implement time period validation for bolus/basal profiles

lib/screens/basal/basal_detail.dart

@@ -4,7 +4,6 @@ import 'package:diameter/config.dart';
 import 'package:diameter/navigation.dart';
 import 'package:diameter/utils/date_time_utils.dart';
 import 'package:flutter/material.dart';
-import 'package:flutter/services.dart';
 import 'package:diameter/components/forms.dart';
 import 'package:diameter/models/basal.dart';
 import 'package:diameter/models/basal_profile.dart';
@@ -116,6 +115,9 @@ class _BasalDetailScreenState extends State<BasalDetailScreen> {
               Row(
                 children: [
                   Expanded(
+                    // TODO fix handling of time zones!
+                    child: Padding(
+                      padding: const EdgeInsets.only(right: 5),
                       child: StyledTimeOfDayFormField(
                         label: 'Start Time',
                         controller: _startTimeController,
@@ -130,7 +132,10 @@ class _BasalDetailScreenState extends State<BasalDetailScreen> {
                         },
                       ),
                     ),
+                  ),
                   Expanded(
+                    child: Padding(
+                      padding: const EdgeInsets.only(left: 5),
                       child: StyledTimeOfDayFormField(
                         label: 'End Time',
                         controller: _endTimeController,
@@ -145,6 +150,7 @@ class _BasalDetailScreenState extends State<BasalDetailScreen> {
                         },
                       ),
                     ),
+                  ),
                 ],
               ),
               TextFormField(

lib/screens/basal/basal_list.dart

@@ -1,5 +1,6 @@
 import 'package:diameter/components/dialogs.dart';
 import 'package:diameter/config.dart';
+import 'package:diameter/utils/date_time_utils.dart';
 import 'package:flutter/material.dart';
 import 'package:diameter/components/progress_indicator.dart';
 import 'package:diameter/models/basal.dart';
@@ -64,6 +65,44 @@ class _BasalListScreenState extends State<BasalListScreen> {
     }
   }
 
+  String? checkBasalValidity(List<Basal> basalRates, int index) {
+    Basal basal = basalRates[index];
+
+    // check for gaps
+    if (index == 0 &&
+        (basal.startTime.toLocal().hour != 0 || basal.startTime.minute != 0)) {
+      return 'First Basal of the day needs to start at 00:00';
+    }
+
+    if (index > 0) {
+      var lastEndTime = basalRates[index - 1].endTime;
+      if (basal.startTime.isAfter(lastEndTime)) {
+        return 'There\'s a time gap between this and the previous rate';
+      }
+    }
+
+    if (index == basalRates.length - 1 &&
+        (basal.endTime.toLocal().hour != 0 || basal.endTime.minute != 0)) {
+      return 'Last Basal of the day needs to end at 00:00';
+    }
+
+    // check for duplicates
+
+    if (basalRates
+        .where((other) => basal != other && basal.startTime == other.startTime)
+        .isNotEmpty) {
+      return 'There are multiple rates with this start time';
+    }
+
+    if (basalRates
+        .where((other) =>
+            basal.startTime.isBefore(other.startTime) &&
+            basal.endTime.isAfter(other.startTime))
+        .isNotEmpty) {
+      return 'This rate\'s time period overlaps with another one';
+    }
+  }
+
   @override
   void initState() {
     super.initState();
@@ -73,51 +112,64 @@ class _BasalListScreenState extends State<BasalListScreen> {
   @override
   Widget build(BuildContext context) {
     return SingleChildScrollView(
-      padding: const EdgeInsets.only(top: 10.0),
       child: Column(
         children: [
           FutureBuilder<List<Basal>>(
             future: widget.basalProfile!.basalRates,
             builder: (context, snapshot) {
               return ViewWithProgressIndicator(
-                // TODO: add warning if time period is missing or has multiple rates
                 snapshot: snapshot,
                 child: snapshot.data == null || snapshot.data!.isEmpty
                     ? const Padding(
                         padding: EdgeInsets.all(10.0),
                         child: Text('No Basal Rates for this Profile'),
                       )
-                    : ListBody(
+                    : ListView.builder(
+                        shrinkWrap: true,
+                        itemCount:
+                            snapshot.data != null ? snapshot.data!.length : 0,
+                        itemBuilder: (context, index) {
+                          final basal = snapshot.data![index];
+                          final error =
+                              checkBasalValidity(snapshot.data!, index);
+                          return ListTile(
+                            tileColor:
+                                error != null ? Colors.red.shade100 : null,
+                            onTap: () {
+                              handleEditAction(basal);
+                            },
+                            title: Row(
+                              mainAxisSize: MainAxisSize.max,
                               children: [
-                          DataTable(
+                                Expanded(
-                            columnSpacing: 10.0,
+                                    child: Text(
-                            showCheckboxColumn: false,
+                                        '${DateTimeUtils.displayTime(basal.startTime)} - ${DateTimeUtils.displayTime(basal.endTime)}')),
-                            rows: snapshot.data != null
+                                const Spacer(),
-                                ? snapshot.data!.map((basal) {
+                                Expanded(child: Text('${basal.units} U')),
-                                    return DataRow(
+                              ],
-                                      cells: basal.asDataTableCells([
-                                        IconButton(
-                                            icon: const Icon(Icons.edit),
-                                            iconSize: 16.0,
-                                            onPressed: () =>
-                                                handleEditAction(basal)),
-                                        IconButton(
-                                          icon: const Icon(Icons.delete),
-                                          iconSize: 16.0,
-                                          onPressed: () =>
-                                              handleDeleteAction(basal),
                             ),
-                                      ]),
+                            subtitle: error != null
-                                    );
+                                ? Text(error,
-                                  }).toList()
+                                    style: const TextStyle(color: Colors.red))
-                                : [],
+                                : Container(),
-                            columns: Basal.asDataTableColumns(),
+                            trailing: Row(
+                              mainAxisSize: MainAxisSize.min,
+                              children: [
+                                IconButton(
+                                  icon: const Icon(
+                                    Icons.delete,
+                                    color: Colors.blue,
+                                  ),
+                                  onPressed: () => handleDeleteAction(basal),
                                 ),
                               ],
                             ),
                           );
                         },
                       ),
+              );
+            },
+          ),
         ],
       ),
     );

lib/screens/basal/basal_profile_detail.dart

@@ -227,7 +227,7 @@ class _BasalProfileDetailScreenState extends State<BasalProfileDetailScreen> {
   Widget build(BuildContext context) {
     bool isNew = widget.basalProfile == null;
     return DefaultTabController(
-      length: 2,
+      length: isNew ? 1 : 2,
       child: Builder(builder: (BuildContext context) {
         final TabController tabController = DefaultTabController.of(context)!;
         tabController.addListener(() {
@@ -235,24 +235,7 @@ class _BasalProfileDetailScreenState extends State<BasalProfileDetailScreen> {
             renderTabButtons(tabController.index);
           }
         });
-        return Scaffold(
+        List<Widget> tabs = [
-          appBar: AppBar(
-            title:
-                Text(isNew ? 'New Basal Profile' : widget.basalProfile!.name),
-            bottom: isNew
-                ? PreferredSize(child: Container(), preferredSize: Size.zero)
-                : const TabBar(
-                    tabs: [
-                      Tab(text: 'PROFILE'),
-                      Tab(text: 'RATES'),
-                    ],
-                  ),
-            actions: appBarActions,
-          ),
-          drawer: const Navigation(
-              currentLocation: BasalProfileDetailScreen.routeName),
-          body: TabBarView(
-            children: [
           SingleChildScrollView(
             child: Column(
               crossAxisAlignment: CrossAxisAlignment.stretch,
@@ -295,9 +278,29 @@ class _BasalProfileDetailScreenState extends State<BasalProfileDetailScreen> {
               ],
             ),
           ),
-              BasalListScreen(basalProfile: widget.basalProfile),
+        ];
+
+        if (!isNew) {
+          tabs.add(BasalListScreen(basalProfile: widget.basalProfile));
+        }
+
+        return Scaffold(
+          appBar: AppBar(
+            title:
+                Text(isNew ? 'New Basal Profile' : widget.basalProfile!.name),
+            bottom: isNew
+                ? PreferredSize(child: Container(), preferredSize: Size.zero)
+                : const TabBar(
+                    tabs: [
+                      Tab(text: 'PROFILE'),
+                      Tab(text: 'RATES'),
                     ],
                   ),
+            actions: appBarActions,
+          ),
+          drawer: const Navigation(
+              currentLocation: BasalProfileDetailScreen.routeName),
+          body: TabBarView(children: tabs),
           bottomNavigationBar: DetailBottomRow(
             onCancel: handleCancelAction,
             onSave: handleSaveAction,

lib/screens/bolus/bolus_detail.dart

@@ -6,11 +6,9 @@ import 'package:diameter/settings.dart';
 import 'package:diameter/utils/date_time_utils.dart';
 import 'package:diameter/utils/utils.dart';
 import 'package:flutter/material.dart';
-import 'package:flutter/services.dart';
 import 'package:diameter/components/forms.dart';
 import 'package:diameter/models/bolus.dart';
 import 'package:diameter/models/bolus_profile.dart';
-import 'package:flutter/widgets.dart';
 
 class BolusDetailScreen extends StatefulWidget {
   static const String routeName = '/bolus';
@@ -31,12 +29,12 @@ class _BolusDetailScreenState extends State<BolusDetailScreen> {
   TimeOfDay _startTime = const TimeOfDay(hour: 0, minute: 0);
   TimeOfDay _endTime = const TimeOfDay(hour: 0, minute: 0);
 
-  final _startTimeController = TextEditingController();
+  final _startTimeController = TextEditingController(text: '');
-  final _endTimeController = TextEditingController();
+  final _endTimeController = TextEditingController(text: '');
-  final _unitsController = TextEditingController();
+  final _unitsController = TextEditingController(text: '');
-  final _carbsController = TextEditingController();
+  final _carbsController = TextEditingController(text: '');
-  final _mgPerDlController = TextEditingController();
+  final _mgPerDlController = TextEditingController(text: '');
-  final _mmolPerLController = TextEditingController();
+  final _mmolPerLController = TextEditingController(text: '');
 
   @override
   void initState() {
@@ -136,7 +134,6 @@ class _BolusDetailScreenState extends State<BolusDetailScreen> {
   }
 
   void convertBetweenMgPerDlAndMmolPerL({GlucoseMeasurement? calculateFrom}) {
-    // TODO figure out why this isnt happening automatically
     int? mgPerDl;
     double? mmolPerL;
 
@@ -182,6 +179,9 @@ class _BolusDetailScreenState extends State<BolusDetailScreen> {
                 Row(
                   children: [
                     Expanded(
+                      child: Padding(
+                        padding: const EdgeInsets.only(right: 5),
+                        // TODO fix handling of time zones!
                         child: StyledTimeOfDayFormField(
                           label: 'Start Time',
                           controller: _startTimeController,
@@ -196,7 +196,10 @@ class _BolusDetailScreenState extends State<BolusDetailScreen> {
                           },
                         ),
                       ),
+                    ),
                     Expanded(
+                      child: Padding(
+                        padding: const EdgeInsets.only(left: 5),
                         child: StyledTimeOfDayFormField(
                           label: 'End Time',
                           controller: _endTimeController,
@@ -211,6 +214,7 @@ class _BolusDetailScreenState extends State<BolusDetailScreen> {
                           },
                         ),
                       ),
+                    ),
                   ],
                 ),
                 TextFormField(
@@ -262,7 +266,9 @@ class _BolusDetailScreenState extends State<BolusDetailScreen> {
                               ),
                               controller: _mgPerDlController,
                               onChanged: (_) =>
-                                  convertBetweenMgPerDlAndMmolPerL,
+                                  convertBetweenMgPerDlAndMmolPerL(
+                                      calculateFrom:
+                                          GlucoseMeasurement.mgPerDl),
                               keyboardType:
                                   const TextInputType.numberWithOptions(),
                               validator: (value) {
@@ -296,7 +302,9 @@ class _BolusDetailScreenState extends State<BolusDetailScreen> {
                               ),
                               controller: _mmolPerLController,
                               onChanged: (_) =>
-                                  convertBetweenMgPerDlAndMmolPerL,
+                                  convertBetweenMgPerDlAndMmolPerL(
+                                      calculateFrom:
+                                          GlucoseMeasurement.mmolPerL),
                               keyboardType:
                                   const TextInputType.numberWithOptions(
                                       decimal: true),

lib/screens/bolus/bolus_list.dart

@@ -1,5 +1,7 @@
 import 'package:diameter/components/dialogs.dart';
 import 'package:diameter/config.dart';
+import 'package:diameter/settings.dart';
+import 'package:diameter/utils/date_time_utils.dart';
 import 'package:flutter/material.dart';
 import 'package:diameter/components/progress_indicator.dart';
 import 'package:diameter/models/bolus.dart';
@@ -64,6 +66,44 @@ class _BolusListScreenState extends State<BolusListScreen> {
     }
   }
 
+  String? checkBolusValidity(List<Bolus> bolusRates, int index) {
+    Bolus bolus = bolusRates[index];
+
+    // check for gaps
+    if (index == 0 &&
+        (bolus.startTime.toLocal().hour != 0 || bolus.startTime.minute != 0)) {
+      return 'First Bolus of the day needs to start at 00:00';
+    }
+
+    if (index > 0) {
+      var lastEndTime = bolusRates[index - 1].endTime;
+      if (bolus.startTime.isAfter(lastEndTime)) {
+        return 'There\'s a time gap between this and the previous rate';
+      }
+    }
+
+    if (index == bolusRates.length - 1 &&
+        (bolus.endTime.toLocal().hour != 0 || bolus.endTime.minute != 0)) {
+      return 'Last Bolus of the day needs to end at 00:00';
+    }
+
+    // check for duplicates
+
+    if (bolusRates
+        .where((other) => bolus != other && bolus.startTime == other.startTime)
+        .isNotEmpty) {
+      return 'There are multiple rates with this start time';
+    }
+
+    if (bolusRates
+        .where((other) =>
+            bolus.startTime.isBefore(other.startTime) &&
+            bolus.endTime.isAfter(other.startTime))
+        .isNotEmpty) {
+      return 'This rate\'s time period overlaps with another one';
+    }
+  }
+
   @override
   void initState() {
     super.initState();
@@ -80,41 +120,58 @@ class _BolusListScreenState extends State<BolusListScreen> {
             future: widget.bolusProfile!.bolusRates,
             builder: (context, snapshot) {
               return ViewWithProgressIndicator(
-                // TODO: add warning if time period is missing or has multiple rates
                 snapshot: snapshot,
                 child: snapshot.data == null || snapshot.data!.isEmpty
                     ? const Padding(
                         padding: EdgeInsets.all(10.0),
-                        child: Text('No Bolus Rates for this Profile'),
+                        child: Text('No Basal Rates for this Profile'),
                       )
-                    : ListBody(
+                    : ListView.builder(
+                        shrinkWrap: true,
+                        itemCount:
+                            snapshot.data != null ? snapshot.data!.length : 0,
+                        itemBuilder: (context, index) {
+                          final bolus = snapshot.data![index];
+                          final error =
+                              checkBolusValidity(snapshot.data!, index);
+                          return ListTile(
+                            tileColor:
+                                error != null ? Colors.red.shade100 : null,
+                            onTap: () {
+                              handleEditAction(bolus);
+                            },
+                            title: Row(
+                              mainAxisSize: MainAxisSize.max,
+                              children: [
+                                Expanded(
+                                    child: Text(
+                                        '${DateTimeUtils.displayTime(bolus.startTime)} - ${DateTimeUtils.displayTime(bolus.endTime)}')),
+                                // TODO: style this
+                                Expanded(
+                                  child: Text(
+                                      '${bolus.units} U per ${bolus.carbs}${nutritionMeasurement == NutritionMeasurement.grams ? ' g' : ' oz'} carbs/${glucoseMeasurement == GlucoseMeasurement.mgPerDl ? bolus.mgPerDl : bolus.mmolPerL} ${glucoseMeasurement == GlucoseMeasurement.mgPerDl ? 'mg/dl' : 'mmol/l'}',
+                                      style: const TextStyle(fontSize: 12.0)),
+                                ),
+                              ],
+                            ),
+                            subtitle: error != null
+                                ? Text(error,
+                                    style: const TextStyle(color: Colors.red))
+                                : Container(),
+                            trailing: Row(
+                              mainAxisSize: MainAxisSize.min,
                               children: [
-                          DataTable(
-                            columnSpacing: 10.0,
-                            showCheckboxColumn: false,
-                            rows: snapshot.data != null
-                                ? snapshot.data!.map((bolus) {
-                                    return DataRow(
-                                      cells: bolus.asDataTableCells(
-                                        [
                                 IconButton(
-                                              icon: const Icon(Icons.edit),
+                                  icon: const Icon(
-                                              iconSize: 16.0,
+                                    Icons.delete,
-                                              onPressed: () =>
+                                    color: Colors.blue,
-                                                  handleEditAction(bolus)),
+                                  ),
-                                          IconButton(
+                                  onPressed: () => handleDeleteAction(bolus),
-                                              icon: const Icon(Icons.delete),
+                                ),
-                                              iconSize: 16.0,
-                                              onPressed: () =>
-                                                  handleDeleteAction(bolus)),
                               ],
                             ),
                           );
-                                  }).toList()
+                        },
-                                : [],
-                            columns: Bolus.asDataTableColumns(),
-                          ),
-                        ],
                       ),
               );
             },

lib/screens/bolus/bolus_profile_detail.dart

@@ -227,7 +227,7 @@ class _BolusProfileDetailScreenState extends State<BolusProfileDetailScreen> {
   Widget build(BuildContext context) {
     bool isNew = widget.bolusProfile == null;
     return DefaultTabController(
-      length: 2,
+      length: isNew ? 1 : 2,
       child: Builder(builder: (BuildContext context) {
         final TabController tabController = DefaultTabController.of(context)!;
         tabController.addListener(() {
@@ -235,24 +235,8 @@ class _BolusProfileDetailScreenState extends State<BolusProfileDetailScreen> {
             renderTabButtons(tabController.index);
           }
         });
-        return Scaffold(
+
-          appBar: AppBar(
+        List<Widget> tabs = [
-            title:
-                Text(isNew ? 'New Bolus Profile' : widget.bolusProfile!.name),
-            bottom: isNew
-                ? PreferredSize(child: Container(), preferredSize: Size.zero)
-                : const TabBar(
-                    tabs: [
-                      Tab(text: 'PROFILE'),
-                      Tab(text: 'RATES'),
-                    ],
-                  ),
-            actions: appBarActions,
-          ),
-          drawer: const Navigation(
-              currentLocation: BolusProfileDetailScreen.routeName),
-          body: TabBarView(
-            children: [
           SingleChildScrollView(
             child: Column(
               crossAxisAlignment: CrossAxisAlignment.stretch,
@@ -294,9 +278,31 @@ class _BolusProfileDetailScreenState extends State<BolusProfileDetailScreen> {
               ],
             ),
           ),
-              BolusListScreen(bolusProfile: widget.bolusProfile),
+        ];
+
+        if (!isNew) {
+          tabs.add(BolusListScreen(bolusProfile: widget.bolusProfile));
+        }
+
+        return Scaffold(
+          appBar: AppBar(
+            title:
+                Text(isNew ? 'New Bolus Profile' : widget.bolusProfile!.name),
+            bottom: isNew
+                ? PreferredSize(child: Container(), preferredSize: Size.zero)
+                : const TabBar(
+                    tabs: [
+                      Tab(text: 'PROFILE'),
+                      Tab(text: 'RATES'),
                     ],
                   ),
+            actions: appBarActions,
+          ),
+          drawer: const Navigation(
+              currentLocation: BolusProfileDetailScreen.routeName),
+          body: TabBarView(
+            children: tabs,
+          ),
           bottomNavigationBar: DetailBottomRow(
             onCancel: handleCancelAction,
             onSave: handleSaveAction,

lib/screens/log/log_entry.dart

@@ -217,7 +217,7 @@ class _LogEntryScreenState extends State<LogEntryScreen> {
     bool isNew = widget.entry == null;
 
     return DefaultTabController(
-      length: 3,
+      length: isNew ? 1 : 3,
       child: Builder(builder: (BuildContext context) {
         final TabController tabController = DefaultTabController.of(context)!;
         tabController.addListener(() {
@@ -225,6 +225,16 @@ class _LogEntryScreenState extends State<LogEntryScreen> {
             renderTabButtons(tabController.index);
           }
         });
+        List<Widget> tabs = [
+          LogEntryForm(
+              formState: logEntryForm, controllers: formDataControllers),
+        ];
+
+        if (!isNew) {
+          tabs.add(LogMealListScreen(logEntry: widget.entry));
+          tabs.add(LogEventListScreen(logEntry: widget.entry));
+        }
+
         return Scaffold(
           appBar: AppBar(
             title: Text(isNew ? 'New Log Entry' : 'Edit Log Entry'),
@@ -241,12 +251,7 @@ class _LogEntryScreenState extends State<LogEntryScreen> {
           ),
           drawer: const Navigation(currentLocation: LogEntryScreen.routeName),
           body: TabBarView(
-            children: [
+            children: tabs,
-              LogEntryForm(
-                  formState: logEntryForm, controllers: formDataControllers),
-              LogMealListScreen(logEntry: widget.entry),
-              LogEventListScreen(logEntry: widget.entry),
-            ],
           ),
           bottomNavigationBar: DetailBottomRow(
             onCancel: handleCancelAction,

lib/screens/log/log_entry_form.dart

@@ -17,6 +17,35 @@ class LogEntryForm extends StatefulWidget {
 }
 
 class _LogEntryFormState extends State<LogEntryForm> {
+  void convertBetweenMgPerDlAndMmolPerL({GlucoseMeasurement? calculateFrom}) {
+    int? mgPerDl;
+    double? mmolPerL;
+    final _mgPerDlController = widget.controllers['mgPerDl'];
+    final _mmolPerLController = widget.controllers['mmolPerL'];
+
+    if (calculateFrom != GlucoseMeasurement.mmolPerL &&
+        _mgPerDlController!.text != '') {
+      mgPerDl = int.tryParse(_mgPerDlController.text);
+    }
+    if (calculateFrom != GlucoseMeasurement.mgPerDl &&
+        _mmolPerLController!.text != '') {
+      mmolPerL = double.tryParse(_mmolPerLController.text);
+    }
+
+    if (mgPerDl != null && mmolPerL == null) {
+      setState(() {
+        _mmolPerLController!.text =
+            Utils.convertMgPerDlToMmolPerL(mgPerDl!).toString();
+      });
+    }
+    if (mmolPerL != null && mgPerDl == null) {
+      setState(() {
+        _mgPerDlController!.text =
+            Utils.convertMmolPerLToMgPerDl(mmolPerL!).toString();
+      });
+    }
+  }
+
   @override
   Widget build(BuildContext context) {
     final _timeController = widget.controllers['time'];
@@ -48,8 +77,6 @@ class _LogEntryFormState extends State<LogEntryForm> {
             //       }
             //),
             Row(
-              // TODO: improve conversion of mg/dl and mmol/l
-              // TODO: display according to settings
               children: [
                 glucoseMeasurement == GlucoseMeasurement.mgPerDl ||
                         glucoseDisplayMode == GlucoseDisplayMode.both ||
@@ -61,6 +88,8 @@ class _LogEntryFormState extends State<LogEntryForm> {
                             suffixText: 'mg/dl',
                           ),
                           controller: _mgPerDlController,
+                          onChanged: (_) => convertBetweenMgPerDlAndMmolPerL(
+                              calculateFrom: GlucoseMeasurement.mgPerDl),
                           keyboardType: const TextInputType.numberWithOptions(),
                           validator: (value) {
                             if (value!.trim().isEmpty &&
@@ -72,6 +101,14 @@ class _LogEntryFormState extends State<LogEntryForm> {
                         ),
                       )
                     : Container(),
+                glucoseDisplayMode == GlucoseDisplayMode.both ||
+                        glucoseDisplayMode == GlucoseDisplayMode.bothForDetail
+                    ? IconButton(
+                        onPressed: () => convertBetweenMgPerDlAndMmolPerL(
+                            calculateFrom: GlucoseMeasurement.mmolPerL),
+                        icon: const Icon(Icons.calculate),
+                      )
+                    : Container(),
                 glucoseMeasurement == GlucoseMeasurement.mmolPerL ||
                         glucoseDisplayMode == GlucoseDisplayMode.both ||
                         glucoseDisplayMode == GlucoseDisplayMode.bothForDetail
@@ -80,19 +117,10 @@ class _LogEntryFormState extends State<LogEntryForm> {
                           decoration: const InputDecoration(
                             labelText: 'mmol/l',
                             suffixText: 'mmol/l',
-                            alignLabelWithHint: true,
                           ),
                           controller: _mmolPerLController,
-                          onChanged: (_) {
+                          onChanged: (_) => convertBetweenMgPerDlAndMmolPerL(
-                            setState(() {
+                              calculateFrom: GlucoseMeasurement.mmolPerL),
-                              _mgPerDlController!.text =
-                                  Utils.convertMmolPerLToMgPerDl(
-                                          double.tryParse(
-                                                  _mgPerDlController.text) ??
-                                              0)
-                                      .toString();
-                            });
-                          },
                           keyboardType: const TextInputType.numberWithOptions(
                               decimal: true),
                           validator: (value) {
@@ -105,6 +133,14 @@ class _LogEntryFormState extends State<LogEntryForm> {
                         ),
                       )
                     : Container(),
+                glucoseDisplayMode == GlucoseDisplayMode.both ||
+                        glucoseDisplayMode == GlucoseDisplayMode.bothForDetail
+                    ? IconButton(
+                        onPressed: () => convertBetweenMgPerDlAndMmolPerL(
+                            calculateFrom: GlucoseMeasurement.mgPerDl),
+                        icon: const Icon(Icons.calculate),
+                      )
+                    : Container(),
               ],
             ),
             TextFormField(
@@ -142,16 +178,6 @@ class _LogEntryFormState extends State<LogEntryForm> {
               keyboardType: TextInputType.multiline,
             ),
           ],
-          // buttons: [
-          //   ElevatedButton(
-          //     onPressed: handleCancelAction,
-          //     child: const Text('CANCEL'),
-          //   ),
-          //   ElevatedButton(
-          //     onPressed: handleSaveAction,
-          //     child: const Text('SAVE'),
-          //   ),
-          // ],
         ),
       ]),
     );

lib/utils/date_time_utils.dart

@@ -3,6 +3,8 @@ import 'package:flutter/material.dart';
 import 'package:intl/intl.dart';
 
 class DateTimeUtils {
+  // TODO fix handling of time zones!
+
   static String displayDateTime(DateTime? date, {String fallback = ''}) {
     if (date == null) {
       return fallback;