Watch<T extends Widget> class

Watch

To watch a signal for changes in Flutter, use the Watch widget. This will only rebuild this widget method and not the entire widget tree.

final signal = signal(10);
...
@override
Widget build(BuildContext context) {
  return Watch((context, _) => Text('$signal'));
}

This will also automatically unsubscribe when the widget is disposed.

Any inherited widgets referenced to inside the Watch scope will be subscribed to for updates (MediaQuery, Theme, etc.) and retrigger the builder method.

There is also a drop in replacement for builder:

final signal = signal(10);
...
@override
Widget build(BuildContext context) {
-  return Builder(
+  return Watch.builder(
    builder: (context, _) => Text('$signal'),
  );
}

Inheritance

• Object
• DiagnosticableTree
• Widget
• StatelessWidget
• Watch

Constructors

Watch(T builder(BuildContext context), {Key? key, String? debugLabel, List<ReadonlySignal> dependencies = const []})

Minimal builder for signal changes that rerender a widget tree.

const

Watch.builder({Key? key, required T builder(BuildContext context), String? debugLabel, List<ReadonlySignal> dependencies = const []})

Drop in replacement for the Flutter builder widget.

const

Properties

builder → T Function(BuildContext context)

The widget to rebuild when any signals change

final

debugLabel → String?

Optional debug label to use for devtools

final

dependencies → List<ReadonlySignal>

List of optional dependencies to watch

final

hashCode → int

The hash code for this object.

no setter, inherited

key → Key?

Controls how one widget replaces another widget in the tree.

final, inherited

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

Methods

build(BuildContext context) → Widget

Describes the part of the user interface represented by this widget.

override

createElement() → StatelessElement

Creates a StatelessElement to manage this widget's location in the tree.

inherited

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