Build RecordCountBanner reactive widget
epic-bufdir-report-period-selection-ui-integration-task-005 — Implement RecordCountBanner as a BlocBuilder widget that consumes PeriodSelectionBloc state. Display record count prominently, show a loading spinner while fetching, and render an incomplete-period warning when the selected range extends beyond the last complete reporting period. Apply design token styles for typography and color.
Acceptance Criteria
Technical Requirements
Execution Context
Tier 3 - 413 tasks
Can start after Tier 2 completes
Handles integration between different epics or system components. Requires coordination across multiple development streams.
Implementation Notes
Use BlocBuilder
Reference design tokens via AppDesignTokens.typography.headingLarge and AppDesignTokens.colors.warning — never hardcode. The warning banner should have role-appropriate contrast: ensure amber warning color meets WCAG 2.2 AA 4.5:1 ratio against its background.
Testing Requirements
Widget tests using flutter_test. Required test cases: (1) loading spinner shown when isCountLoading is true — pump widget with bloc in loading state, verify CircularProgressIndicator present; (2) count displayed correctly — pump with recordCount: 42, verify text '42' present; (3) warning banner shown — pump with showIncompleteWarning: true, verify warning text present; (4) warning banner hidden — pump with showIncompleteWarning: false, verify warning text absent; (5) initial state — pump with PeriodSelectionInitial, verify widget renders a sensible empty/loading state without overflow; (6) overflow test — pump with textScaleFactor 1.3, verify no overflow exceptions. Use MockPeriodSelectionBloc with bloc_test's MockBloc or a fake bloc that emits controlled states.
The record count query is asynchronous and may take up to 1 second on a slow connection. If the BLoC does not manage loading states carefully, the UI may show a stale count or the confirm button may be briefly enabled during the loading transition, allowing premature submission.
Mitigation & Contingency
Mitigation: Define explicit BLoC states: PeriodSelectionLoading, PeriodSelectionCountLoaded, PeriodSelectionValidationError, and PeriodSelectionReady. The confirm button must only be enabled in PeriodSelectionReady. Add a debounce of 300ms on period-change events before triggering the count query to prevent excessive calls.
Contingency: If debouncing is insufficient to prevent UX degradation on slow connections, add an optimistic loading skeleton to the RecordCountBanner that clearly communicates a pending state, and keep the confirm button disabled until the count resolves.
The confirmedReportPeriodProvider Riverpod contract between this feature and the Bufdir Export feature may not be defined yet, causing integration failures when the downstream export screen attempts to read the provider.
Mitigation & Contingency
Mitigation: Define the confirmedReportPeriodProvider as a StateProvider<DateTimeRange?> in a shared providers file at the start of this epic, before any screen code is written. Communicate the provider contract to the Bufdir Export feature team so both sides align on the same provider reference.
Contingency: If the export feature consumes the period through a different mechanism (e.g., navigation arguments), add a thin adapter that writes the confirmed period to both the Riverpod provider and the navigation argument, ensuring backward compatibility.
Flutter's live region support for screen readers is inconsistent across platforms (iOS VoiceOver vs Android TalkBack), and the record count banner must be announced on every change — a pattern that has historically required platform-channel workarounds.
Mitigation & Contingency
Mitigation: Test the live region announcement on both iOS (VoiceOver) and Android (TalkBack) early in implementation using the accessibility_test harness. Reference the project's existing live-region-announcer component (664-accessibility-live-region-announcer) for a proven implementation pattern.
Contingency: If native live region support is insufficient, wrap the record count text in a Semantics widget with a programmatically updated label string, and trigger a SemanticsService.announce call on each count update as a platform-agnostic fallback.