Wire popup deep-link to peer mentor detail screen
epic-geographic-peer-mentor-map-ui-accessibility-task-008 — Implement the deep-link navigation action from MentorInfoPopup to the peer mentor detail screen. On button tap, push the peer mentor detail route with the mentor ID. Ensure the navigation preserves the map state so the back button returns to the map with filters intact. Validate that the deep-link button has correct semantic role (button) and label ('View profile of [mentor name]').
Acceptance Criteria
Technical Requirements
Execution Context
Tier 5 - 253 tasks
Can start after Tier 4 completes
Implementation Notes
Use GoRouter's push (not go) so the back stack is preserved. Store map filter state in the BLoC, not in widget local state, so it survives route pushes. Wrap the button widget in a Semantics widget: Semantics(label: 'View profile of ${mentor.displayName}', button: true, child: ...). Disable the button immediately on tap using a BooleanCubit or onTap guard flag and re-enable only if navigation is cancelled.
Do not pass the full mentor object through the route; only pass the ID and let the detail screen fetch its own data.
Testing Requirements
Write widget tests verifying that tapping the popup button triggers the correct GoRouter/Navigator push with the mentor's ID. Write a BLoC unit test confirming filter state is unchanged after a simulated navigation round-trip. Write a Flutter integration test (flutter_test) using a mock navigator observer to assert route push arguments. Test the semantics tree with tester.getSemantics() to confirm label and role.
Test rapid double-tap does not push route twice.
Flutter's map canvas (flutter_map) does not natively support semantic focus traversal for screen readers, meaning map markers may be entirely invisible to VoiceOver/TalkBack users. If the accessible list fallback is not treated as a first-class view, screen reader users will have no access to the feature.
Mitigation & Contingency
Mitigation: From sprint 1, treat mentor-list-fallback as a fully featured primary view, not an afterthought. Implement and test it in parallel with the map canvas. Make the view-toggle-button keyboard focusable and announced on every screen state. Conduct VoiceOver testing on device before submitting each PR touching UI components.
Contingency: If map canvas accessibility cannot be achieved for marker focus traversal, make the view-toggle-button the default focus target on screen load for VoiceOver users (detected via screen-reader-detection-service) so they are immediately directed to the list fallback without needing to discover the toggle.
The mentor-info-popup must occupy no more than 40% of visible map area on small screens. On devices with screen heights under 667px (iPhone SE), overlapping with the filter panel or obscuring most of the map could severely degrade usability.
Mitigation & Contingency
Mitigation: Implement the popup as a bottom sheet capped at 40% of screen height with a ScrollView for overflow content. Test on iPhone SE (375x667pt) and the smallest commonly used Android form factor in the device lab. Define max-height as a percentage constant in location-privacy-config or design tokens.
Contingency: If the popup cannot fit all required fields within 40% height on smallest targets, truncate assigned contact count and certification badge to icons-only in the compact view, with a 'View Profile' button always visible at the bottom of the popup regardless of scroll position.
Filter state must remain perfectly synchronised between the map view and the list fallback. If the filter panel emits state that is not consumed identically by both views, coordinators switching between views will see inconsistent mentor sets, eroding trust in the feature.
Mitigation & Contingency
Mitigation: Store active filter criteria in a single shared Riverpod provider owned by the map-view-screen and consumed by both map-marker-widget (via mentor-location-service) and mentor-list-fallback. Write integration tests that apply a filter, switch views, and assert identical mentor counts in both views.
Contingency: If filter sync proves brittle, simplify to a single filter state object passed explicitly as a constructor argument to both views on each rebuild, eliminating indirect state sharing.