Watcher class

Stateless widget that supports watching Listenables within a provided builder function.

Examole:

Watcher(builder: (context) {
  final result = notifier.watch(context);
  return Text(switch (result) {
    Data(data: var d) => d,
    Error(error: var e, data: var d) => 'Error ($e) - $d',
    Loading(data: var d) => d != null ? 'Loading - $d' : 'Loading...',
  });
})

See also:

• WatcherWidget
• WatcherMixin
• StatefulWatcherMixin

Inheritance

• Object
• DiagnosticableTree
• Widget
• StatelessWidget
• WatcherWidget
• Watcher

Constructors

Watcher.new({required Widget builder(WatcherContext context), Key? key})

const

Properties

builder → Widget Function(WatcherContext context)

A widget builder in which it's possible to watch Listenables, using the watch extension method.

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

ref → WatcherRef

Object that provides support for watching Listenables within a Widget.

no setter, inherited

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

Methods

build(covariant WatcherContext 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