Implement step transition animations
epic-quick-activity-registration-wizard-ui-task-009 — Add animated forward and backward step transitions inside ActivityRegistrationBottomSheet using AnimatedSwitcher or PageView. Forward transitions should slide left, backward transitions should slide right. Ensure animations respect the OS reduce-motion accessibility setting.
Acceptance Criteria
Technical Requirements
Execution Context
Tier 3 - 413 tasks
Can start after Tier 2 completes
Implementation Notes
AnimatedSwitcher alone cannot handle directional transitions — you must provide a custom transitionBuilder that uses SlideTransition with a direction derived from comparing old vs new step index. A clean pattern is to track a _lastStep variable in the container widget (not in Cubit) solely for animation direction detection, updated in didUpdateWidget or via a ValueNotifier. Alternatively, embed direction into the key passed to AnimatedSwitcher children (e.g., ValueKey('step-$currentStep-forward')). Do NOT use PageView — swipe gestures conflict with DraggableScrollableSheet drag and create accessibility issues for users navigating by switch or external keyboard.
For the reduce-motion check: wrap the AnimatedSwitcher in a Builder that reads MediaQuery.disableAnimations and sets duration: Duration.zero when true.
Testing Requirements
Widget tests: verify forward animation direction using a custom transitionBuilder that is testable (inject as parameter or use a test key). Test that disableAnimations: true results in zero-duration transition. Test that back-navigation triggers opposite slide direction. Use tester.pump(Duration(milliseconds: 125)) to test mid-animation state.
Verify old step widget is absent from widget tree after animation completes (findsNothing).
As wizard steps accumulate additional features (duplicate warning, retroactive date chips, custom duration entry), the two-tap happy path may inadvertently require extra interactions. A step that previously auto-advanced may start requiring a confirmation tap, breaking the core promise of the feature and increasing friction for high-frequency users like HLF's 380-registration peer mentor.
Mitigation & Contingency
Mitigation: Define and automate a regression test that performs the complete two-tap happy path (open bottom sheet → confirm → confirm) and asserts the confirmation view is reached in exactly two tap events. Run this test in CI on every PR touching the wizard. Treat any failure as a blocking defect.
Contingency: If a new feature unavoidably adds a tap to the happy path, provide a 'quick mode' toggle in user settings that collapses the wizard to a single-confirmation screen for users who never change defaults.
Flutter bottom sheets are dismissed on back-button press or background tap by default. If the wizard state is not preserved, a peer mentor who accidentally dismisses mid-flow loses all their entered data and must start over — a significant frustration for users with cognitive disabilities or motor impairments who take longer to fill each step.
Mitigation & Contingency
Mitigation: Implement the wizard state as a persistent Cubit that outlives the bottom sheet widget's lifecycle, scoped to the registration feature route. On re-open, the Cubit restores the previous step and field values. Add a 'discard changes?' confirmation dialog when the user explicitly dismisses a partially filled wizard.
Contingency: If persistent state proves difficult to implement with the chosen routing strategy, implement draft auto-save to a local draft repository every time a field value changes, and restore from draft on the next open.
Multi-step wizard bottom sheets are among the most complex accessibility scenarios in Flutter. Screen readers (TalkBack, VoiceOver) may not announce step transitions, focus may land on the wrong element after advancing, and animated transitions can interfere with the accessibility tree update cycle — making the feature unusable for Blindeforbundet users who rely on screen readers.
Mitigation & Contingency
Mitigation: Assign each wizard step a unique Semantics container with a live region announcement on mount. Use ExcludeSemantics on inactive steps during transition animations. Test each step transition manually with TalkBack and VoiceOver as part of the definition of done for each step component.
Contingency: If animated transitions cause accessibility tree corruption, disable step transition animations entirely in accessibility mode (detected via MediaQuery.accessibleNavigation) and use instant step replacement instead.
The NotesStep relies on the OS keyboard's built-in dictation button for speech-to-text input. This button's availability, position, and behaviour varies significantly between iOS (reliable, visible dictation key) and Android (varies by keyboard, OEM skin, and language settings). HLF and Blindeforbundet specifically requested this capability; if it is unreliable on Android, it fails a SHOULD HAVE requirement for a significant portion of users.
Mitigation & Contingency
Mitigation: Document that the notes dictation feature depends on the device's native keyboard dictation and requires no in-app microphone permission. Add explicit placeholder copy informing users they can use their keyboard's dictation button. Test on a minimum of three Android OEM keyboards (Gboard, Samsung, Swiftkey) and two iOS versions.
Contingency: If native keyboard dictation is too unreliable on Android, implement a fallback in-app microphone button in the NotesStep that triggers the platform's SpeechRecognition API directly via a method channel, scoped only to the notes field with no session recording capability.