Flexible class Null safety

A widget that controls how a child of a Row, Column, or Flex flexes.

Using a Flexible widget gives a child of a Row, Column, or Flex the flexibility to expand to fill the available space in the main axis (e.g., horizontally for a Row or vertically for a Column), but, unlike Expanded, Flexible does not require the child to fill the available space.

A Flexible widget must be a descendant of a Row, Column, or Flex, and the path from the Flexible widget to its enclosing Row, Column, or Flex must contain only StatelessWidgets or StatefulWidgets (not other kinds of widgets, like RenderObjectWidgets).

See also:



Flexible({Key? key, int flex = 1, FlexFit fit = FlexFit.loose, required Widget child})
Creates a widget that controls how a child of a Row, Column, or Flex flexes.


child Widget
The widget below this widget in the tree.
final, inherited
debugTypicalAncestorWidgetClass Type
The RenderObjectWidget that is typically used to set up the ParentData that applyParentData will write to.
read-only, override
fit FlexFit
How a flexible child is inscribed into the available space.
flex int
The flex factor to use for this child.
hashCode int
The hash code for this object.
@nonVirtual, read-only, 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


applyParentData(RenderObject renderObject) → void
Write the data from this widget into the given render object's parent data.
createElement() ParentDataElement<FlexParentData>
Inflates this configuration to a concrete instance.
debugCanApplyOutOfTurn() bool
Whether the ParentDataElement.applyWidgetOutOfTurn method is allowed with this widget.
@protected, inherited
debugDescribeChildren() List<DiagnosticsNode>
Returns a list of DiagnosticsNode objects describing this node's children.
@protected, inherited
debugFillProperties(DiagnosticPropertiesBuilder properties) → void
Add additional properties associated with the node.
debugIsValidRenderObject(RenderObject renderObject) bool
Checks if this widget can apply its parent data to the provided renderObject.
noSuchMethod(Invocation invocation) → dynamic
Invoked when a non-existent method or property is accessed.
toDiagnosticsNode({String? name, DiagnosticsTreeStyle? style}) DiagnosticsNode
Returns a debug representation of the object that is used by debugging tools and by DiagnosticsNode.toStringDeep.
toString({DiagnosticLevel minLevel = DiagnosticLevel.info}) String
A string representation of this object.
toStringDeep({String prefixLineOne = '', String? prefixOtherLines, DiagnosticLevel minLevel = DiagnosticLevel.debug}) String
Returns a string representation of this node and its descendants.
toStringShallow({String joiner = ', ', DiagnosticLevel minLevel = DiagnosticLevel.debug}) String
Returns a one-line detailed description of the object.
toStringShort() String
A short, textual description of this widget.


operator ==(Object other) bool
The equality operator.
@nonVirtual, inherited