FractionallySizedBox class

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

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.
link

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.new({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.
no setterinherited
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.
no setterinherited
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.
inherited
debugFillProperties(DiagnosticPropertiesBuilder properties) → void
Add additional properties associated with the node.
override
didUnmountRenderObject(covariant RenderObject renderObject) → void
This method is called when a RenderObject that was previously associated with this widget is removed from the render tree. The provided RenderObject will be of the same type as the one created by this widget's createRenderObject method.
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, int wrapWidth = 65}) → 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.
inherited