ChannelBuilder<C extends StateChannel<S> , S extends ChannelSignal> class
ChannelBuilder<C> handles building a widget in response to new ChannelSignal broadcasting from ChannelProvider<C> on an . simple usage:
ChannelBuilder<MyChannel,MyChannelSignal>(
condition: (channel,signal) =>signal is CounterStateSignal,
builder:(BuildContext context, channel, child) =>
channel.counterState.busy ? CircularProgressIndicator() : !channel.counterState.success ? Text( channel.counterState.error) :
Row( children: <Widget> [ Te xt( channel.counterState.count.toString()), child ] ),
child: OtherChildWidget(),
),
or
/// ChannelBuilder<MyChannel,MyChannelSignal>(
condition: (channel,signal) =>signal is CounterStateSignal,
builder:(BuildContext context, channel, _ ) =>
channel.counterState.busy ? CircularProgressIndicator() : !channel.counterState.success ? Text( channel.counterState.error) :
Text( channel.counterState.count.toString(), ),
)
- Inheritance
-
- Object
- DiagnosticableTree
- Widget
- StatefulWidget
- ChannelBuilder
Constructors
- ChannelBuilder({Key? key, bool condition(C channel, S signal)?, required Widget builder(BuildContext context, C channel, Widget? child), Widget child()?})
-
const
Properties
- builder → Widget Function(BuildContext context, C channel, Widget? child)
-
final
- child → (Widget Function()?)
-
final
- condition → (bool Function(C channel, S signal)?)
-
When the channel broadcasts a ChannelSignal, the condition function is called.
The condition must be returned a bool which determines whether or not the builder function will be invoked.
condition is optional and if it isn't implemented, it will default to
true
.final - hashCode → int
-
The hash code for this object.
no setterinherited
- key → Key?
-
Controls how one widget replaces another widget in the tree.
finalinherited
- 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< ChannelBuilder< C, S> > -
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}) → 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