RtSignalWatcher class

A StatefulWidget that listens for Signals and re-build when any Signal is changed.

For example:

final count = Signal(0);
final toggle = Signal(false);

class Example extends StatelessWidget {
  Widget build(context) {
    return RtSignalWatcher(
      build: (context, child) {
        return Column(
          children: [
            Text("Count: $count"),
            Text("Toggle is: $toggle"),
          ],
        );
      },
    );
  }
}

Build the widget tree with the values of the Signals contained in the RtSignalWatcher, and with each change of its values, it will re-build the widget tree. Use child property to pass a Widget which to be built once only. It will be sent through the builder callback, so you can incorporate it into your build:

RtSignalWatcher(
  child: Row(
    children: [
      ElevatedButton(
        onPressed: () => signal.value += 1,
        child: const Text("Increase +1"),
      ),
      ElevatedButton(
        onPressed: () => toggle(!toggle.value),
        child: const Text("Toggle"),
      ),
    ],
  ),
  builder: (context, child) {
    return Column(
      children: [
        Text("Count: $count"),
        Text("Toggle is: $toggle"),
        if (child != null) child, // Row with 2 buttons
      ],
    );
  },
);

See also:

• Signal, a reactive state of any type.

Inheritance

• Object
• DiagnosticableTree
• Widget
• StatefulWidget
• RtSignalWatcher

Constructors

RtSignalWatcher({Key? key, Widget? child, required TransitionBuilder? builder})

A StatefulWidget that listens for Signals and re-build when any Signal is changed.

const

Properties

builder → TransitionBuilder?

Method which has the render logic

final

child → Widget?

Provides a widget , which render one time.

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

createElement() → StatefulElement

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

inherited

createState() → State<RtSignalWatcher>

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