FractionallySizedBox class Null safety

A widget that sizes its child to a fraction of the total available space. For more details about the layout algorithm, see RenderFractionallySizedOverflowBox.

link
This sample shows a FractionallySizedBox whose one child is 50% of the box's size per the width and height factor parameters, and centered within that box by the alignment parameter.
To create a local project with this code sample, run:
flutter create --sample=widgets.FractionallySizedBox.1 mysample

See also:

  • Align, which sizes itself based on its child's size and positions the child according to an Alignment value.
  • OverflowBox, a widget that imposes different constraints on its child than it gets from its parent, possibly allowing the child to overflow the parent.
  • The catalog of layout widgets.
Inheritance

Constructors

FractionallySizedBox({Key? key, AlignmentGeometry alignment = Alignment.center, double? widthFactor, double? heightFactor, Widget? child})
Creates a widget that sizes its child to a fraction of the total available space.
const

Properties

alignment → AlignmentGeometry
How to align the child.
final
child → Widget?
The widget below this widget in the tree.
finalinherited
hashCode → int
The hash code for this object.
nonVirtual">@nonVirtualread-onlyinherited
heightFactor → double?
If non-null, the fraction of the incoming height given to the child.
final
key → Key?
Controls how one widget replaces another widget in the tree.
finalinherited
runtimeType → Type
A representation of the runtime type of the object.
read-onlyinherited
widthFactor → double?
If non-null, the fraction of the incoming width given to the child.
final

Methods

createElement() → SingleChildRenderObjectElement
RenderObjectWidgets always inflate to a RenderObjectElement subclass.
inherited
createRenderObject(BuildContext context) → RenderFractionallySizedOverflowBox
Creates an instance of the RenderObject class that this RenderObjectWidget represents, using the configuration described by this RenderObjectWidget.
override
debugDescribeChildren() → List<DiagnosticsNode>
Returns a list of DiagnosticsNode objects describing this node's children.
protected">@protectedinherited
debugFillProperties(DiagnosticPropertiesBuilder properties) → void
Add additional properties associated with the node.
override
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.
protected">@protectedinherited
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 RenderFractionallySizedOverflowBox 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.
override

Operators

operator ==(Object other) → bool
The equality operator.
nonVirtual">@nonVirtualinherited