NotifiableElementMixin mixin Null safety

Mixin this class to allow receiving Notification objects dispatched by child elements.

See also:

Superclass Constraints

Properties

slot Object?
Information set by parent to define where this child fits in its parent's child list. [...]
read-only, inherited
depth int
An integer that is guaranteed to be greater than the parent's, if any. The element at the root of the tree must have a depth greater than 0.
read-only, inherited
widget Widget
The configuration for this element. [...]
read-only, inherited
debugIsDefunct bool
Returns true if the Element is defunct. [...]
read-only, inherited
owner BuildOwner?
The object that manages the lifecycle of this element.
read-only, inherited
renderObject RenderObject?
The render object at (or below) this location in the tree. [...]
read-only, inherited
size Size?
The size of the RenderBox returned by findRenderObject. [...]
read-only, inherited
dirty bool
Returns true if the element has been marked as needing rebuilding.
read-only, inherited
hashCode int
The hash code for this object. [...]
read-only, inherited
runtimeType Type
A representation of the runtime type of the object.
read-only, inherited
debugDoingBuild bool
Whether the widget is currently updating the widget or render tree. [...]
read-only, inherited

Methods

onNotification(Notification notification) bool
Called when a notification of the appropriate type arrives at this location in the tree. [...]
attachNotificationTree() → void
Called in Element.mount and Element.activate to register this element in the notification tree. [...]
override
reassemble() → void
Called whenever the application is reassembled during debugging, for example during hot reload. [...]
@mustCallSuper, @protected, inherited
describeMissingAncestor({required Type expectedAncestorType}) List<DiagnosticsNode>
Adds a description of a specific type of widget missing from the current build context's ancestry tree. [...]
inherited
describeElement(String name, {DiagnosticsTreeStyle style = DiagnosticsTreeStyle.errorProperty}) DiagnosticsNode
Returns a description of the Element associated with the current build context. [...]
inherited
describeWidget(String name, {DiagnosticsTreeStyle style = DiagnosticsTreeStyle.errorProperty}) DiagnosticsNode
Returns a description of the Widget associated with the current build context. [...]
inherited
describeOwnershipChain(String name) DiagnosticsNode
Adds a description of the ownership chain from a specific Element to the error report. [...]
inherited
visitChildren(ElementVisitor visitor) → void
Calls the argument for each child. Must be overridden by subclasses that support having children. [...]
inherited
debugVisitOnstageChildren(ElementVisitor visitor) → void
Calls the argument for each child considered onstage. [...]
inherited
visitChildElements(ElementVisitor visitor) → void
Wrapper around visitChildren for BuildContext.
inherited
updateChild(Element? child, Widget? newWidget, Object? newSlot) Element?
Update the given child with the given new configuration. [...]
@protected, inherited
mount(Element? parent, Object? newSlot) → void
Add this element to the tree in the given slot of the given parent. [...]
@mustCallSuper, inherited
update(covariant Widget newWidget) → void
Change the widget used to configure this element. [...]
@mustCallSuper, inherited
updateSlotForChild(Element child, Object? newSlot) → void
Change the slot that the given child occupies in its parent. [...]
@protected, inherited
detachRenderObject() → void
Remove renderObject from the render tree. [...]
inherited
attachRenderObject(Object? newSlot) → void
Add renderObject to the render tree at the location specified by newSlot. [...]
inherited
inflateWidget(Widget newWidget, Object? newSlot) Element
Create an element for the given widget and add it as a child of this element in the given slot. [...]
@protected, inherited
deactivateChild(Element child) → void
Move the given element to the list of inactive elements and detach its render object from the render tree. [...]
@protected, inherited
forgetChild(Element child) → void
Remove the given child from the element's child list, in preparation for the child being reused elsewhere in the element tree. [...]
@mustCallSuper, @protected, inherited
activate() → void
Transition from the "inactive" to the "active" lifecycle state. [...]
@mustCallSuper, inherited
deactivate() → void
Transition from the "active" to the "inactive" lifecycle state. [...]
@mustCallSuper, inherited
debugDeactivated() → void
Called, in debug mode, after children have been deactivated (see deactivate). [...]
@mustCallSuper, inherited
unmount() → void
Transition from the "inactive" to the "defunct" lifecycle state. [...]
@mustCallSuper, inherited
findRenderObject() RenderObject?
The current RenderObject for the widget. If the widget is a RenderObjectWidget, this is the render object that the widget created for itself. Otherwise, it is the render object of the first descendant RenderObjectWidget. [...]
inherited
dependOnInheritedElement(InheritedElement ancestor, {Object? aspect}) InheritedWidget
Registers this build context with ancestor such that when ancestor's widget changes this build context is rebuilt. [...]
inherited
dependOnInheritedWidgetOfExactType<T extends InheritedWidget>({Object? aspect}) → T?
Obtains the nearest widget of the given type T, which must be the type of a concrete InheritedWidget subclass, and registers this build context with that widget such that when that widget changes (or a new widget of that type is introduced, or the widget goes away), this build context is rebuilt so that it can obtain new values from that widget. [...]
inherited
getElementForInheritedWidgetOfExactType<T extends InheritedWidget>() InheritedElement?
Obtains the element corresponding to the nearest widget of the given type T, which must be the type of a concrete InheritedWidget subclass. [...]
inherited
findAncestorWidgetOfExactType<T extends Widget>() → T?
Returns the nearest ancestor widget of the given type T, which must be the type of a concrete Widget subclass. [...]
inherited
findAncestorStateOfType<T extends State<StatefulWidget>>() → T?
Returns the State object of the nearest ancestor StatefulWidget widget that is an instance of the given type T. [...]
inherited
findRootAncestorStateOfType<T extends State<StatefulWidget>>() → T?
Returns the State object of the furthest ancestor StatefulWidget widget that is an instance of the given type T. [...]
inherited
findAncestorRenderObjectOfType<T extends RenderObject>() → T?
Returns the RenderObject object of the nearest ancestor RenderObjectWidget widget that is an instance of the given type T. [...]
inherited
visitAncestorElements(bool visitor(Element element)) → void
Walks the ancestor chain, starting with the parent of this build context's widget, invoking the argument for each ancestor. The callback is given a reference to the ancestor widget's corresponding Element object. The walk stops when it reaches the root widget or when the callback returns false. The callback must not return null. [...]
inherited
didChangeDependencies() → void
Called when a dependency of this element changes. [...]
@mustCallSuper, inherited
debugGetCreatorChain(int limit) String
Returns a description of what caused this element to be created. [...]
inherited
debugGetDiagnosticChain() List<Element>
Returns the parent chain from this element back to the root of the tree. [...]
inherited
dispatchNotification(Notification notification) → void
Start bubbling this notification at the given build context. [...]
inherited
toStringShort() String
A short, textual description of this element.
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
debugFillProperties(DiagnosticPropertiesBuilder properties) → void
Add additional properties associated with the node. [...]
inherited
debugDescribeChildren() List<DiagnosticsNode>
Returns a list of DiagnosticsNode objects describing this node's children. [...]
inherited
markNeedsBuild() → void
Marks the element as dirty and adds it to the global list of widgets to rebuild in the next frame. [...]
inherited
rebuild() → void
Cause the widget to update itself. In debug builds, also verify various invariants. [...]
inherited
performRebuild() → void
Cause the widget to update itself. [...]
@protected, inherited
toStringShallow({String joiner = ', ', DiagnosticLevel minLevel = DiagnosticLevel.debug}) String
Returns a one-line detailed description of the object. [...]
inherited
toStringDeep({String prefixLineOne = '', String? prefixOtherLines, DiagnosticLevel minLevel = DiagnosticLevel.debug}) String
Returns a string representation of this node and its descendants. [...]
inherited
toString({DiagnosticLevel minLevel = DiagnosticLevel.info}) String
A string representation of this object. [...]
inherited
noSuchMethod(Invocation invocation) → dynamic
Invoked when a non-existent method or property is accessed. [...]
inherited

Operators

operator ==(Object other) bool
Compare two widgets for equality. [...]
@nonVirtual, inherited