switched checkbox detection to regex, also moved it to helper function

lib/components/BucketTaskCard.dart

@@ -136,27 +136,22 @@ class _BucketTaskCardState extends State<BucketTaskCard> with AutomaticKeepAlive
         backgroundColor: label.color,
       ));
     });
-    if (widget.task.description.isNotEmpty) {
-      final uncompletedTaskCount = '* [ ]'.allMatches(widget.task.description).length;
-      final completedTaskCount = '* [x]'.allMatches(widget.task.description).length;
-      final taskCount = uncompletedTaskCount + completedTaskCount;
-      if (taskCount > 0) {
-        final iconSize = (theme.textTheme.labelLarge.fontSize ?? 14) + 2;
-        labelRow.children.add(Chip(
-          avatar: Container(
-            constraints: BoxConstraints(maxHeight: iconSize, maxWidth: iconSize),
-            child: CircularProgressIndicator(
-              value: uncompletedTaskCount == 0
-                  ? 1 : uncompletedTaskCount.toDouble() / taskCount.toDouble(),
-              backgroundColor: Colors.grey,
-            )  ,
+    if (widget.task.hasCheckboxes) {
+      final checkboxStatistics = widget.task.checkboxStatistics;
+      final iconSize = (theme.textTheme.labelLarge.fontSize ?? 14) + 2;
+      labelRow.children.add(Chip(
+        avatar: Container(
+          constraints: BoxConstraints(maxHeight: iconSize, maxWidth: iconSize),
+          child: CircularProgressIndicator(
+            value: checkboxStatistics.checked / checkboxStatistics.total,
+            backgroundColor: Colors.grey,
           ),
-          label: Text(
-              (uncompletedTaskCount == 0 ? '' : '$completedTaskCount of ')
-                  + '$taskCount tasks'
-          ),
-        ));
-      }
+        ),
+        label: Text(
+            (checkboxStatistics.checked == checkboxStatistics.total ? '' : '${checkboxStatistics.checked} of ')
+                + '${checkboxStatistics.total} tasks'
+        ),
+      ));
     }
     if (widget.task.attachments != null && widget.task.attachments.isNotEmpty) {
       labelRow.children.add(Chip(

lib/models/task.dart

@@ -5,47 +5,53 @@ import 'package:vikunja_app/components/date_extension.dart';
 import 'package:vikunja_app/models/label.dart';
 import 'package:vikunja_app/models/user.dart';
 import 'package:vikunja_app/models/taskAttachment.dart';
+import 'package:vikunja_app/utils/checkboxes_in_text.dart';
 
 @JsonSerializable()
 class Task {
-  int id, parentTaskId, priority, listId, bucketId;
-  DateTime created, updated, dueDate, startDate, endDate;
-  List<DateTime> reminderDates;
-  String title, description, identifier;
-  bool done;
-  Color color;
-  double kanbanPosition;
-  User createdBy;
-  Duration repeatAfter;
-  List<Task> subtasks;
-  List<Label> labels;
-  List<TaskAttachment> attachments;
-  bool loading = false;
+  final int id, parentTaskId, priority, listId, bucketId;
+  final DateTime created, updated, dueDate, startDate, endDate;
+  final List<DateTime> reminderDates;
+  final String title, description, identifier;
+  final bool done;
+  final Color color;
+  final double kanbanPosition;
+  final User createdBy;
+  final Duration repeatAfter;
+  final List<Task> subtasks;
+  final List<Label> labels;
+  final List<TaskAttachment> attachments;
   // TODO: add position(?)
 
-  Task(
-      {@required this.id,
-      this.title,
-      this.description,
-      this.identifier,
-      this.done = false,
-      this.reminderDates,
-      this.dueDate,
-      this.startDate,
-      this.endDate,
-      this.parentTaskId,
-      this.priority,
-      this.repeatAfter,
-      this.color,
-      this.kanbanPosition,
-      this.subtasks,
-      this.labels,
-      this.attachments,
-      this.created,
-      this.updated,
-      this.createdBy,
-      this.listId,
-      this.bucketId});
+  // // TODO: use `late final` once upgraded to current dart version
+  CheckboxStatistics _checkboxStatistics;
+
+  bool loading = false;
+
+  Task({
+    @required this.id,
+    this.title,
+    this.description,
+    this.identifier,
+    this.done = false,
+    this.reminderDates,
+    this.dueDate,
+    this.startDate,
+    this.endDate,
+    this.parentTaskId,
+    this.priority,
+    this.repeatAfter,
+    this.color,
+    this.kanbanPosition,
+    this.subtasks,
+    this.labels,
+    this.attachments,
+    this.created,
+    this.updated,
+    this.createdBy,
+    this.listId,
+    this.bucketId,
+  });
 
   Task.fromJson(Map<String, dynamic> json)
       : id = json['id'],
@@ -117,6 +123,24 @@ class Task {
       ? color.computeLuminance() > 0.5 ? Colors.black : Colors.white
       : null;
 
+  CheckboxStatistics get checkboxStatistics {
+    if (_checkboxStatistics != null)
+      return _checkboxStatistics;
+    if (description.isEmpty)
+      return null;
+
+    _checkboxStatistics = getCheckboxStatistics(description);
+    return _checkboxStatistics;
+  }
+
+  bool get hasCheckboxes {
+    final checkboxStatistics = this.checkboxStatistics;
+    if (checkboxStatistics != null && checkboxStatistics.total != 0)
+      return true;
+    else
+      return false;
+  }
+
   Task copyWith({
     int id, int parentTaskId, int priority, int listId, int bucketId,
     DateTime created, DateTime updated, DateTime dueDate, DateTime startDate, DateTime endDate,

lib/utils/checkboxes_in_text.dart

@@ -0,0 +1,51 @@
+import 'package:meta/meta.dart';
+
+class CheckboxStatistics {
+  final int total;
+  final int checked;
+
+  const CheckboxStatistics({
+    @required this.total,
+    @required this.checked,
+  });
+}
+
+class MatchedCheckboxes {
+  final Iterable<Match> checked;
+  final Iterable<Match> unchecked;
+
+  const MatchedCheckboxes({
+    @required this.checked,
+    @required this.unchecked,
+  });
+}
+
+MatchedCheckboxes getCheckboxesInText(String text) {
+  const checkedString = '[x]';
+  final checked = <Match>[];
+  final unchecked = <Match>[];
+
+  final matches = RegExp(r'[*-] \[[ x]]').allMatches(text);
+
+  for (final match in matches) {
+    if (match[0].endsWith(checkedString))
+      checked.add(match);
+    else
+      unchecked.add(match);
+  }
+
+  return MatchedCheckboxes(
+    checked: checked,
+    unchecked: unchecked,
+  );
+}
+
+CheckboxStatistics getCheckboxStatistics(String text) {
+  final checkboxes = getCheckboxesInText(text);
+
+  return CheckboxStatistics(
+    total: checkboxes.checked.length + checkboxes.unchecked.length,
+    checked: checkboxes.checked.length,
+  );
+}
+