PositionedDirectional class Null safety

A widget that controls where a child of a Stack is positioned without committing to a specific TextDirection.

The ambient Directionality is used to determine whether start is to the left or to the right.

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

If a widget is wrapped in a PositionedDirectional, then it is a positioned widget in its Stack. If the top property is non-null, the top edge of this child/ will be positioned top layout units from the top of the stack widget. The start, bottom, and end properties work analogously.

If both the top and bottom properties are non-null, then the child will be forced to have exactly the height required to satisfy both constraints. Similarly, setting the start and end properties to non-null values will force the child to have a particular width. Alternatively the width and height properties can be used to give the dimensions, with one corresponding position property (e.g. top and height).

See also:

Inheritance

Constructors

PositionedDirectional({Key? key, double? start, double? top, double? end, double? bottom, double? width, double? height, required Widget child})
Creates a widget that controls where a child of a Stack is positioned.
const

Properties

bottom double?
The distance that the child's bottom edge is inset from the bottom of the stack.
final
child Widget
The widget below this widget in the tree.
final
end double?
The distance that the child's trailing edge is inset from the trailing edge of the stack.
final
hashCode int
The hash code for this object.
@nonVirtual, read-only, inherited
height double?
The child's height.
final
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
start double?
The distance that the child's leading edge is inset from the leading edge of the stack.
final
top double?
The distance that the child's top edge is inset from the top of the stack.
final
width double?
The child's width.
final

Methods

build(BuildContext context) Widget
Describes the part of the user interface represented by this widget.
override
createElement() StatelessElement
Creates a StatelessElement to manage this widget's location in the tree.
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.
inherited
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

Operators

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