Build RecordingStateIndicator animated overlay widget
epic-speech-to-text-input-user-interface-task-003 — Implement the RecordingStateIndicator Flutter widget as a floating overlay that renders above active report fields during dictation. The overlay must display an animated waveform visualisation during recording and a spinner/pulse animation during processing. Colour-code states: recording (primary brand colour), processing (amber), error (destructive). All animations must respect the system reduce-motion accessibility setting.
Acceptance Criteria
Technical Requirements
Implementation Notes
For the waveform animation, use a CustomPainter driven by an AnimationController value rather than rebuilding the widget tree — this keeps animation work on the raster thread. Expose the animation as a `Listenable` and use `AnimatedBuilder` to repaint only the CustomPainter canvas. Pattern: `AnimationController _controller = AnimationController(vsync: this, duration: const Duration(milliseconds: 800))..repeat(reverse: true)`. Check `MediaQuery.of(context).disableAnimations` in `initState()` (and in a `didChangeDependencies()` override for dynamic changes) and skip `_controller.repeat()` if true.
For overlay positioning, the widget likely needs to be used with an `OverlayEntry` or a `Stack` in the field's parent — coordinate with task-001 to decide the compositional approach. Color tokens: use `AppColors.primary` for recording, `AppColors.warning` (amber) for processing, `AppColors.destructive` for error — verify these token names exist in the design token system before using them.
Testing Requirements
Widget tests: (1) Pump with recording state — verify waveform widget is present and AnimationController is ticking (check isAnimating). (2) Pump with processing state — verify spinner/pulse widget is present and waveform is absent. (3) Pump with error state — verify error indicator uses destructive token color. (4) Pump with idle state — verify widget is not visible and semantics tree contains no indicator node.
(5) Pump with MediaQuery.disableAnimations = true in recording state — verify AnimationController is NOT started (isAnimating == false) and a static icon is shown instead. (6) Pump with disableAnimations = true and verify opacity transition is instant (no AnimatedOpacity with duration > 0). (7) Golden tests for each state (recording, processing, error) at standard and large text sizes. (8) Verify IgnorePointer by simulating tap on overlay area and confirming underlying widget receives the tap.
Merging dictated text at the current cursor position in a TextField that already contains user-typed content is non-trivial in Flutter — TextEditingController cursor offsets can behave unexpectedly with IME composition, emoji, or RTL characters, potentially corrupting the user's existing notes.
Mitigation & Contingency
Mitigation: Implement the merge logic using TextEditingController.value replacement with explicit selection range calculation rather than direct text manipulation. Write targeted widget tests covering edge cases: cursor at start, cursor at end, cursor mid-word, existing content with emoji, and content that was modified during an active partial-results stream.
Contingency: If cursor-position merging proves too fragile for the initial release, scope the merge behaviour to always append dictated text at the end of the existing field content and add the cursor-position insertion as a follow-on task after the feature is in TestFlight with real user feedback.
VoiceOver on iOS and TalkBack on Android handle rapid sequential live region announcements differently. If recording start, partial-result, and recording-stop announcements arrive within a short window, they may queue, overlap, or be dropped, leaving screen reader users without critical state information.
Mitigation & Contingency
Mitigation: Implement announcement queuing in AccessibilityLiveRegionAnnouncer with a minimum inter-announcement delay and priority ordering (assertive recording start/stop always takes precedence over polite partial-result updates). Test announcement behaviour on physical iOS and Android devices with VoiceOver/TalkBack enabled as part of the acceptance test plan.
Contingency: If platform differences make reliable queuing impossible, reduce partial-result announcements to a single 'transcription updating' message with debouncing, preserving the critical start/stop announcements. Coordinate with the screen-reader-support feature team to leverage the existing SemanticsServiceFacade patterns already established in the codebase.
The DictationMicrophoneButton must integrate with the dynamic-field-renderer which generates form fields from org-specific schemas at runtime. If the renderer does not expose a stable field metadata API for dictation eligibility checks, the scope guard and button visibility logic will require invasive changes to the report form architecture.
Mitigation & Contingency
Mitigation: Coordinate with the post-session report feature team early in the epic to confirm that dynamic-field-renderer exposes a field metadata interface including field type and sensitivity flags. Add a dictation_eligible flag to the field schema that the renderer passes to DictationMicrophoneButton as a constructor parameter.
Contingency: If the renderer cannot be modified without breaking changes, implement dictation eligibility as a separate lookup against org-field-config-loader using the field key as the lookup identifier, bypassing the renderer integration and keeping the dictation components fully decoupled from the report form architecture.