Meshtastic-Android/specs/20260513-160000-m3-expressive-adoption/data-model.md

Data Model: M3 Expressive Design System Adoption

Date: 2025-07-18 | Branch: 20260513-160000-m3-expressive-adoption

Overview

This feature is primarily a UI/styling upgrade with minimal data model impact. The only new persistent state is the swipe-action discoverability hint preference.

New Entities

SwipeHintPreference

Location: core/datastore (user preferences)

Field	Type	Default	Description
hasCompletedSwipeAction	Boolean	false	Permanently dismisses swipe hint after first successful swipe action

Storage: DataStore UserPreferences proto or preferences file (existing infrastructure).

State Transitions:

false → true  (on first successful swipe-to-action completion)

One-way flag. Never resets to false (permanent dismissal).

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SwipeHintSessionState (transient)

Location: In-memory, ViewModel-scoped

Field	Type	Default	Description
hasShownHintThisSession	Boolean	false	Prevents repeated hint animation within same process lifecycle

Lifecycle: Resets on process death. Within a session, hint shows once per list screen visit until hasCompletedSwipeAction becomes true.

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Modified Entities

AppTypography (Type.kt)

Current State: val AppTypography = Typography() — empty default

Target State: Full expressive typescale definition:

Property	Value Source
displayLarge	Standard M3 default (auto-emphasized by expressive theme)
displayMedium	Standard M3 default
displaySmall	Standard M3 default
headlineLarge	Standard M3 default
headlineMedium	Standard M3 default
headlineSmall	Standard M3 default
titleLarge	Standard M3 default
titleMedium	Standard M3 default
titleSmall	Standard M3 default
bodyLarge	fontSize = 16.sp minimum (design standards §5)
bodyMedium	fontSize = 16.sp minimum (design standards §5)
bodySmall	Standard M3 default
labelLarge	Standard M3 default
labelMedium	Standard M3 default
labelSmall	Standard M3 default

Note: Emphasized variants (displayLargeEmphasized, titleMediumEmphasized, etc.) are auto-generated by MaterialExpressiveTheme based on the standard scale. No manual definition needed.

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Component State Models

SwipeToRevealState

Location: core/ui/component/SwipeToRevealBox.kt

Field	Type	Description
anchoredDraggableState	AnchoredDraggableState<SwipeAnchor>	Manages drag position and anchoring
currentAnchor	SwipeAnchor	Current snapped position

SwipeAnchor Enum:

enum class SwipeAnchor {
    Start,       // Resting position (0 offset)
    RevealEnd,   // Left-swipe reveals end actions
    RevealStart, // Right-swipe reveals start actions
}

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Relationships

UserPreferences (DataStore)
  └── hasCompletedSwipeAction: Boolean

NodeListScreen
  ├── uses SwipeToRevealBox (per item)
  │     └── owns AnchoredDraggableState
  └── reads hasCompletedSwipeAction (via ViewModel)

MessageListScreen
  ├── uses SwipeToRevealBox (per item)
  │     └── owns AnchoredDraggableState
  └── reads hasCompletedSwipeAction (via ViewModel)

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Validation Rules

Rule	Constraint
bodyLarge.fontSize	>= 16.sp (design standards §5 minimum)
bodyMedium.fontSize	>= 16.sp (design standards §5 minimum)
Touch target minimum	44.dp × 44.dp on all interactive elements (design standards accessibility)
Swipe threshold	Action reveals at ≥ 56.dp horizontal drag (comfortable thumb distance)
Swipe velocity threshold	Fling detected at ≥ 400.dp/s (standard Material swipe velocity)