Activity<T extends ActiveController> class

Expose an existing shared controller to descendant consumers.

Create the controller outside build. Descendants borrow it; the owner disposes it. Replacing the controller rebinds scope subscriptions. Widget examples require Flutter, including Flutter web, rather than a plain Dart console.

Gallery walkthrough · browser route /#/start. These examples use the current checkout; published 1.x APIs can differ.

import 'dart:async';
import 'package:activity/activity.dart';
import 'package:flutter/material.dart';

class CounterController extends ActiveController {
  final count = ActiveInt(0);
  @override
  Iterable<ActiveType> get activities => [count];
}

void main() => runApp(const MaterialApp(home: CounterOwner()));

class CounterOwner extends StatefulWidget {
  const CounterOwner({super.key});
  @override
  State<CounterOwner> createState() => _CounterOwnerState();
}

class _CounterOwnerState extends State<CounterOwner> {
  final controller = CounterController();
  @override
  void dispose() {
    unawaited(controller.dispose());
    super.dispose();
  }

  @override
  Widget build(BuildContext context) => Scaffold(
    body: Activity<CounterController>(
      controller,
      child: Builder(
        builder: (context) {
          final shared = Activity.getActivity<CounterController>(context);
          return TextButton(
            onPressed: shared.count.increment,
            child: Text('Count ${shared.count.value}'),
          );
        },
      ),
    ),
  );
}

Combine a scope and selective view

import 'dart:async';
import 'package:activity/activity.dart';
import 'package:flutter/material.dart';

class CounterController extends ActiveController {
  final count = ActiveInt(0);
  @override
  Iterable<ActiveType> get activities => [count];
}

void main() => runApp(const MaterialApp(home: CounterOwner()));

class CounterOwner extends StatefulWidget {
  const CounterOwner({super.key});
  @override
  State<CounterOwner> createState() => _CounterOwnerState();
}

class _CounterOwnerState extends State<CounterOwner> {
  final controller = CounterController();
  @override
  void dispose() {
    unawaited(controller.dispose());
    super.dispose();
  }

  @override
  Widget build(BuildContext context) => Scaffold(
    body: Activity<CounterController>(
      controller,
      child: ActivitySelector<CounterController, int>(
        controller: controller,
        select: (c) => c.count.value,
        builder:
            (_, count, child) => TextButton(
              onPressed: controller.count.increment,
              child: Text('Count $count'),
            ),
      ),
    ),
  );
}

Inheritance

Constructors

Activity(T activeController, {Key? key, required Widget child, String onActivityStateChanged()?, bool developerMode = false}): const

Properties

activeController → T: final
child → Widget: final
developerMode → bool: final
hashCode → int: The hash code for this object.
no setterinherited
key → Key?: Controls how one widget replaces another widget in the tree.
finalinherited
onActivityStateChanged → String Function()?: final
runtimeType → Type: A representation of the runtime type of the object.
no setterinherited

Methods

createElement() → StatefulElement: Creates a StatefulElement to manage this widget's location in the tree.
inherited
createState() → State<Activity<T>>: Creates the mutable state for this widget at a given location in the tree.
override
debugDescribeChildren() → List<DiagnosticsNode>: Returns a list of DiagnosticsNode objects describing this node's children.
inherited
debugFillProperties(DiagnosticPropertiesBuilder properties) → void: Add additional properties associated with the node.
inherited
noSuchMethod(Invocation invocation) → dynamic: Invoked when a nonexistent method or property is accessed.
inherited
toDiagnosticsNode({String? name, DiagnosticsTreeStyle? style}) → DiagnosticsNode: Returns a debug representation of the object that is used by debugging tools and by DiagnosticsNode.toStringDeep.
inherited
toString({DiagnosticLevel minLevel = DiagnosticLevel.info}) → String: A string representation of this object.
inherited
toStringDeep({String prefixLineOne = '', String? prefixOtherLines, DiagnosticLevel minLevel = DiagnosticLevel.debug, int wrapWidth = 65}) → String: Returns a string representation of this node and its descendants.
inherited
toStringShallow({String joiner = ', ', DiagnosticLevel minLevel = DiagnosticLevel.debug}) → String: Returns a one-line detailed description of the object.
inherited
toStringShort() → String: A short, textual description of this widget.
inherited

Operators

operator ==(Object other) → bool: The equality operator.
inherited

Static Methods

getActivity<T extends ActiveController>(BuildContext context) → T: Gets the current Controller based on the Activator and context.
of<T extends ActiveController>(BuildContext context) → Activator<T>: Gets the instance of the Activator that matches the generic type argument T.