Observer class

A StatelessObserverWidget that delegate its build method to builder.

See also:

Inheritance

Constructors

Observer({Key? key, required WidgetBuilder? builder, String? name, bool? warnWhenNoObservables})
Observer.withBuiltChild({Key? key, required TransitionBuilder? builderWithChild, required Widget? child, String? name, bool? warnWhenNoObservables})
Observer which excludes the child branch from being rebuilt

Properties

builder WidgetBuilder?
regular builder, suitable for most cases
final
builderWithChild TransitionBuilder?
builder function with child parameter
final
child Widget?
The child widget to pass to the builderWithChild.
final
debugConstructingStackFrame String?
The stack frame pointing to the source that constructed this instance.
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
warnWhenNoObservables bool?
Whether to warn when there is no observables in the builder function null means true
finalinherited

Methods

build(BuildContext context) Widget
Describes the part of the user interface represented by this widget.
override
createElement() StatelessObserverElement
Creates a StatelessElement to manage this widget's location in the tree.
inherited
createReaction(dynamic onInvalidate(), {dynamic onError(Object, Reaction)?}) → Reaction
A convenience method used for testing.
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
getContext() → ReactiveContext
The context within which its reaction should be run. It is the mainContext in most cases.
inherited
getName() String
An identifiable name that can be overriden for debugging.
override
log(String msg) → void
Convenience method to output console messages as debugging output. Logging usually happens when some internal error needs to be surfaced to the user.
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

Static Methods

debugFindConstructingStackFrame([StackTrace? stackTrace]) String?
Finds the first non-constructor frame in the stack trace.