSwitcher.
Skeleton→content: cross-fade m-slow, no pop.
Reduced motion (accessibility setting): all transitions become fades ≤ m-instant; no parallax, no stagger, no shimmer loop.
Density: never animate layout shifts; use AnimatedSize for expanding sections.

Interaction	Detail
Row tap	Ink ripple + 2% surface darken; 40 ms press latency feedback
FAB appear	Scale-in `m-entrance`; hide on scroll-down
Tab switch	Indicator slide `m-base`
Badge update	Scale pop on unread count change
Pull-to-refresh	Spinner `primary`, m-slow; on success + `lightImpact`
Submit button	Loading spinner replaces label; success → brief check + snackbar
Infinite scroll load	Bottom spinner fade-in `m-instant`

Every interactive element responds within 100 ms of press (press state visible).
Network-bound actions always show pending state — never a silent wait.
Repeated taps on submit are disabled while pending (anti-double-submit).
m-fast ripple only — no full-screen flashes.