Placeholder class Null safety

A widget that draws a box that represents where other widgets will one day be added.

This widget is useful during development to indicate that the interface is not yet complete.

By default, the placeholder is sized to fit its container. If the placeholder is in an unbounded space, it will size itself according to the given fallbackWidth and fallbackHeight.

Inheritance

Constructors

Placeholder({Key? key, Color color = const Color(0xFF455A64), double strokeWidth = 2.0, double fallbackWidth = 400.0, double fallbackHeight = 400.0, Widget? child})
Creates a widget which draws a box.
const

Properties

child → Widget?
The child contained by the placeholder box.
final
color → Color
The color to draw the placeholder box.
final
fallbackHeight → double
The height to use when the placeholder is in a situation with an unbounded height.
final
fallbackWidth → double
The width to use when the placeholder is in a situation with an unbounded width.
final
hashCode → int
The hash code for this object.
nonVirtual">@nonVirtualread-onlyinherited
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
strokeWidth → double
The width of the lines in the placeholder box.
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.
override
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