PaddingModifier class

A widget that insets its child by the given padding.

When passing layout constraints to its child, padding shrinks the constraints by the given padding, causing the child to layout at a smaller size. Padding then sizes itself to its child's size, inflated by the padding, effectively creating empty space around the child.

{@tool snippet}

This snippet creates "Hello World!" Text inside a Card that is indented by sixteen pixels in each direction.

const Card(
  child: Padding(
    padding: EdgeInsets.all(16.0),
    child: Text('Hello World!'),
  ),
)

{@end-tool}

Design discussion

There isn't really any difference between the two. If you supply a Container.padding argument, Container simply builds a Padding widget for you.

Container doesn't implement its properties directly. Instead, Container combines a number of simpler widgets together into a convenient package. For example, the Container.padding property causes the container to build a Padding widget and the Container.decoration property causes the container to build a DecoratedBox widget. If you find Container convenient, feel free to use it. If not, feel free to build these simpler widgets in whatever combination meets your needs.

In fact, the majority of widgets in Flutter are simply combinations of other simpler widgets. Composition, rather than inheritance, is the primary mechanism for building up widgets.

Constructors

PaddingModifier({Key? key, Widget? child, Key? modifierKey, required EdgeInsetsGeometry padding}): Creates a widget that insets its child.
const

Properties

hashCode → int: The hash code for this object.
no setterinherited
key → Key?: Controls how one widget replaces another widget in the tree.
finalinherited
modifierKey → Key?: The actual key of the widget, which Modifier wrapped
finalinherited
padding → EdgeInsetsGeometry: The amount of space by which to inset the child.
final
runtimeType → Type: A representation of the runtime type of the object.
no setterinherited

Methods

build(BuildContext context) → Widget: Describes the part of the user interface represented by this widget.
inherited
buildWithChild(BuildContext context, Widget? child) → Widget: A build method that receives an extra child parameter.
override
createElement() → SingleChildStatelessElement: Create a SingleChildStatelessElement
inherited
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.
inherited
modified() → Modifier: Available on Widget, provided by the ModifierTransformer extension
Transform normal widget to Modifier
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

Operators

operator ==(Object other) → bool: The equality operator.
inherited