feat(sensors): show expected and actual sampling rates

open_wearable/docs/pages/sensor-pages.md

@@ -43,6 +43,7 @@
 - Does:
   - Builds sensor cards for all active sensors across wearables.
   - Supports no-graph mode and hide-empty-graphs mode.
+  - Can show expected and actual sampling rates on sensor charts. Labels are off by default; the preference is saved under Settings → General settings → Live data → Show sampling rates.
   - Uses merged provider listenables for efficient live refresh.
 - Provides:
   - Live chart/value surface for all connected sensors.

open_wearable/lib/assets/fonts/OFL.txt

@@ -0,0 +1,93 @@
+Copyright 2015 The Roboto Mono Project Authors (https://github.com/googlefonts/robotomono)
+
+This Font Software is licensed under the SIL Open Font License, Version 1.1.
+This license is copied below, and is also available with a FAQ at:
+https://openfontlicense.org
+
+
+-----------------------------------------------------------
+SIL OPEN FONT LICENSE Version 1.1 - 26 February 2007
+-----------------------------------------------------------
+
+PREAMBLE
+The goals of the Open Font License (OFL) are to stimulate worldwide
+development of collaborative font projects, to support the font creation
+efforts of academic and linguistic communities, and to provide a free and
+open framework in which fonts may be shared and improved in partnership
+with others.
+
+The OFL allows the licensed fonts to be used, studied, modified and
+redistributed freely as long as they are not sold by themselves. The
+fonts, including any derivative works, can be bundled, embedded,
+redistributed and/or sold with any software provided that any reserved
+names are not used by derivative works. The fonts and derivatives,
+however, cannot be released under any other type of license. The
+requirement for fonts to remain under this license does not apply
+to any document created using the fonts or their derivatives.
+
+DEFINITIONS
+"Font Software" refers to the set of files released by the Copyright
+Holder(s) under this license and clearly marked as such. This may
+include source files, build scripts and documentation.
+
+"Reserved Font Name" refers to any names specified as such after the
+copyright statement(s).
+
+"Original Version" refers to the collection of Font Software components as
+distributed by the Copyright Holder(s).
+
+"Modified Version" refers to any derivative made by adding to, deleting,
+or substituting -- in part or in whole -- any of the components of the
+Original Version, by changing formats or by porting the Font Software to a
+new environment.
+
+"Author" refers to any designer, engineer, programmer, technical
+writer or other person who contributed to the Font Software.
+
+PERMISSION & CONDITIONS
+Permission is hereby granted, free of charge, to any person obtaining
+a copy of the Font Software, to use, study, copy, merge, embed, modify,
+redistribute, and sell modified and unmodified copies of the Font
+Software, subject to the following conditions:
+
+1) Neither the Font Software nor any of its individual components,
+in Original or Modified Versions, may be sold by itself.
+
+2) Original or Modified Versions of the Font Software may be bundled,
+redistributed and/or sold with any software, provided that each copy
+contains the above copyright notice and this license. These can be
+included either as stand-alone text files, human-readable headers or
+in the appropriate machine-readable metadata fields within text or
+binary files as long as those fields can be easily viewed by the user.
+
+3) No Modified Version of the Font Software may use the Reserved Font
+Name(s) unless explicit written permission is granted by the corresponding
+Copyright Holder. This restriction only applies to the primary font name as
+presented to the users.
+
+4) The name(s) of the Copyright Holder(s) or the Author(s) of the Font
+Software shall not be used to promote, endorse or advertise any
+Modified Version, except to acknowledge the contribution(s) of the
+Copyright Holder(s) and the Author(s) or with their explicit written
+permission.
+
+5) The Font Software, modified or unmodified, in part or in whole,
+must be distributed entirely under this license, and must not be
+distributed under any other license. The requirement for fonts to
+remain under this license does not apply to any document created
+using the Font Software.
+
+TERMINATION
+This license becomes null and void if any of the above conditions are
+not met.
+
+DISCLAIMER
+THE FONT SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT
+OF COPYRIGHT, PATENT, TRADEMARK, OR OTHER RIGHT. IN NO EVENT SHALL THE
+COPYRIGHT HOLDER BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+INCLUDING ANY GENERAL, SPECIAL, INDIRECT, INCIDENTAL, OR CONSEQUENTIAL
+DAMAGES, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+FROM, OUT OF THE USE OR INABILITY TO USE THE FONT SOFTWARE OR FROM
+OTHER DEALINGS IN THE FONT SOFTWARE.

open_wearable/lib/models/app_shutdown_settings.dart

@@ -19,6 +19,7 @@ class AppShutdownSettings {
       'app_disable_live_data_graphs';
   static const String _hideLiveDataGraphsWithoutDataKey =
       'app_hide_live_data_graphs_without_data';
+  static const String _showSamplingRatesKey = 'app_show_sampling_rates';
   static const String _keepAppInForegroundKey = 'app_keep_in_foreground';
 
   static final ValueNotifier<bool> _shutOffAllSensorsOnAppCloseNotifier =
@@ -27,6 +28,8 @@ class AppShutdownSettings {
       ValueNotifier<bool>(false);
   static final ValueNotifier<bool> _hideLiveDataGraphsWithoutDataNotifier =
       ValueNotifier<bool>(false);
+  static final ValueNotifier<bool> _showSamplingRatesNotifier =
+      ValueNotifier<bool>(false);
   static final ValueNotifier<bool> _keepAppInForegroundNotifier =
       ValueNotifier<bool>(false);
 
@@ -36,6 +39,8 @@ class AppShutdownSettings {
       _disableLiveDataGraphsNotifier;
   static ValueListenable<bool> get hideLiveDataGraphsWithoutDataListenable =>
       _hideLiveDataGraphsWithoutDataNotifier;
+  static ValueListenable<bool> get showSamplingRatesListenable =>
+      _showSamplingRatesNotifier;
   static ValueListenable<bool> get keepAppInForegroundListenable =>
       _keepAppInForegroundNotifier;
 
@@ -44,13 +49,15 @@ class AppShutdownSettings {
   static bool get disableLiveDataGraphs => _disableLiveDataGraphsNotifier.value;
   static bool get hideLiveDataGraphsWithoutData =>
       _hideLiveDataGraphsWithoutDataNotifier.value;
+  static bool get showSamplingRates => _showSamplingRatesNotifier.value;
   static bool get keepAppInForeground => _keepAppInForegroundNotifier.value;
 
   static Future<void> initialize() async {
     await Future.wait([
       loadShutOffAllSensorsOnAppClose(),
       loadDisableLiveDataGraphs(),
       loadHideLiveDataGraphsWithoutData(),
+      loadShowSamplingRates(),
       loadKeepAppInForeground(),
     ]);
   }
@@ -97,6 +104,22 @@ class AppShutdownSettings {
     return enabled;
   }
 
+  /// Loads whether live graphs show their expected and actual sampling rates.
+  static Future<bool> loadShowSamplingRates() async {
+    final prefs = await SharedPreferences.getInstance();
+    final enabled = prefs.getBool(_showSamplingRatesKey) ?? false;
+    _showSamplingRatesNotifier.value = enabled;
+    return enabled;
+  }
+
+  /// Persists label visibility and updates all live graphs immediately.
+  static Future<bool> saveShowSamplingRates(bool enabled) async {
+    final prefs = await SharedPreferences.getInstance();
+    await prefs.setBool(_showSamplingRatesKey, enabled);
+    _showSamplingRatesNotifier.value = enabled;
+    return enabled;
+  }
+
   static Future<bool> loadKeepAppInForeground() async {
     final prefs = await SharedPreferences.getInstance();
     final enabled = prefs.getBool(_keepAppInForegroundKey) ?? false;

open_wearable/lib/widgets/sensors/values/sensor_chart.dart

@@ -6,6 +6,7 @@ import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
 import 'package:flutter_platform_widgets/flutter_platform_widgets.dart';
 import 'package:open_earable_flutter/open_earable_flutter.dart' hide logger;
+import 'package:open_wearable/models/app_shutdown_settings.dart';
 import 'package:open_wearable/view_models/sensor_configuration_provider.dart';
 import 'package:open_wearable/view_models/sensor_data_provider.dart';
 import 'package:open_wearable/view_models/wearables_provider.dart';
@@ -301,9 +302,40 @@ class _SensorChartState extends State<SensorChart> {
             child: LiveDataGraphSurface(
               settings: widget.settings,
               onDisabledTap: widget.onDisabledTap,
-              child: LineChart(
-                chartData,
-                duration: const Duration(milliseconds: 0),
+              child: Stack(
+                fit: StackFit.expand,
+                children: [
+                  LineChart(
+                    chartData,
+                    duration: const Duration(milliseconds: 0),
+                  ),
+                  Positioned(
+                    top: 4,
+                    right: 4,
+                    child: ValueListenableBuilder<bool>(
+                      valueListenable:
+                          AppShutdownSettings.showSamplingRatesListenable,
+                      builder: (context, showSamplingRates, _) {
+                        if (!showSamplingRates) return const SizedBox.shrink();
+                        return IgnorePointer(
+                          child: Text(
+                            _samplingRateLabel(
+                              sensor,
+                              sensorValues,
+                              referenceTimestamp,
+                              sensorConfigurationProvider,
+                            ),
+                            style: const TextStyle(
+                              color: Colors.grey,
+                              fontSize: 10,
+                              fontFamily: 'RobotoMono',
+                            ),
+                          ),
+                        );
+                      },
+                    ),
+                  ),
+                ],
               ),
             ),
           ),
@@ -587,6 +619,42 @@ class _SensorChartState extends State<SensorChart> {
     }
   }
 
+  String _samplingRateLabel(
+    Sensor sensor,
+    Queue<SensorValue> values,
+    int referenceTimestamp,
+    SensorConfigurationProvider? configurationProvider,
+  ) {
+    double? expectedHz;
+    for (final configuration in sensor.relatedConfigurations) {
+      final activeValue = _activeFrequencyValueForConfiguration(
+        configuration,
+        configurationProvider,
+      );
+      if (activeValue == null) continue;
+      final rate = _isStreamingFrequencyValue(configuration, activeValue)
+          ? activeValue.frequencyHz
+          : 0.0;
+      expectedHz = max(expectedHz ?? 0, rate);
+    }
+
+    // Use the existing rolling buffer, including silence since the last sample.
+    final elapsed = values.isEmpty
+        ? 0.0
+        : (referenceTimestamp - values.first.timestamp) *
+            pow(10, sensor.timestampExponent);
+    final actualHz =
+        values.length < 2 || elapsed <= 0 ? 0.0 : (values.length - 1) / elapsed;
+    // Round up below the target, but only show an excess of at least 1 Hz.
+    final actual = expectedHz != null && actualHz < expectedHz + 1
+        ? min(actualHz.ceil(), expectedHz.round())
+        : actualHz.round();
+    final expected = expectedHz?.round().toString() ?? '—';
+    // Reserve only as many digits as the expected rate needs.
+    return 'Expected $expected Hz · '
+        'Actual ${actual.toString().padLeft(expected.length)} Hz';
+  }
+
   _FilterFrequencyBounds _frequencyBoundsForSensor(
     Sensor sensor, {
     SensorConfigurationProvider? sensorConfigurationProvider,

open_wearable/lib/widgets/settings/general_settings_page.dart

@@ -74,6 +74,26 @@ class _GeneralSettingsPageState extends State<GeneralSettingsPage> {
     }
   }
 
+  Future<void> _setShowSamplingRates(bool enabled) async {
+    if (_isSaving) {
+      return;
+    }
+
+    setState(() {
+      _isSaving = true;
+    });
+
+    try {
+      await AppShutdownSettings.saveShowSamplingRates(enabled);
+    } finally {
+      if (mounted) {
+        setState(() {
+          _isSaving = false;
+        });
+      }
+    }
+  }
+
   Future<void> _setAutoConnectEnabled(bool enabled) async {
     if (_isSaving) {
       return;
@@ -263,6 +283,25 @@ class _GeneralSettingsPageState extends State<GeneralSettingsPage> {
                                       'Hides live data graphs in Sensors › Live Data until samples arrive',
                                     ),
                                   ),
+                                  ValueListenableBuilder<bool>(
+                                    valueListenable: AppShutdownSettings
+                                        .showSamplingRatesListenable,
+                                    builder: (context, showSamplingRates, _) =>
+                                        SwitchListTile.adaptive(
+                                      value: showSamplingRates,
+                                      onChanged: _isSaving
+                                          ? null
+                                          : _setShowSamplingRates,
+                                      secondary: const Icon(
+                                        Icons.speed_rounded,
+                                        size: 18,
+                                      ),
+                                      title: const Text('Show sampling rates'),
+                                      subtitle: const Text(
+                                        'Show expected and actual sampling rates on live graphs',
+                                      ),
+                                    ),
+                                  ),
                                 ],
                               ),
                             ],

open_wearable/pubspec.yaml

@@ -92,12 +92,18 @@ flutter:
   # the material Icons class.
   uses-material-design: true
 
+  fonts:
+    - family: RobotoMono
+      fonts:
+        - asset: lib/assets/fonts/RobotoMono.ttf
+
   # To add assets to your application, add an assets section, like this:
   assets:
     - lib/apps/posture_tracker/assets/
     - lib/apps/heart_tracker/assets/
     - lib/apps/seal_check/assets/
     - lib/assets/devices/phone-app.png
+    - lib/assets/fonts/OFL.txt
     - android/app/src/main/res/mipmap-xxxhdpi/ic_launcher.png
 
   # An image asset can refer to one or more resolution-specific "variants", seeq