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">@nonVirtualread-onlyinherited
height → double?
The child's height.
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
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">@protectedinherited
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">@nonVirtualinherited