Center class - widgets library

A widget that centers its child within itself.

This widget will be as big as possible if its dimensions are constrained and widthFactor and heightFactor are null. If a dimension is unconstrained and the corresponding size factor is null then the widget will match its child's size in that dimension. If a size factor is non-null then the corresponding dimension of this widget will be the product of the child's dimension and the size factor. For example if widthFactor is 2.0 then the width of this widget will always be twice its child's width.

See also:

• Align, which lets you arbitrarily position a child within itself, rather than just centering it.
• Row, a widget that displays its children in a horizontal array.
• Column, a widget that displays its children in a vertical array.
• Container, a convenience widget that combines common painting, positioning, and sizing widgets.
• The catalog of layout widgets.

Inheritance

• Object
• DiagnosticableTree
• Widget
• RenderObjectWidget
• SingleChildRenderObjectWidget
• Align
• Center

Constructors

Center({Key? key, double? widthFactor, double? heightFactor, Widget? child})

Creates a widget that centers its child.

const

Properties

alignment → AlignmentGeometry

How to align the child.

final, inherited

child → Widget?

The widget below this widget in the tree.

final, inherited

hashCode → int

The hash code for this object.

heightFactor → double?

If non-null, sets its height to the child's height multiplied by this factor.

final, 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.

read-only, inherited

widthFactor → double?

If non-null, sets its width to the child's width multiplied by this factor.

final, inherited

Methods

createElement() → SingleChildRenderObjectElement

RenderObjectWidgets always inflate to a RenderObjectElement subclass.

inherited

createRenderObject(BuildContext context) → RenderPositionedBox

Creates an instance of the RenderObject class that this RenderObjectWidget represents, using the configuration described by this RenderObjectWidget.

inherited

debugDescribeChildren() → List<DiagnosticsNode>

Returns a list of DiagnosticsNode objects describing this node's children.

debugFillProperties(DiagnosticPropertiesBuilder properties) → void

Add additional properties associated with the node.

inherited

didUnmountRenderObject(covariant RenderObject renderObject) → void

A render object previously associated with this widget has been removed from the tree. The given RenderObject will be of the same type as returned by this object's createRenderObject.

noSuchMethod(Invocation invocation) → dynamic

Invoked when a non-existent 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

updateRenderObject(BuildContext context, covariant RenderPositionedBox renderObject) → void

Copies the configuration described by this RenderObjectWidget to the given RenderObject, which will be of the same type as returned by this object's createRenderObject.

inherited

Operators

operator ==(Object other) → bool

The equality operator.