morphing_sheet 0.2.0

A production-ready multi-stage, gesture-driven, spatially continuous UX sheet with physics-based snapping and morphing fullscreen transitions.

Changelog

All notable changes to this project will be documented in this file.

The format is based on Keep a Changelog, and this project adheres to Semantic Versioning.

0.2.0 - 2026-03-03

Added

• List-driven mode via MorphingSheet.listDriven<T>() — context-aware, item-selection-based sheet with three content layers:
  • DynamicListLayer — lazy ListView.builder for collapsed state (supports 200+ items at 60fps)
  • PreviewLayer — selected item preview at half-expanded state
  • DetailLayer — fullscreen scrollable detail at expanded state with scroll-to-drag handoff
• SheetItem<T> model — lightweight value object wrapping user data for list-driven mode.
• ItemMorphTween — pure-function interpolation helpers for item-to-sheet morph transitions (morphRect, morphRadius, morphElevation, listOpacity, previewOpacity, detailOpacity).
• SheetController item selection API:
  • selectItem(Object item) — select item + animate to half-expanded preview
  • clearSelection() — deferred selection clearing (null-out after collapse animation completes)
  • animateToSnap(SnapPoint) — named snap animation
  • animateToItemDetail(Object item) — select + animate directly to expanded detail
  • selectedItem / hasSelection getters
• SheetState.selectedItem and SheetState.hasSelection for list-driven mode context.
• SheetScaffold.contentLayerBuilder — custom content composition hook for list-driven mode.
• Magnetic snap attraction in DefaultSheetPhysics (opt-in via enableMagneticSnap).
• Platform-aware physics tuning (iOS/macOS softer rubber-band, Android stiffer).
• Configurable flickSensitivity multiplier on DefaultSheetPhysics.
• SheetPhysics.magneticForce() abstract method with default no-op implementation.
• Dual-mode example app with navigation hub for both page-driven and list-driven demos.
• Commerce-style list-driven example (product list, preview, detail, persistent cart bar).

Changed

• SheetScaffold barrier tap now calls clearSelection() when in list-driven mode (falls back to collapse() otherwise).
• SheetController._onAnimationStatus now handles deferred selection clearing via _pendingClearSelection flag.
• DefaultSheetPhysics uses flickSensitivity multiplier in snap resolution.

Migration from 0.1.x

No breaking changes. All existing MorphingSheet(...) usage works identically. New features are accessed via MorphingSheet.listDriven<T>(...) and the new SheetController selection API.

0.1.0 - 2026-03-03

Added

• Core MorphingSheet widget with multi-stage snap points (collapsed, half-expanded, fully expanded).
• SheetController (extends ChangeNotifier) for state-management-agnostic integration.
• Physics engine with abstract SheetPhysics and DefaultSheetPhysics implementation.
• Velocity-based snap resolution with configurable thresholds.
• Rubber-band resistance at sheet bounds.
• Continuous animation progress (0.0-1.0) driving all visual interpolations.
• Background scale + blur transform driven by sheet progress.
• Horizontal PageView switching (disabled at fully-expanded state).
• Custom curve presets (SheetCurves) optimized for sheet motion.
• TransitionSpec for per-element animation intervals.
• SheetConfig for full customization of snap points, curves, radii, elevation, and background effects.
• Sealed SheetVisualState hierarchy for type-safe state matching.
• Example app demonstrating all three sheet states with horizontal pages.