StreamControllerWrapper<T> class

A StatefulWidget that provides a StreamController to its child builder and handles the controller's lifecycle.

StreamControllerWrapper is useful for managing a StreamController within a widget subtree, ensuring the controller is properly created and disposed, and allowing callbacks for stream listen and cancel events.

This widget is commonly used in scenarios where a local StreamController is required for event handling, such as for reactive UI updates, simplified state management, or custom input streams.

Example

StreamControllerWrapper<int>(
  child: (controller) {
    return StreamBuilder<int>(
      stream: controller.stream,
      builder: (context, snapshot) {
        return ElevatedButton(
          onPressed: () => controller.add(1),
          child: Text('Current value: ${snapshot.data ?? 0}'),
        );
      },
    );
  },
)

See also:

Inheritance

Constructors

StreamControllerWrapper({required CallbackWidgetBuilder<StreamController<T>> child, VoidCallback? onListen, VoidCallback? onCancel, bool sync = false, Key? key})
Creates a StreamControllerWrapper.
const

Properties

child → CallbackWidgetBuilder<StreamController<T>>
Called to build the widget subtree and provides the StreamController.
final
hashCode → int
The hash code for this object.
no setterinherited
key → Key?
Controls how one widget replaces another widget in the tree.
finalinherited
onCancel → VoidCallback?
Optional callback when the stream subscription is canceled.
final
onListen → VoidCallback?
Optional callback when the stream is first listened to.
final
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited
sync → bool
Whether the StreamController is synchronous.
final

Methods

createElement() → StatefulElement
Creates a StatefulElement to manage this widget's location in the tree.
inherited
createState() → State<StreamControllerWrapper<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